JP4779733B2 - Distribution system, distribution system control method, storage device, storage device program, node device, and node device program - Google Patents

Description

  The present application belongs to the technical field of a distribution system and a distribution system control method, a storage device and a storage device program, and a node device and a node device program, and more specifically, content such as a movie (distribution) via a network such as the Internet. Information distribution system and distribution system control method, storage device and storage device program, and node device and node device program included in the distribution system.

  In recent years, so-called content distribution in which a terminal device accesses a server or the like storing the above content via a network such as the Internet, and distributes the content desired to be viewed on the terminal device to the terminal device. Research and development is thriving.

  Here, the basic configuration of a conventional distribution system that distributes the content is a server that stores the content from the terminal device that desires the distribution of the content via the network as exemplified in Patent Document 1 below, for example. The terminal device receives the distribution of the desired content, that is, the transmission of the content data corresponding to the content after establishing the connection.

  On the other hand, in recent years, there is a so-called P2P (Peer to Peer) grid type distribution system (hereinafter simply referred to as a distribution system) as another configuration of the distribution system that performs the content distribution. Here, the distribution system is a distribution system that distributes the content using the network, and content data corresponding to the content is directly exchanged between terminal devices belonging to the network ( In other words, it is a distribution system in which content is shared among a plurality of terminal devices, and all the terminal devices subscribing to the distribution system have functions as the server and receive distribution of the content This is a distribution system that also has a function as a device (in the following description, the terminal device is simply referred to as a node).

  In the distribution system, when a content distribution is to be received at a certain node, the node identifies other nodes storing content data corresponding to the content desired to be distributed on the network. Node identification information for identifying the content and content identification information for identifying the content from other content (hereinafter, the information is referred to as index information), and the nodes in the index information It is necessary to receive distribution of desired content from the node indicated by the identification information.

  Therefore, in a general distribution system, as exemplified in Patent Document 2 below, for example, the index information related to one or a plurality of contents is collectively stored (distributed storage) in a plurality of nodes, and this is stored in the distribution system. It is configured to be referenced from a node that receives content distribution. More specifically, for example, when the network constituting the distribution system is the Internet, search information (for example, a title name of a movie) that can specify content desired to be distributed and the IP of the node storing the search information It is necessary to recognize a pair with an (Internet Protocol) address and exchange the desired content using the IP address as a clue.

  Accordingly, in a distribution system in which a large number of unspecified nodes such as the above distribution system share content, each node recognizes a set of search information of all content and the IP address of the node storing it. It is necessary to keep it.

  However, when the number of nodes connected to the network increases, the search information of all contents and the nodes storing the contents are stored because of the limitation of the physical recordable amount in each node. It is not realistic for each node to record the IP address of each node (for example, when 1 million nodes are connected to the network, the IP addresses for 1 million nodes are all connected to each other). It's not realistic to record it).

  Also, when each node records search information of all contents and the IP address of the node storing it, the power switch at each node in the network is frequently turned on / off (for example, the node is a personal computer). In the case of realizing the above, the power switch can be frequently operated). However, the IP address and the like recorded in each node are frequently updated, and practically it is difficult to operate the entire network.

  Therefore, in order to deal with the problems as described above, only the index information including the IP address of the minimum necessary node is recorded and distributed to the other nodes that do not recognize the IP address. Research has been conducted on a distribution system in which content to be transferred is delivered via another node, and one of them is a distribution system using a so-called DHT (Distributed Hash Table).

  Next, an outline of the distribution system using the DHT will be described.

In the distribution system using the DHT, a node ID (Identification) for identifying each node is assigned to each node. At this time, the node ID is assigned a unique number for each node in the distribution system in which they participate, that is, a number different from other nodes. This number has a number of bits (bit length) that can accommodate the maximum number of nodes in the network. More specifically, for example, when a 128-bit node ID is used, a maximum of 2 ¹²⁸ ≈340 × 10 ³⁶ nodes can be connected in one network. The node ID is generally a hash value for a unique value for each node, such as an IP address assigned to the node itself, a so-called MAC (Media Access Control) address, or a serial number of the node itself. Use the value obtained by applying the function.

  Next, in the distribution system using the DHT, a unique content ID different from other content is assigned to the content itself distributed by the distribution system as the corresponding content identification information. The bit length of the content ID is also the same as the bit length of the node ID. In general, the content ID includes title data indicating the title of the content, attribute data indicating the attributes of the data constituting the content, data for several bytes from the top of the data configuring the content, and the like. A value obtained by applying a hash function is used.

  However, as a weak point of the distribution system using the DHT, when the content ID is calculated from the title data, when trying to find the content in the distribution system, the exact title of the content is known in advance. Otherwise, the content ID cannot be calculated, and the inquiry for the discovery itself ends in failure.

  More specifically, for example, when it is desired to acquire the content of the title “Seidon Adventure”, if the title of the content actually distributed is “Saydon Adventure” or “Seidon Adventure”, This will not be found. This is because, in the content ID calculation method described above, even if the titles themselves are subtle, the content IDs calculated from the different titles are completely different. That is, when a user intends to receive distribution of desired content at a node that is operated by the user, before the actual distribution of the corresponding content data is received, what kind of title the content desired by the user is originally given. It is necessary to search and confirm whether or not distribution is possible.

  In order to cope with this problem, a search catalog that describes a list of contents that can be actually distributed (or actually distributed) in the distribution system can be used as a viewing device for the contents. It should be stored in the node. As a result, the user who views the content decides what he / she wants to view while viewing the catalog. The catalog may include not only the title of the corresponding content but also auxiliary information such as the director name, the name of the actor or the singer who appears in the catalog. The more supplementary information, the more complex the search is possible, for example, “Is the movie starring“ Caprio ”directed by“ James Melon ”distributed?”. Furthermore, in order to ensure fairness among the nodes, it is desirable that the same and latest catalogs are stored in all the nodes.

For this reason, in the conventional distribution system, for example, a dedicated catalog distribution server for maintaining the latest catalog corresponding to all the contents that can be distributed in the distribution system is provided. Sometimes all nodes access the server, receive a new catalog containing a catalog record corresponding to new content scheduled to be released the next week from the server, and are stored in all terminal devices in the distribution system It is possible to consider a configuration of updating
Japanese Unexamined Patent Publication No. 2000-122954 JP 2004-265273 A

  However, according to the centralized catalog updating method using the catalog distribution server described above, the processing load on the catalog distribution server suddenly increases at 0:00 every Saturday, which is the update timing. As the number of existing terminal devices becomes enormous, the processing load increases extremely.

  In order to cope with this, the scale of the catalog distribution server as a device is increased in preparation for an increase in the processing load, including the network environment surrounding the catalog distribution server, or a network line is transferred. There is a problem in that it is necessary to provide an expensive and large-scale catalog distribution server, such as replacing it with a higher speed, and the maintenance cost also increases.

  Therefore, the present invention has been made in view of the above problems, and the problem is that catalog data in each terminal device is always the latest without requiring unnecessary costs and labor for maintenance management as a distribution system. It is an object to provide a distribution system and a distribution system control method capable of being maintained in a state, a storage device and a storage device program, a node device and a node device program included in the distribution system.

In order to solve the above-mentioned problem, the invention according to claim 1 is configured such that a plurality of node devices are connected via a network, and the storage device such as a content holder which is any one of the node devices. In the distribution system that distributes the distribution information stored in the storage device to any one of the other node devices, each of the distribution information stored in the storage device includes one distribution information as another distribution information. catalog data of the continuous identification information magnitude relationship between the value for each of the distribution information a continuous identification information such as a serial number for identifying is continuous, in order to find the distribution information in said distribution system from and retrieval information equal, but the distribution information is previously added in the distribution server device for distributing the storage device, new to the continuous identification information corresponding is set When the distribution information is stored in the storage device together with the corresponding search information, a public message including the search information corresponding to the new distribution information and the continuous identification information is sent to each node via the network. Each of the node devices includes a storage unit such as a storage unit that stores the search information and the continuous identification information in association with each other, a display unit that displays various information, and the like. and display means, when the public message has been transmitted over the network, receives the continuous identification information in the node device included in the public message, the storage and the continuous identification information the received the continuity between the said continuous identification information stored in the unit, the control unit such that checked against the magnitude of the value of the continuous identification information And when the confirmation means and the continuity are confirmed, the retrieval information and the continuous identification information stored in the storage means are included in the transmitted public message. An update unit such as a control unit that updates using information and the continuous identification information, and a notification such as a control unit that displays the updated search information on the display unit at a timing when the search information is updated by the update unit Means.

Therefore, when new distribution information is stored in the storage device, the search information of each node device is updated based on the continuity of the continuous identification information , and the updated search information is displayed on the display means at the update timing. is Runode, maintains search information always up to date in the distribution system, it can be immediately subjected to selection of the distribution information by the user.

  Further, as the distribution information is accumulated, the search information in each node device is autonomously updated in each node device. Therefore, a separate server device or the like is provided for the update and management of the search information. There is no need to provide it inside.

  In order to solve the above-described problems, a second aspect of the present invention is a storage device included in the distribution system according to the first aspect, and includes the distribution unit.

Therefore, when new distribution information is stored in the storage device, a public message including search information and continuous identification information corresponding to the new distribution information is distributed to each node device via the network. In the node device, search information is updated based on the continuity of the continuous identification information , and the updated search information is displayed on the display means at the update timing, so that the search information in the distribution system is always up-to-date It can be maintained and used immediately for distribution of distribution information.

  Further, as a result, the search information in each node device is autonomously updated in each node device in accordance with the accumulation of the distribution information, and therefore a separate server device is used for updating and managing the search information. Etc. in the distribution system.

  In order to solve the above-described problem, the invention described in claim 3 is the storage device according to claim 2, wherein the confirmation unit includes the continuous identification information corresponding to the newly stored distribution information and the continuous identification information. Continuity with the continuous identification information stored in the storage means in the storage device is confirmed, and the update means is stored in the storage means when the continuity is confirmed. The search information and the continuous identification information are updated using the search information and the continuous identification information corresponding to the newly accumulated distribution information.

  Therefore, when continuity is recognized with continuous identification information corresponding to existing distribution information in relation to continuous identification information corresponding to newly accumulated distribution information, the continuity stored in the storage device Since the identification information is updated using the continuous identification information corresponding to the newly accumulated distribution information, when new distribution information is accumulated in the accumulation device, it is quickly and autonomously stored in the accumulation device. Search information that is being updated can be updated.

In order to solve the above-described problem, the invention according to claim 4 is a node device included in the distribution system according to claim 1, wherein the storage unit, the display unit, the confirmation unit, The update means and the notification means.

Therefore, when new distribution information is stored in the storage device, the continuity of the continuous identification information is confirmed, the search information of each node device is updated , and the updated search information is used at the updated timing. Therefore, the user can execute the search of the distribution information by using the latest search information by keeping the search information in the distribution system always up-to-date and notifying immediately. .

  Further, as the distribution information is accumulated, the search information in each node device is autonomously updated in each node device. Therefore, a separate server device or the like is provided for the update and management of the search information. There is no need to provide it inside.

In order to solve the above problem, the invention according to claim 5 is the node device according to claim 4 , wherein when it is confirmed that there is no continuity, the storage means in another node device is provided. the acquisition message for acquiring the search information corresponding to the continuous identification information and the successive identification information corresponding to the interruptions of the continuity of the search information stored in, towards the other said node device Further including an acquisition message transmission means such as a control unit for transmitting via the network, wherein the update means corresponds to the interrupted portion corresponding to the transmitted acquisition message and the continuous identification information. When the search information corresponding to is returned via the network, the previous identification information in the storage means is stored using the continuous identification information and search information returned. Configured to update the continuity identification information and the search information.

