JPH06325495A - Data memory medium and data memory method and data erasing method - Google Patents

Abstract

PURPOSE:To enhance the volumetric efficiency of recording data and to increase the processing speed by constituting a data recording region of unit recording regions bisected recurrently so as to have a hierarchical structure. CONSTITUTION:The data recording region of, for example, 8k byte (K) is recurrently bisected so as to have the hierarchical structure to obtain the unit recording regions. The entire part of the data recording region is defined as one piece of cell S00 of 8k byte (K) of a class 0. Cells S10, S11 respectively of 4k byte (K) of a class 1 are defined by bisecting the cell S00. The respective cells S20, S21, S22, S23 of 4k byte (K) of a class 2 are defined by respectively bisecting these cells S10, S11. Four hierarchies and fifteen pieces are defined in such a manner and generally, 2N-1 pieces of the cells are obtd. if the number of the hierarchies is assumed to be N. The capacity efficiency of the recording data is thus enhanced and the processing speed is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for a data recording medium such as a hard disk (magnetic disk), a floppy disk (magnetic disk), a magneto-optical disk, a magnetic tape, and a storage device such as a semiconductor memory. Also, the present invention relates to a data storing method and a data erasing method thereof.

[0002]

2. Description of the Related Art A recording area of a conventional hard disk will be described with reference to FIG. The recording area of the hard disk is divided into a recording management area U1 and a data recording area U2 as shown in (a). Furthermore, the data recording area U
2 is divided into some unit recording areas (clusters) of fixed length, as shown in (b). That is, when the recording capacity of the data recording area U2 is L and the cluster length is M, the data recording area U2 has L / M clusters S0, S1,
It is divided into S2, ... S (n-2), S (n-1).

These clusters S0, S1, S2, ...
... Flags (allocation bits) F0, F1, F indicating whether or not these clusters are used for S (n-2) and S (n-1) as shown in (c).
2, ... F (n-2) and F (n-1) are held in the recording management area U1 so as to form an allocation map. When any flag Fi is Fi = 0, the corresponding cluster Si is empty, and when Fi = 1, the corresponding cluster Si is in use. For each data recorded in the data recording area U2, a file name (data A, data B, data C, ...) As a data identifier and a cluster number i used
(1, 3 for data A, 0 for data B,
A directory Tk composed of 2, 9 and 8, 9) for data C is created, and as shown in (d), a directory list composed of several directories Tk is created and held in the recording management area U1. This data list is referred to by the CPU or the like when reproducing or erasing data.

The procedure for recording a file on a hard disk having such a recording area is as follows. (1) Scan the allocation map and look for allocation bits (flags) Fi whose value is 0. (2) The contents of the file are recorded in the cluster Si whose allocation bit is 0. (3) Set the allocation bit of the cluster Si to 1. (4) Add the directory Tk consisting of the file name and cluster number i to the directory list.

The reproduction procedure of the file thus recorded on the hard disk is as follows. (1) The directory list is scanned to obtain the directory Tk having the file name to be reproduced. (2) Obtain the cluster number i from the directory Tk. (3) The recorded data is reproduced from the cluster Si of that number.

The procedure for erasing a file recorded on a hard disk is as follows. (1) Scan the directory list to obtain the directory Tk having the file name of the file to be deleted. (2) Set the allocation bit to 0. Directory T
Delete k from the directory list.

Next, as an example, the operation of recording data A first, recording data B next, erasing data A, then recording data C, and recording data A again This will be described with reference to FIG. However, here, it is assumed that two Class 2 sectors are required to record the data A, and only one sector is required to record the data B and C, respectively.

(1) (Initial state) As shown in FIG. 45 (a), allocation bits F0, F1, F2, ...
........, F (n-1) are all 0. Next, the following process will be described with reference to FIG. (2) (Recording of data A) The allocation map is scanned to obtain empty bits F0 and F1. (3) (Recording of data A) The contents of data A are recorded in clusters S0 and S1. (4) (Recording of data A) Allocation bits F0, F
Set 1 to 1. (5) (Recording of data A) A directory T0 including a file name "data A" and cluster numbers 0 and 1 is added to the directory list. The above results are shown in FIG. Next, the following process will be described with reference to FIG. (6) (Recording of data B) The allocation map is scanned to obtain an empty F2. (7) (Recording of data B) The contents of data B are recorded in the cluster S2. (8) (Record data B) Set allocation bit F2 to 1
To (9) (Recording of data B) A directory T2 including the file name "data B" and the cluster number 2 is added to the directory list. The above results are shown in FIG. Next, the following process will be described with reference to FIG.

(10) (Erase of data A) The directory is scanned to obtain data T0 having the file name "data A". (11) (Erase of data A) Cluster numbers 0 and 1 are obtained from the directory T0. (12) (Erase of data A) Allocation bits F0, F
Set 1 to 0. (13) (Delete Data A) Delete directory T0 from the directory list. The above results are shown in FIG. Next, the following process will be described with reference to FIG.

(14) (Recording of data C) The allocation map is scanned to obtain an empty bit F0. (15) (Recording of data C) The contents of data C are recorded in the cluster S0. (16) (Record data C) Set allocation bit F0 to 1
To (17) (Recording of data C) A directory T0 having a file name "data C" and a cluster number 0 is added to the directory list. The above results are shown in FIG. Next, the following process will be described with reference to FIG.

(18) (Recording of data A) The allocation map is scanned to obtain empty bits F1 and F3. (19) (Recording of data A) The contents of data A are recorded in the clusters S1 and S3. (20) (Recording of data A) Allocation bits F1, F
Set 3 to 1. (21) (Recording of data A) A directory consisting of a file name "data A" and cluster numbers 1 and 3 is added to the directory map. The above results are shown in FIG.

[0012]

By the way, there are the following drawbacks because the clusters forming the data recording area of the above-mentioned conventional hard disk have a constant length. Since the data occupies one cluster even if the amount of data is small, the remaining area of the cluster is wasted and the capacity efficiency is poor. When the amount of data is large, a large directory list is required because a large number of clusters are required in proportion to the amount of data. When the recording / erasing of data is repeated when the amount of each data is not constant, as can be seen from FIG. 45 (f), a discontinuous file of clusters may be formed like the data A in the above example. It becomes big.

However, recently, as represented by a magneto-optical disk, a large-capacity recording medium has appeared and it has become possible to store a large amount of data such as digital image data. Since the amount of image data is proportional to the square of the side length of the image, the amount of data is extremely diverse. Also, due to the spread of image compression technology, even if the original image size is the same,
The encoded data amount is not always the same.

Therefore, when such image data is recorded on a hard disk having a unit recording area of a constant length such as a conventional cluster, the following problems occur. As described above, the amount of information to be managed by the CPU is extremely large, and the processing speed of the CPU is decreasing. As described above, since the head seek is performed many times while transferring one file, the transfer speed is significantly reduced. In order to improve the above-mentioned problems (1) and (2), lengthening the cluster results in a decrease in capacity efficiency as described above.

In order to solve the above problems (1) and (2), a plurality of zones are provided on the same hard disk and the size of the cluster is made different for each zone. This will be described with reference to FIG. Figure 4
In 6 (A), the data area is 3 of U3, U4, and U5.
The area is divided into zones A, B, and C, respectively. Then, the zone A is divided into clusters each having a size of 1 kbyte and used for recording a relatively small file such as character data. Zone B is divided into clusters having a size of 64 kbytes, and is used for recording a medium-sized file such as compressed image data. Zone C is divided into clusters each having a size of 1 Mbyte and is used for recording a large-scale file such as uncompressed image data.

However, as shown in FIG. 46A, when the data area is divided into zones having different cluster sizes, in order to determine the size of each cluster, the application of the hard disk is specified and the future file is determined. The size has to be predicted and not practical. Also, if the application is changed while the hard disk is in use, it is difficult to change the zone allocation on the way.

Next, the relationship between the unit recording area and the allocation flag in the conventional example will be described with reference to FIG. For example, the data recording area of, for example, 8 kbytes (K) shown in (a) is 2 kbytes (K) each.
Consider dividing into clusters S0, S1, S2, S3 of. If this changes the point of view, 8 sectors r0,
A large unit recording area is defined by combining r1, r2, ..., R7 into groups of two. According to this, when considering an allocation flag indicating whether or not data can be recorded, eight flags are required in the case of a sector, but four flags are required in the case of a cluster. Management burden is reduced.

However, in the case of a sector, the recording unit is 1 kbyte (K), but in the case of a cluster, the recording unit is as large as 2 kbyte (K). For example, when recording 512 bytes of data. , 512 bytes indicated by diagonal lines are wasted when recording on the sector r0, but 1536 bytes are wasted as indicated by diagonal lines when recording on the cluster S0, resulting in a significant decrease in capacity efficiency. As described above, in the conventional method of setting the unit recording area, it is difficult to achieve both good capacity efficiency and easy recording management.

In view of the above points, the main object of the present invention is to
The capacity efficiency of recorded data is high, and the number of unit recording areas required is small regardless of the amount of recorded data, discontinuity of unit recording areas for the same file hardly occurs, and the processing speed is increased. It is to propose a data storage medium, a data storage method and a data erasing method that can be achieved.

Another object of the present invention is that the capacity efficiency of recording data is high and that the number of unit recording areas required is small regardless of the amount of recording data, and the unit recording areas for the same file are not required. It is an object of the present invention to propose a data storage medium, a data storage method, and a data erasing method that are less likely to cause continuity and can achieve a higher processing speed.

