JPS63317829A - Data division processing method - Google Patents

Abstract

PURPOSE:To reduce a working area required when a single block is extracted in division by forming a block on a job memory area based on a management area set at the head of each block and performing the block processing. CONSTITUTION:When the data of the fixed length to be processed next is read into a job memory area 5, a processor 1 discriminates in the management area 40 that said data is coincident with the first half part of the block read after division. Then this first half part is copied at the head of the area 5. The data length of the block is decided from the data length display 43 of the end of the area 40. Then the data on only the data length obtained by subtracting the size of said first half art already read from the data length of the block, i.e., the data on the second half of the block is read into a position following the first half part at the head of the area 5. Thus a block is completed on the area 5 and the prescribed processing is carried out for a single block.

Description

[Detailed Description of the Invention] [Summary] Concerning a computer data processing method in which data consisting of successive blocks of variable length is extracted for each fixed length and predetermined processing is sequentially performed for each block, one block is divided. The purpose of this data division processing method is to efficiently process data when it is retrieved using a relatively small working memory area. In a computer that divides the data into blocks and processes them sequentially, the length of the data for each block is displayed at a predetermined position in a management area of a predetermined length provided at the beginning of each block, and the maximum length of the data divided for each predetermined length is displayed. If the block is divided and the first half of the divided block includes an indication of the data length, prepare a storage area with a data length determined by the indication of the data length, and store the first half of the divided block. If the display does not include the display of the data length, the second half of the management area is combined with the first half to prepare a storage area of the data length determined by the display of the data length of the management area. On the prepared storage area, the divided second half of the block is combined with the first half to perform the required processing of the block.

[Industrial application field]

The present invention relates to a data division processing method for extracting consecutive variable-length blocks of data every fixed length in a computer and sequentially performing predetermined processing for each block.

[Prior art and problems to be solved by the invention] FIG. 3 is a block diagram showing an example of the configuration of a computer. A processing program 2 executed by the processing device 1 shown in the figure is stored in an external storage device 3.
A process of sequentially reading and processing data 4 held in a memory into a working storage area 5 on the memory of the processing device 1 in constant data length increments, and sequentially outputting the processed data as output data 6 to the external storage device 3, for example. I do.

For example, when the data 4 is data representing a figure according to a certain specification, and the processing program 2 performs processing to convert it into figure data according to another specification, the data 4 consists of blocks of data representing individual figures. , the processing program 2 sequentially analyzes and converts each block.

As shown in FIG. 4(a), the blocks 10a to 10g constituting such data 4 are generally so-called variable length blocks having different data lengths depending on the type of figure defined in each block. Yes, block boundaries cannot be determined without sequentially tracing the contents of each consecutive block.

Therefore, when reading a constant data length that fits into the working memory area 5, the end of the data does not necessarily coincide with the block boundary, and in many cases, as shown in Figure 4, The first half 11 of the block 10e in Figure (a) is divided into sections.

In that case, when processing the first half 11 of the block, data of the same length as described above starting from the second half of the subsequent block 10d and ending with the first half 12 of the block 10g, for example, is connected to the first half 11. The data is read into the working storage area 5, and processing for block 1()d and subsequent blocks is performed.

That is, as shown in the processing flow in FIG. 5, in processing step 20, a certain length of data to be processed next is read, and in processing step 21, processing is performed to convert and output one block in order from the beginning, and the process is completed. If so, processing step 22
The blocks are sequentially processed in a loop that returns to processing step 21. If there is no block to be processed next in the working storage area, it is identified in processing step 23, and if there is still data to be processed, processing returns to processing step 20.

As a result of processing the block, the block is divided,
If the process cannot be completed, proceed to process step 24;
Copy the first half of the block being processed to the beginning of working storage,
Subsequently, the next data is set to be read from the position and returns to processing step 20, so the fixed length data starting from the second half of the divided block is read, and at the beginning, the first half that was read first is read. The blocks are combined to form a complete block, and processing of that block is resumed in processing step 21.

As a result of the above processing, it is necessary to secure an area in the working storage area 5 that has a certain length for the data read unit and a margin corresponding to the size of the largest block, resulting in a problem that the required storage area becomes large.

The object of the present invention is to provide a data division processing method that allows efficient processing when one block is divided and retrieved as described above, using a relatively small working storage area.

[Means for solving problems]

FIG. 1 is a process flowchart showing the configuration of the present invention.

The figure shows the flow of processing data consisting of consecutive blocks, and 30 to 38 are processing steps.

