JPH0320841A - File access system - Google Patents

Abstract

PURPOSE:To make access to a large amount of data at high speed by providing a file access OS(operating system) exclusive for direct disk input/output operated by utilizing a part of the managing area of the operating system. CONSTITUTION:When it is desired to display, for example, the title (doc 01) of a document, a retrieval part issues an instruction to make access to a file (doc 01 sub, dat) for document file management stored in the managing area of the OS to the OS by issuing the instruction to instruct the fact to the retrieval part which handles the access of a hard disk with an application program, and also, the access to a document file (doc 01, dat) stored in the managing area of a file access system is instructed to a second OS. The retrieval part develops data in the file (doc 01, dat) to the format of a title for display while referring to the content of the file (doc 01, sub, dat), and displays it on a display device.

Description

[Detailed description of the invention] [Industrial application field]

The present invention allows image data etc. to be accessed at high speed. Regarding file access systems for accessing files, especially traditional OS (
This invention relates to a file access system that enables faster speeds by providing a file access OS dedicated to direct disk input/output that is separate from the functions of the operating system. [Prior Art] File access using a conventional OS has focused on versatility, and no consideration has been given to file access for rapidly accessing large amounts of data such as image data. Regarding this, for example, the Electronic Information and Communication Handbook '88 (edited by the Institute of Electronics, Information and Communication Engineers,
The descriptions in Volumes 24 and 25 (published by Ohmsha, 1988) are helpful. [Problems to be Solved by the Invention] The above-mentioned conventional technology had a problem in that it took a long time to process because no consideration was given to file access for rapidly accessing a large amount of data such as image data. The present invention has been made in view of the above circumstances, and its purpose is to solve the above-mentioned problems in the conventional technology and to provide a file access system for accessing large amounts of data such as image data at high speed. The purpose is to provide. [Means for Solving the Problems] The above-mentioned object of the present invention is to provide a direct disk input/output system that operates using a part of the OS management area in a file access system for rapidly accessing image data, etc. This is achieved by a file access system featuring a dedicated file access OS. [Operation] In the file access system according to the present invention, O
A part of the disk area that was centrally managed by S is restricted, and this restricted area is used as the management area of this system to allow file access exclusively for direct disk input/output.
S is provided, and by using a file access OS dedicated to direct disk input/output, high-speed file access is achieved. More detailed operation will be explained in the Examples section below. [Example] Hereinafter, an example of the present invention will be described in detail based on the drawings. In the following explanation, the present invention is applied to an optical filing system, image data is filed on an optical disk, a document file is the title information, and a document file management file is the document file management information. Let's take an example of building a system in which files are stored on a hard disk (magnetic disk, etc.). For example, if you want to display the title of a document called rdoc 014, as shown in Figure 1, the application instructs the search unit that controls access to the hard disk to that effect, and the search unit will, as described later,
For example, rdoc, which is stored in the management area of the OS.
01 sub, datJ, which instructs the OS to access the document 77 file for file management, and which is stored in the management area of the file access system according to the present invention (which can also be called the "second ○S"). ,rd
The second OS is instructed to access the document file ocOf, dat4. The search unit searches the data in the file rdoc Of, datJ as the file r
doc 01 sub, dat'', develop it into a display title format, and display it on the display device. This will be explained in more detail below. FIG. 2 shows the file access system (hereinafter referred to as rDDI○ (DirectDis)) according to the present invention described above.
The configuration of the area managed by the k I nput-output (also referred to as system j) is shown. As shown in the figure, the areas managed by this system are the control area and the FA
It consists of four areas: a file allocating table (T) area, a directory area (prime area and overflow area), and a data area. First, we will explain the control area. This area is about 32 bytes, which is relatively small in terms of data amount, but it is the core of this system. This control area, as shown in Figure 3,
ck blood: stores the number of free blocks), FN○ (F
ileNa: stores the number of files used) and B
It has a MAP (Bit Map) that manages directory information, particularly directories in the prime area, which will be described later. Next, we will explain the FAT area.The FAT area is a collection of data in word units, and each word corresponds to each block of the data area, which will be described later. The connections between blocks are also managed here. How this FAT area is used will be explained using Figure 4. First, in step 41, U B in the directory information
H P (Used B lock Head Poi