Still another object of the present invention is that the capacity efficiency of recording data is high and that the number of unit recording areas required is small regardless of the size of the recording data, and the unit recording areas for the same file are It is an object of the present invention to propose a data storage medium, a data storage method, and a data erasing method that are less likely to cause discontinuity, can narrow the data management area, and can further increase the processing speed.

[0022]

A data recording (or storage) medium according to the first aspect of the present invention is a data recording (or storage) medium having a data recording (or storage) area and a data management area. The (or storage) area is configured by a unit recording (or storage) area that is recursively divided into two so as to have a hierarchical structure. The data management area is provided with a hierarchical recording (or storage) management area having a node indicating the possibility of data recording (or storage) in each unit recording (or storage) area. A data list showing the identifier of the data recorded (or stored) in the data recording (or storage) area and the position and size of the unit recording (or storage) area to be used in the data recording (or storage) area or the data management area. Area is provided.

Secondly, the data recording (or storage medium) according to the present invention is, firstly, in the hierarchical recording (or storage) management area in the data recording (or storage medium) according to the present invention,
A record (or store) reference area indicating the number of nodes and the positions of data record (or store) nodes for each layer is provided.

A data recording (or storage) medium according to the third aspect of the present invention is a data recording (or storage) medium having a data recording (or storage) area and a data management area,
The data recording (or storage) area is composed of unit recording (or storage) areas that are recursively divided into two so as to have a hierarchical structure. In the data management area, a recording (or storage) management area having a hierarchical list of identifiers of recordable (or memorable) unit recording (or storage) areas is provided. A data list showing the identifier of the data recorded (or stored) in the data recording (or storage) area and the position and size of the unit recording (or storage) area to be used in the data recording (or storage) area or the data management area. Area is provided.

A fourth aspect of the present invention is a method of recording (or storing) data using the data recording (or storage) medium according to the first aspect of the present invention. When recording (or storing) desired data, the possibility of data recording (or storing) for a unit recording (or storing) area having the minimum capacity for recording (or storing) the desired data is hierarchically recorded (or stored). If there is a unit recording (or storage) area that has a possibility of data recording (or storage) detected by the node of the management area, record (or store) desired data in that unit recording (or storage) area, and record the data. If there is no unit recording (or storage) area that has the possibility of (or storage), data recording (or storage) is possible for the upper unit recording (or storage) area that has double that recording (or storage) capacity. Property is detected by the node of the hierarchical recording (or storage) management area, and if there is a higher unit recording (or storage) area that has the possibility of data recording (or storage), that unit recording (or storage) ) The area 2
The desired data is recorded (or stored) in one of the unit recording (or storage) areas obtained by division, and the upper unit recording (or storage) area is recorded (or stored) in the hierarchical recording (or storage) management area. ) Record (or store) the impossible as a node. Along with this, the fact that the unit recording (or storing) area in which the desired data is recorded (or storing) in the hierarchical recording (or storage) management area cannot be recorded (or stored) is recorded (or stored) as a node. At the same time, the position and size of the identifier of the desired data and the unit recording (or storing) area where the desired data is recorded (or stored) are recorded (or stored) in the data list area.

A fifth aspect of the present invention is the data recording (or storing method) according to the fourth aspect, wherein the data recording (or storage) for each layer is performed in the hierarchical recording (or storage) management area of the data recording (or storage) medium. A record (or store) reference area indicating the number of nodes that can be stored and their positions is provided.

A sixth aspect of the present invention is a data erasing method using the data recording (or storage) medium according to the first aspect of the present invention. When erasing desired data, the node for the unit recording (or storage) area in which the desired data to be erased (or storage) in the hierarchical recording (or storage) management area is changed to a recording (or storage) recordable state ( (Or storing), and the unit recording (or storing) area paired with the unit recording (or storing) area in which the desired data to be erased (or stored) has a possibility of data recording (or storing). Changes (records or stores) nodes to both unit recording (or storage) areas of the hierarchical recording (or storage) management area to a state in which recording (or storage) is not possible, and both unit recording (or storage) areas Are combined, and the node for the combined unit recording (or storage) area is changed and recorded (or stored) in a recordable (or memorable) state. At the same time, the position and size of the unit recording (or storage) area of the desired data to be erased in the data list area are erased.

A seventh aspect of the present invention is the same as the sixth aspect of the present invention.
Hierarchical recording (or storage) of data recording (or storage) media
In the management area, a record (or storage) indicating the number of nodes and their positions where data can be recorded (or stored) for each layer
Provide a reference area.

The eighth aspect of the present invention is a data recording (or storing) method using the data recording (or storing) medium according to the third aspect of the present invention. When recording (or storing) desired data, the possibility of data recording (or storing) for a unit recording (or storing) area having the minimum capacity for recording (or storing) the desired data is hierarchically recorded (or stored). Recordable (or memorable) unit in the management area Detected by the hierarchical list of identifiers of the recordable (or memorable) area, and there is a unit recordable (or memorable) area where data recording (or memory) is possible When the desired data is recorded (or stored) in the recording (or storage) area, the identifier of the data is deleted from the data list area, and there is no unit recording (or storage) area where data recording (or storage) is possible. Indicates the possibility of data recording (or storage) with respect to a higher unit recording (or storage) area having a doubled recording (or storage) capacity in the hierarchical recording (or storage) management area. Position recording (or storage) is detected by hierarchical list of identifiers of areas,
If there is a higher unit recording (or storage) area that has the possibility of data recording (or storage), the desired data is stored in one unit recording (or storage) area obtained by dividing the unit recording (or storage) area into two. Is recorded (or stored). Along with this, the identifier of the upper unit recording (or storage) area is deleted from the hierarchical recording (or storage) management area, and the identifier of the other unit recording (or storage) area divided into two is recorded ( In addition to storing (or storing), the identifier and the position and size of the unit recording (or storing) area in which the desired data is recorded (or stored) are recorded (or stored) in the data list area.

A ninth aspect of the present invention is a method of erasing data using the data recording (or storage) medium according to the third aspect of the present invention. When erasing desired data, the identifier of the unit recording (or storage) area in which the desired data to be erased is recorded (or stored) is recorded (or stored) in the hierarchical recording (or storage) management area and is also erased. The identifier of the unit recording (or storage) area paired with the unit recording (or storage) area where the desired data to be recorded (or stored) is recorded (or stored) in the hierarchical recording (or storage) management area. In this case, both unit recording (or storage) areas are combined to obtain an upper unit recording (or storage) area, the identifiers of both unit recording (or storage) areas are erased, and the upper unit recording (or storage) area is deleted. The identifier of the storage area is recorded (or stored) in the hierarchical recording (or storage) management area. At the same time, the position and size of the unit recording (or storage) area of the desired data to be erased in the data list area are erased.

[0031]

Embodiments of the present invention will now be described in detail with reference to the drawings. [Embodiment 1] Embodiment 1 is a data recording medium according to the above-described first present invention, and a data recording method and a data erasing method using the data recording medium.

In the first embodiment, in a recording medium such as a hard disk or a floppy disk having a data recording area and a data management area, a unit recording area (cell) is formed by recursively dividing the data recording area into two so as to have a hierarchical structure.
In the data management area, a hierarchical recording management area (node map) having a flag (node) indicating the possibility of data recording in each unit recording area is provided, and the data recording area or the data management area ( In the data recording area, a data list area (directory) indicating the identifier of the data recorded in the data recording area and the position and size of the unit recording area (cell) to be used is provided.

First, a method of dividing the data recording area of the data recording medium of the first embodiment will be described with reference to FIG. For example, a unit recording area is obtained by recursively dividing an 8-kbyte (K) data recording area into two so as to have a hierarchical structure. This unit recording area will be called a cell. First, the entire data recording area is 8k bytes (K) of class 0
It is defined as one cell S00. This cell S00 is divided into two to define 4 kbyte (K) cells S10 and S11 of class 1, respectively. These cells S10, S11
Is divided into two, and four 2 kbyte (K) cells of class 2, S20, S21, S22, and S23, are defined. These four cells S20, S21, S22,
S23 is divided into two, and each of class 3 is 1k
8 bytes (K) cells S30, S31, S32, S3
3, S34, S35, S36 and S37 are defined.

By the above, four layers and fifteen cells are defined. Generally speaking, when the data recording area is recursively divided into two so as to have a hierarchical structure, 2 ^N -1 cells are obtained, where N is the number of layers. For convenience of explanation, a class having a class number smaller than its own class is called an upper class, and a class having a larger number is called a lower class.

Next, with reference to FIG. 2, a hierarchical recording management area having a flag indicating whether or not there is a possibility of data recording in each cell in the data management area of the data recording medium of the embodiment will be described. Corresponding to each cell in FIG. 1, a 1-bit flag indicating whether or not new data can be recorded in the cell, that is, the possibility of recording data in the cell is defined. Each of them will be referred to as a node map. As the code of each flag corresponding to each cell, the same number as that following the code "S" of each cell in FIG. 1 is shown after "F". The node map is arranged for each class in order from the upper class to the lower class corresponding to the cells. Open when each node is 1
(Recordable), 0 indicates Close (record prohibited).

As shown in FIG. 3, node numbers are sequentially assigned to this node from the upper class to the lower class. That is, 1 to node F00 to F37, respectively.
A node number of 15 is added. This node number is represented by a binary number as described later.

