JP2990625B2 - Font cache control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a font cache control system for providing fonts to a printer or the like at high speed.

[0002]

2. Description of the Related Art In order to provide fonts to printers and the like at high speed, a small-capacity but high-speed cache memory is provided in addition to a large-capacity storage device for storing all fonts. Font cache systems are known in which expensive fonts are temporarily copied to and served from.

FIG. 9 is a diagram showing the configuration of such a font cache system. In FIG. 9, 1 is a font cache system, 2 is a CPU (central processing unit), 3 is an address bus, 4 is a data bus, and 5 is a ROM.
(Read only memory), 6 is work RAM (RAM ...
Random access memory), 7 an interface, 8 a font cache RAM, 9 a page memory, 10 a DMA controller (DMA ... Direct Memory Acces)
s), 11 denotes a SCSI controller (SCSI ... Skudge; interface for hard disk), 12 denotes a hard disk, 13 denotes a host computer, and 14 denotes a printer engine.

[0004] The ROM 5 is for storing various programs to be executed by the CPU 2.
Provides a working memory area when executing a program. All fonts are stored on the hard disk 12 in the form of vector data. Printer engine 1
Print information (eg, character code) such as characters to be printed in step 4
It is provided from the host computer 13 via the interface 7.

[0005] A font corresponding to the character code is first searched for in the font cache RAM 8, and if so, read out therefrom and expanded in the page memory 9. If there is no data, the data is read from the hard disk 12, bitmap data of a desired size is generated based on the vector data, and is developed in the page memory 9 and stored in the font cache RAM 8. When the font of one page is developed in the page memory 9, the printer engine 1
Then, a print start command is transmitted through the interface 17 of the P.4, print data (bitmap data is transmitted serially) is transmitted to the printer engine 14 via the DMA controller 10, and printing is executed.

[0006] Initially, the font cache RAM 8
Does not contain anything. Each time the data is read from the hard disk 12, a record related to the font is stored in the font cache RAM 8 (the structure of the record is
Will be recorded).

In the conventional font cache control method (that is, the method of registering and deleting fonts in the font cache RAM 8), when the number of registrations increases and becomes full, the registration points are deleted in order from the oldest one and the new one is deleted. Many of them adopt a so-called “FIFO algorithm” for registering things. However, in this case, even a frequently used font is automatically deleted when it becomes old, so that the font providing speed is reduced.

Therefore, a record which is in the order of being deleted from the font cache RAM 8 in the near future (which can be known by the fact that the pointer indicating the location to be newly registered is approaching a predetermined range) is hit. In such a case, a technique has been proposed in which the registration is re-registered at the position of the newly registered pointer. Next, it will be described.

FIG. 10 is a diagram for explaining re-registration in a conventional cache area. CP is a newly registered pointer, H is an arrow indicating the direction of registration, K is a predetermined range, R
_D and _RH are records. Now, newly registered pointer CP
Has come to the position of the record _RD , and proceeds sequentially in the direction of the arrow H. The predetermined range K is a range in which the newly registered pointer CP is coming soon, and records in this range are destined to be deleted soon.

However, according to the above proposal, when a record _RH within a predetermined range K is used (hit), FIG.
Font data to the page memory 9 of
Re-register at the position of record _RD . Thereafter, the newly registered pointer CP is advanced to the next record. As a result, at least until the next newly registered pointer CP comes around,
The record _RH is left in the cache area 8-2.

[0011] Conventional documents relating to such a font cache control system include, for example, Japanese Unexamined Patent Publication No.
There is 8660 publication.

[0012]

[Problems to be solved by the invention]

(Problems) However, the above-described conventional technology has the following problems. The first problem is that the record pointed to by the newly registered pointer CP (record R in FIG. 10)
_{Even if D} ) is frequently used, it is deleted at the time of re-registration, so that the number of times of new registration from the hard disk 12 increases, and the font providing speed cannot be increased.