  Therefore, when the continuity with the continuous identification information corresponding to the search information transmitted from another node device is not confirmed, the search information and the continuous identification information corresponding to the interruption portion of the continuity correspond to the acquisition message. Therefore, the search information and the continuous identification information transmitted in this manner are used to make up for each node device, so that the continuity of the search information can be maintained autonomously in each node device.

In order to solve the above-described problem, the invention according to claim 6 is the node device according to claim 4 or 5 , wherein the distribution information corresponding to the search information is included in the search information. A distribution permission flag indicating whether or not the distribution information is to be distributed to each of the node devices in the distribution system, and the notification means uses the distribution permission flag to indicate each of the nodes in the distribution system. Only the search information indicated to be the distribution information to be distributed to the device is displayed on the display means .

Therefore, since only the search information corresponding to the distribution information that should be distributed by the public message included in the search information is displayed on the display means, the distribution information that can be distributed at that time Since only the search target is changed, distribution permission / non-permission change for convenience of the system administrator can be efficiently applied to all node devices.

In order to solve the above problems, the invention according to claim 7, in the node device according to claim 6, wherein the distribution information to be distributed to each said node devices in the distribution system by the distribution permission flag It further includes deletion means such as a control unit for deleting the search information indicated as not being from the storage means.

  Therefore, the search information corresponding to the distribution information that should not be distributed by the distribution permission flag is deleted from the storage means, so that the search information about the distribution information that cannot be distributed is erroneously notified. The distribution information can be searched efficiently while preventing the problem.

In order to solve the above-described problem, the invention according to claim 8 is the node device according to any one of claims 4 to 7 , which is to be transmitted to the other node device. When transmitting the message, the adding means such as a control unit for adding the message to the latest continuous identification information which is the newest continuous identification information among the continuous identification information stored in the storage means, and the latest continuous Message transmitting means such as a control unit for transmitting the message to which the identification information is added to the other node device.

  Therefore, when transmitting a message to another node device, because the latest continuous identification information stored in the storage unit is added and transmitted, in the other node device that acquired the latest continuous identification information, By updating the search information stored in the other node device every time any message is acquired, the search information can be autonomously maintained in the latest state.

In order to solve the above problem, the invention according to claim 9 is the node device according to any one of claims 4 to 8, wherein the message from the node device according to claim 8 is received. When the confirmation unit obtains the message via the network, the confirmation unit includes the latest continuous identification information included in the obtained message and the continuous identification information stored in the storage unit. The continuity is confirmed by comparing the magnitude relationship of the values of the continuity identification information, and when it is confirmed that the continuity is not present, the continuity identification information corresponding to a range in which the continuity is interrupted. And acquisition means for acquiring the search information corresponding to the continuous identification information from the other node devices in the distribution system.

  Therefore, when any message is acquired, it is determined whether or not the search information stored in its own storage means is the latest in relation to the latest continuous identification information included in the message. If this is not the case, the latest search information is acquired from another node device, so by updating the continuous identification information every time any message is acquired, the continuous identification information is autonomously updated to the latest state. Can be maintained.

In order to solve the above-described problem, the invention according to claim 10 is the node device according to any one of claims 4 to 9 , wherein the confirmation unit is configured to identify the continuous identification transmitted. Confirm whether the information and the continuous identification information stored in the storage means are equal, and confirm that the transmitted continuous identification information and the stored continuous identification information are equal And a message generation means such as a control unit for generating a new message using the stored continuous identification information.

  Therefore, when it is confirmed that the transmitted continuous identification information is equal to the stored continuous identification information, a new message is generated using the stored continuous identification information. The update state of the continuous identification information can be kept up-to-date.

In order to solve the above problem, an invention according to claim 11 causes a computer to function as the storage device according to claim 2 or claim 3.

Therefore, when the computer is caused to function as the storage device according to claim 2, when new distribution information is stored in the storage device, search information and continuous identification information corresponding to the new distribution information are stored. Since the computer functions to distribute the public message including it to each node device via the network, the search information is updated based on the continuity of the continuous identification information in each node device, and updated at the update timing. By displaying the later search information on the display means, the search information in the distribution system can always be kept up-to-date and used for distribution of distribution information.

  Further, as a result, the search information in each node device is autonomously updated in each node device in accordance with the accumulation of the distribution information, and therefore a separate server device is used for updating and managing the search information. Etc. in the distribution system.

  Further, when the computer is caused to function as the storage device according to claim 3, in addition to the case where the computer is caused to function as the storage device according to claim 2, continuous identification corresponding to newly accumulated distribution information is performed. When continuity is recognized between continuous identification information corresponding to existing distribution information in relation to information, the continuous identification information stored in the storage device corresponds to newly accumulated distribution information. Since the computer functions to update using continuous identification information, when new distribution information is stored in the storage device, the search information stored in the storage device is quickly and autonomously updated. can do.

In order to solve the above problem, an invention according to claim 12 causes a computer to function as the node device according to any one of claims 4 to 10 .

Therefore, when the computer is caused to function as the node device according to claim 4, when new distribution information is stored in the storage device, the continuity of the continuous identification information is confirmed and the search information of each node device is confirmed. immediately but is updated and maintained further since functions the computer as searching the updated information in the update timing is notified to the user, the always up to date search information within the distribution system By notifying, distribution information can be distributed using the latest search information.

  Further, as the distribution information is accumulated, the search information in each node device is autonomously updated in each node device. Therefore, a separate server device or the like is provided for the update and management of the search information. There is no need to provide it inside.

Further, when the computer is caused to function as the node device according to claim 5 , in addition to the case where the computer is caused to function as the node device according to claim 4 , a search transmitted from another node device. When the continuity with the continuous identification information corresponding to the information is not confirmed, the search information and the continuous identification information corresponding to the acquisition message are sent as the search information and the continuous identification information corresponding to the interruption portion of the continuity. Since the computer functions so as to make up for it, each node device can autonomously maintain the continuity of the search information.

Further, when the computer functions as the node device according to claim 6 , it is included in the search information in addition to the case where the computer functions as the node device according to claim 4 or 5 . Since the computer functions so that only search information corresponding to distribution information that should be distributed by a public message is displayed on the display means, only distribution information that can be distributed at that time is searched. By being a target, it is possible to efficiently search for distribution information without waste.

Further, when the computer functions as the node device according to claim 7 , it should not be distributed by the distribution permission flag in addition to the case where the computer functions as the node device according to claim 6. Since the computer functions so that the search information corresponding to the distributed information is deleted from the storage means, it is efficient while preventing the search information about the distribution information that cannot be distributed from being erroneously notified. It is possible to search for distribution information.

Furthermore, when the computer functions as the node device according to claim 8 , in addition to the case where the computer functions as the node device according to any one of claims 4 to 7 , When transmitting a message to a node device, the latest continuous identification information stored in the storage means is added and transmitted. Therefore, in the other node device that acquired the latest continuous identification information, any message The search information stored in the other node device is updated every time the search information is acquired, so that the search information can be autonomously maintained in the latest state.

When the computer is caused to function as the node device according to claim 9 , in addition to the case where the computer is caused to function as the node device according to any one of claims 4 to 7 , When the message is acquired, it is determined whether the search information stored in its storage means is the latest in relation to the latest continuous identification information included in the message. Since the computer functions to acquire the latest search information from another node device, the continuous identification information is updated autonomously by updating the continuous identification information every time any message is acquired. Can be maintained in a state.

Further, when the computer is caused to function as the node device according to claim 10 , the computer is transmitted in addition to the case where the computer is caused to function as the node device according to any one of claims 4 to 9. When it is confirmed that the received continuous identification information is equal to the stored continuous identification information, a new message is generated using the stored continuous identification information. Update status can be kept up to date.

In order to solve the above-described problem, the invention according to claim 13 is configured such that a plurality of node devices are connected via a network and are stored in any of the storage devices that are the node devices. In a distribution system control method executed in a distribution system that distributes distributed distribution information to any one of the other node devices, each node device stores the search information and the continuous identification information in association with each other means and includes a display means for displaying various information, and the husband of the distribution information s is continuous identification information for identifying the one the distribution information from other such distribution information is stored in the storage device a continuous identification information magnitude relationship between the value for each of the distribution information is continuous there is, a search information for searching the delivery information within the distribution system, but the distribution information It is previously added in the distribution server device for distributing, when the new the distribution information continuous identification information is set corresponding is stored in the storage device together with the search information corresponding, in the storage device, A transmitting step of transmitting a public message including the search information corresponding to the new distribution information and the continuous identification information to each of the node devices via the network; and the public message via the network at each of the node devices. In each of the node devices, the continuity between the continuous identification information included in the public message and the continuous identification information stored in the storage means is determined by the continuous identification information. checking step and, said there is continuity smell each said node device be checked by comparing the magnitude relation of the values When confirmed, in each node device, the search information and the continuous identification information stored in the storage means are used for the search information and the continuous identification information included in the acquired public message. An update process for updating the search information, and a notification process for displaying the updated search information on the display means at a timing when the search information is updated in the update process in each of the node devices.

Therefore, when new distribution information is stored in the storage device, the search information of each node device is updated based on the continuity of the continuous identification information , and the updated search information is displayed on the display means at the update timing. is Runode, maintains search information always up to date in the distribution system, it can be immediately subjected to selection of the distribution information by the user.

  Further, as the distribution information is accumulated, the search information in each node device is autonomously updated in each node device. Therefore, a separate server device or the like is provided for the update and management of the search information. There is no need to provide it inside.

As described above, according to the invention described in claim 1 or claim 13 , when new distribution information is stored in the storage device, the search information of each node device is based on the continuity of the continuous identification information. There is updated, the search information after updating the update timing is displayed on the display unit Runode, search information in the delivery system can always be immediately subjected to the delivery of maintenance to deliver information to date.

  In addition, according to the invention described in claim 1 or 14, the search information in each node device is autonomously updated in each node device in accordance with the accumulation of distribution information. There is no need to provide a separate server device or the like in the distribution system for updating / managing.

According to the second aspect of the present invention, when new distribution information is stored in the storage device, a public message including search information and continuous identification information corresponding to the new distribution information is transmitted via the network. Therefore, each node device updates the search information based on the continuity of the continuous identification information and displays the updated search information on the display means at the update timing. The search information in the system can always be kept up-to-date and immediately used for distribution of distribution information.

  Further, according to the invention described in claim 2, as a result, the search information in each node device is autonomously updated in each node device in accordance with the accumulation of distribution information. There is no need to provide a separate server device or the like in the distribution system for updating / managing search information.

  Furthermore, according to the invention described in claim 4, when new distribution information is stored in the storage device, the continuity of the continuous identification information is confirmed and the search information of each node device is updated. Since the updated search information is notified to the user, the distribution information is distributed using the latest search information by always maintaining the search information in the distribution system in the latest state. be able to.

  According to the invention described in claim 4, since the search information in each node device is autonomously updated in each node device in accordance with the accumulation of distribution information, the search information is updated.・ There is no need to provide a separate server device in the distribution system for management.

Accordingly, claim 1, claim 2, according to the invention described in any one of claims 4 or claim 13, each node device without requiring unnecessary costs and labor for maintenance such as distribution system Since the search information in can be always kept up-to-date, the distribution can be performed while improving the convenience and reliability with respect to the distribution of the distribution information in the distribution system.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 2, it corresponds to the existing distribution information in relation to the continuous identification information corresponding to the newly accumulated distribution information. When continuity is recognized with the continuous identification information, the continuous identification information stored in the storage device is updated using the continuous identification information corresponding to the newly stored distribution information. When new distribution information is accumulated, search information stored in the accumulation device can be updated quickly and autonomously.