Next, with reference to FIG. 4, a description will be given of the data list area indicating the identifier of the data recorded in the data recording area and the position and size of the cell to be used in the data management area of the data recording medium of the embodiment. To do. Data identifiers D0, D1, D2, ..., Di such as file names of data recorded in the data recording area, and node numbers I00, I01, ..
I0j, I10, I11, ..., I1j, ....
, Ii0, Ii1, ..., Iij are defined as tables T0, T1, T2, ..., Ti, and the set is called a directory. In the initial state, the node number lists I00 to Iij are all 0.

Next, with reference to FIG. 5, the operation of dividing the cell and recording the data will be described. For example, when recording 4 kbyte (K) data in the data recording area of the recording medium, it is recorded in the cell S10 or S11 of class 1, but in the initial state, only the node F00 of the cell S00 of class 0 is recorded. It consists of 1 (0 pen). Therefore,
First, the node F00 of the cell S00 is set to 0 (Close), and the nodes F10 and F11 of the cells S10 and S11 are set to 1 respectively.
By setting (0pen), the cell S00 becomes two cells S
10 and S11 are divided into respective cells S10 and S1.
1 is in a data recordable state. Then, after recording 4 kbyte (K) data in the cell S10, the node F10 is set to 0 (Close).

Referring now to FIG. 6, generally node n
A method of dividing a cell of class N represented by _N (n _N shall be represented by a binary number) will be described. In the initial state, the node n _N is 1 (Open) (step ST-
1). After that, the node n _{N is set} to 0 (Close) (step ST-2). After that, the node n _N is left-shifted (bit-shifted) to obtain the lower node n _{N + 1} (step ST-
3). After that, the obtained node n _{N + 1} is used for data recording, so that it remains 0, and the paired node n _{N + 1} +1.
Is set to 1 (0 pen) and opened for later use (step ST-4).

Next, referring to FIG. 7, the operation of erasing data and combining cells will be described. For example, when the cell S10 has been recorded, its node F10 is 0
(Close). Therefore, set this node F10 to 1 (0pe
By setting n), the data in the cell S10 is erased. At this time, if the node F11 paired with the node F10 is 1 (0pen), both the nodes F10 and F11 are set to 0 (Close), and the node F00 of the higher class of the node F10 is changed from 0 to 1 By this, the cell S00 can be used, that is, data can be recorded.

Next, referring to FIG.
A method for combining cells of class N represented by _N (n _N shall be represented by binary numbers) will be described. In the initial state, the node n _N ∧1 constituting the node n _N paired is 1 (step ST-1). Here, “∧” indicates an exclusive OR. After that, when erasing the cell of the node n _N ,
Normally, the node n _N is changed from 0 (Close) to 1 (0 pen), but since the node n _N ∧ 1 paired with this node n _N is 1, this node n _N ∧ 1 is also set to 0 (step ST
-2). After that, the node n _N is right-shifted to obtain the node n _N-1 of the higher class (step ST-3). After that, the node n _{N-1 is set} to 1 (0 pen).

Next, a method of recording a file in a cell of class N will be described with reference to FIG. Step ST-1
Then, after writing the file name Di in the directory Ti of FIG. 4, the process proceeds to step ST-2. In step ST-2, of the node maps shown in FIG. 3, the node map of class N is scanned, and then the process proceeds to step ST-3.
In step ST-3, it is determined whether or not there is a node of 1 (0pen), that is, a free node n _N (represented by a binary number), and if YES, the process proceeds to step ST-4,
If NO, the process proceeds to step ST-7. If there is a free node n _N , data is recorded (written) in the cell of the node n _N in step ST-4, and then step ST-
Go to 5. At step ST-5, the node n _{N is set} to 0.
Then, the process proceeds to step ST-6. Step ST
At -6, the number of the node n _N is recorded (written) in the node number list Ii0 of the directory Ti.

If there is no free node n _N in step ST-3, the procedure moves to the procedure of dividing the upper node. That is,
After scanning the upper class N-1 node map in step ST-7, the process proceeds to step ST-8. In step ST-8, it is determined whether or not there is a node of 1 (0 pen), that is, a free node n _N-1. If YES, the process proceeds to step ST-9, and if NO, step ST-11.
Move to. When it is determined in step ST-8 that there is a free node n _N-1, node n is determined in step ST-9.
After setting _N-1 to 0, the process proceeds to step ST-10. In step ST-10, the node n _N-1 is left-shifted to obtain the lower node n _N , and the node n _N which forms a pair with the lower node n _N.
Set +1 to 1 and return to step ST-4.

If there is no free node n _{N-1 in} step ST-8, the procedure moves to a procedure for further dividing the upper node.
After scanning the upper class N-2 node map in step ST-11, the process proceeds to step ST-12. In step ST-12, the node that is 1 (0pen), that is,
It is determined whether or not there is a free node n _N-2 , and if YES, the process proceeds to step ST-13, and if NO, the process moves to a procedure of dividing the upper node and moves to a step not shown. If it is determined in step ST-12 that there is a free node n _{N- 2} , in step ST-13 the node n
After setting _N-2 to 0, the process proceeds to step ST-14. At step ST-14, the node n _N-2 is left-shifted to obtain the lower node n _N-1 and the node n which forms a pair therewith.
_N-1 + 1 is set to 1, and the process returns to step ST-9. Or later,
Repeat these processes.

Next, with reference to FIG. 10, a method of erasing a file of a cell of class N will be described. Step ST-
In No. 1, after obtaining the number of the node n _N (which is a binary number) from the node number list Ii0 of the directory Ti shown in FIG. 4, the process proceeds to step ST-2. Step ST-
In 2, the exclusive OR of the node n _N and 1, to give the node n _N ∧1 constituting the node n _N paired node n
It is determined whether or not _N ∧ 1 is 0 (Close). If YES, the process proceeds to step ST-3, and if NO, the process proceeds to step ST-5. In step ST-2, the node n _N
If ∧1 is 0 (Close), the node n _{N is set} to 1 in step ST-3, and then the process proceeds to step ST-4. At step ST-4, 0 is written in the node number list Ii0 of the directory Ti to erase the node n _N.

At step ST-2, node n_N∧1 is 1
If so, the procedure moves to join both nodes. That is,
Node n in step ST-5_NShift right to
Don't _N-1After obtaining the number, go to step ST-6
It At step ST-6, the node n_N-1Exclusive with 1
By logical OR, node n_N-1Node n paired with_N-
1∧1 is obtained and this node n_N-1∧1 is 0 (Close)
If YES, the process moves to step ST-7.
If NO, the process proceeds to step ST-9. Ste
At ST-6, node n_N-1If ∧1 is 0 (Close)
For example, the merging ends in class N-1, and step ST-7
And node n_N-1After setting 1 (0pen), step ST
Move to -8. In step ST-8, the pair of class N is
Node n_NAfter setting ∧1 to 0, step ST-4
Return to.

At step ST-6, the node n _N-1 ∧1 becomes 1
If, then the procedure moves to the procedure for joining both higher nodes. That is, in step ST-9, the node n _N-1 is right-shifted to obtain the number of the upper node n _N-2 , and then step ST
Move to -10. In step ST-10, node n
The exclusive OR of the _N-2 1 and, to give the node n _N-2 ∧1 forming the node n _N-2 pair, whether this node n _N-2 ∧1 is 0 (Close) If YES, the process proceeds to step ST-11, and if NO, the process proceeds to the procedure of connecting both higher nodes and moves to the next step. At step ST-10, the node n _N-2 ∧1 becomes 0 (Cl
ose), the coupling ends in class N-2, and the node n _{N-2 is set} to 1 (0pen) in step ST-11, and then the process proceeds to step ST-12. At step ST-12, the node n _N-1 ∧ ₁ forming the pair of class N-1 is set to 0, and then the process returns to step ST-8. After that, these processes are repeated.

Next, referring to FIGS. 11 to 16, operation examples (A) to (F) of the node map and the directory in the case of the first embodiment shown in FIGS. 1 and 2 will be described.
This is for comparison with the operation example of the conventional example described in FIG. Therefore, like the conventional example, first, the data A
{2 kbyte (K)} is recorded, then data B {1 kbyte (K)} is recorded, then data A is erased, then data C {1 kbyte (K)} is recorded, and again. The operation of recording the data A will be described. In this case, the data A is recorded in the class 2 cell of FIG. 1, and the data B and C are recorded in the class 2 cell of FIG.

(1) (Initial state) As shown in the operation example (A) of FIG. 11, the node F00 is 1 (0 pen) and the other node F1
0 to F37 are all 0 (Close). Next, FIGS.
The following process will be described with reference to the operation examples (A) and (B). (2) (Recording of data A) Class 2 nodes F20 to F2
I'm looking for 1 (0pen) of 3, but I can't find it. (3) (Recording of data A) Upper class 1 node F1
I look for 0 (0pen) of F11, but I can't find it. (4) (Recording of data A) Node F00 of class 0 is 1
Since it is (0pen), class S cell S00 is divided into class 1 cells S10 and S11, and class 0 node F0 is divided.
The 0 is set to 0 (Close), the cell S10 is used, and the paired node F11 is set to 1 (Open). (5) (Recording of Data A) Class 1 cell S10 is divided into class 2 cells S20 and S21, and class 1 node F
10 is set to 0 (Close) and the node F2 of class 2
Set 0 and F21 to 1 (0pen) respectively. (6) (Recording of data A) The contents of data A are recorded in the cell S20 of class 2 obtained in (5). (7) (Recording of data A) The directory T0 including the file name "data A" and the node number 4 (= F20) is added to the directory list. The above results are shown as an operation example (B) in FIG. The following process will be described below with reference to operation examples (B) and (C) of FIGS.

