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When a reference that existed in the packed-refs file is deleted, the packed-refs file must be rewritten. Previously, the file was rewritten without any peeled refs, even if the file contained peeled refs when it was read. This was not a bug, because the packed-refs file header didn't claim that the file contained peeled values. But it had a performance cost, because the repository would lose the benefit of having precomputed peeled references until pack-refs was run again. Teach repack_without_ref() to write peeled refs to the packed-refs file (regardless of whether they were present in the old version of the file). This means that if the old version of the packed-refs file was not fully peeled, then repack_without_ref() will have to peel references. To avoid the expense of reading lots of loose references, we take two shortcuts relative to pack-refs: * If the peeled value of a reference is already known (i.e., because it was read from the old version of the packed-refs file), then output that peeled value again without any checks. This is the usual code path and should avoid any noticeable overhead. (This is different than pack-refs, which always re-peels references.) * We don't verify that the packed ref is still current. It could be that a packed references is overridden by a loose reference, in which case the packed ref is no longer needed and might even refer to an object that has been garbage collected. But we don't check; instead, we just try to peel all references. If peeling is successful, the peeled value is written out (even though it might not be needed any more); if not, then the reference is silently omitted from the output. The extra overhead of peeling references in repack_without_ref() should only be incurred the first time the packed-refs file is written by a version of Git that knows about the "fully-peeled" attribute. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
73 lines
2 KiB
Bash
Executable file
73 lines
2 KiB
Bash
Executable file
#!/bin/sh
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test_description='tests for the peel_ref optimization of packed-refs'
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. ./test-lib.sh
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test_expect_success 'create annotated tag in refs/tags' '
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test_commit base &&
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git tag -m annotated foo
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'
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test_expect_success 'create annotated tag outside of refs/tags' '
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git update-ref refs/outside/foo refs/tags/foo
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'
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# This matches show-ref's output
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print_ref() {
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echo "$(git rev-parse "$1") $1"
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}
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test_expect_success 'set up expected show-ref output' '
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{
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print_ref "refs/heads/master" &&
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print_ref "refs/outside/foo" &&
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print_ref "refs/outside/foo^{}" &&
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print_ref "refs/tags/base" &&
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print_ref "refs/tags/foo" &&
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print_ref "refs/tags/foo^{}"
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} >expect
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'
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test_expect_success 'refs are peeled outside of refs/tags (loose)' '
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git show-ref -d >actual &&
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test_cmp expect actual
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'
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test_expect_success 'refs are peeled outside of refs/tags (packed)' '
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git pack-refs --all &&
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git show-ref -d >actual &&
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test_cmp expect actual
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'
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test_expect_success 'create old-style pack-refs without fully-peeled' '
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# Git no longer writes without fully-peeled, so we just write our own
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# from scratch; we could also munge the existing file to remove the
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# fully-peeled bits, but that seems even more prone to failure,
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# especially if the format ever changes again. At least this way we
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# know we are emulating exactly what an older git would have written.
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{
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echo "# pack-refs with: peeled " &&
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print_ref "refs/heads/master" &&
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print_ref "refs/outside/foo" &&
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print_ref "refs/tags/base" &&
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print_ref "refs/tags/foo" &&
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echo "^$(git rev-parse "refs/tags/foo^{}")"
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} >tmp &&
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mv tmp .git/packed-refs
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'
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test_expect_success 'refs are peeled outside of refs/tags (old packed)' '
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git show-ref -d >actual &&
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test_cmp expect actual
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'
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test_expect_success 'peeled refs survive deletion of packed ref' '
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git pack-refs --all &&
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cp .git/packed-refs fully-peeled &&
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git branch yadda &&
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git pack-refs --all &&
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git branch -d yadda &&
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test_cmp fully-peeled .git/packed-refs
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'
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test_done
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