According to the invention described in claim 5 , in addition to the effect of the invention described in claim 4 , when continuity with the continuous identification information corresponding to the search information transmitted from another node device is not confirmed. The search information and the continuous identification information corresponding to the interrupted portion of the continuity are made up by using the search information and the continuous identification information transmitted in response to the acquisition message, so that each node device searches autonomously. Information continuity can be maintained.

According to the invention described in claim 6 , in addition to the effects of the invention described in claim 4 or claim 5 , the distribution information to be distributed by the public message included in the search information Since only the search information corresponding to is displayed on the display means, only the distribution information that can be distributed at that time is the search target, and the distribution information can be efficiently searched without waste. .

According to the invention described in claim 7 , in addition to the effect of the invention described in claim 6 , the search information corresponding to the distribution information that should not be distributed by the distribution permission flag is stored from the storage means. Since the information is deleted, it is possible to efficiently search for the distribution information while preventing the search information about the distribution information that cannot be distributed from being erroneously notified.

In addition to the effect of the invention according to any one of claims 4 to 7 , the invention according to claim 8 is stored in the storage means when a message is transmitted to another node device. The search is stored in the other node device every time one of the messages is acquired in the other node device that has acquired the latest continuous identification information. By updating the information, the search information can be maintained autonomously in the latest state.

In the invention described in claim 9 , in addition to the effect of the invention described in claim 8 , when any message is acquired, it is stored in its own storage means in relation to the latest continuous identification information included therein. It is determined whether or not the stored search information is the latest, and if it is not the latest, the latest search information is acquired from another node device. By updating the identification information, the continuous identification information can be autonomously maintained in the latest state.

According to the invention described in claim 10 , in addition to the effect of the invention described in any one of claims 4 to 9 , the transmitted continuous identification information and the stored continuous identification information When it is confirmed that they are equal, a new message is generated using the stored continuous identification information, so that the update state of the continuous identification information in the distribution system can be kept up-to-date.

According to the eleventh aspect of the present invention, when the computer functions as the storage device according to the second aspect, when new distribution information is stored in the storage device, it corresponds to the new distribution information. Since the computer functions to deliver a public message including search information and continuous identification information to each node device via the network, the search information is updated by using the continuity of the continuous identification information in each node device. Then, the updated search information is displayed on the display means at the update timing, so that the search information in the distribution system can always be kept up-to-date and immediately provided for distribution of distribution information.

  Further, as a result, the search information in each node device is autonomously updated in each node device in accordance with the accumulation of the distribution information, and therefore a separate server device is used for updating and managing the search information. Etc. in the distribution system.

  Accordingly, convenience and reliability for distribution of distribution information in the distribution system can be maintained by constantly maintaining the search information in each node device without requiring unnecessary costs and labor for maintenance and the like as the distribution system. The distribution can be performed while improving the above.

  Further, when the computer functions as the storage device according to claim 3, in addition to the case where the computer functions as the storage device according to claim 2, the continuous identification information corresponding to the newly accumulated distribution information When the continuity is recognized with the continuous identification information corresponding to the existing distribution information, the continuous identification information stored in the storage device is replaced with the continuous information corresponding to the newly stored distribution information. Since the computer functions to update using the identification information, when new distribution information is stored in the storage device, the search information stored in the storage device is quickly and autonomously updated. be able to.

According to the twelfth aspect of the present invention, when the computer functions as the node device according to the fourth aspect, the continuity of the continuous identification information is confirmed when new distribution information is stored in the storage device. Since the computer functions so that the search information of each node device is updated and the updated search information is immediately notified to the user at the updated timing, the search information in the distribution system is By always maintaining the latest state and making a notification, the distribution information can be distributed using the latest search information.

  Further, as the distribution information is accumulated, the search information in each node device is autonomously updated in each node device. Therefore, a separate server device or the like is provided for the update and management of the search information. There is no need to provide it inside.

  Accordingly, convenience and reliability for distribution of distribution information in the distribution system can be maintained by constantly maintaining the search information in each node device without requiring unnecessary costs and labor for maintenance and the like as the distribution system. The distribution can be performed while improving the above.

Further, when the computer is caused to function as the node device according to claim 5 , in addition to the case where the computer is caused to function as the node device according to claim 4 , search information transmitted from another node device. When the continuity with the continuous identification information corresponding to is not confirmed, the search information and the continuous identification information corresponding to the interrupted portion of the continuity, the search information and the continuous identification information transmitted corresponding to the acquisition message are Since the computer functions so as to make up for it, the continuity of search information can be maintained autonomously in each node device.

Furthermore, when the computer is caused to function as the node device according to claim 6 , it is included in the search information in addition to the case where the computer is caused to function as the node device according to claim 4 or 5 . Since the computer functions so that only search information corresponding to distribution information that should be distributed by a public message is displayed on the display means, only distribution information that can be distributed at that time is searched. By being a target, it is possible to efficiently search for distribution information without waste.

Furthermore, when the computer is caused to function as the node device according to claim 7 , in addition to the case where the computer is caused to function as the node device according to claim 6 , it should not be distributed by the distribution permission flag. The computer functions so that the search information corresponding to the distribution information is deleted from the storage means, so that the search information about the distribution information that cannot be distributed is prevented from being erroneously notified, and the efficiency is improved. Search of distribution information can be performed.

When the computer functions as the node device according to claim 8 , in addition to the case where the computer functions as the node device according to any one of claims 4 to 7 , other nodes When transmitting a message to the device, the latest continuous identification information stored in the storage means is added and transmitted. Therefore, in the other node device that acquired the latest continuous identification information, any message is sent. By updating the search information stored in the other node device every time it is acquired, the search information can be autonomously maintained in the latest state.

Further, when the computer is caused to function as the node device according to claim 9 , it is included when any one of the messages is acquired in addition to the case where the computer is caused to function as the node device according to claim 8. It is determined whether or not the search information stored in its own storage means is the latest in relation to the latest continuous identification information, and if it is not the latest, the latest search information is transferred to another node. Since the computer functions so as to be acquired from the apparatus, the continuous identification information can be autonomously maintained in the latest state by updating the continuous identification information every time any message is acquired.

Furthermore, when the computer is caused to function as the node device according to claim 10 , it is transmitted in addition to the case where the computer is caused to function as the node device according to any one of claims 4 to 9. When it is confirmed that the continuous identification information received and the stored continuous identification information are equal, the computer functions to generate a new message using the stored continuous identification information. The update state of the continuous identification information in the distribution system can be kept up-to-date.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to the delivery system that delivers the content using a network such as the Internet.

Initially the principle of (I) the present invention, before the specifically described embodiments of the present invention, per the principles of the present invention, by referring to outline of a distribution system according to the embodiment.

(A) Overview of Distribution System First, an overview of a distribution system according to an embodiment will be described with reference to FIGS. 1 and 2. 1 and 2 are schematic diagrams showing an outline of the distribution system.

  In general, in the distribution system using the DHT described above, the node and content in the distribution system are identical to each other in relation to the fact that the corresponding node ID and content ID are expressed with the same bit length. It can be considered as being scattered on a ring-like virtual ID space. That is, as shown in FIG. 1A in which one node is displayed with ● and one content is displayed with ○, the ring Rc to which the content belongs and the ring Rn to which the node belongs are virtually concentrically assumed. Further, if it is defined that the value of each ID increases counterclockwise in each ring Rc and Rn, it can be assumed that each node or each content exists without overlapping on each ring Rc and Rn. If each ID is expressed in 128-bit length as in the above example, the number of digits becomes too large. In FIG. 1A, for simplicity of explanation, the bit length of each ID is set to 32 bits. Expressed (the same applies hereinafter). Then, as described above, due to the use of the hash function in determining the value of each ID, each node and each content exist in a substantially distributed manner on each of the above rings Rc and Rn. Become.

  On the other hand, in the distribution system using the DHT, “a node that manages content to which a certain content ID is assigned is a node to which a node ID having a value closest to the value of the content ID is assigned”. ing.

  Here, “near” may be any definition as long as it is consistent in various provisions related to the distribution system. Specifically, for example, “a value that does not exceed the value of the content ID”. And having the smallest difference between values as IDs ”.

  More specifically, for example, as illustrated in FIG. 1A, a node having a node ID value “A0334055” and a node having a node ID value “A03340FF” are adjacent to each other on the ring Rn. If it exists, the content ID value “A0334080” is managed by the node whose node ID value is “A0334055”. Note that in FIG. 1A, the nodes that manage the contents of the circles are indicated by arrows extending from the circles. In this way, various contents can be managed by being distributed among a large number of nodes.

  At this time, “management” does not mean that the content assigned with the content ID is recorded therein, but recognizes the location of the node where the content is recorded (for example, an IP address). It means that The node where the content is actually recorded may be different from the managed node, or the content to be managed may be recorded in the managed node.

  The above-described content management node is referred to as a “root node”. The root node records the index information including at least a pair of a content ID indicating the content that is to be managed and an IP address of a node in which the content indicated by the content ID is recorded, This is recorded so that it can be referred to from other nodes in the distribution system.

  In addition, when the content IDs indicating different contents are close to coincidence, and there is no other node having a node ID close to that value, a plurality of indexes corresponding to a plurality of contents by one root node Information will be recorded. Furthermore, when the same content is recorded in a plurality of different nodes and the node recording the same content is close to one root node by chance, The index information of a plurality of nodes each recording content is recorded. An example of the index information EX in the root node described above is shown in FIG.

  Further, a node that actually records each content itself is referred to as a “content holder”. At this time, since the content holder itself is essentially a node, the node ID exists on the ring Rn in FIG.

  Next, in the distribution system using the DHT, as described above, the DHT (hereinafter also referred to as a routing table as appropriate) is one of the devices for eliminating the necessity for each node to record the IP addresses of all nodes. Will be described.

  In the DHT according to the embodiment, the ID space illustrated in FIG. 1 is subdivided while increasing the number of levels for each stepped level (for example, in the case of level 1, the ID space is divided into four). Routing information that describes a pair of a node ID of an arbitrary node and its IP address is described for each area (for each area subdivided in stages). For example, when the distribution source inquiry information for requesting the content distribution source information is transferred to the root node in which the index information is recorded, the inquiry information is transferred to the target root node while referring to the routing information. To do. That is, every time the level in DHT increases, the node ID of the routing destination matches the node ID of the root node to be reached one digit at a time, and the request information finally reaches the root node to be reached. Will do.

  In the distribution system using DHT, the inquiry information (query) as described above, distribution request information for requesting distribution of the content itself, a public message described later, and the like are simply referred to as “message”. When the DHT having the above-described mechanism is used, the message can be efficiently transferred to the target node in the ID space as illustrated in FIG.

  Further, there are two types of messages: messages that are transferred by the DHT routing mechanism using the routing information, and messages that are not transferred by the messages. Most of the messages according to the embodiment described below are the former type, but the delivery request message that appears later is a message that is not transferred.

  In the following description, when a new content is recorded in the content holder, a message generated in the content holder is referred to as the public message so that it can be discovered (published) from other nodes. A message transmitted from a requester described later to a root node or a cache node described later is referred to as a distribution source inquiry message.