(8) (Recording of data B) From the nodes F30 to F37 of class 3, the one of 1 (0pen) is searched but not found. (9) (Recording of data B) Class 2 nodes F20 to F2
Searching for 1 (0pen) from 7, the node F21 is found. (10) (Recording of data B) Class 2 cell S21 is divided into class 3 cells S32 and S33, and class 2 node F
21 is set to 0 (Close), the class S cell S32 is used, and the paired node F33 is set to 0 (Close). (11) (Recording of data B) The content of data B is recorded in the cell S32 of class 3 obtained in (10). (12) (Recording of data B) The directory T1 including the file name "data B" and the node number 10 (= F32) is added to the directory list. The above results are shown in FIG.
Is shown as an operation example (C). The following process will be described below with reference to operation examples (C) and (D) of FIGS.

(13) (Erase of data A) The directory list is scanned to obtain the directory T0 having the file name "data A". (14) (Erase of data A) The node number 4 (= F20) is obtained from the directory T0. (15) (Erase data A) Set node F20 of class 2 to 1
(0pen), but class 2 node F21 is 0 (Clos
e) so cells are not combined. (16) (Delete data A) Delete directory T0 from the directory. The above result is the operation example (D) of FIG.
Shown in. Next, the following process will be described with reference to operation examples (D) and (E) of FIGS.

(17) (Recording of data C) 1 (0pen) is searched from the nodes F30 to F37 of class 3 and the node F3 is searched.
Get 3. (18) (Recording of data C) The contents of data C are recorded in the cell S33 of class 3. (19) (Recording of data C) Class 3 node F33 is set to 0
Set to (Close). (20) (Recording of data C) The directory T0 including the file name "data C" and the node number 11 (= F33) is added to the directory list. The above results are shown in FIG.
The operation example (E) is shown. Next, the following process will be described with reference to the operation examples (E) and (F) of FIGS.

(21) (Recording of data A) 1 (0pen) is searched from the nodes F20 to F23 of class 2 to obtain the node F20 of class 2. (22) (Recording of data A) The contents of data A are recorded in the cell S20 of class 2. (23) (Recording of data A) Class F node F20 is set to 0
Set to (Close). (24) (Recording of data A) The file name "data A" and the data T2 having the node number 4 (= F20) are added to the directory list. The above results are shown in an operation example (F) of FIG.

In the conventional example described with reference to FIG.
To record data A as shown in 5 (b), 2
While one cluster S0, S1 was required, in the case of this embodiment, as shown in FIG. 12, since only one cell S20 is required to record the data A, a smaller directory can be used. It has the advantage of managing files. In the above embodiment, the case where the data size is 2 kbytes (K) has been described, but the larger the data size, the greater the effect.

When erasing and recording are repeated, the data A is recorded in the discontinuous clusters S1 and S3 in the conventional example as shown in FIG. , Cells 20 and 1 of class 20
It is recorded in one continuous area. For this reason, since already divided unrecorded cells are preferentially used, small data tend to be collected under a specific upper class, and the seek time of the head can be reduced. Since one upper class unrecorded cell is left without being divided, there is a high probability that a continuous area can be secured even after erasing and recording are repeated, so that it is possible to reduce the number of seeks of the head.

In the specific example shown in FIG. 1 of the above-described first embodiment, a disk device having a data recording area of 8 sectors was used as a model. However, when the disk device has 2 n sectors, it is easy. Can be expanded to a total of 2 ^{(n + 1)} -1 cell structures divided into n + 1 layers from class 0 to class n. That is, when n = 3, class 0
15 (= 2 ⁴ -1) cell structures divided into 4 layers up to 3 are created.

By the way, a general disk device does not always have to be a sector to the power of 2. At this time, this can be dealt with by virtually capturing the sector and setting it to the power of 2 and setting the supplemented sector as recorded and initializing the node map. As a specific example, consider the case of 11 sectors. To this device, 5 sectors are virtually added, and a cell is defined as having 16 sectors. As a result, as shown in FIG. 17, five layers and 31 nodes F00 to F4F are defined.
Of these nodes, the values of the nodes F10, F34, and F4A are each set to 1, and all other values are initialized to 0. That is, the following cell is 1 (Open) in the initialized state of this disk device.

[0058]

Generally, in a disk in which the data recording area is composed of N sectors, in order to initialize the node map, N is represented by a binary number, each bit is regarded as a class of hierarchization, and from the top (or in order). 1)
Set the node of the class where is standing to 1 (Open). FIG. 17 is an example taken from the higher order. When 11 is represented by a binary number, since it is 01011, it agrees with the result of FIG.

Next, expressing the node number in binary will be described. For example, FIG. 18 shows the correspondence between the node numbers and the nodes when the node numbers 1 to 31 of the 31 nodes F00 to F31 of the five layers of FIG. 17 described above are represented by a binary number (6 bits). If the node number is represented by a binary number in this way, the following processing can be performed.

In the binary node number, the first bit in which 1 appears represents the class of the node, and the lower bits thereof represent the order in the class. For example, node F00
Node number is "000001", but the 0th bit is 1, so it can be seen that this is a class 0 node. For example, the node number of the node F22 is “00011
0 ", but since the second bit is 1, this is class 2
It turns out that this is a node.

By inverting the least significant bit of the node number, a pair of nodes belonging to the same upper node is obtained. For example, the node number of the node F22 is “00011
0 ", but the paired node number is" 000111 "
Becomes

By shifting the node number to the right by 1 bit, the node number of the higher class is obtained. For example,
The node number of the node F22 is "000110", but if this is shifted right by 1 bit, the node number "0"
A node F11 of "00011" is obtained.

By shifting the node number to the left by one bit, the node number of the lower class is obtained. For example,
The node number of the node F22 is "000110", but if this is shifted left by 1 bit, the node number "0"
The node F34 of "01100" is obtained. "001101" obtained by inverting the least significant bit of this node number becomes the node number of the node F35. The above circuit for binary node number processing
19 to 22 will be described by taking an example of an 8-bit node number, and an example of the node number processing will be shown in the transition diagram of FIG.

Next, FIG. 19A shows a circuit for obtaining a class number from a node number. The circuits a, b, and c that are connected in series in this order are TTL circuits LS240 manufactured by Texas Instruments Incorporated.
(3-state output inverter), LS148 (8 lines-3 lines 8 priority encoder)) and LS0
4 (6 inverters). The TTL circuit LS148
The truth table of is shown in FIG.

Binary 8-bit node number "D7 D6
D5 D4 D3 D2 D1 D0 "is the inverter a
And the 3-bit binary class number “A2 A1 A0” is obtained from the inverter c. In the node number of the current class in FIG. 22, the bit that first becomes 1 is D2, so it can be represented by class 2, and this can be represented by a binary number, which is "010".

The assembler program when the 6800 is used as the CPU when the class number is obtained from the node number is as follows.

FIG. 20A shows a circuit for obtaining a paired node number. In this circuit, the least significant bit "D0" of the 8-bit binary node number "D7 D6 D5 D4 D3 D2 D1 D0" on the input side is set to the exclusive OR circuit X.
It is inverted by -OR to obtain the node number "D7 'D6' D5 'D4' D3 'D2' D1 'D0'" forming a pair on the output side. Output least significant bit "D
"0 '" is an inversion of the least significant bit "D0" on the input side. In the node number of the current class in FIG. 22, the least significant bit of the node number “00101100” of the current class is inverted to obtain the paired node number “00101101”.

An assembler program for obtaining a paired node number is as follows. XOR # 1, NODE

FIG. 20B shows a circuit for obtaining the node number of the higher class. By shifting the 8-bit binary node number "D7 D6 D5 D4 D3 D2 D1 D0" on the input side to the right by 1 bit like "0 D7 D6 D5 D4 D3 D2 D1", An 8-bit binary node number "D7 'D6' D5 'D4' D3 'D2' D1 'D0'" is obtained. In the node number of the current class in FIG. 22, the node number of the current class is “00101100”.
The node number “000101010” of the upper class is obtained by shifting the right one bit.

The assembler program for obtaining the node number of the upper class is as follows. LSR # 1, NODE

FIG. 21 shows a circuit for obtaining the node number of the lower class. The 8-bit binary node number on the input side "D7 D6 D5 D4 D3 D2 D1 D0" is shifted to the left by 1 bit like "D6 D5 D4 D3 D2 D1 D0 0". An 8-bit binary node number "D7 'D6' D5 'D4' D3 'D2' D1 'D0'" is obtained. In the node number of the current class in FIG. 22, the node number of the current class is “00101100”.
Is shifted to the left by 1 bit to obtain the node number "01011000" of the lower class.

The assembler program for obtaining the node number of the lower class is as follows. LSL # 1, NODE [Second Embodiment] In the above-described first embodiment, in a recording medium such as a hard disk or a floppy disk having a data recording area and a data management area, the data recording area is recursively set to have a hierarchical structure. It is composed of divided unit recording areas (cells), and the data management area is provided with a hierarchical recording management area (node map) having a flag (node) indicating the possibility of data recording in each unit recording area. A data list area (directory) indicating the identifier of the data recorded in the data recording area and the position and size of the unit recording area (cell) to be used is provided in the data recording area or the data management area (the data recording area may be used). Provided.