The second problem is that the font cache RA
M8 loses its contents when the power is turned off due to the original nature of the RAM. Therefore, when the power is turned on and the printing operation is performed next, the operation is started and the operation is to be used for a while. All the fonts to be printed must be read from the hard disk 12, and high-speed printing cannot be performed.

(Explanation of Problem) The second problem will not require any special explanation, so the first problem will be described. A use request for the record _RD deleted when re-registering the record _RH at the position of the new registration pointer CP will be issued soon if the font is frequently used. by the time,
It is necessary to read vector data from the hard disk 12, obtain bitmap data by calculation, and newly register the bitmap data in the cache area 8-2. However, this takes a long time. In the prior art, since the record pointed to by the new registration pointer CP is deleted without evaluating the frequency of use without evaluating it, the number of times such new registration must be performed increases, and the font providing speed increases. I can't speed it up.

An object of the present invention is to solve the above problems.

[0016]

According to the present invention, there is provided a font cache control system in which a registration area of a font is determined by a new registration pointer which moves in a specific direction and in a ring shape in a font cache. In the record of the registered font, an area for recording the number of hits is included, and if an empty record larger than the size of the record to be registered is pointed to by the new registration pointer, the record is registered in the empty record and newly registered. If the record pointed to by the pointer is not an empty record, only records whose hit count is smaller than a predetermined value are sequentially converted into empty records until the total size becomes equal to or larger than the size required for registration of a newly registered record, and then merged. Registered in the empty record that was created, and a new Hit count a predetermined value or more records in the recording pointer passes was able to reset the hit count and save.

Further, before a power supply of the apparatus including the font cache is turned off, when a predetermined condition is satisfied (for example, a predetermined time (for example, 60 hours) after the printing operation is completed).
Second) When the print operation does not occur again) The contents of the font cache are stored in an external storage device, and when the power is turned on next time, the contents are loaded from the external storage device into the font cache.

[0018]

[Operation] When registering a font record in the font cache RAM, the number of hits is set as one of the items described in the record. Then, even if the number of hits is older than the value registered in the font cache RAM and the order of deletion comes, if the number of hits is equal to or more than a predetermined value, the number of hits is reset to 0 and the font record is not deleted. Even if a frequently used font is deleted, a use request will be issued immediately, so that the font must be newly registered again. This takes time because an operation for converting vector data into bitmap data is also required. However, in the present invention, since such fonts are not deleted from the font cache RAM, the number of times of new registration is reduced. Therefore, processing time is shortened,
Fonts can be provided at high speed.

Further, every time a predetermined condition is satisfied, the contents of the font cache RAM are saved in an external storage device, and when the apparatus including the font cache is turned on next time, the contents are stored in the font cache RAM. When loaded, a high-speed font can be provided from the beginning of operation of the device.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. The overall hardware configuration of the font cache system is the same as that of FIG. 9, and a description thereof will be omitted.

[Structure of Font Cache RAM] First, the structure of the font cache RAM 8 in the present invention will be described. FIG. 7 shows a font cache RAM.
8 is a diagram illustrating the overall configuration of FIG. In FIG. 7, 8-
1 is a font search table, 8-2 is a cache area, 80 is a table section column, 81 is a used record, 82
Is empty record, CP ₁ new registration pointer, CP ₂ is a registered area check pointer.

The font cache RAM 8 includes a font search table 8-1 and a cache area 8-2. Records related to fonts such as bitmap data are registered in the cache area 8-2, and information indicating the location where the records are registered is recorded in the font search table 8-1.

The font search table 8-1 is divided into the same number of sections as the number of font codes, and one specific font code is associated with one specific section. For example, a section called a table section column 80 is assigned to a font code representing the character A.

If the font A is registered in the cache area 8-2, information indicating the registered location (address) is written in the table section column 80. When a plurality of fonts having the same font code are registered, one of the registered locations is written. If not registered, it is not written (Nu
ll)

In the cache area 8-2, a portion with a dot is a portion used to register a record relating to a font read from the hard disk 12, that is, a portion of a used record. The portions without dots are the portions of empty records that are not so used. A straight line drawn horizontally indicates a record break.