  Here, as described above, the value of the node ID of the root node is closest to the value of the node ID of the content holder that manages the content of the root node. Immediately before the distribution source inquiry message arrives at the content holder described in the distribution request message requesting the distribution, the root node that manages the distribution request target content is reached. Then, the root node that has received the distribution source inquiry message returns the IP address of the content holder storing the content requested by the distribution source inquiry message to the transmission source of the distribution source inquiry message. That is, the IP address of the node serving as the content holder that records the content requested by the distribution source inquiry message is distributed from the index information (see FIG. 1B) recorded in the root node. It is returned to the node that is the source of the original inquiry message. By utilizing such DHT, the location of the desired content can be efficiently recognized at the distribution request source, for example. The node that is the content distribution request source described above is hereinafter referred to as a “requester”.

  Next, the content publishing process when new content is stored in a certain node will be described.

  When new content is stored in a node, that is, the content holder of the content, the content holder will publish that the content has been stored to other nodes in the distribution system.

  That is, when new content is stored in a certain node, the node serving as a content holder for the stored content calculates a content ID corresponding to the content based on the title of the stored content.

  Next, the content holder transmits a public message with a node having a node ID having the same value as the calculated content ID as a destination (regardless of whether or not a node having the node ID actually exists). This public message includes the content ID indicating the content and the IP address of the node as the content holder, and is sequentially transferred to the node as the destination of each level via each routing destination according to the description of the DHT. The

  Then, when the node having the closest node ID is reached, the node recognizes that there is no node in the ID space to which the public message is to be forwarded afterwards ( Recognizing that the node to be transferred is itself), at this point, the node to which the public message has reached becomes the root node for managing new content. Then, the node that has become the root node records the content ID included in the public message and the IP address indicating the content holder as index information EX illustrated in FIG. 1B.

  Next, the concept of “cache node” in the distribution system according to the embodiment will be described with reference to FIG. In FIG. 2 and FIG. 3 to be described later, the root node is indicated by a double circle, the content holder is indicated by a circle marked with “X”, and the requester is indicated by a circle marked with “|” inside, which will be described later. A cache node is indicated by a circle with + in the inside, and other general nodes are indicated by a circle.

  When the distribution source inquiry message QRmsg (Query Message) from the requesters RQ1 to RQ3 is transferred to the root node RN (or content holder CH) by routing using the DHT described above, the transfer route (FIG. 2A and FIG. 2) (B) is indicated by a broken line), as shown in FIG. 2 (a), and is the path followed by the above-described public message PUBmsg (Publish Message) (shown by a solid line in FIGS. 2 (a) and 2 (b)). Since the route is similar, if the index information EX illustrated in FIG. 1B is recorded in each node (indicated by reference numeral CN in FIG. 2A) on this route, the route passes through that route. Corresponding to the distribution source inquiry message QRmsg, the distribution source inquiry message is sent to the destination route node RN or content holder CH. Before the sage QRmsg arrives, the response corresponding to the distribution source inquiry message QRmsg can be returned to the requesters RQ1 to RQ3 at an early stage.

  That is, requesters RQ1 to RQ3 that request distribution of content published in the distribution system transmit a distribution source inquiry message QRmsg requesting the IP address of the node (that is, content holder CH) in which the content is recorded. Then, the distribution source inquiry message QRmsg is transferred to the routing destination described in the DHT in each node and approaches the root node RN. Finally, the route joins the route of the public message PUBmsg from the content holder CH and reaches the root node RN.

  Here, when the path on the ring Rc shown in FIG. 2A is replaced with a tree structure, it becomes as shown in FIG. 2B, and this is generally called a “spanning tree”.

  The term “spanning tree” is a term originally used in the router technology for preventing the connection of the IP router from forming a loop, but even in the case shown in FIG. One transfer path tree can be defined for each content ID (not shown in FIG. 2B), but a spanning tree including all the nodes participating in the distribution system at that time is described. can do).

  On the other hand, as shown in FIG. 2A, the route of the distribution source inquiry message QRmsg sent from each requester RQ and the route of the public message PUBmsg sent from the content holder CH are either Eventually at the node. Therefore, the index information EX included in the public message PUBmsg is recorded in a temporary recording area that can be temporarily recorded in each of the nodes on the path for reaching the public message PUBmsg to the root node RN ( That is, the public message PUBmsg is transferred (temporarily cached). Then, the reply to the distribution source inquiry message QRmsg from the requester RQ is sent before the distribution source inquiry message QRmsg arrives at the root node RN from the node at which the distribution source inquiry message QRmsg arrives on the route to the root node RN. It can be done. A node that is a node other than the root node RN and temporarily stores the index information EX is generally referred to as a cache node CN.

(B) Principle of the Present Invention Next, the principle of the present invention based on the distribution system described above will be described with reference to FIG.

  In the distribution system having the above-described configuration, it is desirable that the catalog for searching for the contents that can be distributed in the distribution system is stored in the same and the latest in each node as described above.

  Therefore, in the present invention, the catalog stored in each node is maintained as the same and up-to-date with respect to each node without providing a special and large-scale device such as a catalog distribution server in the distribution system. When new content data corresponding to new content is recorded (registered) in the content holder according to the present invention, catalog records to which serial numbers corresponding to the content data are added (corresponding to each title respectively) New content data is recorded in the content holder together with a record corresponding to one title to be included in one catalog).

  Specifically, for this recording, first, from a content input device (not shown) on the system administrator side who manages the entire distribution system S (assuming that it has participated in the distribution system in advance), “system administrator data center” A recording instruction message stating “Record new content in” is sent to a node having a randomly selected node ID. At this time, the serial number according to the present invention is increased by “1” by the system administrator every time one content is newly added, so that catalog records corresponding to different contents have the same serial number. It avoids that it becomes.

  That is, as shown in FIG. 3, when the content data is recorded in the content holder CH from the server SV that has accumulated the new content data, the content is searched in each node N in the distribution system S. A recording instruction message RImsg (Register Instruction Message: not including the content data itself) added with a catalog record CTGR as search information used for search is urged to be recorded in the content holder CH.

  At this time, in the catalog record CTGR, as illustrated in FIG. 3, for example, “serial number”, “content ID (CID)”, “publication date”, “title (content Names ”,“ distribution permission flags ”, and“ search keys ”are described with values (or specific contents) corresponding to the respective items.

  Here, the “serial number” as the continuous identification information is a serial number that is assigned differently for each content, and a serial number that is registered later in the content holder CH is assigned a larger serial number. Note that what serial number is added to which content is selected by an administrator who manages the server SV (in other words, an administrator who manages distribution in the distribution system S). As the registered contents are newer in time series, those having a larger serial number are assigned.

  The “content ID” is given in accordance with the general rules for the distribution system S described above in principle. However, in the case of the present invention, since correspondences between all titles and content IDs are described in the catalog, a general method in the above DHT in which content IDs are determined from the titles using a hash function. Even if the content ID is not duplicated, the content ID may be assigned by any method as long as the content ID does not overlap.

  Further, “Date of publication” and “Title” respectively describe the date when the content can be distributed in the distribution system S (in principle, the date recorded in the content holder CH) and the name of the content. Has been.

  Furthermore, the “distribution permission flag” is a flag indicating whether or not the content can be distributed to each node N in the distribution system S at present, from the viewpoint of copyright protection, for example. As a typical value, the value “E” is described when the distribution is possible, and the value “D” is described when the distribution is impossible.

  In addition, as a method of using the distribution permission flag, a certain content is once registered in the catalog, but later, for example, when there is a change in intention to stop distribution from the copyright holder, or in the content data itself When there is a video / audio noise or when it is found that the content of speech or expression in the content is ethically inappropriate, the content cannot be distributed. Can be used for

  That is, in the method of the present invention, the number of catalog records that are input is increasing, and it is difficult to delete any one of the catalog records, so such a flag is provided. In other words, even if there is a past catalog record, if there is a new catalog record with the same content ID, that (that is, the catalog data with the larger serial number) is preferentially interpreted. If the distribution permission flag in the catalog record with the larger serial number is set to “non-distributable”, it can be controlled not to execute distribution of the corresponding content.

  Finally, the “search key” includes, for example, the name of the producer of the content (or the name of the director if the content is a movie), the name of the character in the content or the name of the actor who plays them, the synopsis, and the content. Are represented as information that can be used as a clue to reach the content in the search processing in each node N.

  When such a catalog record CTGR is recorded in the content holder CH together with the content data CD recorded via another route, the public message PUBmsg is transmitted from the content holder CH to each node N. However, this public message is transmitted after the serial number (in other words, the serial number having the maximum value at that time) corresponding to the content published by the public message PUBmsg is added. The

  Next, in the present invention, when each message MSG is transmitted from any node N for all the messages MSG including the public message PUBmsg, the catalog stored in the node N at that time Is transmitted after the maximum serial number is added. Thus, in the other node N that has received the message MSG, the serial number in the catalog stored in the other node N at that time and the serial number included in the transmitted message MSG are displayed. In comparison, if the serial number included in the transmitted message MSG is larger, it is recognized that new content not recognized by the other node N is registered in the distribution system S. Then, the catalog record CTGR corresponding to the catalog for searching for the new content is autonomously acquired from the node that is the relay transmission source of the message MSG or from another node N in the distribution system S.

  The above series of processing is autonomously executed at each node N using the serial number as a clue, so that each node N in the distribution system S autonomously acquires the same and latest catalog record CTGR. It becomes possible to do.

(II) Embodiment Next, an embodiment according to the present invention based on the above-described principle will be specifically described with reference to FIGS. In the distribution system according to the embodiment described below, for the sake of simplification of description, it is assumed that the cache node CN does not exist in the distribution system.

  First, a schematic configuration of a node according to the embodiment will be described with reference to FIG. FIG. 4 is a block diagram illustrating a schematic configuration of the node according to the embodiment. In the embodiment, the content holder CH, the requester RQ, the root node RN, and the other nodes N basically have the same hardware configuration, and thus represent the general node N on behalf of them. The outline of the configuration will be described with reference to FIG.

  As shown in FIG. 4, the node N included in the distribution system according to the embodiment includes a CPU having a calculation function, a working RAM (Random Access Memory), and a ROM (Read Only Memory) for recording various data and programs. And the like, and an HDD for recording and storing (storing) the content data as the content itself, the DHT and other necessary programs, and storing the index information EX. Storage unit 12 (the content data is recorded only in storage unit 12 in node N as content holder CH before distribution), buffer memory 13 for temporarily storing the received content data, content Encoded video data (video information) and audio data included in the data A decoder unit 14 that decodes (audio information) and the like (data expansion and decoding), a video processing unit 15 that performs a predetermined drawing process on the decoded video data and outputs the video signal, and the video A display unit 16 such as a CRT (Cathode Ray Tube) or a liquid crystal display for displaying an image based on the video signal output from the processing unit 15, and the decoded audio data as an analog audio signal D / A (Digital / Analog) After the conversion, the audio processing unit 17 that amplifies this by an amplifier or the like and outputs it, the speaker 18 that outputs the audio signal output from the audio processing unit 17 as a sound wave, and information between other nodes N through the network The communication unit 20 for controlling the communication of the mobile station and an instruction signal corresponding to the instruction received from each user. The control unit 11, the storage unit 12, the buffer memory 13, the decoder unit 14, and the communication unit 20 include an input unit (for example, a keyboard, a mouse, or an operation panel) 21 that outputs to the control unit 11. Data are exchanged with each other via the bus 22.

  Then, when the CPU in the control unit 11 executes various programs recorded in the storage unit 12 or the like, the control unit 11 is one of the requester RQ, the root node RN, the content holder CH, and other general nodes N. Overall control of the overall operation as one.

