| 摘要 |
PURPOSE:To compress the data of the data file efficiently with high compressibility by an easy method by providing a compressing means which has a record exclusive OR operation part and a record string-length compression part. CONSTITUTION:When an application program issues a compression command, a compressing process is started. An input data read-in part 2 reads data out of the input file specified with the compression command into an input buffer 7. The record EOR part 3 EORs a record taken out of the input buffer 7 with the last record held in a work buffer. When the taken-out record is the head record, this EOR process 18 bypassed. The record string-length compression part 4 performs the string-length compression of the record itself when the taken-out record is the head record or the EOR result when the record is the 2nd or succeeding record. As a result of the string-length compression, the compressed record is written in an output buffer 9. A compressed data write part 5 writes the compressed data of the output buffer 9 to a compression file 6. |
