| 摘要 |
A compression system stores meta-data in the compressed record to allow better access and manage merging data. Markers are added to the compression stream to indicate various things. Each compressed record has a marker to indicate the start of the compressed data. These markers have sector number as well as the relocation block numbers embedded in their data. A second marker is used to indicate free space. When compressed data is stored on the disk drive, free space is reserved so that future compression of the same, or modified, data has the ability to expand slightly without causing the data to be written to a different location. Also the compressed data can shrink and the remaining space can be filled in with this free space marker. A third type of marker is the format pattern marker. Compression algorithms generally compress the format pattern very tightly. However, the expectation is that the host will write useful data to the storage device. The compressor is fed typical data in the region of the format pattern, but a marker is set in front of this data to allow the format pattern to be returned rather than the typical data.
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