When the node N is a content holder CH as a storage device according to the present invention, the control unit 11 functions as a distribution unit. Further, when the node N is a node device according to the present invention, the storage unit 12 functions as a storage unit, and the control unit 11 performs a confirmation unit, an update unit, an acquisition message transmission unit, a deletion unit, an addition unit, and a message transmission. The display unit 16 functions as a notification unit.

  Next, operations according to the embodiment will be described by dividing into basic common operations as a general node (including a root node RN, a content holder CH, and a requester RQ), operations of the content holder CH, and operations of the requester RQ.

(A) General Operation as a Node First, a general operation as a node N according to the embodiment, that is, a basic common operation as a node N in the distribution system S will be described with reference to FIG. FIG. 5 is a flowchart showing a general operation as the node N according to the embodiment, and is mainly executed mainly by the control unit 11.

  As shown in FIG. 5, in the common operation as the node N according to the embodiment, first, the control unit 11 performs an initialization process for starting the node N (step S1), A participation request message for the node N to participate is transmitted to a contact node, which is another node N that acts as an intermediary when the node N participates in the distribution system S (step S2), and whether or not the participation is possible (Step S3). Then, for some reason that the node N cannot participate in the distribution system S (for example, when a fee is charged when a new participation is made in the distribution system S, the payment of the fee is not confirmed). When there is (step S3; NO), the fact is displayed on the display unit 16 of the node N to notify the user (step S15), and the processing according to the embodiment as the node N is performed. finish.

  On the other hand, if it is determined in step S3 that the node N is permitted to participate in the distribution system S (step S3; YES), the routing information effective at that time in the distribution system S is acquired from the contact node. If the newly participating node N stores content that can be distributed to other nodes N in the distribution system S, the content holder CH corresponds to the content. The public message PUBmsg is generated and transmitted into the distribution system S (step S5).

  Then, a reproduction instruction flag (to be described later) and a terminal termination instruction flag (to be described later) in the storage unit 12 are initialized to “0”, and distribution is received in the distribution system S to the user of the newly participating node N. A process for starting a thread for searching for and selecting content that can be performed (details of the thread will be described later with reference to FIG. 6) is performed (step S6).

  Here, the reproduction instruction flag is a flag in the control unit 11 that becomes “1” when the user of the node N selects and determines the content desired to be viewed by the input operation performed using the input unit 21. On the other hand, the terminal termination instruction flag is a flag in the control unit 11 that becomes “1” when the user performs an operation to terminate the use of the node N using the input unit 21.

  Then, the process waits for each instruction flag to be updated and changed to “1” by processing in the thread, and waits for reception of various messages from other nodes N of the participating distribution system S (step S8; NO).

  When any instruction flag changes or any message is received by the user (step S8; YES), whether or not the reproduction instruction flag is “1”, that is, the content of the user It is confirmed whether or not a distribution request operation has been performed (step S9).

  If it is determined in step S9 that the user has made a distribution request (step S9; YES), the node N will subsequently operate as the requester RQ. The process or the reproduction process after the acquisition is executed (step S13). The process of step S13 will also be described in detail later.

  When the reproduction instruction flag becomes “1”, the content ID of the content selected by the user during the thread processing is stored at the same time, and the discovery / reproduction processing is performed using the content ID.

  After the reproduction of the content is started, the reproduction instruction flag is returned to “0” (step S16), and the process proceeds to step S8 in preparation for the next distribution request.

  On the other hand, if it is determined in step S9 that the process in step S8 is not a distribution request operation by the user (step S9; NO), the process in step S8 is an input operation other than the distribution request operation or other message MSG. Since it is a reception process, it is confirmed whether or not a message has been received (step S10). If it is a message MSG reception process (step S10; YES), a process corresponding to the received message MSG (specifically, a routing information update process, a message MSG transfer process to another node N) Etc.) (step S14), and the process proceeds to step S8. The processing in step S14 will also be described in detail later.

  On the other hand, if it is determined in step S10 that no message MSG has been received yet (step S10; NO), is the previous input operation an operation to end the operation as the node N? It is confirmed whether or not (step S11). And when the said operation is not performed (step S11; NO), it considers that the invalid operation was made and transfers to the process of said step S8.

  On the other hand, when an operation to end the operation as the node N is performed (step S11; YES), a withdrawal process such as a process of transmitting a withdrawal message to the distribution system S is executed (step S12). Then, the operation as the node N according to the embodiment is terminated.

  Next, the contents of the thread executed as part of the process of step S6 will be specifically described with reference to FIG. FIG. 6 is a flowchart showing the contents of the thread.

  Specifically, as shown in FIG. 6, when a thread for content search and selection operation is started, first, a search screen set in advance for content search is displayed on the display unit 16 as shown in FIG.

  Here, the search screen will be specifically described with reference to FIG. 7A. As the search screen, a title column 30 in which a title as the search screen is displayed and a title of the content are clues. A title input field 31 in which the title is input when performing a search, a name input field 32 in which the name is input when performing a search using a name of an actor or the like appearing in the content as a clue, A name input field 33 in which the name is entered when searching using the name of the content director as a clue, and a keyword (corresponding to a “search key” in the catalog record CTGR illustrated in FIG. 3) that indicates the content. When searching using a keyword) as a clue, a keyword input field 34 in which the keyword is input and the input search condition A search operation button 35 that is operated when searching in the catalog, a list display operation button 36 that is operated when displaying as a list according to the registration order of the catalog, and an information display field 38 for displaying various information An operation button 39 operated to display the continuation of the information, an end button 40 for instructing the end of the operation as the node N, an information display field 37 for displaying various other information, Is displayed on the display unit 16 (step S60).

  When the search screen is displayed, first, characters can be input in the title input field 31 (step S61), and then any key operation or button operation on the input unit 21 is waited for (step S62). When an up / down key (not shown) in the input unit 21 is operated (step S63; YES), the column in the search screen that allows character input is moved to another input column such as the name input column 32, for example. (Step S66), the process returns to step S62 and waits for the next input operation.

  If the input operation is not an up / down key (step S63; NO), it is next checked whether a left / right key, a character key, a delete key or the like (not shown) in the input unit 21 has been operated (step S64). . When any character or the like is input (step S64; YES), the search keyword editing process using the input character or the like in the input field where the character input is enabled at that time (step S64; YES) More specifically, search keyword determination processing or the like is executed (step S67), and the process returns to step S62 again to wait for the next input operation.

  On the other hand, if the operation of the character key or the like is not performed in the determination in step S64 (step S64; NO), it is confirmed whether or not the search execution button 35 has been operated (step S65). When the search execution button 35 is not operated (step S65; NO), it is finally checked whether or not the end button 41 is operated (step S68), and the end button 41 is not operated. If so (step S68; NO), the process returns to step S63 to wait for a further input operation.

  On the other hand, when the end button 41 is operated in the determination in step S68 (step S68; YES), the value of the terminal end instruction flag is set to “1” in the control unit 11 (step S69). It returns to S62 and waits for further input operation.

  On the other hand, when the search execution button 35 is operated in the determination in step S65 (step S65; YES), it is determined that the catalog search is performed with the search keyword input in each input field at this time. Become. That is, contents having titles that match the determined search keyword are extracted from the catalog currently stored in the storage unit 12 (step S70), and the extracted contents are displayed in a list (step S71). ). At this time, the list is displayed as a search result list on a screen different from the content reproduction display screen.

  Here, the search result list will be described with reference to FIG.

  As the search result list, for example, as shown as a list LT in FIG. 7B, for the content having a title that matches the determined search keyword, the title of the content and the keyword for the search Is displayed in a list by quoting a part of the information of the catalog record CTGR. In FIG. 7B, the contents selected at that time in the list LT are highlighted by hatching.

  At the same time as the list LT, up and down keys 41 and 42 for moving the content selected in the list LT and viewing / reproduction of the content selected using the list LT are started. A viewing button 43 to be operated and a return button 44 for displaying the search screen shown in FIG. 7A again to execute a search keyword re-input operation and the like are displayed on the display unit 16.

  Furthermore, when displaying the list LT, the distribution permission flag (see FIG. 3) included in the extracted catalog record CTGR (step S70) becomes “E”, that is, can be disclosed. Show only what you have. That is, when the same content ID is written multiple times in the catalog, the one with the largest serial number is valid, so only the content with the largest serial is “E” is displayed and the largest serial number is displayed. Content whose “D” is “D” is not displayed in the list.

  After the list LT is displayed on the display unit 16 by the process of step S71, the above-described up / down key 41 or the above-described key is used to change the content to be selected while waiting for any button or key operation (step S72). It is monitored whether 42 is operated (step S73).

  When the up / down key 41 or 42 is operated (step S73; YES), the highlight display of the display content in the list LT is switched in accordance with the operated up / down key 41 or 42 (step S77). The process returns to step S72 again to wait for the next input operation.

  On the other hand, if it is determined in step S73 that neither the up / down key 41 or 42 has been operated (step S73; NO), then it is confirmed whether or not the return button 44 has been operated (step S74). . When the return button 44 is operated (step S74; YES), the process returns to step S60 and the process is repeated from the new display of the search screen (step S60).

  On the other hand, if it is determined in step S74 that the return button 44 is not operated (step S74; NO), it is finally checked whether or not the viewing button 43 is operated (step S75). When the viewing button 43 is not operated, it is a case where an invalid input button is operated (step S75; NO). Therefore, the process returns to step S72 and waits for the next input operation. (Step S75; YES), the content ID of the content to be viewed is stored in the control unit 11 and the reproduction instruction flag in the control unit 11 is set to “1” (step S76). The process returns to step S62 and waits for the next input operation.

  Next, details of the processing operation of the message MSG according to the embodiment as the processing of step S14 shown in FIG. 5 will be specifically described with reference to FIGS. 8 is a flowchart showing the entire processing operation, and FIG. 9 is a flowchart showing the operation when the recording instruction message RImsg, which is one of the messages MSG, is received in the content holder CH. FIG. 5 is a diagram illustrating an example of how catalog records CTGR are updated according to the embodiment.

  The processing operation shown in FIG. 8 is executed when a new message MSG (see FIG. 3) is transmitted from any other node N.

  That is, first, it is determined whether or not the message MSG is the recording instruction message RImsg (step S30). If it is the recording instruction message RImsg (step S30; YES), a process of receiving the recording instruction message RImsg is executed (step S95), and a standby state (see step S8 in FIG. 5) is prepared for the next process. enter. The process of step S95 will be described in detail later.

  On the other hand, if it is determined in step S30 that the message MSG is not the recording instruction message RImsg, cont_sn_max (the information “cont_sn_max” included in the message header MHD in the message MSG is stored in any other node N. In the case of a message MSG of a relayed type, it is information indicating the maximum serial number in the catalog held by the node N that has performed the relay processing, and the “Received” field and the “Routed” field in the message MSG Are stored in the storage unit 12 of the node N at that time (refer to FIG. 9B) (refer to the maximum value among them in the process of step S31). Compare with the value of the largest serial number in the catalog that Confirms whether the higher value of the serial number (step S31).

  If it is determined in step S31 that the serial number value in the received message MSG is not larger (step S31; NO), the message including the maximum serial number value stored in the storage unit 12 at that time. A header MHD (see FIG. 9B) is generated (step S36), and the process proceeds to step S37 described later. The message header MHD is used when the message MSG is transmitted (transferred) to another node N later, and details will be described later.

  On the other hand, if it is determined in step S31 that the serial number value in the received message MSG is larger (step S31; YES), only the catalog record CTGR corresponding to the serial number in the received message MSG is stored in the message. The request is obtained from the node N that has transmitted the MSG, and the catalog stored in the storage unit 12 is updated using the obtained catalog record CTGR (step S32; see FIG. 12A).