However, in the first embodiment, since the lower unrecorded unit recording areas (cells) are combined and combined into a small number of upper unit recording areas (cells), a node consisting of 1 (0pen) Is extremely small. Therefore,
When traversing the node map looking for cells of a certain class,
It is extremely unlikely that an empty unit recording area (cell) will be found, and the search will reach the upper unit recording area (cell).

In order to avoid such unnecessary scanning of the node map, in the second embodiment, in the data management area of the data recording medium of the first embodiment, a flag indicating the possibility of data recording in each unit recording area. In addition to (node), the number of flags that can record data for each layer {1
(A node counter that holds the number of nodes (0pen))} and a recording reference area (start pointer that holds the node number to start scanning) indicating its position.

The second embodiment is a data recording medium according to the above-mentioned second invention, and a data recording method and a data erasing method using this data recording medium.

First, the node counter is updated according to the following rules. -When the node of the class is changed from 0 (Close) to 1 (0pen), the node counter is incremented by 1. -When the node of the class is changed from 1 (0pen) to 0 (Close), the node counter is decremented by 1. Next, the start pointer is updated according to the following rules (see FIG. 23).・ When the node map is scanned and a node of 1 (0pen) is found, the position of the next node is set {Fig. 23.
See (A)}.・ 1 (0pen) by erasing data or dividing upper cells
When the node is born, if the position of the node is before the node pointed by the startponter, the position of the new node is set {see FIG. 23 (B)}.

As a result of updating the node counter of each class according to the above-mentioned rule, it is always 1 (0pen) of the class.
The CPU that scans the node map does not need to scan the node map of the class in which the node counter is 0, because the number of nodes that are defined as follows is reflected. Also, since the start pointer of each class is updated according to the above rule, it is guaranteed that there is no node that has 1 (0pen) before the position indicated by the start pointer in the node map of the class. Therefore, unnecessary scanning can be avoided. Therefore, according to the second embodiment, the load on the CPU due to the scanning of the node map is reduced, and the recording of the data on the recording medium can be speeded up.

However, the "position of the next node" and "before the node pointed to by the start pointer" in the above description of the start pointer are not in the order of the node numbers but in the order in which the CPU scans the node map. . Therefore, the implementation means of this embodiment is different between the ascending order scanning and the descending order scanning of the node map.

Referring to FIG. 24, an operation example of the node counter C _N and start pointer P _N of class N when the CPU scans the node map in ascending order from the smallest node number to the largest node number will be described. To do. (Division 1) Since the node n _N cell of the class N found by the ascending scan is divided, if the node is set to 0 (Close), the node counter C _N is decremented by 1 and the start pointer P _N indicates the node n _N +1. Set the number. (Division 2) By dividing the cell of node n _N , nodes n _{N + 1} and n _{N + 1} +1 forming a pair of lower class N + 1 are set to 1 (0p
en), the node counter C _{N + 1} is incremented by 2, and the start pointer P _{N + 1} has the current value P _{N + 1} and the node n _{N + 1.}
Set the smaller one of the. (Recording) Data is recorded in the cell of the node n _{N + 1} found by the ascending scan, and when the node becomes 0 (Close),
The node counter C _{N + 1} is decremented by ₁ , and the number of the node n _{N + 1} is set in the start pointer P _{N + 1} . (Erase) In order to erase the data of the cell of the node n _N of the class N, if the node is set to 0 (Close), the node counter C _N is incremented by 1, and the start pointer P _N is the current value, P _N and the node The smaller one of the numbers n _N is set. (Join 1) If these nodes 0 (Close) are used to join the cells of two nodes n _N and n _N +1 forming a pair,
The node counter C _N is decremented by 2 and the start pointer P
_N is unchanged. (Coupling 2) As a result of combining the cells of class N, After the node n _N-1 of the upper class N-1 is a 0 (Close), the node counter C _N-1 was increased by 1, the start pointer Current The smaller of the value P _N-1 and the node n _N-1 is set.

Next, with reference to FIG. 25, an example of the operation of the node counter C _N and the start pointer P _N of the class N when the CPU scans the node map in descending order from the node with the largest node number. explain. (Division 1) Since the cell of the node n _N of the class N found by the descending scan is divided, the node is set to 0 (Close)
Then, the node counter C _N is decremented by 1, and the number of the node n _N -1 is set in the start pointer P _N. (Split 2) Lower class N + by splitting node n _N
The node n _{N + 1} -1 and the node n _{N + 1} forming a pair of ₁ are set to 0 (Cl
ose), the node counter C _{N + 1} is incremented by 2,
The start pointer P _{N + 1} has a current value P _{N + 1} and a node n.
Set the larger of _{N + 1} numbers. (Recording) Data is recorded in the cell of the node n _{N + 1} found by the descending scan, and when it becomes the node 0 (Close), the node counter C _{N + 1} is decremented by 1, and the start pointer P
_The node n _{N + 1} -1 is set in _{N + 1} . (Erase) In order to erase the data of the cell of the node n _N of the class N, if the node is set to 0 (Close), the node counter C _N is incremented by 1 and the start pointer P _N has the current value P _N and the node n. Set the larger of the _N numbers. (Join 1) Since cells of two nodes n _N −1 and n _N forming a pair are joined, if these nodes are set to 0 (Close), the node counter C _N is decremented by 2 and the start pointer P _N is not changed. . (Coupling 2) As a result of combining the cells of class N, After the node n _N-1 of the upper class N-1 is a 0 (Close), the node counter C _N-1 was increased by 1, the start pointer Current The larger of the value P _N-1 and the number of the node n _N-1 is set.

Next, a method of recording a file in the cell of class N of the second embodiment will be described with reference to the flow charts divided and shown in FIGS. However, for simplification of description, the scanning of the node map is in ascending order. In FIG. 24, when the cells are divided and recorded, the two nodes are temporarily set to 1
After setting (0pen), one of them is set to 0 (Close), but in FIGS. 26 and 27, only the unused nodes are set to 1
Simplified to (0pen).

First, in step ST-1, the delay of FIG.
After writing the file name Di in the folder Ti, step ST
-2. In step ST-2, the node count
Ta C _N= 0, if YES, empty node
Since there is not, there is no step ST-1 to divide the upper node.
0, and if NO, moves to step ST-3
It

If the node C _N = 0 is not found at step ST-2, there is always an empty node after the position pointed to by the start pointer P _N , so at step ST-3 the class N node map is set at the position of the start pointer P _N. After scanning from, the process proceeds to step ST-4. In step ST-4, after the number of the free node n _N is obtained, the process proceeds to step ST-5. At step ST-5, the node n _{N is set} to 0 (Cl
ose), the process proceeds to step ST-6. At step ST-6, the node n _N +1 is set to the start pointer P _N.
After substituting, shifts to step ST-7. At step ST-7, after decrementing the node counter C _N by 1,
Then, the process proceeds to step ST-8. In step ST-8,
After writing the data in the node n _N cells obtained by the above-mentioned scanning or the division of the upper-class nodes described later, the process proceeds to step ST-9. In step ST-9, the numbers of the nodes N _N of the cells used are written in the node number list Ii0 of the directory Ti.

Next, in step ST-10, the node C
_It is determined whether _N-1 = 0, and if YES, there is no free node, so step ST-21 should be performed to divide the upper node.
If NO, the process proceeds to step ST-11.

At step ST-10, the node C_N-1= 0
If not, the start pointer P _N-1From the position pointed to by
Since there is always an empty node in the
Start node P on the node map of Lath N-1_N-1of
After scanning from the position, the process proceeds to step ST-12.
In step ST-12, an empty node n_N-1Got the number of
Then, it transfers to step ST-13. Step ST-1
In 3, node n_N-1After setting 0 (Close),
Transition to ST-14. In step ST-14,
Boot pointer P_N-1To node n_N-1After substituting +1
Then, the process proceeds to step ST-15. In step ST-15
Is the node counter C_N-1After decrementing by 1, step
Transition to ST-16.

At step ST-16, the number (binary number) of the node n _N-1 obtained by the above-mentioned scanning or the division of the node of the higher class is shifted, and the number of the node n _N of the lower class is shifted. After obtaining, go to step ST-17. At step ST-17, a pair of nodes n _N +
After the number 1 is set to 1 (0 pen), the process proceeds to step ST-18. In step ST-18, it is determined whether or not the number of the node n _N +1 set to 1 (0pen) is smaller than the start pointer P _N of the class N. If YES, the process proceeds to step ST-19 and NO. If so, step ST
Move to -20. Node n _N +1 which has been set to 1 (0pen)
When number is smaller than the start pointer P _N class N in step ST-19, after assigning the number of nodes n _N +1 in the start pointer P _N to return the start pointer, proceeds to step ST-20 To do. In step ST-18, when the number of the node n _N +1 set to 1 (0pen) is the start pointer P _N of the class _N or more,
Alternatively, after the processing in step ST-19, step S
After incrementing the node counter C _N by 1 at T-20,
Return to step ST-8.

Next, in step ST-21, the node C
_It is determined whether or not _N-2 = 0. If YES, there is no free node, so the process proceeds to a step not shown to divide the upper node, and if NO, the process proceeds to step ST-22.