The new registration pointer CP ₁ is a pointer to the location of registering a record for font new, this is similar to the known ones, the ring illustrating a cache area 8-2 in a constant direction Proceed to If the certain direction is a direction from top to bottom in FIG. 7, the lowermost end is advanced to the uppermost end.

[0027] In the present invention, in addition to the new registration pointer CP _1, providing a registration area check pointer CP ₂ becomes pointer. This is a pointer indicating the position of the record where the frequency of use of the font, that is, the number of uses (the number of hits) after being registered in the font cache RAM 8 is to be checked next.

[Structure of Record] FIG. 8 is a diagram for explaining the structure of a used record and an empty record. FIG.
(B) shows the configuration of the empty record 82. It has an "empty flag" to indicate that it is empty,
An “empty size” indicating the size of the area of the empty record is described.

FIG. 8A shows the structure of the usage record 81, which is composed of areas for recording the following items. That is,
Font type (eg, Mincho, Gothic), font code (character code, etc.), font size (length, width), number of hits, same code NEXT pointer, same code BEFORE pointer, bitmap data. . In FIG. 8A, as an example of bitmap data,
"A" is indicated.

The hit count is the number of times that the font has been used while the pointer circulating in the cache area 8-2 in a certain direction makes one round.

When a plurality of fonts of the same code are registered in the font cache RAM 8, the “same code NEXT pointer” and the “same code BEFORE pointer” are used before the use record 81 is used. And a pointer indicating the location of a record used later. That is, the same code BEFORE pointer indicates the location of the font hit by the same code before the usage record 81 hits. The same code NEXT pointer indicates the location of the font hit by the same code after the usage record 81 is hit.

By following the same code NEXT pointer and the same code BEFORE pointer, fonts of the same code registered in the font cache RAM 8 can be searched one after another, and the hit order can be known. Fonts of the same code can be seen to be connected in a chain via these pointers, thus forming a "search chain". The most recent hit will be at the top of the search chain.

[Search Chain] FIG. 5 is a diagram for explaining a search chain. Numerals correspond to those of FIG. 7, R ₄ ~
R ₇ is, although the same font codes (assumed character font code of A), different in font type ( "A _1" in the figure, "A _2", "A _3", "A _4" is , Indicating that the font type is different). Indicates a ranking of hit newness (hit latest ranking). Of record R ₄ is a record of a hit-to-date.

[0034] When attention is paid to rank records R _5, These include the same code NEXT pointer, location of records R ₄ hit after this is written, a record in the same code BEFORE pointer, hit before that R ₆ locations are written.

[Operation at Hit] Next, the operation of the control method of the font cache RAM 8 configured as described above will be described.
A description will be given separately for a case where a hit has occurred (→ FIG. 6) and a case where no hit has occurred (for a case of new registration → FIG. 1).

FIG. 6 shows the font cache control of the present invention.
It is a flowchart explaining operation | movement at the time of a cache hit in a method . Step 1: When the font code to be printed is received from the host computer 13, the font of the font code is cached by examining a table section defined in the font search table 8-1 corresponding to the font code. Check whether it is registered in area 8-2. If not registered, it is read from the hard disk 12, expanded into a bit map, and newly registered in the font cache RAM 8. The processing procedure in that case will be described later with reference to FIG.

Step 2: If registered, access the record (use record). Suppose, for as seeking is record R ₆ in FIG. 5 (b). The font code is "A". In the table section column 80 defined corresponding to the font code A in the font search table 8-1, the font code A
Because of the record group, is written the location of records R ₄ is located at the head () of the search chain is first access thereto.