  Next, the presence / absence of continuity between the serial numbers in the serial number relationship determined in step S31 is confirmed (step S33). At this time, the serial numbers are usually continuous. For example, when the power of the node N on which the processing shown in FIG. 8 is executed is temporarily turned off, the power is turned off. In the case where new content is input while the power is turned off and then another new content is input after the power is turned off, the numbers may not be consecutive. .

  If it is determined in step S33 that the serial numbers are consecutive (step S33; NO), the maximum serial number value in the new catalog after the update (that is, the serial number in the received message MSG). A message header MHD (see FIG. 9B) including (value) is generated (step S35), and the process proceeds to step S37 described later.

  On the other hand, in the determination in step S33, if the above-described void is present between the two serial numbers that were compared in the determination in step S31 (step S33; YES), the serial corresponding to the void portion is present. For the catalog record CTGR including the number, the catalog record CTGR corresponding to the hollow portion is acquired from the other node N. For this purpose, a catalog list acquisition message (Get Catalog List Message) including a serial number corresponding to the hollow portion is separately generated and transmitted to an arbitrary node N in the distribution system S.

  Here, as the contents of the acquisition message, serial numbers necessary for making up for the above-described missing portions are listed. At this time, in addition to listing all the necessary serial numbers, the first and last serial numbers in the requested serial number range may be described.

  Further, the node N as the destination at this time is determined at random, for example. The catalog list acquisition message is a message MSG of a type transferred using DHT. As a result, if there is a node N that stores the requested catalog record CTGR during the transfer of the acquisition message, the node N performs a corresponding reply to the node N of the acquisition message transmission source ( Details will be described later).

  When a catalog record CTGR corresponding to the hollow portion corresponding to the acquired message is returned from any node N, the catalog in the storage unit 12 is stored using the returned catalog record CTGR. (The void portion) is updated (step S34; see FIG. 12A). At this time, when a catalog record CTGR with the distribution permission flag “D” is added, it is checked whether or not the corresponding content is accumulated, and if it is accumulated, the content data is deleted. Also do. Then, the process proceeds to steps S35 and S37.

  In other words, the processing shown in FIG. 8 is executed when the serial number of the distribution system S as a whole is increased by “1” (that is, new content is input into the distribution system S). If it is detected at the node N, the latest catalog record CTGR can be obtained from the node N that is the relay transmission source of the message MSG, but the serial number of the distribution system S as a whole has increased by “2” or more. In this case, since the above-mentioned hollow is detected only by acquiring the latest catalog record CTGR from the node N that is the relay transmission source of the message MSG, the catalog record CTGR corresponding to the hollow portion is detected from the other nodes N. Is acquired, and the supplement processing as a catalog is further performed.

  Next, it is confirmed whether or not the received message MSG (see step S31) is a message MSG to be transferred to another node N (that is, whether the message type of the message MSG is a type to transfer). If it is a type to be transferred, the DHT routing table is referred to determine whether or not the transfer destination is itself (step S37), and if it is the message MSG to be transferred ( (Step S37; YES), the message MSG to be transferred including the message header MHD generated by the process of Step S35 or S36 at its head is generated and transferred to another node N in the distribution system S (Step S38). In preparation for the next processing, a standby state is entered (see step S8 in FIG. 5).

  On the other hand, if it is determined in step S37 that the message MSG is not to be transferred to another node N (step S37; NO), the node N itself performs processing corresponding to the received message MSG (step S39). The process shifts to the standby state (see step S8 in FIG. 5).

  By executing the above operation in each node N, the autonomous update of the catalog record CTGR in each node N is completed.

  Here, as the processing in step S39, individual processing is performed for each type of message MSG.

  On the other hand, if it is determined in step S30 that the message MSG is the recording instruction message RImsg (step S30; YES), processing corresponding to the flowchart shown in FIG. 9A is executed. Here, FIG. 9A shows a recording instruction message as a message indicating an instruction to record new content data in each node N (in other words, node N that will later become the content holder CH). 6 is a flowchart showing processing executed when RImsg (see FIG. 3) is transmitted from a content input device (not shown) and received. Note that a catalog record CTGR corresponding to the new content is added to the recording instruction message RImsg.

  As shown in FIG. 9A, the node N (the node N that becomes the content holder CH) that has received the recording instruction message RImsg first checks the contents of the distribution permission flag in the catalog record CTGR of the recording instruction message RImsg. (Step S20), it is determined whether or not distribution is possible (Step S80). When the distribution permission flag is “D” (step S80; NO), the content data is not acquired from the content input device, and if the content is stored in the content itself, Is deleted (step S81), and the process proceeds to step S21.

  Specifically, in the process of step S81, if the node N that is the content holder CH has already accumulated content data corresponding to the content, the content data is deleted, and then the following is shown. Similarly to the case where the distribution permission flag is “E”, the update processing of the catalog stored by the confidence is executed. Further, when the node N has not accumulated the content data, the timing at which it is deleted is when the catalog update process in step S34 is executed.

  On the other hand, if it is determined in step S80 that the distribution permission flag is “E” (step S80; YES), the content described in the catalog record CTGR is acquired from a content input device (not shown) (step S82).

  Next, the serial number value of the catalog record CTGR included in the original recording instruction message RImsg is compared with the maximum serial number value in the catalog stored in the storage unit 12 at that time, and recorded. It is confirmed whether or not the serial number value in the instruction message RImsg is larger (step S21).

  If the serial number value in the recording instruction message RImsg is not larger in the determination in step S21 (step S21; NO), a message including the maximum serial number value stored in the storage unit 12 at that time. A header MHD (see FIG. 9B) is generated (step S25), and the process proceeds to step S26 described later. In FIG. 9B, the maximum value among the values indicated by “cont_sn_max” is the value of the maximum serial number at the present time.

  Here, the message header MHD will be described more specifically with reference to FIG.

  The message header MHD is used as a header in all message MSGs handled in the present embodiment, and is also used as a header in the public message PUBmsg transmission (step S29 in FIG. 9A) described later. It is. The fields in the message header MHD will be described. First, in the “Return-Path” field, the IP address of the original node N that has transmitted the message MSG is described. At this time, the content of the “Return-Path” field does not change during the transfer even in the type of message MSG to be transferred.

  Next, in the “Received” field, information indicating from which node N the message MSG is received is described by the IP address of the transmitting node N. At this time, in the type of message MSG to be transferred, the content of the “Received” field is updated each time the message is transferred. In the present invention, the maximum serial number cont_sn_max in the catalog is described in the “Received” field (the “version” information described in the “Received” field is used in the present invention. do not do).

  Next, the information described in the “Routed” field indicates the transfer history of the message MSG. That is, in a certain node N, when transferring a message MSG received from another node N, the contents of the “Received” field in the message MSG are moved to the “Routed” field, and the “Routed” up to that point is transferred. Rewrite the information in the field by shifting it down one record. As a result, the “Routed” field increases each time the message MSG is transferred.

  Next, the information described in the “Message-ID” field is information used to detect duplicate arrival of the message MSG, and is a unique value based on the IP address, transmission time, etc. of the source node N. Is granted.

  Next, the “Message-Date” field describes the date and time when the message MSG is transmitted, and is used for the purpose of recording in the operation history, for example.

  Further, in the “Event-Type” field, information indicating the type of the message MSG is described. As processing of step S39, referring to information described in the “Event-Type” field, different processing is executed for each type of message MSG.

  Finally, in the “Contents-Id” field, the content ID of the content of interest at that time is described. For example, in the public message PUBmsg, the content ID of the content to be disclosed is described. In the distribution source inquiry message QRmsg, the content ID of the content to be found is described. Further, depending on the type of the message MSG, there is a case where this “Contents-Id” field does not exist.

  In FIG. 9B, the “Routed” field is described for detailed explanation of the message header MHD. However, the public message PUBmsg used for the processing in step S29 described later is the largest source. Message MSG (which is the type of message MSG to be transferred, but this is the first transmission source), the “Routed” field is not generated in the steps S23 and S25 described later.

  Thus, all the various message MSGs used in the present invention describe the maximum serial number cont_sn_max in the catalog of each node N.

  Returning to FIG. 9A, when the value of the serial number in the recording instruction message RImsg is larger in the determination in step S21 (step S21; YES), a new catalog record CTGR is added by the system administrator. Therefore, the catalog stored in the storage unit 12 at that time is updated using the catalog record CTGR (step S22), and the maximum serial number in the new catalog after the update is updated. (That is, the serial number value in the recording instruction message RImsg) is generated (step S23).

  Note that the reason why the serial number value in the recording instruction message RImsg is determined not to be larger in the processing of step S21 is that the recording instruction message RImsg indicating that the content already distributed in the distribution system S should be recorded. Is when it arrives. This is performed when the system administrator wants to prepare an extra copy of popular content.

  Next, it is confirmed whether or not the two serial numbers to be compared are consecutive in the magnitude relationship between the serial numbers determined in step S21 (step S26). If the result of the confirmation is that they are continuous (step S26; NO), then the content holder CH becomes the content holder CH in accordance with the rules as the distribution system S shown using FIG. 1 and FIG. The node N confirms whether or not the node N also serves as the root node RN corresponding to the content (that is, the content ID of the input content is close to its own node ID, and even if the DHT is referred to) When no other node N to be transferred can be found, it becomes the root node RN (step S28), and when it does not become the root node RN (step S28; NO), the message header generated by the process of step S25 or S23 above. The public message PUBmsg including the MHD at its head is generated and transmitted in the distribution system S (step S29). Subsequent processing of the content holder CH (e.g., distribution processing or the like corresponding to the distribution request message from the requester RQ) enters a standby state in preparation for.

  On the other hand, in the determination of step S28, when the function as the root node RN is also performed (step S28; YES), the process is ended as it is.

  Furthermore, in the determination in step S26, when the two serial numbers to be compared in the determination in step S21 are not consecutive (that is, there is a “missing” between them) (step S26; YES). 8, similar to the processing in step S <b> 34, for example, other content that was input while the power of the node N on which the processing illustrated in FIG. 9A is executed is temporarily turned off, and the corresponding catalog Since this means that the record CTGR exists in another node N, the catalog record CTGR corresponding to the hollow portion is acquired from the other node N in the same manner as the processing in step S34.

  When the catalog record CTGR corresponding to the hollow portion is returned from any node N, the catalog record CTGR in the storage unit 12 is updated with the catalog record CTGR transmitted (step S27). ), The process proceeds to step S28.

  Next, the difference acquisition processing in steps S34 and S27 will be described as a specific example with reference to FIG.

  That is, FIG. 12A shows a catalog configured by the catalog record CTGR stored in the storage unit 12 before receiving the message MSG (including the recording instruction message RImsg (in the case of step S27)). If it is the catalog list CTGL1 and the serial number included in the recording instruction message RImsg at that time is “1011”, the catalog list shown in FIG. 12A is obtained at the time when the steps S34 and S27 are started. It becomes CTGL2, and it is determined that the serial numbers “1009” and “1010” are missing (see step S26; YES, S33; YES).

  Therefore, the node N that is recognized by the distribution system S that there is another catalog record CTGR that is not recognized by the node N itself that is the content holder CH includes the serial number corresponding to the above-described hollow portion. An acquisition message of the catalog record CTGR is transmitted to another node N (the destination node ID itself at the time of transmission can be set at random, for example). In this case, catalog records CTGR with serial numbers “1009” and “1010” are requested to the other node N.

