JP3439364B2 - Storage and retrieval methods for undefined length data - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing indefinite length data in a memory and a method for retrieving indefinite length data stored in the memory. These methods are, for example,
It is used for writing and reading an array of indefinite length data.

[0002]

2. Description of the Related Art An example of a conventional method for storing indefinite length data in a memory is described in Japanese Patent Laid-Open No. 2-287739.

In this conventional method, the use efficiency of the memory is improved by storing indefinite length data in the memory in order and storing the size of each data in a separately prepared table.

When retrieving data stored in this way, the storage position of the corresponding data is obtained by summing the sizes of the data up to the data immediately before the data to be retrieved.

[0005]

Recently, however, a large-capacity memory has been installed as a microcomputer for controlling the system so that more data can be stored as the system becomes more sophisticated / multifunctional. Things have come to be used.

In such a case, in the method of simply storing data, if the number of data is large, the sizes from the first data to the data immediately before the corresponding data may be summed in order. Since it takes time to search, it was necessary to speed up the processing time by dividing the data into blocks. An example of the block is shown in FIG.

When searching the blocked data shown in this example, the operation is performed according to the flow shown in FIG.

However, in this conventional technique, as shown in FIG. 3, there is a problem that a blank is formed at the end of each block because it is made into blocks.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a storage method for storing indefinite length data in a memory in consideration of high speed search without reducing the memory usage efficiency, and a high speed search method corresponding to the storage method. .

[0010]

According to a method of storing undefined length data according to the present invention, a plurality of unfixed length data are continuously stored in a memory divided into a plurality of blocks having a predetermined capacity arranged from a leading address without a gap from the leading address. And storing each length of the plurality of indefinite length data in the first table, the indefinite length data stored from the first block to each block of the plurality of blocks And a step of storing, in a second table, the cumulative number of each of the plurality of blocks and the length of the last excess of the indefinite length data stored in each of the plurality of blocks, for each block.
It is characterized by having.

The method for searching indefinite length data according to the present invention is
From the plurality of indefinite length data continuously stored in the memory divided into a plurality of blocks having a predetermined capacity arranged from the start address without a gap from the start address, the indefinite length data of a predetermined number is converted into the plurality of indefinite length data. A first table storing the length of each of the blocks, the cumulative number of the indefinite length data stored from the first block to each block of the plurality of blocks, and stored in each of the plurality of blocks. It is characterized in that the last excess length of the indefinite length data is searched by referring to the second table storing each block.

Further, in the method for retrieving indefinite length data according to the present invention, in the above method for retrieving indefinite length data, the number of the indefinite length data to be retrieved and the cumulative number are referred to by referring to the second table. First, the first step of obtaining the block to which the indefinite length data to be searched belongs and the excess length related to the block before the block to which the indefinite length data to be searched belong are based on the second table. The second step of obtaining the position of the first indefinite length data in the block to which the indefinite length data to be searched belongs, and the first step.
And referring to the second table, the position of the first indefinite length data in the block to which the indefinite length data to be searched belongs,
A third position for finding the unfixed-length data to be searched based on the number of the unfixed-length data to be searched, the cumulative number of blocks to which the unfixed-length data to be searched belongs, and the length of the unfixed-length data in a predetermined range. And the steps of.

Further, in the method for retrieving indefinite length data according to the present invention, in the above method for retrieving indefinite length data, in the first step, the number of the indefinite length data to be retrieved and the cumulative number of each block are calculated. Compared with the first block, the number of the undefined length data to be searched is less than the cumulative number
It is characterized in that the block when it becomes is a block to be obtained.

Further, in the method for retrieving indefinite length data according to the present invention, in the above method for retrieving indefinite length data, in the third step, the cumulative number of blocks before the block to which the indefinite length data to be retrieved belongs. Of the first variable length data in the block to which the variable length data to be searched belongs to the sum of the lengths of the variable length data from the number next to the number before the number of the variable length data to be searched. It is characterized in that the position of the undefined length data to be searched for is obtained by adding to the position.

A computer-readable recording medium according to the present invention is characterized by recording a program for causing a computer to execute the above-described method for storing indefinite length data.

A computer-readable recording medium according to the present invention is characterized by recording a program for causing a computer to execute the above-described method for searching for indefinite length data.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In FIG. 1, an indefinite length data group is stored in a DATA memory 2 composed of a plurality of blocks having the same size. Also, apart from this,
As information for each block, the number of stored data from the head to the block and the number of Bytes that the last data of the block exceeds in the next block are separately stored in the block information table 3.