At step ST-21, the node C_N-2= 0
If not, the start pointer P _N-2From the position pointed to by
Since there is always an empty node in the
Start pointer P on the node map of Las N-2_N-2of
After scanning from the position, the process proceeds to step ST-23.
In step ST-23, an empty node n_N-2Got the number of
Then, it transfers to step ST-24. Step ST-2
In 4, the node n_N-2After setting 0 (Close),
Transition to ST-25. In step ST-25,
Boot pointer P_N-2To node n_N-2After substituting +1
Then, the process proceeds to step ST-26. In step ST-26
Is the node counter C_N-2After decrementing by 1, step
Transition to ST-27.

In step ST-27, the number (binary number) of the node n _N-2 obtained by the above-mentioned scanning or the division of the node of the higher class is shifted so that the node n _N-1 of the lower class is shifted. After obtaining the number, the process proceeds to step ST-28. In step ST-28, the pair of nodes n
After setting the number of _N-1 + 1 to 1 (0pen), step ST-
Move to 29. At step ST-29, 1 (0pen)
It is determined whether or not the +1 number of the node n _N-1 that has been set is smaller than the start pointer P _{N-1 of the} class N-1.
If YES, the process proceeds to step ST-30, and if NO, the process proceeds to step ST-31. When the number of the node n _N-1 +1 set to 1 (0pen) is smaller than the start pointer P _{N-1 of the} class N-1, step ST-30
Then, in order to return the start pointer, the start pointer P
After substituting the number of nodes n _N-1 +1 to _N-1, the process proceeds to step ST-31. In step ST-29, 1 (0p
en), the number of the node n _N-1 +1 set to en) is the class N-1
Of the start pointer P _N-1 or more, or after the process of step ST-30, the node counter C _N-1 is incremented by ₁ in step ST-31, and then step ST
Return to -16.

Next, with reference to the flow charts divided into FIGS. 28 and 29, a method of erasing a class N file of the second embodiment will be described. In FIG. 24, when erasing files and merging cells, the cells to be erased
After setting (0pen), set the two nodes that make a pair to 0 (Close)
However, in FIGS. 28 and 29, the simplification is made such that only the partner node to be joined is set to 0 (Close).

First, in step ST-1, the number of the node n _N is obtained from the node number list Ii0 of the directory Ti shown in FIG. 4, and then the process proceeds to step ST-2. In step ST-2, it is determined whether or not the number of the node n _N ∧ 1 forming a pair obtained by the exclusive OR of n _N and 1 is 0 (Close), and if YES, the process proceeds to step ST-3, If it is a node, the process proceeds to step ST-8. Step ST-
2, if the number of nodes n _N ∧1 a is 0 (Close), at step ST-3, after the node n _N to 1 (0pen),
The process proceeds to step ST-4. In step ST-4, 1
It is determined whether or not the number of the node n _{N set} to (0pen) is smaller than the start pointer P _{N of the} class N. If YES, the process proceeds to step ST-5, and if NO, the process proceeds to step ST-6. To do. Node n _{N in} step ST-4
When is it is determined that the start pointer P _N is smaller than, in order to return the start pointer in a step ST-5, after substituting the number of nodes n _N to the start pointer P _N, the process proceeds to step ST-6. Step ST-4
When it is determined that the node n _N is equal to or _larger than the start pointer P _N or after step ST-5, the node counter C _N is incremented by 1, and then the process proceeds to step ST-7. In step ST-7, 0 (Close) is written in the node number list Ii0 of the directory Ti to erase the number of the node n _N.

At step ST-2, the pair of nodes n _N
If ∧1 is not 0 (Close), the node n _N ∧1 is set to 0 (Close) in step ST-8, and then the process proceeds to step ST-9. In step ST-9, after decrementing 1 from the node counter C _{N of} class N, the process proceeds to step ST-10. At step ST-10, the node n _N-1 number (2
After shifting the (decimal number) to the right to obtain the number of the node n _N-1 of the upper class, the process proceeds to step ST-11. Step S
At T-11, it is determined whether or not the number of the node n _N-1 ∧ ₁ forming a pair obtained by the exclusive OR of n _N-1 and 1 is 0 (Close). If YES, the process proceeds to step ST-12. If the result is NO, the process proceeds to step ST-16. Step ST-
11, if the node n _N-1 ∧1 number is a 0 (Close), in step ST-12, the node n _N-1 a 1 (0pen)
After that, the process proceeds to step ST-13. Step S
At T-13, it is determined whether or not the number of the node n _{N-1 set} to 1 (0pen) is smaller than the start pointer P _{N-1 of the} class N-1, and if YES, the process proceeds to step ST-14. If NO, the process proceeds to step ST-15. In step ST-13, the node n _N-1 sets the start pointer P
_If it is determined that it is smaller than _N-1 , step ST-1
In order to return the start pointer in step 4, the number of the node n _N-1 is assigned to the start pointer P _N-1 , and then step S
Move to T-15. In step ST-13, node n
_When it is determined that _{N-1 is} greater than or equal to the start pointer P _N-1 , or after step ST-14, the node counter C _N-1 is incremented by _1, and then the process returns to step ST-7.

In step ST-11, the pair of nodes n
_{If N-1} ∧1 is not 0 (Close), step ST-16
After setting the node n _N-1 ∧1 to 0 (Close), step S
Move to T-17. Class N in step ST-17
After subtracting ₁ from the node counter C _{N-1 of} -1, the process proceeds to step ST-18. In step ST-18, the number (binary number) of the node n _N-1 is right-shifted to obtain the number of the node n _N-2 of the higher class, and then the process proceeds to step ST-19. At step ST-19, the number of the node n _N-2 ∧ 1 forming a pair obtained by the exclusive OR of n _N-2 and 1 is 0.
It is determined whether or not it is (Close), and if YES, step ST-2.
If it is NO, the process proceeds to the next step (not shown). At step ST-19, the node n _N-2 ∧1
If the number is 0 (Close), in step ST-20,
After setting the node n _N-2 to 1 (0pen), step ST-2
Move to 1. In step ST-21, it is determined whether or not the number of the node n _{N-2 set} to 1 (0pen) is smaller than the start pointer P _{N-2 of the} class N-2, and if YES, the process proceeds to step ST-22. If the result is NO, the process proceeds to step ST-23. Node n in step ST-21
_If it is determined that _{N-2 is} smaller than the start pointer P _N-2 , after substituting the number of the node n _N-2 into the start pointer P _N-2 to return the start pointer in step ST-22, Then, the process proceeds to step ST-23. In step ST-21, the node n _N-2 has the start pointer P _N-2.
When it is determined that the above is the case, or step ST-2
After 2, after incrementing the node counter C _N-2 by 1,
Return to step ST-7.

[Third Embodiment] In the first embodiment described above, in a recording medium such as a hard disk or a floppy disk having a data recording area and a data management area, the data recording area is recursively divided into two so as to have a hierarchical structure. A unit recording area (cell), and the data management area is provided with a hierarchical recording management area (node map) having a flag (node) indicating the possibility of data recording in each unit recording area. A data list area (directory) indicating the identifier of the data recorded in the data recording area and the position and size of the unit recording area (cell) to be used is provided in the recording area or the data management area (may be the data recording area). .

However, in the first embodiment, since a flag (node) indicating the possibility of data recording in each unit recording area is defined for each unit recording area (cell), recording on a hard disk, floppy disk, etc. The larger the capacity of the medium, the larger the hierarchical recording management area (node map) is required in proportion to the number of sectors constituting the recording medium. That is, a disc having N sectors requires a hierarchical recording management area (node map) of at least 2N-1 bits. Taking a 3.5-inch magneto-optical disk currently in practical use as an example, since it has a capacity of 128 Mbytes composed of 512-byte sectors, the number of sectors N = 256k sectors. Therefore, the required hierarchical recording management area (node map) size is 512 kbits = 64 kbytes.

Scanning such a large amount of hierarchical recording management area (node map) increases the load on the CPU,
Not only will this cause a decrease in processing speed, but the capacity of the main storage means consumed for the hierarchical recording management area (node map) will become so large that it cannot be ignored as the capacity of the recording medium increases.

Therefore, in the third embodiment, the hierarchical recording management area (node map) in the first embodiment is abolished, and instead, a list of identifiers of recordable unit recording areas (cells) is added to the data management area. The recording management area is provided, and the data recording area or the data management area is provided with a data list area indicating the identifier of the data recorded in the data recording area (cell) and the position and size of the unit recording area (cell) to be used. It is a thing.

The third embodiment is a data recording medium according to the third aspect of the present invention described above, a data recording method and a data erasing method using this data recording medium.

In the case of the first embodiment described above, the number of nodes of 1 (0pen) is extremely small. The maximum number of nodes that can be 1 (0pen) is when all the sectors on the disk are erased after the data has been recorded on all the sectors on the disk, and the total number of sectors is N. , N / 2 nodes become 1 (0 pen). However, in the actual operation of the disk device, recording / erasing several files is repeated and the disk capacity is gradually consumed, and the node with 1 (0pen) is the largest. Can never be. In this case, the maximum number of nodes that is substantially 1 (0pen) does not depend much on the capacity of the disk and is determined by the combination of recording and erasing that occurs at random, so the number is predicted here. Is difficult, and we have to wait for a statistical survey depending on the application. However, roughly speaking, 1 (0p
en) nodes, regardless of disk capacity
At most 10 to several tens in each class, 1
It is unlikely that it will greatly exceed 00. According to such a prediction, when the disk capacity is large, 1 (0p
Even if all the numbers of the nodes that are defined as en) are recorded as a list, in the case of the third embodiment, it is significantly smaller than the node map in the case of the first embodiment.