  The acquired message is transferred to a plurality of nodes N according to the routing operation of the DHT, and stores the catalog record CTGR corresponding to the hollow portion among the other nodes N that have received the acquired message. The node N (the catalog record CTGR stored in the node N has a serial number stored continuously from “1005” to “1011”, for example) A difference data list CTGL-S (see FIG. 12A) including the corresponding catalog record CTGR is generated and returned to the node N that transmitted the acquisition message.

  Thereby, the node N (content holder CH) that has received the reply of the difference data list CTGL-S synthesizes the difference data list CTGL-S with the catalog list CTGL2 stored in its storage unit 12, At the time, the latest catalog is formed and stored again. Thus, in the catalog stored in the node N at the time when the steps S34 and S27 are completed, the serial numbers are consecutive from “1005” to “1011”, for example.

  Even when the acquisition message of the catalog record CTGR is transmitted, any node N that has received the acquisition message may not store the requested catalog record CTGR. Since a reply “not stored” is returned, the destination node ID is changed to another random node ID, and a retry is made.

  In the above description using FIG. 12 (a), the catalog record CTGR acquisition message is sent to a random node ID. This corresponds to the serial number of the omission (the maximum value if there are multiple). The content may be addressed to the root node RN. In this case, since there is a high probability that the root node RN stores the latest catalog, the above-mentioned reply “not stored” is less likely to be returned, and wasteful retries can be reduced. it can.

  However, on the other hand, the acquisition messages of the catalog record CTGR arrive at the root node RN corresponding to the latest input content, and there is a possibility that the processing load on the root node RN becomes excessive. In order to avoid this, an item “content input date / time” is added to the catalog record CTGR, and “cont_sn_max” is additionally written, and “content input date / time corresponding to the maximum serial number” is added to the message header MHD. When each node N receives this, if the time has not passed since the input date and time (for example, if 3 days have not passed), it sends it to the root node RN, and if the time has passed, It may be possible to take a method of sending to a random ID.

  By performing the operation including the above steps S34 and S27, the update of the catalog record CTGR as the new content holder CH is completed. In addition, the catalog record CTGR of the newly input content initially exists only in this node N, but as described above, the latest serial number in the message MSG transmitted by this node N is set to the other node N. As a result, the latest catalog record CTGR is gradually diffused in the distribution system S. In the processing described with reference to FIGS. 8 and 9 above, since the latest catalog record CTGR is first propagated by the public message PUBmsg, the node N in the transfer path quickly notices the latest catalog record CTGR. In other words, it is spread sequentially from the node N on this transfer path.

(B) Operation as Requester Next, details of the content discovery and the reproduction operation (see step S13 in FIG. 5) at the node N as the requester RQ (see FIG. 2) according to the embodiment will be described with reference to FIG. I will explain it. FIG. 10 is a flowchart showing the operation of content discovery / reproduction processing as the requester RQ.

  As a premise that the process shown in FIG. 10 is executed, the requester RQ user uses the search screen described with reference to FIG. 7 to determine which content is requested for distribution. (That is, the state where selection of content is completed by the thread described with reference to FIG. 6).

  As shown in FIG. 10, first, the content ID of the content selected by the user is described in, for example, the “Contents_Id” field of the distribution source inquiry message QRmsg as shown in FIG. It transmits toward the root node RN (step S40). That is, referring to the DHT routing table, the distribution source inquiry message QRmsg is transmitted to the node N having the node ID closest to the content ID. Then, the transmitted distribution source inquiry message QRmsg is similarly transferred at the next node N in the transfer order, and finally reaches the root node RN.

  Next, the root node RN that has received the distribution source inquiry message QRmsg returns the IP address of the node N that stores the content by referring to the index cache stored therein, so that the requester RQ waits for the inquiry response message (step S41; NO).

  When the inquiry response message is received (step S41; YES), the IP address indicating the corresponding content holder CH should be described therein (step S42), so that the content is based on the IP address. This time, the delivery request message is transmitted to the node N as the holder CH (step S43).

  Next, since the content holder CH that has received the distribution request message transmits content data as a content body to the requester RQ that is the transmission source of the distribution request message, the requester RQ receives the content data. (Step S44).

  When the reception of all the content data is completed (step S45; YES), the reproduction process (viewing process) is performed (step S46). When the reproduction to the end of the content data is completed (step S47; YES), the requester RQ. The content discovery / playback process is completed.

  In the content discovery / reproduction process shown in FIG. 10, the search screen (see FIG. 7) and the reproduction screen (screen on which an image as the content is displayed) can be displayed separately on the display unit 16, respectively. It is preferable to do this. That is, it is desirable that the search screen can be displayed even during playback of the content. Specifically, for example, the search screen may be displayed so as to be overlaid on the playback screen by overlay display (superimpose display), or the display unit 16 may be configured to display the search screen. It is also possible to divide the single screen into two parts for search screen and playback screen, respectively. Alternatively, the display unit 16 may be configured to have, for example, a CRT (Cathode Ray Tube) display and a liquid crystal display so that either the search screen or the playback screen is displayed.

  Furthermore, it is also possible to configure such that playback of content is stopped during playback.

(C) Operation of Optimization Process as General Node Next, the operation of the catalog optimization process according to the embodiment using the distribution permission flag executed in each node N in the distribution system S is shown in FIG. 11 and FIG. 12 (b). FIG. 11 is a flowchart showing the operation of the optimization process.

  In the optimization processing described below, the catalog corresponding to the content that can be actually played back (viewed) is deleted by deleting the catalog record CTGR indicating the content that has been made private at each node N from the storage unit 12. This is a process of storing a catalog including only the record CTGR in the storage unit 12.

  Here, in the optimization process, the catalog record CTGR corresponding to the content and having the value of the distribution permission flag “D” is obtained for the content whose distribution permission flag value has been “E”. When the published content is unpublished by newly entering the distribution system S as the recording instruction message RIMG, the catalog record CTGR that is useless (that is, corresponding to the content that cannot be published) increases in the catalog. Therefore, this is deleted to suppress useless use of the storage unit 12.

  The optimization processing is performed at least at every preset period, every preset time, or whenever the catalog list (see FIG. 12A) stored in the node N is updated. It starts at one timing.

  That is, as shown in FIG. 11, in the optimization process, first, a parameter indicating the number of the catalog record CTGR (number from the top when arranged in the serial number order) stored in the storage unit 12 at that time. I is initialized (step S50), and then the content of the distribution permission flag in the I-th catalog record CTGR is confirmed (step S51). If the content is not “D” (step S51; NO), the value of the parameter I is incremented (step S53), and the value of the parameter I after the increment is stored in the storage unit 12 at that time. It is confirmed whether or not the number is larger than the number of all catalog records CTGR (step S54).

  If it is determined in step S54 that the value of the parameter I is larger than the number of all catalog records CTGR (step S54; YES), all contents currently recognized by the node N can be disclosed. Therefore, the optimization process is not necessary, and the optimization process is completed as it is.

  On the other hand, if it is determined in step S54 that the value of parameter I is not greater than the number of all catalog records CTGR (step S54; NO), this corresponds to the value of parameter I after the increment (step S53). In order to execute steps S51 to S54 for the catalog record CTGR, the process returns to step S51.

  On the other hand, when the catalog record CTGR having the distribution permission flag whose value is “D” (that is, the distribution is newly prohibited) is found in the determination in step S52 (step S52; YES), In addition, the value of the parameter del_ID indicating the content ID of the content to be deleted from the catalog currently stored in the storage unit 12 is the same as the content ID of the content whose distribution permission flag is “D”. (Step S55), and, similarly to the parameter I, another parameter J indicating the number of the catalog record CTGR stored at that time in the storage unit 12 is initialized (Step S56), and the Jth catalog record CTGR is initialized. The content of the distribution permission flag in is confirmed (step S57).

  Next, the content ID of the content for which the content of the distribution permission flag is confirmed is equal to the value of the parameter del_ID at that time (step S58; YES), and the value of the confirmed distribution permission flag is “E”. If so (step S59; YES), the J-th catalog record CTGR is deleted (step S90), and the value of the parameter J is incremented (step S91). If the value of the parameter J after the increment is equal to or greater than the value of the parameter I at that time (step S92; YES), the process returns to the step S51 and the catalog record CTGR having the number indicated by the current value of the parameter I is returned. The above steps S51 to S92 are repeated.

  On the other hand, whether the content ID of the content for which the content of the distribution permission flag is confirmed in step S58 is not equal to the value of the parameter del_ID at that time (step S58; NO), or in the determination in step S59, If the confirmed value of the distribution permission flag is not “E” (step S59; NO), the process proceeds to step S91 as it is.

  Through the process described above, the catalog stored in the storage unit 12 at that time is searched in order from the beginning to the end, and if a content record CTGR whose distribution permission flag value is “D” is found (the above step) S52; see YES), whether there is any catalog record CTGR that has the same content ID as the content ID of the content record CTGR and whose distribution permission flag value is “E” from the top of the catalog. It is possible to search to the position where the catalog record CTGR with the distribution permission flag “D” is found and delete the content record CTGR with the distribution permission flag “E”.

  Next, the optimization process shown in FIG. 11 will be specifically described with reference to FIG.

  The content that has been publicly available until that time (ie, the distribution permission flag = “E”) (the content with the content ID “4875” in the example shown in FIG. 12B) cannot be newly released (that is, the distribution is permitted). When the flag = “D”), the catalog record CTGR indicating the fact is updated as a new catalog record CTGR, as shown in FIG. A larger serial number (in the example shown in FIG. 12B, a serial number “1011”) is added and transmitted as a recording instruction message RImsg.

  Therefore, in the process shown in FIG. 11, the catalog record with the serial number “1006” is deleted from the catalog list CTGL3 among the two catalog records CTGR indicated by hatching in FIG. 12B (step S90).

  Through the above optimization processing, a catalog including only the catalog record CTGR corresponding to the latest publicly available content is always maintained and stored in each node N.

  Note that when the above optimization process is performed, a state in which there is a hollow portion in the catalog list CTGL (see FIG. 12A) can be obtained. And at first glance, it seems that this hollow portion is returned to the original (continuous serial number) again by the difference acquisition process (see step S34 in FIG. 8 or step S27 in FIG. 9), but step S26 in FIG. Alternatively, when determining whether or not there is a hollow portion in the process of step S33 in FIG. 8, such a determination does not occur because the determination is performed in a range larger than the maximum serial number in the catalog held by itself.

  As described above, according to the operation in each node N (including the content holder CH and the requester RQ) according to the embodiment, when new content is accumulated in the content holder CH, it is stored in each node. Since the catalog of each node N is updated based on the continuity of the serial number in the catalog, the catalog in the distribution system S can always be kept up-to-date and used for content distribution.

  In addition, the catalog in each node N is autonomously updated in each node N as new content is accumulated, and therefore a server device or the like is separately provided for the update / management of the catalog. There is no need to provide it inside. When new content is accumulated in the content holder CH, the public message PUBmsg including the catalog record CTGR and serial number corresponding to the new content is distributed to the root node RN via the network. In each node N on the transfer path, the catalog is updated based on the continuity of the serial number, so that the catalogs of the plurality of nodes N can always be kept up-to-date and used for content distribution.

  In addition, since the latest serial number is added to the message MSG issued by these nodes N and transmitted, the node N that has received this also updates the catalog to the latest state. The catalogs of all nodes N are gradually updated to the latest state. As a result, the catalog in each node N is autonomously updated in each node N by exchanging messages between the nodes N after the content has been input, so that the catalog is updated and managed separately. There is no need to provide a server device or the like in the distribution system S.

  Furthermore, when new content is stored in the content holder CH, the catalog of each node N is updated by confirming the continuity of the serial number, and the updated catalog is notified to the user. Therefore, the user can use the latest catalog to select which content is desired to be distributed.

