US5276840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disk caching method for writing data from computer memory including a step of writing a plurality of physically adjacent blocks in a single I/O operation
Assignee: Wistron Corp
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Filing: 1991-03-22
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Granted: 1994-01-04
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Expires: 2011-03-22
Abstract
Abstract A method for synchronously writing data from memory to a disk drive memory device minimizes the number of actual I/O operations by writing data to disk in large chunks. The method comprises the steps of: allocating an array for saving buffer pointers; mapping the data to the disk space; allocating a buffer for each block of disk space; copying the data into the buffer; saving a pointer to the buffer in the array and then writing physically adjacent blocks to disk in one I/O operation. The method also updates and reads address blocks in the buffer pool and writes them to disk only at the end of the write request.
Inventors
- 👤 Ying-King Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:32
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G06F12/00; G06F12/02; G06F12/0223; G06F12/023; G06F12/08; G06F12/0802; G06F12/0866; G06F3/0628; G06F3/0655; G06F3/0656
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
108 words
A method for writing a given set of data in a computer system including memory, a buffer pool, and a disk having a disk space, said method comprising the steps of: allocating a data structure in memory which contains an array for saving buffer pointers; mapping the data onto the disk space; allocating a buffer from the buffer pool for each block of disk space; copying a block of the data from the memory into the buffer; saving a pointer to the buffer in the array; and writing a plurality of buffers, corresponding to physically adjacent blocks in the disk space, to the disk in one I/O operation.
Claim 2
Independent Claim
108 words
A method for writing a given set of data in a computer system including memory, a buffer pool, and a disk having a disk space, said method comprising the steps of: allocating a data structure in memory which contains an array for saving buffer pointers; mapping the data onto the disk space; allocating a buffer from the buffer pool for each block of disk space; copying a block of the data from the memory into the buffer; saving a pointer to the buffer in the array; and writing a plurality of buffers, corresponding to physically adjacent blocks in the disk space, to the disk in one I/O operation.
Claim 3
Dependent Claim
67 words
The method of claim 1, wherein the step of mapping further comprises the steps of: allocating a buffer for each address block; saving a pointer to the buffer in the array; updating the buffer for the address block using a saved buffer pointer in the array; and writing the buffer for the address block to the disk drive only once at the end of a write request.
Claim 4
Independent Claim
145 words
A method for synchronously writing data to a disk in response to a write request identifying the amount of data to be transferred to the disk, said method comprising the steps of: (a) allocating a data structure in memory which contains an array for saving buffer pointers; (b) determining a physical area of disk where a buffer of the data may be written; (c) allocating a buffer in a buffer pool for the data and corresponding to the physical area of the disk of step b; (d) copying the data from memory into the buffer allocated in the buffer pool; (e) saving a pointer to the buffer in the array; (f) repeating steps "b" through "e" for each buffer of data in the write request; and (g) writing the data stored in buffers corresponding to physically adjacent areas on the disk in one I/O operation.
Claim 5
Independent Claim
145 words
A method for synchronously writing data to a disk in response to a write request identifying the amount of data to be transferred to the disk, said method comprising the steps of: (a) allocating a data structure in memory which contains an array for saving buffer pointers; (b) determining a physical area of disk where a buffer of the data may be written; (c) allocating a buffer in a buffer pool for the data and corresponding to the physical area of the disk of step b; (d) copying the data from memory into the buffer allocated in the buffer pool; (e) saving a pointer to the buffer in the array; (f) repeating steps "b" through "e" for each buffer of data in the write request; and (g) writing the data stored in buffers corresponding to physically adjacent areas on the disk in one I/O operation.
Claim 6
Dependent Claim
23 words
The method of claim 3, further comprising the step of repeating step "g" until all buffers have been written to the disk drive.
Claim 7
Dependent Claim
25 words
The method of claim 3, further comprising the step of freeing the buffers after the data stored therein has been written to the disk drive.
Claim 8
Dependent Claim
25 words
The method of claim 3, wherein the step of determining the physical area further comprises the step of mapping data to a free disk space.
Claim 9
Dependent Claim
73 words
The method of claim 6, wherein the step of mapping further comprises the steps of: saving pointers to buffers associated with address blocks in the array; searching for an address block in the array; reading an address block from the disk only if it is not found in the array; updating the address blocks through the saved buffer pointers; and writing the buffers to disk only at the end of the write request.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-03 | 1997-07-05 | 1998-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-03 | 2001-07-05 | 2002-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-03 | 2005-07-05 | 2006-01-04 | $7700.00 | Window Closed / Lapsed |