Now, the data DAT stored in the Xth position
When reading Ax, first, BLOCK information table 3
BLOCKx, which is a block in which DATAx is stored, is searched from the information on the number of stored data. This is performed by repeatedly comparing until the storage number X becomes equal to or less than the number of stored data.

The start address of the first data DATAx0 stored in this BLOCKx is obtained by the following equation.

Start address = (block number-1) .times.block size + (number of excess bytes of previous block) Further, the storage number of DATAx0 is the data storage number of the previous block + 1.

Therefore, the start address of DATAx required for reading DATAx can be obtained by sequentially adding the data size from DATAx0 to DATA (x-1) to the start address of DATAx0.

That is, continuous storage of indefinite length data in a blocked memory enables both high-speed retrieval and efficient use of the memory.

FIG. 1 is a memory block diagram showing an embodiment of the data storage method of the present invention.

FIG. 2 is a flow chart showing the processing at the time of data search in this embodiment.

Referring to FIG. 1, according to the embodiment of the present invention, a DATA memory 2 for storing indefinite length data and a D memory for storing the data size of each of the stored indefinite length data.
It is composed of an ATA size table 1 and a BLOCK information table 3 which stores information for each block of the DATA memory 2.

Further, the BLOCK information table 3 stores, as information for each block, the number of stored data and the number of excess bytes by which the data at the end of the block exceeds the next block.

The method of storing the above-mentioned data in the DATA size table 1, the DATA memory 2, and the BLOCK information table 3 includes a step of continuously storing a plurality of indefinite length data in the DATA memory 2 without a gap from the start address, and a plurality of steps. Storing the number of bytes of each of the indefinite length data in the DATA size table 1, and storing from the first block of the plurality of blocks of a predetermined number of bytes lined up from the first address of the DATA memory 2 to the corresponding block. And a step of storing in the BLOCK information table 3 the cumulative number of the indefinite length data and the number of excess bytes of the last indefinite length data stored in each of the plurality of blocks.

Further, in the flow chart of FIG.
A block search step 221 for searching in which block the data to be searched is stored, an address setting step 222 for obtaining the first data storage address of the searched block, and a data search step 223 for searching the data to be searched in the block. Including and

An outline of these steps will now be described.

In the block search step 221, the storage number of the data to be searched is sequentially compared with the cumulative data storage number from the head of the BLOCK information table 3 and the block whose storage number is equal to or less than the cumulative data storage number is searched.

In the address setting step 222, the first data storage address of the block storing the data to be searched for is obtained from the number of the block found and the number of excess bytes in the BLOCK information table 3.

In the data search step 223, the data size from the first data in the block to the data immediately before the data to be searched is summed up by referring to the DATA size table 1 to obtain an address for reading the search data. .

Next, the search operation of this embodiment will be described in detail with reference to the flow chart of FIG.

First, an initial value 1 is set in the variable BLOCK counter (step A1).

Next, the cumulative data storage number of the block indicated by the BLOCK counter is referenced from the BLOCK information table 3 and compared with the storage number of the data to be searched (step A2).

As a result of the comparison, if the storage number of the retrieval data exceeds the cumulative data storage number of the block, BLO
1 is added to the CK counter (step A3).

As a result of the addition, if the value of the BLOCK counter does not exceed the number of blocks, the process is returned to the step A2, and the repeated comparison is performed until the storage number becomes less than the accumulated data storage number (step A4). If the value of the BLOCK counter exceeds the number of blocks, it is determined that the search data is not stored and the process proceeds to error processing.

In step A2, when the storage number of the search data is less than or equal to the cumulative number of stored data of blocks, it means that the block storing the search data has been detected, and the block search is terminated. Where BL
Check if the OCK counter is 1 (step A5),
If it is 1, the variable READ address is set to 0 (step A6), and the variable DATA counter is set to 1 (step A7).

If the BLOCK counter is other than 1, BLO
The CK counter is decremented by 1 (step A13).

Next, the value obtained by multiplying the value of the BLOCK counter by 1 by the size of the block is set to the READ address (step A14).

Further, the number of excess bytes of the block indicated by the BLOCK counter is referred to from the BLOCK information table 3 and added to the READ address (step A15).