  Therefore, the catalog in each node N can always be kept up-to-date without requiring unnecessary costs and labor for the maintenance and the like as the distribution system S, and convenience and reliability for content distribution in the distribution system S The distribution can be performed while improving the above.

  In addition, when continuity is recognized with the serial number corresponding to the existing content in relation to the serial number corresponding to the newly accumulated content, the maximum serial number stored in the content holder CH is set to Since the update is performed using the serial number corresponding to the newly accumulated content, when new content is accumulated in the content holder CH, the catalog stored in the content holder CH quickly and autonomously Can be updated.

  Further, when the catalog record CTGR is transmitted from another node N, the continuity with the serial number included in the catalog record CTGR is confirmed, and when the continuity is confirmed, the transmitted serial number is confirmed. Since the maximum serial number up to now is updated using, the catalog in each node N can be updated autonomously.

  When the continuity with the serial number corresponding to the catalog record CTGR transmitted from another node N is not confirmed, the catalog record list CTGRL corresponding to the interrupted portion of the continuity is acquired from the other node N. Therefore, in each node N, catalog continuity can be maintained autonomously.

  Furthermore, since only the information of the catalog record CTGR corresponding to the content that is supposed to be distributed by the distribution permission flag included in the catalog record CTGR is notified (displayed), the content once disclosed is copyrighted. It can be made private if necessary for the convenience of the holder.

  Furthermore, although there are a plurality of catalog records CTGR for the contents that are supposed to be distributed by the distribution permission flag after being once published, unnecessary catalog records CTGR are deleted appropriately. Therefore, it is possible to efficiently search for contents while preventing the catalog from being unnecessarily enlarged.

  In addition, when the message MSG is transmitted to another node N, the latest serial number stored in the storage unit 12 is added and transmitted. Therefore, the other node N that has acquired the latest serial number is transmitted. , The catalog stored in the other node N is updated each time any message MSG is acquired, so that the catalog can be autonomously maintained in the latest state.

  Further, when any message MSG is acquired, it is determined whether or not the catalog stored in its own storage unit 12 is the latest in relation to the latest serial number included in the message MSG, If it is not the latest, the catalog record list CTGRL, which is the difference between the latest catalog and its own catalog, is acquired from the other nodes N, so that it can be autonomously maintained in the latest state.

  In the embodiment described above, the case where the present invention is applied when searching for the content to be reproduced in the distribution system S has been described. However, in addition to this, only the distribution of the desired content is received. It is also possible to apply the present invention to the recording.

  Furthermore, the program corresponding to the flowcharts shown in FIGS. 5, 6 and 8 to 11 is recorded on an information recording medium such as a flexible disk or a hard disk, or is acquired and recorded via the Internet or the like. These can be read and executed by a general-purpose computer so that the computer can function as the content holder CH, the requester RQ, and the control unit 11 in another node N according to the embodiment.

  Further, the initial insertion of the content into the distribution system S is performed by a method different from the recording instruction message RImsg, for example, a CD-ROM (Compact Disk-Read Only Memory) is mailed to the user of the node N It is also possible to use a method of accumulating in the node N. In this case, the processing corresponding to the flowchart shown in FIG. 9A is started when the reading of the CD-ROM in the node N is completed and the new content is stored in the node N. It is preferable to configure.

  Alternatively, on the premise that each node N is functioning a so-called FTP (File Transfer Protocol) server, the input center connects to the FTP server as an FTP client and records a new content file by FTP. Input is possible.

  As described above, the present invention can be used in the field of content distribution via a network, and particularly when applied to the field of content distribution in a download format, a particularly remarkable effect can be obtained.

It is a schematic diagram (I) which shows the outline | summary of the delivery system which concerns on embodiment, (a) is a schematic diagram which shows ID space in the said delivery system, (b) is a figure which illustrates index information. It is a schematic diagram (II) which shows the outline | summary of the delivery system which concerns on embodiment, (a) is a schematic diagram which shows the transmission state of the message in the said delivery system, (b) is transmission of the said message represented as a spanning tree. It is a figure which shows a state. It is a figure explaining the principle of this invention. It is a block diagram which shows the outline structure of the node which concerns on embodiment common about a content holder etc. It is a flowchart which shows the whole common operation | movement in the node which concerns on embodiment. It is a flowchart which shows the detail of the common operation | movement in the node which concerns on embodiment. It is a figure which illustrates composition of a search screen etc. concerning an embodiment, (a) is a figure which illustrates the contents of the search screen concerned, and (b) is a figure which illustrates the contents of a list. It is a flowchart which shows the operation | movement of the message process in the general node which concerns on embodiment. It is the flowchart etc. which show the reception process of the recording instruction | indication message in the content holder which concerns on embodiment, (a) is the said flowchart, (b) is a figure which illustrates the content of the message header. It is a flowchart which shows the operation | movement of the acquisition / reproduction | regeneration process of the content in the requester which concerns on embodiment. It is a flowchart which shows the operation | movement of the optimization process in the general node which concerns on embodiment. It is a figure which illustrates the update etc. of the catalog data which concern on embodiment, (a) is a figure which illustrates the update of the said catalog data, (b) is a figure which illustrates the optimization process of a catalog data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Control part 12 Memory | storage part 13 Buffer memory 14 Decoder part 15 Image | video processing part 16 Display part 17 Audio | voice processing part 18 Speaker 20 Communication part 21 Input part 22 Bus 30 Title column 31 Title input column 32, 33 Name input column 34 Keyword input column 35 Search operation button 36 List display operation button 37, 38 Information display field 39 Operation button 40 End button 41, 42 Up / down key 43 View button 44 Back button LT list Rc, RN Ring EX Index information CH Content holder RQ, RQ1, RQ2 , RQ3 Requester RN Root node CN Cache node PUBmsg Public message QRmsg Delivery source inquiry message N Node S Distribution system SV server CTGR Catalog record RImsg Recording instruction message M SG message MHD message header CTGL1, CTGL2, CTGL3 Catalog list CTGL-S Difference data list

Claims (13)

A distribution system configured by distributing a plurality of node devices connected via a network, and distributing distribution information stored in a storage device that is one of the node devices to any one of the other node devices In
Wherein the each of the distribution information stored in the storage device, the magnitude relationship between the values for each of the distribution information is continuously a continuous identification information for identifying the one the distribution information from other such distribution information Continuous identification information and search information for searching for the distribution information in the distribution system are added in advance in a distribution server device that distributes the distribution information ,
The storage device
When the new distribution information in which the corresponding continuous identification information is set is stored in the storage device together with the corresponding search information, the search information and the continuous identification information corresponding to the new distribution information are displayed. A transmission means for transmitting a public message including the node message to each of the node devices via the network;
Each of the node devices
Storage means for storing the search information and the continuous identification information in association with each other;
Display means for displaying various information;
When the public message is transmitted via the network, the node device receives the continuous identification information included in the public message and stores the received continuous identification information and the storage means. Confirmation means for confirming continuity between the continuous identification information and the magnitude relation of the values of the continuous identification information ;
When it is confirmed that there is continuity, the search information and the continuous identification information stored in the storage means are used as the search information and the continuation included in the transmitted public message. Updating means for updating using identification information;
Notification means for displaying the updated search information on the display means at a timing when the search information is updated by the update means;
A distribution system comprising: A storage device included in the distribution system according to claim 1,
A storage device comprising the distribution means. The storage device according to claim 2,
The confirmation means confirms continuity between the continuous identification information corresponding to the newly accumulated distribution information and the continuous identification information stored in the storage means in the storage device,
When it is confirmed that the updating means has the continuity, the search information and the continuous identification information stored in the storage means are updated with the search information corresponding to the newly accumulated distribution information. And an update device using the continuous identification information. A node device included in the distribution system according to claim 1,
The storage means;
The display means;
The confirmation means;
The updating means;
The notification means;
A node device comprising: The node device according to claim 4, wherein
When it is confirmed that there is no continuity, the continuous identification information and the continuous identification information corresponding to the interruption portion of the continuity in the search information stored in the storage means in the other node device Further comprising an acquisition message transmitting means for transmitting an acquisition message for acquiring the search information corresponding to the other node device to the other node device,
The update means, when the continuous identification information corresponding to the interrupted portion corresponding to the transmitted acquisition message and the search information corresponding to the continuous identification information are returned via the network, A node device , wherein the continuity identification information and the search information in the storage means are updated using the returned continuous identification information and search information . In the node device according to claim 4 or 5,
The search information includes a distribution permission flag indicating whether the distribution information corresponding to the search information is the distribution information to be distributed to each of the node devices in the distribution system,
The notifying means displays only the search information, which is indicated by the delivery permission flag to be the delivery information to be delivered to each node device in the delivery system, on the display means. Node device to perform. The node device according to claim 6 , wherein
The apparatus further comprises a deletion unit that deletes, from the storage unit, the search information indicating that the distribution permission flag is not the distribution information to be distributed to each node device in the distribution system. Node device. The node device according to any one of claims 7 claims 4,
When transmitting any message to be transmitted to another node device, the latest continuous identification information which is the newest continuous identification information among the continuous identification information stored in the storage means is the message. An additional means for adding to
Message transmitting means for transmitting the message to which the latest continuous identification information is added to the other node device;
Node device comprising: a. The node device according to any one of claims 4 to 7, wherein the node device receives the message from the node device according to claim 8 .
When the confirmation unit obtains the message via the network, the confirmation unit includes the latest continuous identification information included in the obtained message and the continuous identification information stored in the storage unit. The continuity is confirmed by comparing the magnitude relationship between the values of the continuous identification information,
Further, when it is confirmed that there is no continuity, the continuous identification information corresponding to the range in which the continuity is interrupted and the search information corresponding to the continuous identification information are transmitted to the other in the distribution system. A node device comprising acquisition means for acquiring from the node device. In the node apparatus as described in any one of Claims 4-9,
The confirmation unit confirms whether the transmitted continuous identification information is equal to the continuous identification information stored in the storage unit, and
A message generating means for generating a new message using the stored continuous identification information when it is confirmed that the transmitted continuous identification information and the stored continuous identification information are equal; node device, characterized in that it comprises. A storage device program for causing a computer to function as the storage device according to claim 2 . Computer program for the node and wherein the to function as a node device according to claims 4 to claims 10. A distribution system configured by distributing a plurality of node devices connected via a network, and distributing distribution information stored in a storage device that is one of the node devices to any one of the other node devices In the delivery system control method executed in
Each of the node devices includes storage means for storing the search information and the continuous identification information in association with each other, and display means for displaying various types of information.
Each of the distribution information stored in the storage device is continuous identification information for identifying one piece of the distribution information from other pieces of the distribution information. Continuous identification information and search information for searching for the distribution information in the distribution system are added in advance in the distribution server device that distributes the distribution information,
When the new distribution information in which the corresponding continuous identification information is set is stored in the storage device together with the corresponding search information, the search information corresponding to the new distribution information in the storage device and A transmission step of transmitting a public message including the continuous identification information to each of the node devices via the network;
When each of the node devices acquires the public message via the network, in each of the node devices, the continuous identification information included in the public message and the continuous identification information stored in the storage unit Confirming the continuity between and by comparing the magnitude relationship of the values of the continuous identification information,
When it is confirmed in each of the node devices that the continuity is present, the search information and the continuous identification information stored in the storage unit are included in the acquired public message in each of the node devices. Updating using the search information and the continuous identification information,
In each of the node devices, a notification step of displaying the updated search information on the display means at a timing when the search information is updated in the update step;
Distribution system control method comprising the.

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