[0038] By looking at the matters shown in FIG. 8 in the step 3 ... record R ₄ accessed (b), font type of fonts that are seeking now, see if consistent with the size and the like. Step 4: If they do not match, check whether there are any other records connected in the search chain. If so, return to step 2 to access it. If not, it must be obtained from the hard disk 12 and newly registered in the font cache RAM 8, so the new registration processing of FIG. 1 is performed. Figure 5 case (i), following the record R ₅ hits recency ranking the records R ₄
Although will be accessed, font type, the size does not yet match, again repeating the steps 3 and 4, to access the record R ₆ hits recency ranking, to reach seeks finally (hit).

Step 5: If the record matches the desired one, the record is positioned at the head of the search chain. The meaning of being positioned at the head of the search chain will be described with reference to FIG. First, the head of the search chain (hit recency rank) refers to the position of the next record to be accessed from the font search table 8-1 in a plurality of records linked by the search chain. The dotted arrow in FIG. 5 indicates a record accessed from the font search table 8-1.
In FIG. 5A, the record R ₄ is stored in the table section column 80.
Where is located.

Assuming that the record hit in step 3 in FIG. 6 is not record R ₄ but record R ₆ ,
As shown in FIG. 5 (b) in step 5, the position of the hit recency ranking of search chain, allowed to position the record R _6. Along with that, also hit the latest rank of other records, to a record R _4, is changed to the degree that in the record R _5.

[0041] Specifically, the contents of the table partition column 80, rewritten to indicate the location of the record R _6.
Since the contents of the table section column 80 are represented by, for example, about 4 bytes, the time required for this rewriting is extremely short.
Further, with the change of the hit recency ranking, the same code NEXT pointer and the same code BEFORE in each record are changed.
Rewrite the pointer as needed. Incidentally, the same code BEFORE pointer record R ₆ of is rewritten to represent the location of the record R _4.
NEXT pointer of record R ₄ , R ₅ , BEFORE
The pointer is also rewritten so as to connect the records R ₄ and R ₅ to each other.

Step 6: The value of the number of hits described in the hit record is increased by one from the current hit. Step 7: The bitmap data of the hit record is transferred to the page memory 9. This bitmap data is used for printing by the printer engine 14.

[Operation at Mishit] FIG. 1 is a flowchart for explaining the operation at the time of new registration in the font cache control method of the present invention. Even if the font cache RAM 8 is searched, if there is no desired font (at the time of a mishit), new registration is performed.
Before describing the steps in the flowchart in detail, an outline of a registration method will be described with reference to FIGS.

FIG. 3 is a diagram showing a situation in which a new record is written in an empty record in the cache area. The symbols correspond to those in FIG.
R ₁ and R ₂ are records, and _RF is a new record. The portion with a dot indicates that it is a used record portion. There are empty record (R ₁₎ in the cache area 8-2, the size if the size capable of accommodating a new record R _F, and registers a new record R _F thereto. Portion of the R ₁ -R _F shows the remaining empty record portion. When there is no empty record or when there is insufficient size, the processing is performed as shown in FIG.

FIG. 4 is a diagram showing a situation where a new record is written in a cache area where there is no empty record. Numerals correspond to those of FIG. 3, R ₃ is record. Figure 4 (a) ... the state has no free records checks hit count of records R ₁ where registration area check pointer CP ₂ points. Figure 4 (b) ... a result of the check, if less than the predetermined number N, the records R ₁ in the empty record.

[0046] When FIG. 4 (c) ... record R ₁ can not accommodate the new record R _F at the lack of size, proceed with the registration area check pointer CP ₂ to the next record R _2. Figure 4 (d) ... the hit count of the record R ₂ is assumed to be equal to or greater than N, which is not removed, Katayoseru to the top of the empty record. Then, both pointers are moved to the head of the area of the new empty record obtained as a result of the offset.

[0047] FIG. 4 (e) ... to check the hit number of the next record R _3. If it is smaller than N as a result of the check, it is also set as an empty record. Then, record R ₁
Free record that the sum of the record R ₃ and can be. Fig. 4 (f) ... new record R in the empty record
Register _F. Then, both pointer advances to the next position of the new record R _F registered.