Then, the DATA counter is set to BLOCK.
The data storage number of the block indicated by the counter is set to +1 (step A16).

Finally, the READ thus obtained
The search data is searched by the address and the DATA counter. First, the DATA counter is compared with the storage number of the search data (step A8).

If the comparison result is a mismatch, the data size indicated by the DATA counter is referenced from the DATA size table 1 and added to the READ address (step A9).

Next, 1 is added to the DATA counter (step A10).

As a result of the addition, if the value of the DATA counter does not exceed the total number of stored data, the process is returned to the step A8 and repeated comparison is performed until the DATA counter and the storage number of the search data match (step A11). .
When the value of the DATA counter exceeds the total number of stored data, it is determined that the search data has not been stored and the process proceeds to error processing.

Then, in step A8, DATA
If the counter and the storage number of the search data match, it means that the search data could be detected.
Data is read from the address (step A1)
7).

Next, a specific example will be described.

As shown in FIG. 1, undefined length data DATA
1, DATA2, DATA3, ... are DATA memories 2
Are sequentially stored from the beginning of. In this example, the DATA memory 2 has 256 bytes, that is, 16 bytes.
It is divided into blocks of 100H each. X now
When reading the data DATAx stored in the second position, first in the block search step 221, DATAx
Search for the block in which is stored. This is performed until BLOCKx at which the storage number X is equal to or smaller than the number of stored data is detected. Next, in the address setting step 222, the start address of the first data DATAx0 stored in BLOCKx is obtained based on the following equation.

Start address = (block number-1) × 1
00H + (excessive number of bytes of the block immediately before) Further, the storage number of DATAx0 is the number of data storages of the block immediately before + 1.

Therefore, the start address of DATAx required when reading DATAx can be obtained by sequentially adding the data size from DATAx0 to DATA (x-1) to the start address of DATAx0.

It should be noted that it is also possible to retrieve the block containing the undefined length data to be retrieved from the final block. In this case, the number of the undefined length data to be searched and the cumulative number of each block are compared retroactively from the last block, and the number of the undefined length data to be searched is equal to or less than the cumulative number.
A block for determining the closest block to the beginning of the composed satisfy blocks.

In the data search step 223, the variable length data to be searched is determined from the data length from the variable length data at the final position in the block to which the variable length data to be searched to the variable length data to be searched and the number of excess bytes in the block. You can also find the position of. In this case, the search is performed by subtracting the sum of the data lengths from the indefinite length data at the final position to the indefinite length data to be searched from the address of the block next to the block, and then adding the number of excess bytes related to the block. Determine the position of undefined length data.

Further, the method according to the above embodiment is
It can also be realized by the CPU reading and executing the program from a recording medium such as a CD-ROM in which a program for causing the U to execute the method is recorded.

Furthermore, the device according to the above-mentioned embodiment is a CP
It can also be realized by the CPU reading and executing the program from a recording medium such as a CD-ROM that records a program for causing U to function as each unit of the apparatus.

At this time, normally, the CPU once transfers the program from the recording medium to the main memory by the operating system, then reads the program from the main memory and executes it.

Further, the excess byte number may be managed as the excess byte number at the head position of each block. In this case, the number of excess bytes in the first block is 0.

Further, instead of the excess byte number, the number of bytes of the final unfixed length data of each block that fits in the block may be used.

Further, instead of the cumulative data storage number of each block, the data storage number of each block is stored in the block information table, and the cumulative data storage number is calculated from the data storage number of each block. Is also good.

Further, instead of managing in units of bytes, bits or several bytes may be managed in units.

Further, the data size table 1 stores the accumulated number of bytes of indefinite length data instead of the number of bytes of each indefinite length data, and based on that, stores the indefinite length data of a predetermined range. You may make it obtain | require the total of the number of bytes.

Furthermore, the method according to the above-mentioned embodiment is
It can also be realized by the CPU reading and executing the program from a program recording medium such as a CD-ROM in which a program for causing the U to execute the method is recorded. At this time, normally, the CPU temporarily transfers the program from the recording medium to the main memory by the operating system or the like, then reads the program from the main memory and executes the program.

The program may be generated by a text format file in which an interpreter format instruction is described and an interpreter that reads this file and converts it into an execution instruction.

[0064]

As described above, according to the present invention, it is possible to store indefinite length data without deteriorating the memory efficiency even when it is divided into blocks for speeding up data retrieval when storing the data in the memory. The effect is played.

