25 lines
1.2 KiB
Markdown
25 lines
1.2 KiB
Markdown
`git-annex unused` has to compare large sets of data
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(all keys with content present in the repository,
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with all keys used by files in the repository), and so
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uses more memory than git-annex typically needs; around
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60-80 mb when run in a repository with 80 thousand files.
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I would like to reduce this. One idea is to use a bloom filter.
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For example, construct a bloom filter of all keys used by files in
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the repository. Then for each key with content present, check if it's
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in the bloom filter. Since there can be false negatives, this might
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miss finding some unused keys. The probability/size of filter
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could be tunable.
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Another way might be to scan the git log for files that got removed
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or changed what key they pointed to. Correlate with keys with content
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currently present in the repository (possibly using a bloom filter again),
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and that would yield a shortlist of keys that are probably not used.
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Then scan thru all files in the repo to make sure that none point to keys
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on the shortlist.
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----
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`git annex unused --from remote` is much worse, using hundreds of mb of
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memory. It has not been profiled at all yet, and can probably be improved
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somewhat by fixing whatever memory leak it (probably) has.
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