[Operation at Miss Hit ... Details] Step 1: The outline data of the font to be newly registered is read from the hard disk 12. Step 2... Based on the outline data (vector data), the data is developed into bitmap data of the currently required size by calculation.

[0049] Step 3 ... record a new registration pointer CP ₁ of the cache area 8-2 is pointing is, to check whether or not the empty record. If it is an empty record, as shown in FIG. 8 (b), an "empty flag" indicating an empty state is set, so that it can be known by that.

[0050] Step 4 ... This step is the first process to be performed when the free record was not firstly hit count record registration area check pointer CP ₂ is pointing is examined whether there are more than a predetermined number of times N . N is
This value is used as a criterion for determining whether or not the frequency of use is high enough to have a value stored in the font cache RAM 8.
For example, N = 10 is appropriately determined. Step 4
In the context of FIG. 4 (a) corresponds to checking a hit count of records R ₁ where registration area check pointer CP ₂ points.

[0051] If the step 5 ... registration area check pointer CP ₂ is hit the number of records R _1, which pointed to greater than or equal to N, the record R ₁ is left in the cache area 8-2. Accordingly, rewrite the hit count of records R ₁ to 0 (reset).

The reason for this is as follows.
Register pointers CP ₁ and registration area check pointer CP ₂ proceeds cache area 8-2 to a certain direction (direction of the upper → lower in FIG. 4), proceeds circulated so on jumps to the upper end from the lower end In this case, the number of hits indicates the number of hits while the pointer makes one round. Therefore, if the record is not deleted when the pointer makes one round, the number of hits must be returned to 0. If the number of hits is 0
Otherwise, the memory that records the number of hits eventually reaches the maximum value that can be recorded, and the hit count value will not be updated even after a subsequent hit.

Step 6: The new registration pointer CP ₁ and the registration area check pointer CP ₂ are advanced to the next record. Step 7... In step 4, if the number of hits is smaller than N, the record is determined to be deleted, and the record is made empty. That is, the configuration shown in FIG. FIG.
If If the hit count of records R ₁ in (b) it was smaller than N, to reduction empty record a record R ₁ as shown in FIG. 4 (b).

[0054] Step 8 ... size of the free record, to check whether the future has the size needed to accommodate the new record R _F that you are trying to register a new one. Step 9: If it has the required size, FIG. 3 (b)
As shown in, to register a new record R _F to there. R
Portion of the ₁ -R _F is a free remaining area. The detailed processing routine will be described later with reference to the flowchart of FIG.

Step 10: If the size does not have the size necessary for registering the new record, the registration area check pointer CP ₂ is advanced to the next record (R ₂ ) (FIG. 4C). FIG. 4B shows the record R of FIG.
₁ is shown as an empty record, but the record R ₁ is originally an empty record (FIG. 3).
(B)) the same can, if they do not have any case required size it advances the registration area check pointer CP ₂ to the next.

Step 11: Record pointed to by advanced registration area check pointer CP ₂ (R _{2 in} FIG. 4C)
It is checked whether or not the number of hits is N or more. Step 12: If the number of hits is smaller than N, the record is converted to an empty record. The empty record processing routine in this case will be described later with reference to the flowchart of FIG.

Step 13: If the number of hits is N or more, the record is not deleted. However, the record is moved to the top portion of side dishes to bear in its position, the empty record registration area check pointer CP ₂ was pointing last. In other words, they are offset. The non-deleted record offset processing routine will be described later with reference to the flowchart in FIG.

FIG. 2 is a diagram showing each processing routine of the flowchart of FIG. FIG. 2 (a) shows the details of the "Registration process for empty records" in step 9 of FIG. 1. This will be described below with reference to FIG. Step 9-1 ... is a free record record R ₁ is in Figure 3 (a), new registration pointer CP _1, the record R ₁
Pointing to. In this step, the newly registered pointer C
The bitmap data and the like (new record R _F ) developed in step 2 of FIG. 1 are moved to the record R ₁ pointed to by P ₁ . As a result, a new record R _F
Is registered in the cache area 8-2.

