Patent US5548757A successfully refreshed from Google Patents.
US5548757A
Expired / Lapsed
US
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Method and apparatus for appending information to data files, ensuring proper end-of-file indication
Assignee: Fujitsu Ltd
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Filing: 1995-05-23
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Granted: 1996-08-20
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Expires: 2015-05-23
Abstract
Abstract New data is appended to a file having a first end-of-file information at the end thereof, and even in the case where a hazardous state such as a system failure or shortage of storage area unexpectedly occurs during data write operation, the data in the file which existed before the occurrence of the hazard can be read. First, new data having a second end-of-file information at the end thereof is written subsequently to the first end-of-file information of the file, and when the writing of the new data with the second end-of-file information is completed, the first end-of-file information of the file is altered to continuation information indicating continuity of the file. Accordingly, even if the write operation unexpectedly fails due to system failure or shortage of storage area, at least one end-of-file mark exists in the file, whereby the effective last update point can be specified by the second end-of-file information.
Inventors
- 👤 Tsutoshi Matsuyama
- 👤 Hideyuki Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:11
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/004; G06F11/07; G06F11/0796; G06F11/30; G06F11/34; G06F11/3466; G06F11/3476
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
99 words
A record appending method for appending new data to a file having first end-of-file information at an end thereof, comprising the steps of: writing new data having second end-of-file information at an end thereof, subsequently to the first end-of-file information of the file, wherein the new data follows the first end-of-file information at the end of the file; and altering the first end-of-file information of the file to be continuation information indicating continuity of the file, wherein the continuation information links the new data to the file and the second end-of-file information indicates a new end of the file.
Claim 2
Dependent Claim
99 words
A record appending method for appending new data to a file having first end-of-file information at an end thereof, comprising the steps of: writing new data having second end-of-file information at an end thereof, subsequently to the first end-of-file information of the file, wherein the new data follows the first end-of-file information at the end of the file; and altering the first end-of-file information of the file to be continuation information indicating continuity of the file, wherein the continuation information links the new data to the file and the second end-of-file information indicates a new end of the file.
Claim 3
Dependent Claim
91 words
The record appending method according to claim 1, wherein said new data writing step includes receiving a record length and a record of data to be appended, creating a writing data including the record length, the record, and second end-of-file information in an output buffer in a format according to which data is to be written to the file, providing a request to write contents of the output buffer to the file, and writing the contents of the output buffer at a location of the file specified by a file pointer.
Claim 4
Dependent Claim
110 words
The record appending method according to claim 1, wherein said information altering step includes moving a file pointer backward by an amount corresponding to a length of the first end-of-file information, creating continuation information having a length equal to that of the first end-of-file information, in an output buffer, providing a request to write contents of the output buffer to the file, writing the contents of the output buffer at a location of the file specified by the file pointer, and moving the file pointer forward by an amount corresponding to the length of the continuation information plus a length of the written new data with the second end-of-file information.
Claim 5
Dependent Claim
179 words
A record appending apparatus for appending new data to a file having first end-of-file information at an end thereof, comprising: file access control means for controlling read and write operationls of information and operation of a file pointer with respect to the file; information creating means for creating a record length, a record, second end-of-file information, and continuation information to be written in the file; output buffer means for storing the record length, the record, the second end-of-file information, and the continuation information created by said information creating means according to respective write units; record information control means for detecting continuation information and a record length to identify a record when information is read from the file; input buffer means for temporarily storing any length of information read from the file; file managing means for writing the information stored in said output buffer means to the file, and for reading the information into said input buffer means; file pointer storing means for storing a data write or read position of the file; and storage means for storing the file.
Claim 6
Dependent Claim
179 words
A record appending apparatus for appending new data to a file having first end-of-file information at an end thereof, comprising: file access control means for controlling read and write operationls of information and operation of a file pointer with respect to the file; information creating means for creating a record length, a record, second end-of-file information, and continuation information to be written in the file; output buffer means for storing the record length, the record, the second end-of-file information, and the continuation information created by said information creating means according to respective write units; record information control means for detecting continuation information and a record length to identify a record when information is read from the file; input buffer means for temporarily storing any length of information read from the file; file managing means for writing the information stored in said output buffer means to the file, and for reading the information into said input buffer means; file pointer storing means for storing a data write or read position of the file; and storage means for storing the file.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-08-20 | 2000-02-19 | 2000-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-20 | 2004-02-19 | 2004-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-20 | 2008-02-19 | 2008-08-20 | $7700.00 | Window Closed / Lapsed |