nter: Take the first block number used (the first 2 bytes of UBOT in Figure 3) into X. Next, by dividing X by 2, the block address within the data area where the data is located is determined (step 43), and the block is accessed (step 44). The block pointer to be used next ([x
1), the same procedure is further repeated (steps 42 to 45). Finally, when the contents of the FAT entry become OxFFFF, the file is considered to have ended. By having such a table, it becomes possible to detect block access positions smoothly. Next, we will explain the directory area. As shown in FIG. 2, the directory area is roughly divided into two areas: a prime area and an overflow area. When searching for a necessary file name from the directory area written on the hard disk, it is wasteful to check all the areas each time, so use part of the file name and fix the storage location of the directory in advance. take the method of doing so. The prime area is used at this time. For example, as shown in FIG. Apply Z to each number from O to 35, multiply the 5th character by 35, add the 6th character, and add it to 64.
Find the remainder after dividing by (step 67). This is the prime area (
64) record number. Here, if the prime area becomes full, the overflow area is used. In FIG. 6, X→X-"0" and y→y-"0" in steps 63 and 66 are respectively x. y
This shows that the code is encoded as follows. In this case, if X and y are numbers 0 to 9, the code "O" can be subtracted, but if they are letters A to Z, the code "A" is subtracted and then lO is added. Next, the contents of the above directory will be explained (see Figure 5). First, F is a flag that indicates whether or not information is stored in that directory; "00" indicates that it is in use, "E5" indicates that it is unused, and "FF" in the overflow area indicates that it will not be used after that. This indicates that the specified directory does not exist. And D N A M E (D irec
tory Name), DTYPE (
Directory Type) indicates the file name and file type, respectively. Furthermore, the UB
The first word before OT contains the offset (UBHP) that indicates the first block of the file as shown in the FAT explanation.
is included, and the last L word is the final one (UBT
P) is included. In addition, information specific to the file such as the number of blocks used, the number of records used, and the logical address on the disk is stored. The procedure for searching the directory of the specified file will be explained using FIG. First, obtain the record number from the file name using the method (hash) shown in Figure 6 (step 7).
1) Read the record and find the file name. When it is not found, the overflow area is read sequentially from the beginning, as it cannot exist in records in other prime areas, and the first byte is OxFF.
Repeat until . Finally, the aforementioned data area is an area that actually stores various information such as files, and is managed by FAT as described above. The operation of this embodiment configured as described above is as follows. As mentioned above, in this embodiment, the present invention is applied to an optical filing system, and image data is filed on an optical disk, and a document file containing title information and a document file containing management information thereof are stored. Let's take an example of building a system in which management files are stored on the hard disk. For example, as described above, if a document called rdoc OIJ is specified, the record in the prime area where the document is stored is calculated and accessed. If the corresponding file is not found there, the overflow area is sequentially searched, and if it is still not found, it is determined that the file does not exist and an error is set. When the file is found, the FAT example (see Figure 4)
Access according to the following. Thereby, a large amount of data such as image data can be accessed at high speed. It goes without saying that the above-mentioned embodiment is shown as an example, and the present invention should not be limited thereto.

【Effect of the invention】

As described in detail above, according to the present invention, in a file access system for high-speed access to image data, etc., direct disk input/output dedicated file access operates using a part of the management area of the OS. Since an OS is provided, it has the remarkable effect of realizing a file access system for rapidly accessing large amounts of data such as image data.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the operation of a file access system showing an embodiment of the present invention, FIG. 2 is a diagram showing an example of the configuration of an area managed by the DDIO system, and FIG. 3 is a diagram showing an example of the configuration of a control area. Figure 4 is a flowchart showing how to use the FAT area, Figure 5 is a diagram showing an example of the structure of the directory area, Figure 6 is a flowchart showing how to use the prime area, and Figure 7 explains how to use the directory area. This is a flowchart. 41-45.61-69.71-78: Processing steps. Figure 1 Directory area Figure 4 Figure 6

Claims (2)

[Claims] (1) A file access system for high-speed access to image data, etc., characterized by the provision of a file access operating system dedicated to direct disk input/output that operates by using part of the operating system's management area. File access system. (2) The direct disk input/output-only file access operating system uses a part of the management area of the operating system as a control area for managing directory information, and a part of the file name to fix the storage location of the directory. 2. The file access system according to claim 1, wherein the file access system is used as a prime area and a file data storage area.