Step 9-2: The font corresponding to the record just registered is located at the head of the search chain. The method of positioning at the top is as described with reference to FIG. Step 9-3: The hit count of the registered record is set to 1
And This is because, as described in step 9-4, the bitmap data registered this time is developed in the page memory 9 (FIG. 9) and used for printing.

Step 9-4: The bitmap data is transferred to the page memory 9 for use in the printer engine 14. Step 9-5: Both the new registration pointer CP ₁ and the registration area check pointer CP ₂ are advanced to the next record.
FIG. 3B shows this state. Both pointers are
Has been advanced to the top of the empty record that remains after registering a new record _{R F (R 1 -R F)} . Step 9-6 ... empty record, since changes from the record R ₁ to record (R ₁ -R _F), should correct the value of the size of the empty record to the new value.

FIG. 2B shows the details of the "empty record processing routine" in step 12 of FIG. This is 1
When one empty record does not have a size necessary to accommodate a new record, this is a process for converting the next record into an empty record. Hereinafter, this will be described.

[0062] a record that step 12-1 ... registration area check pointer CP ₂ is pointing to the empty record. Step 10 before this step (FIG. 1
), The registration area check pointer CP ₂ is advanced to the next use record (R ₂ ) (FIG. 4C).
Turns that record into an empty record. (Note: Fig. 4
Since the hit count of records R ₂ depicts the case were more than N (if advanced in the direction of YES at step 11), the record R ₂ is although not of free records. )

[0063] step 12-2 ... As a result, record the new registration pointer CP ₁ and the registration area check pointer CP ₂ is pointing, although both becomes a free record,
The two empty records are merged. Step 12-3: Registration area check pointer CP ₂
The position pointed to, to match the position of the new registration pointer CP _1. That is, both pointers are positioned at the head of the combined empty record.

FIG. 2C shows the details of the "non-deleted record offset processing routine" in step 13 of FIG. This, for example, FIG. 4 (c), as shown in (d), when one of the empty record R ₁ does not have the size needed to accommodate the new record R _F, the next record R ₂ I tried to make a blank record (delete)
This is the process when the number of hits is large and it is decided not to delete. Hereinafter, this will be described.

Step 13-1... The record (record R _{2 in} FIG. 4C) indicated by the registration area check pointer CP ₂ is pointed to by the new registration pointer CP ₁ (FIG. 4).
In (c), to register a new record R _F is moved to the top) of the record R ₁ of the lack of size. In other words, the non-deleted records are shifted to the head of the empty record.

Step 13-2: The moved record (R
The value of the number of hits described in ₂ ) is returned to 0. The reason for doing so is the same as the reason for returning the number of hits to 0 in step 5 of FIG. Step 13-3: The moved trace is made an empty record. As a result, a vacant record having the same size as the vacant record (R ₁ ) starting from the newly registered pointer CP ₁ is moved upward (R ₂ ).
, It appears as if the original empty record (R ₁ ) has moved.

Step 13-4: New registration pointer CP
₁ and the registration area check pointer CP ₂ are both moved to a position indicating the empty record. FIG. 4D shows such a state.

As described above, according to the present invention, after the cache area 8-2 becomes full, the new registration pointer CP
Also come ₁ is around, the hit count is equal to or greater than a predetermined value record, so that to save and return the hit count to 0, the hit count is only of free records those of less than a predetermined value, to register a new record to there I made it. Therefore, even if the record pointed to by the newly registered pointer is frequent,
Compared to the conventional font cache control system in which new registration or re-registration is performed without questions and answers, the number of records to be deleted and registered is reduced, and the font provision speed is increased.