First, a method of dividing the data recording area of the data recording medium will be described with reference to FIG. still,
This is similar to the method of dividing the data recording area of the data recording medium in the first embodiment shown in FIG. 1, but in this example, for example, the 16 kbyte (K) data recording area has a hierarchical structure. This is a case where the unit recording area is obtained by recursively dividing into two. This unit recording area will be called a cell. First, the entire data recording area is defined as one cell S00 of 16 k bytes (K) of class 0. This cell S00 is divided into two to define 8 kbyte (K) cells S10 and S11 of class 1, respectively.
Each of these cells S10 and S11 is divided into two, and four cells S20 and S of 4 kbytes (K) of class 2, respectively.
21, S22 and S23 are defined. These four cells S
20, S21, S22, S23 are each divided into two,
8 cells S3 of 2k bytes (K) each of class 3
0, S31, S32, S33, S34, S35, S3
6, S37 is defined. These eight cells S30, S3
1, S32, S33, S34, S35, S36, S37
Are divided into two, and 16 cells of 1 kbyte (K) each of class 4, S40, S41, S42, S43,
S44, S45, S46, S47, S48, S49, S
4A, S4B, S4C, S4D, S4E and S4F are defined. With the above, 31 cells are defined in 5 layers.

The cells S00, S10, ... Of this FIG.
, S4E, S4F, serial numbers (1), (2), ..., (30), (31) are defined as node numbers. Then, as shown in FIG. 31, a node list in which each node number (1), (2), ..., (30), (31) is classified by class is provided. The node number of a recordable cell is written in this node list.
When the cells S21 and S22 of class 2 can be recorded,
The numbers of the nodes 5 and 6 are recorded in the node list of class 2. When recording data, the node number may be extracted from this node list and the data may be recorded in that cell. When erasing data, the cell number may be written in the node list.

Next, with reference to FIG. 32, an operation of dividing a cell and recording data will be described. FIG. 32A shows an initial state, in which the node list of class N has no node number, and the node list of class N-1 records the number of node n _N-1 . FIG. 32B shows a method of dividing a cell of a higher class. The number of the node n _N-1 is extracted from the node list of the class N-1. The number (binary number) of the node n _N-1 of the class N-1 is left-shifted to obtain the number of the node n _N of the class N. 1 is added to the number (binary number) of the node n _N of the class N to obtain the number of the paired node n _N +1. Record the number of node n _N +1 in the node list.

FIG. 32 (c) shows the result obtained by the operation of FIG. 32 (b). According to this, the class N-1 node was the node list of n _N-1 nodes in the node list of classes N on behalf of numbers n _N +1 number is recorded. On the other hand, the node n _N constituting the node n _N +1 pair
Is not written to the node list and is used for recording data.

CPU of this upper class cell division method
When the 6800 is used as the assembler program, it is as follows. MOVE (TABLE [N-1]) +, NODE LSL # 1, NODE ADD # 1, NODE MOVE NODE,-(TABLE [N]) SUB # 1, NODE

Next, with reference to FIG. 33, the operation of erasing the data in the cell and coupling it to the paired node will be described.
FIG. 33A shows the initial state, and the node n _N +1 forming a pair with the node n _N of the cell of the data to be erased is in the class list in the node list. FIG. 33B shows a method of combining cells in accordance with the erasing of data. The node list of class N is traversed looking for the number of paired node n _N +1. A pair of nodes n _{N in} the node list of class _N
Delete the number +1. Right-shift the number of the node n _{N to be} deleted, and
Get the number of the node n _N-1 of -1. Record the number of the node n _N-1 obtained in the above in the node list of the class N-1.

FIG. 33 (c) shows the result of the process of FIG. 33 (b). Node n _N + that was in the class N node list
1 in place of node n in the node list of class N-1
_N-1 is recorded.

The node list simulation program in C language according to the third embodiment will be described below with reference to FIGS.
Program list (part 1 to part 8)
Will be described with reference to. This program consists of the following parts.

1. Definition part The node list and directory are defined as variables. -"D0" represents a node list and is defined as an array of stack frames. -"Dbuf0 []" reserves the memory area for the node list. -"U0" represents a virtual directory and is defined as a stack frame. -"Ubuf0 []" reserves the memory area for the virtual directory. 2. main () receives commands from the keyboard, "get", "put", "qui
Execute each command of "t" .- "get" retrieves the node number of the specified class from the node list and records it in the virtual directory .- "put" records the node number of the specified node in the virtual directory. Retrieved from and returned to node list- "quit" terminates this program 3. getline (str) Input a character string of one line from keyboard 4. showtbl (& d, & u) node list "d" And display the status of virtual directory "u" 5. nodeinit (& d, & tbl) Initialize node list "d" and allocate it to memory area "tbl" 6. push (& d, cls, node) node list " Node number "node" in class "cls" of d "
Put in. -When the stack of class "cls" reaches the upper limit, the stack is expanded. 7. pop (& d, cls) Extracts the node number of class "cls" from node list "d". -If the stack of class "cls" is empty, "pop (& d, cl
s-1) "to call recursively, and use" push (& d, cls, node +
1) "divides the upper class node. 8. delete (& d, node) returns the node number" node "to the node list" d "to delete the data. ・ By" classof (node), Get the class of node number "node".・ If there is a paired node number, "delete (& d, nod
e) Call recursively by ">>1)", delete the number of paired nodes and join the nodes.・ If there is no paired node number, "push (& d, cls, n
ode) "to put the node number" node "in the node list. 9. eject (& u, node) The node number" node "specified from the virtual directory" u ".
To delete. 10. classof (node) Get the class from the node number "node".

Next, an execution example of this program divided into FIGS. 42 and 43 will be described. The following operation is performed in order to compare the conventional example and the third example shown in FIG. First get the class 2 node number from the node list, then get the class 3 node number from the node list, then return the class 2 node number to the node list, then Retrieve the node number from the node list, and again: retrieve the class 2 node number from the node list. Further, the following operation is performed to show the operation of cell combination. Return the number of class 3 nodes to the node list, then return the number of class 3 nodes to the node list, then return the number of class 2 nodes to the node list.

1. Is the initial state. -Only the node 0001 of class 0 has 1 (0pen). 2. Is the result of getting the number of the node of class 2. -Class 0 node 0001 is divided to leave class 1 node 0003-Class 1 node 0002 is divided to leave class 2 node 0005-Class 2 node 0004 is obtained 3. Is the result of getting the number of the node of class 3. The class 2 node 0005 is divided to leave the class 3 node 000b, and the class 3 node 000a is obtained. 4. Is the result of returning the node number 0004 in the node list. The node number 0004 is returned to the class 2 stack of the node list. 5. Is the result of getting the number of the node of class 3. -A node 000b of class 3 is obtained. 6. Is the result of getting the number of the node of class 2. A class 2 node 0004 is obtained. 7. Is the result of returning the node number 000a to the node list. The node number 000a is returned to the class 3 stack of the node list. 8. Is the result of returning the node number 000b to the node list. The node number 000b is combined with the node number 000a in the class 3 stack and the class 2 node 000
5 is set to 1 (0 pen). 9. This is the result of returning the node number 0004 to the node list. The node number 0004 is combined with the node 0005 on the class 2 stack to form the node number 0002, and the node number 0002 is combined with the node 0003 on the class 1 stack and the class 0 node 0001. Is 1
(0pen)

Thus, the above 6. As a result, it can be seen that the node 0003 is left in the class 1 stack of the node list and the nodes 0004, 000a, and 000b are recorded.

In the above embodiments, the case where the present invention is applied to the hard disk and the data recording method and the data erasing method using this hard disk has been described.
In addition to being applicable to a data recording medium such as a floppy disk, a magneto-optical disk, and a magnetic tape, and a data recording method and a data erasing method using the data recording medium, a storage device such as a semiconductor memory and a data recording using the storage device The method and the data erasing method are also applicable.

[0114]

According to the first, fourth and sixth aspects of the present invention described above, the capacity efficiency of recording data is high, and the number of unit recording areas required is small regardless of the amount of recording data. Thus, it is possible to obtain a data storage medium, a data storage method, and a data erasing method in which discontinuity of unit recording areas for the same file hardly occurs and the processing speed can be increased.

According to the second, fifth and seventh aspects of the present invention described above, the capacity efficiency of recording data is high, and the number of unit recording areas required is small regardless of the amount of recording data. Thus, it is possible to obtain a data storage medium, a data storage method, and a data erasing method that are unlikely to cause discontinuity of unit recording areas for the same file and can further increase the processing speed.

According to the second, eighth and ninth aspects of the present invention described above, the capacity efficiency of recording data is high, and the number of unit recording areas required is small regardless of the amount of recording data. To obtain a data storage medium, a data storage method, and a data erasing method that are less likely to cause discontinuity of unit recording areas for the same file, can narrow the data management area, and can further increase the processing speed. You can

[Brief description of drawings]

FIG. 1 is a diagram showing how to divide a data recording area according to an embodiment.

FIG. 2 is a diagram showing a node map of the divided data recording area of FIG.

FIG. 3 is a diagram showing allocation of node numbers to nodes.