The reason for this is that by having a table for storing the number of excess bytes in which the data at the end of a block exceeds the next block, it is possible to store indefinite length data in a memory continuously regardless of the block. This is because.

[Brief description of drawings]

FIG. 1 is a diagram showing the contents of a data size table, a data memory, and a block information table formed by a method of storing indefinite length data according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing flow of a method for searching indefinite length data according to the embodiment of the present invention.

FIG. 3 is a diagram showing contents of a data size table, a data memory, and a block information table formed by a method of storing undefined length data according to a conventional example.

FIG. 4 is a flowchart showing a processing flow of a method for searching for indefinite length data according to a conventional example.

[Explanation of symbols]

1 Data size table 2 data memory 3 block information table

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Claims (9)

(57) [Claims] 1. A step of continuously storing a plurality of indefinite length data in a memory divided into a plurality of blocks of a predetermined capacity arranged from a head address without a gap from the head address, and each of the plurality of indefinite length data. Storing information related to length in a first table, information related to the number of the undefined length data stored in each block of the plurality of blocks, and each of the plurality of blocks A step of storing, for each block, information relating to a fractional length of the indefinite length data stored at the end in a second table, the indefinite length data storing method. 2. A step of continuously storing a plurality of indefinite length data in a memory divided into a plurality of blocks of a predetermined capacity arranged from a start address without a gap from the start address, and each of the plurality of indefinite length data. Storing a length in a first table; a cumulative number of the indefinite length data stored from the first block to each block of the plurality of blocks;
Storing the last excess length of the indefinite length data stored in each of the plurality of blocks for each block in a second table, the indefinite length data storing method. 3. An indefinite length data having a predetermined number is stored from a plurality of indefinite length data continuously stored in the memory divided into a plurality of blocks having a predetermined capacity arranged from the start address without a gap from the start address. A first table storing information relating to the length of each of the plurality of indefinite length data; information relating to the number of the indefinite length data stored in each block of the plurality of blocks; An indefinite length data retrieving method characterized in that information relating to a fraction length of the indefinite length data stored at each end of a plurality of blocks is retrieved by referring to a second table in which each block is stored. . 4. An indefinite length data of a predetermined number is stored from a plurality of indefinite length data continuously stored in the memory divided into a plurality of blocks having a predetermined capacity arranged from the start address without a gap from the start address. A first table storing the length of each of the plurality of indefinite length data, a cumulative number of the indefinite length data stored from the first block to each block of the plurality of blocks, and the plurality of blocks And a second table storing, for each block, the excess length of the last unfixed length data stored in each of the unspecified length data search methods. 5. The variable length data search method according to claim 4, wherein the variable length data to be searched is searched based on the number of the variable length data to be searched and the cumulative number by referring to the second table. A block to which the indefinite length data to be searched is referred to based on the excess length of the block before the block to which the indefinite length data to be searched belongs, with reference to the second table. A second step of obtaining the position of the first indefinite length data in the block to which the variable belongs, and referring to the first and second tables, the first indefinite length data in the block to which the indefinite length data to be searched belongs Based on the position, the number of the variable length data to be searched, the cumulative number of blocks to which the variable length data to be searched belongs, and the length of the variable length data in a predetermined range, the variable length data to be searched is And a third step of obtaining the position of the data, and a method for retrieving indefinite length data. 6. The method for searching indefinite length data according to claim 4 or 5, wherein in the first step, the number of the indefinite length data to be searched and the cumulative number of each block are compared from the top block. A method for searching for indefinite length data, wherein the block is obtained when the number of the indefinite length data to be searched becomes equal to or less than the cumulative number. 7. The method for retrieving indefinite length data according to claim 4, wherein in the third step, the cumulative number of blocks preceding the block to which the indefinite length data to be retrieved belongs. Of the first variable length data in the block to which the variable length data to be searched belongs to the sum of the lengths of the variable length data from the number next to the number before the number of the variable length data to be searched. A method for retrieving indefinite length data, characterized by obtaining the position of the indefinite length data to be retrieved by adding to the position. 8. A computer-readable recording medium having recorded thereon a program for causing a computer to execute the method for storing indefinite length data according to claim 1. 9. A computer-readable recording medium having recorded thereon a program for causing a computer to execute the method for searching for indefinite length data according to any one of claims 3 to 7.