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25 lines
1.3 KiB
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25 lines
1.3 KiB
Plaintext
From the README:
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I propose this delta generator as a replacement for "diff" in applications
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where the insert/delete delta is not required. Since the copy/insert delta
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is easier to compute, it does not have to make the reduction in input size
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by breaking the file into lines. The delta generator works well on binary
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files.
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The next question is whether it is actually desirable to compute deltas
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between binary files. The answer is certainly yes, even though some binary
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file formats will not have a great degree of similarity between versions
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which were generated between minor modifications to their sources. First, I
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have evidence that some file formats (notably FrameMaker documents) work
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very well. Machine-dependant object files and executables don't work very
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well, but it is still worth doing. The reason it is still worthwhile is
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that compression takes longer than finding these deltas, so any space
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savings the delta generator produces it very likely to reduce the total
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archival time. Even if the delta generator saves no space, the total time
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well end up less than twice the time of compression. I will include some
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measurements at the end of this writing.
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Please send any comments, questions, thoughts, or interest to me,
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jmacd@cs.berkeley.edu.
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Eric. <erich@FreeBSD.org>
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