[For production]

It is assumed that the data to be processed consists of a plurality of variable-length blocks, each block having a management area of a predetermined length at the beginning thereof, and a part for displaying the data length of the block in the management area.

In processing step 30, the processing device reads data of a fixed data length into the working storage area, sequentially processes each block on the working storage area, and completes the block by performing a loop of processing steps 31 to 33 as before. Proceed with the process.

When the divided and read block is processed in the processing step 31, the data length display of the management area is known in the processing steps 34 to 38, and the second half of the block with the data length determined by that value is read. Then, a block is completed in the working memory area, and in processing step 31, that one block is processed.

The above processing method eliminates the need to enlarge the working memory area for processing divided blocks.

〔Example〕

In processing graphic data etc. consisting of a plurality of blocks of variable length, each block is configured such that a management area 40 of a predetermined length is provided at the beginning of the block, followed by a main body 41 of the block, as shown in FIG. The management area 40 is provided with a control information section 42 at the beginning of the control information section 42 indicating, for example, the format of data defined in the block, followed by a data length display 43 that displays the data length of the block.

The above-mentioned predetermined length of the management area 40 may be a fixed data length (for example, 4 bytes), or if the required data length is often short, for example, 2 bytes and 4 bytes.
The control information portion 42 includes information that can identify the size of the management area 40.

In any case, a data display 43 of the size thus determined is placed, for example, at the end of the management area 40, and the data length of the block is displayed using a predetermined bit length.

As in conventional processing, when the processing device reads a certain length of data to be processed next into the working memory area in processing step 30, it processes one block sequentially from the beginning in processing step 31, and when the processing is completed, Processing blocks sequentially in a loop that returns to processing step 31 via processing step 32,
If there is no block to be processed next, it is identified in processing step 33, and if there is still processing data, the process returns to processing step 30.

If it is identified in processing step 31 that this is the first half of the block that has been read in parts, processing step 3
4, the first half is copied to the beginning of the working storage area.

In processing step 35, it is determined whether the management area 40 has been completely read into the first half by comparing the data length of the management area determined by the control information section 42 at the beginning with the length of the first half.

If the management area 40 has been read, the data length of the block is determined by the data length display 43 at the end of the management area in processing step 36, and the processing step knob 37 determines whether the data length of the block has already been read. The data of the remaining data length after subtracting the size of the first half, that is, the data of the second half of the block, is read into the position following the first half at the beginning of the working memory area, completing the block in the working memory area, and processing. The process returns to step 31 and predetermined processing for that one block is performed.

If it is determined in processing step 35 that the management area 40 has not been completely read, the process proceeds to processing step 38 to read the remainder of the management area of a predetermined length and save the management area 40 on the working storage area. Once completed, processing step 36
The process proceeds as described above.

In this way, when processing of the divided blocks is finished in processing step 31, processing step 32.
33, the process returns to process step 30, and the process is restarted from reading the following data of a certain length, or it is determined in process step 33 that the process of all data has been completed, and the process ends.

From the above, the size of the work area required for processing divided blocks is as shown in FIG.
The case corresponding to C) is shown in fd),
There is no need to make the working memory area particularly large.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in a computer that sequentially processes graphic data, etc. consisting of successive blocks of variable length, block by block, processing can be performed using a relatively small working memory area. It has a significant industrial effect of improving the processing efficiency.

[Brief explanation of drawings]

FIG. 1 is a process flowchart showing the configuration of the present invention, FIG. 2 is a diagram explaining the block configuration, FIG. 3 is a block diagram showing an example of the configuration of a computer, and FIG. 4 is an explanatory diagram of the working storage area. FIG. 5 is a flowchart of conventional processing. In the figure, 1 is a processing device, 2 is a processing program, 3 is an external storage device, 4 is data, 5 is a working storage area,
10a-10g is pro tsuku, 20-24.30-3
8 is a processing step, 40 is a management area, 42 is a control information portion, and 43 is a data length display.

Claims (1)

[Claims] In a computer that sequentially processes data consisting of successive blocks of variable length data by dividing them into blocks of predetermined length, , displays the data length of the block, and when the last block of the data divided into the predetermined length is divided, and the first half of the divided block includes the display of the data length. , prepare a storage area of the data length determined by the display of the data length (35 to 37).
), If the first half does not include the display of the data length, combine the second half of the management area with the first half (35,
38) Prepare a storage area with a data length determined by displaying the length of the data in the management area (36, 37), and on the prepared storage area, insert the divided second half of the block into the first half. Combine and perform the required processing of the block (
31) A data division processing method characterized by being configured to perform the following.