[Saving Cache Data] Next, in the present invention, every time a predetermined condition is satisfied, the font cache RAM 8 is stored in the hard disk 12 which is an external storage device which does not lose its data contents even if the power is turned off. Save the contents (ie transfer and save). this is,
Immediately after the power of the font cache system 1 shown in FIG.
This is because the contents of the previous use are transferred to the AM 8 so that the font can be provided from the font cache RAM 8 from the beginning of the printing operation.

The above-mentioned predetermined condition can be defined as, for example, a case where a new printing operation is not performed even after a lapse of a fixed time (for example, 60 seconds) after the printing by the printer engine 14 is completed. .

FIG. 13 is a diagram showing files stored in the hard disk 12, which is an external storage device. In FIG. 13, 15 is a first storage file, 15-1 is a write flag, 16 is a second storage file, and 16-1 is a write flag. The write flag 15-1 is a flag that is set (set) when writing to the first storage file 15 is in progress. Write flag 16-1
Is the same. When the writing is completed, the flag is cleared (set is released). Therefore, if the flag is set, the contents of the save file are still incomplete.

FIG. 11 is a flowchart for explaining a process for saving cache data in an external storage device, and FIG. 12 is a flowchart showing a save process routine for saving to a save file. Step 1: When the above-mentioned predetermined condition for starting the storage process is satisfied, first, it is checked whether the first storage file 15 exists (is provided) in the hard disk 12 which is an external storage device. Step 2: If the first storage file 15 exists,
Next, it is checked whether the write flag 15-1 is set. That is, it is checked whether writing is in progress.

Step 3: If the first storage file 15 is being written, the contents are incomplete, so that new cache data may be overwritten. Therefore, the contents of the font cache RAM 8 are saved in the first storage file 15. The specific processing routine is
This will be described later with reference to FIG.

Step 4: If the first storage file 15
If the write flag 15-1 is not set,
This includes the font cache RAM 8
Is completely preserved. Therefore, when saving this time, the contents are saved without being destroyed, and are saved in the second save file 16. The specific processing routine will be described later with reference to FIG.
This will be described with reference to (b).

Step 5: If the check in step 1 shows that the first storage file 15 does not exist, that is, if the first storage file 15 has not yet been provided in the hard disk 12, the second
Check whether the save file 16 exists. Step 6: If the second storage file 16 exists, check whether the write flag 16-1 is set. If it is set, the contents of the second storage file 16 are incomplete, so the cache data of the font cache RAM 8 is transferred there and overwritten.

Next, a save processing routine for saving to the first storage file 15 will be described with reference to FIG. Step 3-1: Check whether the first storage file 15 exists. Step 3-2: If not, create the first storage file 15. Step 3-3: Prior to writing, write flag 1
Set 5-1. Step 3-4: Save the cache data in the font cache RAM 8 to the first storage file 15. Step 3-5: After saving, write flag 1
Clear 5-1 (cancel the set). Step 3-6: Since the latest complete cache data is stored in the first storage file 15, the second storage file 16 is deleted.

FIG. 12B is a flowchart of a save processing routine for saving to the second storage file 16.
Since this is the same as the save processing routine for the save file 15, the description is omitted.

FIG. 14 shows a state where the data is saved in an external storage device.
The cached data from the font cache RA
13 is a flowchart illustrating a process of loading data into M.
Hereinafter, the loading process will be described accordingly. Step 1: Check whether the first storage file 15 exists. Step 2: If present, write flag 15
Check if -1 is set. Step 3: If it is not set, it means that the cache data is completely stored in the first storage file 15, so that the content is loaded into the font cache RAM 8.

Step 4 If the first storage file 15 does not exist in Step 1 or if the write flag 15-1 is set even if it exists, the first storage file 15 Since the provision of cache data in an unconditional state cannot be received, the second
Check whether the save file 16 exists. Step 5: If present, write flag 16
Check if -1 is set. Step 6: If it is not set, it means that the cache data is stored in the second storage file 16 in a complete state, so that the content is loaded into the font cache RAM 8.