FIG. 4 is a diagram showing a directory of data.

5 is a diagram showing a method of dividing cells of the node map of FIG.

FIG. 6 is a flowchart showing a method of dividing a cell of class N.

FIG. 7 is a diagram showing a method of combining cells of the node map of FIG.

FIG. 8 is a flowchart illustrating a method for pairing Class N cells.

FIG. 9 is a flowchart showing a method for recording file data in a class N cell.

FIG. 10 is a flowchart showing a method for erasing file data of a cell of class N.

FIG. 11 is a diagram showing an operation example (A) of a node map and a directory.

FIG. 12 is a diagram showing an operation example (B) of a node map and a directory.

FIG. 13 is a diagram showing an operation example (C) of a node map and a directory.

FIG. 14 is a diagram showing an operation example (D) of a node map and a directory.

FIG. 15 is a diagram showing an operation example (E) of a node map and a directory.

FIG. 16 is a diagram showing an operation example (F) of a node map and a directory.

FIG. 17 is a diagram showing a method for initializing a node map.

FIG. 18 is a diagram showing a correspondence table of node numbers and nodes expressed in binary numbers.

FIG. 19 is a block diagram showing a circuit for obtaining a class number from a node number and a diagram showing a truth table of a part of the circuit.

FIG. 20 is a connection diagram showing a circuit for obtaining a paired node number and a circuit for obtaining a higher node number.

FIG. 21 is a connection diagram showing a circuit for obtaining a younger one of lower node numbers.

FIG. 22 is a diagram showing a method of obtaining upper and lower classes and node numbers to be paired.

FIG. 23 is a diagram showing an operation example of a start pointer.

FIG. 24 is a diagram showing an operation example of a node counter and a start pointer (for ascending scan).

FIG. 25 is a diagram showing an operation example of a node counter and a start pointer (in the case of descending scan).

FIG. 26 is a flowchart showing a method (1) of recording a data file in a cell of class N.

FIG. 27 is a flowchart showing a method (No. 2) of recording a data file in a cell of class N.

FIG. 28 is a flowchart showing a method (1) of recording a data file in a class N cell.

FIG. 29 is a flowchart showing a method (part 2) of recording a data file in a cell of class N.

FIG. 30 is a diagram showing how to divide the data recording area of the embodiment.

FIG. 31 is a diagram showing a node list of the divided cells of FIG. 30.

FIG. 32 is a diagram showing a method of obtaining a node number by dividing an upper node.

FIG. 33 is a diagram showing a method of joining a pair of open nodes.

FIG. 34 is a table showing a program list (part 1) of a method for realizing the third embodiment.

FIG. 35 is a table showing a program list (part 2) of the method for realizing the third embodiment.

FIG. 36 is a table showing a program list (part 3) of a method for realizing the third embodiment.

FIG. 37 is a table showing a program list (Part 4) of the method for realizing the third embodiment.

FIG. 38 is a table showing a program list (Part 5) of the method for realizing the third embodiment.

FIG. 39 is a table showing a program list (part 6) of a method for realizing the third embodiment.

FIG. 40 is a table showing a program list (No. 7) of the method for realizing the third embodiment.

FIG. 41 is a table showing a program list (Part 8) of the method for realizing the third embodiment.

FIG. 42 is a table showing an execution example (1) of the program.

FIG. 43 is a table showing an execution example (part 2) of the program.

FIG. 44 is a diagram showing a recording area of a conventional hard disk.

FIG. 45 is a diagram showing an operation example of a conventional allocation map and a directory.

FIG. 46 is a diagram showing how to divide a data recording area of a conventional hard disk.

Claims (9)

[Claims] 1. A data storage medium having a data storage area and a data management area, wherein the data storage area is configured by a unit storage area that is recursively divided into two so as to have a hierarchical structure. Providing a hierarchical storage management area having a node indicating whether or not there is a possibility of data storage in each of the unit storage areas, and in the data storage area or the data management area, an identifier of data stored in the data storage area and A data storage medium comprising a data list area indicating the position and size of the unit storage area to be used. 2. The data storage medium according to claim 1, wherein the hierarchical storage management area is provided with a storage reference area indicating the number of nodes capable of data storage and the positions thereof for each hierarchy. . 3. A data storage medium having a data storage area and a data management area, wherein the data storage area is recursively divided into two unit storage areas having a hierarchical structure, A storage management area having a hierarchical list of identifiers of the unit storage areas that can be stored is provided, and the data storage area or the data management area has an identifier of data stored in the data storage area and the unit to be used. A data storage medium having a data list area indicating the position and size of the storage area. 4. A data storage medium having a data storage area and a data management area, wherein the data storage area is recursively divided into two unit storage areas having a hierarchical structure, and the data management area is provided in the data management area. Providing a hierarchical storage management area having a node indicating whether or not there is a possibility of data storage in each of the unit storage areas, wherein the data storage area or the data management area has an identifier of data stored in the data storage area, A method for storing data using a data storage medium provided with a data list area indicating the position and size of the unit storage area to be used, which has a minimum capacity for storing the desired data when storing the desired data. The possibility of data storage in the unit storage area is detected by the node in the hierarchical storage management area, and the data storage If there is the unit storage area with the capability, the desired data is stored in the unit storage area, and if there is no unit storage area with the possibility of data storage, the upper unit having a storage capacity that is double that The possibility of data storage for the storage area is detected by the node of the hierarchical storage management area, and if there is the above-mentioned upper unit storage area with the possibility of data storage, the unit storage area is obtained by dividing it into two. Storing the desired data in the unit storage area, storing that the upper unit storage area cannot be stored in the hierarchical storage management area as the node, and storing the desired data in the hierarchical storage management area. The fact that the unit storage area storing the desired data cannot be stored is stored as the node, and the identifier and the desired data of the desired data are stored in the data list area. Data storage method characterized by storing the position and size of the stored said unit storage regions of the desired data. 5. The data storage method according to claim 4, wherein the hierarchical storage management area is provided with a storage reference area indicating the number and the position of nodes capable of storing data for each hierarchy. . 6. A data storage medium having a data storage area and a data management area, wherein the data storage area is recursively divided into two unit storage areas having a hierarchical structure, and the data management area is provided in the data management area. Providing a hierarchical storage management area having a node indicating whether or not there is a possibility of data storage in each of the unit storage areas, wherein the data storage area or the data management area has an identifier of data stored in the data storage area, A method of erasing data using a data storage medium provided with a data list area indicating the position and size of the unit storage area to be used, which should be erased in the hierarchical storage management area when erasing desired data. While changing and storing the above node in a storable state for the unit storage area in which desired data is stored,
When the unit storage area forming a pair with the unit storage area storing the desired data to be erased can store data, the nodes for both unit storage areas of the hierarchical storage management area cannot be stored. And uniting the two unit storage areas together, changing and storing the node for the combined unit storage area into a storable state, and the unit of the desired data to be erased in the data list area. A data erasing method characterized by erasing the position and size of a storage area. 7. The data erasing method according to claim 6, wherein the hierarchical storage management area is provided with a storage reference area indicating the number of nodes capable of data storage and the positions thereof for each hierarchy. . 8. A data storage medium having a data storage area and a data management area, wherein the data storage area is recursively divided into two unit storage areas having a hierarchical structure, and the data management area is provided in the data management area. A hierarchical storage management area having a hierarchical list of identifiers of the unit storage areas that can be stored is provided, and the data storage area or the data management area has an identifier of data stored in the data storage area and A data storage method using a data storage medium provided with a data list area indicating the position and size of a unit storage area, wherein the unit storage has a minimum capacity for storing the desired data when storing the desired data. The possibility of data storage for an area is a hierarchical list of identifiers of the storable unit storage areas of the hierarchical storage management area. Thus detected,
If there is the unit storage area with the possibility of data storage, the desired data is stored in the unit storage area and the identifier of the data is deleted from the data list area, and the unit storage area with the possibility of data storage. If there is not, it is possible to store data by detecting the possibility of data storage in the upper unit storage area having double the storage capacity by the hierarchical list of the unit storage area identifiers in the hierarchical storage management area. If there is an upper unit storage area having a property, the desired data is stored in one of the unit storage areas obtained by dividing the unit storage area into two, and the upper unit with respect to the hierarchical storage management area. The identifier of the storage area is deleted, the identifier of the other unit storage area divided into two is stored, and the desired data of the desired data is stored in the data list area. A data storage method comprising storing the position and size of the unit storage area in which the identifier and the desired data are stored. 9. A data storage medium having a data storage area and a data management area, wherein the data storage area is recursively divided into two unit storage areas having a hierarchical structure, and the data management area is provided in the data management area. A hierarchical storage management area having a hierarchical list of identifiers of the unit storage areas that can be stored is provided, and the data storage area or the data management area has an identifier of data stored in the data storage area and A method of erasing data using a data storage medium provided with a data list area indicating a position and a size of a unit storage area, wherein when erasing desired data, the unit storage area in which the desired data to be erased is stored The identifier is stored in the hierarchical storage management area and is paired with the unit storage area in which the desired data to be erased is stored. Together with the identifier of the storage area when it is stored in the hierarchical storage management area, give the unit storage area of the upper by combining both said unit storage area, erases the identifier of the both unit storage area,
The identifier of the upper unit storage area is stored in the hierarchical storage management area, and the position and size of the unit storage area of the desired data to be deleted in the data list area are deleted. Data erasing method.