Step 7: Even if the second storage file 16 does not exist, or exists, the write flag 16-1
Is set, the cache data cannot be provided from any of the stored files. In this case, the font cache RAM 8 is initialized to make it straight. In this case, every time print information is sent from the host computer 13 in FIG. 9, the corresponding font is read from the hard disk 12 and stored in the font cache RAM 8.

FIG. 13 shows an example in which two storage files are provided in the hard disk 12, but only one may be provided. However, in this case, if the power is turned off during transfer from the font cache RAM 8,
Since only a part of the cache data ends up being transferred, it cannot be said that the data can be saved reliably. If two are provided, even if the power is turned off in the middle, all the cache data is stored in the save file that is not being written this time, although it has the contents of the previous save, Better than

As described above, according to the font cache control method of the present invention, a frequently used font is not deleted even when a newly registered pointer is circulated, so that the number of times of deletion and registration is reduced. Decrease. Therefore, the font providing speed is increased, and the printing operation can be performed at high speed.

Each time a predetermined condition is satisfied, the contents of the font cache RAM are saved in an external storage device, and the contents are stored in the font cache RAM the next time the power supply including the font cache is turned on. Since loading is performed, high-speed font provision can be realized from the beginning of operation of the device.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an operation at the time of new registration in a font cache control method of the present invention.

FIG. 2 is a diagram showing each processing routine of the flowchart of FIG. 1;

FIG. 3 is a diagram showing a situation in which a new record is written to an empty record in a cache area.

FIG. 4 is a diagram showing a situation where a new record is written in a cache area where there is no empty record.

FIG. 5 is a diagram illustrating a search chain.

FIG. 6 is a flowchart for explaining a cache hit operation in the font cache control method according to the present invention;

FIG. 7 is a view for explaining the overall configuration of a font cache RAM;

FIG. 8 is a view for explaining the configuration of a used record and an empty record;

FIG. 9 is a diagram showing a configuration of a font cache system.

FIG. 10 is a diagram illustrating re-registration in a conventional cache area.

FIG. 11 is a flowchart illustrating a process of storing cache data in an external storage device.

FIG. 12 is a flowchart showing a save processing routine for a save file.

FIG. 13 is a view showing a file stored in an external storage device.

FIG. 14 is a flowchart illustrating a process of loading cache data stored in an external storage device into a font cache RAM.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Font cache system, 2 ... CPU, 3 ... Address bus, 4 ... Data bus, 5 ... ROM, 6 ... Work RAM, 7 ... Interface, 8 ... Font cache RAM, 8-1 ... Font search table, 8-2 ... cache area, 9 ... page memory, 10 ... DMA controller, 11 ... SCSI controller, 12 ... hard disk, 13 ... host computer, 14 ... printer engine, 15 ... first storage file, 16 ... second storage file, 15-1 , 16-1 Write flag, 17 Interface, 80 Table partition column, 81 Used record, 82 Empty record, CP1 New registration pointer, CP2 Registration area check pointer, R1 to R6
… Record, RF… New record

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 5/44 B41J 29/38 G06F 3/12 G06F 12/08 310

Claims (2)

(57) [Claims] In a font cache control method in which a font registration area is determined by a new registration pointer that moves in a specific direction and in a ring shape in a font cache, a registered font record includes Include an area to record the number of hits, and if an empty record larger than the size of the record to be registered is indicated by the new registration pointer, register it in the empty record and make the record indicated by the new registration pointer empty. If the record is not a record, only records whose hit count is smaller than a predetermined value are sequentially converted into empty records until the total size is equal to or larger than the size required for registration of a newly registered record, merged, registered in the merged empty record, and registered in the empty record. Number of hits that the newly registered pointer has passed in the process of merging records Font cache control method de, characterized in that the resetting the hit count and save. 2. A method for storing the contents of a font cache in an external storage device when a predetermined condition is satisfied before a power supply of a device including a font cache is turned off, and when the power supply is turned on next time, stores the contents of the external storage device. A font cache control method, wherein the content is loaded from an apparatus into a font cache.