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git/t/t1419-exclude-refs.sh

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refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
#!/bin/sh
test_description='test exclude_patterns functionality in main ref store'
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
TEST_PASSES_SANITIZE_LEAK=true
. ./test-lib.sh
t1419: mark test suite as files-backend specific With 59c35fac54 (refs/packed-backend.c: implement jump lists to avoid excluded pattern(s), 2023-07-10) we have implemented logic to handle excluded refs more efficiently in the "packed" ref backend. This logic allows us to skip emitting refs completely which we know to not be of any interest to the caller, which can avoid quite some allocations and object lookups. This was wired up via a new `exclude_patterns` parameter passed to the backend's ref iterator. The backend only needs to handle them on a best effort basis though, and in fact we only handle it for the "packed-refs" file, but not for loose references. Consequently, all callers must still filter emitted refs with those exclude patterns. The result is that handling exclude patterns is completely optional in the ref backend, and any future backends may or may not implement it. Let's thus mark the test for t1419 to depend on the REFFILES prereq. An alternative would be to introduce a new prereq that tells us whether the backend under test supports exclude patterns or not. But this does feel a bit overblown: - It would either map to the REFFILES prereq, in which case it feels overengineered because the prereq is only ever relevant to t1419. - Otherwise, it could auto-detect whether the backend supports exclude patterns. But this could lead to silent failures in case the support for this feature breaks at any point in time. It should thus be good enough to just use the REFFILES prereq for now. If future backends ever grow support for exclude patterns we can easily add their respective prereq as another condition for this test suite to execute. Signed-off-by: Patrick Steinhardt <ps@pks.im> Reviewed-by: Christian Couder <christian.couder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-01-29 14:07:30 +03:00
if test_have_prereq !REFFILES
then
skip_all='skipping `git for-each-ref --exclude` tests; need files backend'
test_done
fi
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref__exclude () {
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
GIT_TRACE2_PERF=1 test-tool ref-store main \
for-each-ref--exclude "$@" >actual.raw
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
cut -d ' ' -f 2 actual.raw
}
for_each_ref () {
git for-each-ref --format='%(refname)' "$@"
}
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
assert_jumps () {
local nr="$1"
local trace="$2"
grep -q "name:jumps_made value:$nr$" $trace
}
assert_no_jumps () {
! assert_jumps ".*" "$1"
}
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
test_expect_success 'setup' '
test_commit --no-tag base &&
base="$(git rev-parse HEAD)" &&
for name in foo bar baz quux
do
for i in 1 2 3
do
echo "create refs/heads/$name/$i $base" || return 1
done || return 1
done >in &&
echo "delete refs/heads/main" >>in &&
git update-ref --stdin <in &&
git pack-refs --all
'
test_expect_success 'excluded region in middle' '
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
for_each_ref__exclude refs/heads refs/heads/foo >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref refs/heads/bar refs/heads/baz refs/heads/quux >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_jumps 1 perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_expect_success 'excluded region at beginning' '
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
for_each_ref__exclude refs/heads refs/heads/bar >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref refs/heads/baz refs/heads/foo refs/heads/quux >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_jumps 1 perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_expect_success 'excluded region at end' '
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
for_each_ref__exclude refs/heads refs/heads/quux >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref refs/heads/foo refs/heads/bar refs/heads/baz >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_jumps 1 perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_expect_success 'disjoint excluded regions' '
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
for_each_ref__exclude refs/heads refs/heads/bar refs/heads/quux >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref refs/heads/baz refs/heads/foo >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_jumps 2 perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_expect_success 'adjacent, non-overlapping excluded regions' '
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
for_each_ref__exclude refs/heads refs/heads/bar refs/heads/baz >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref refs/heads/foo refs/heads/quux >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_jumps 1 perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_expect_success 'overlapping excluded regions' '
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
for_each_ref__exclude refs/heads refs/heads/ba refs/heads/baz >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref refs/heads/foo refs/heads/quux >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_jumps 1 perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_expect_success 'several overlapping excluded regions' '
for_each_ref__exclude refs/heads \
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
refs/heads/bar refs/heads/baz refs/heads/foo >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref refs/heads/quux >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_jumps 1 perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_expect_success 'non-matching excluded section' '
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
for_each_ref__exclude refs/heads refs/heads/does/not/exist >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_no_jumps perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_expect_success 'meta-characters are discarded' '
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
for_each_ref__exclude refs/heads "refs/heads/ba*" >actual 2>perf &&
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
for_each_ref >expect &&
refs/packed-backend.c: add trace2 counters for jump list The previous commit added low-level tests to ensure that the packed-refs iterator did not enumerate excluded sections of the refspace. However, there was no guarantee that these sections weren't being visited, only that they were being suppressed from the output. To harden these tests, add a trace2 counter which tracks the number of regions skipped by the packed-refs iterator, and assert on its value. Suggested-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:31 +03:00
test_cmp expect actual &&
assert_no_jumps perf
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s) When iterating through the `packed-refs` file in order to answer a query like: $ git for-each-ref --exclude=refs/__hidden__ it would be useful to avoid walking over all of the entries in `refs/__hidden__/*` when possible, since we know that the ref-filter code is going to throw them away anyways. In certain circumstances, doing so is possible. The algorithm for doing so is as follows: - For each excluded pattern, find the first record that matches it, and the first record that *doesn't* match it (i.e. the location you'd next want to consider when excluding that pattern). - Sort the set of excluded regions from the previous step in ascending order of the first location within the `packed-refs` file that matches. - Clean up the results from the previous step: discard empty regions, and combine adjacent regions. The set of regions which remains is referred to as the "jump list", and never contains any references which should be included in the result set. Then when iterating through the `packed-refs` file, if `iter->pos` is ever contained in one of the regions from the previous steps, advance `iter->pos` past the end of that region, and continue enumeration. Note that we only perform this optimization when none of the excluded pattern(s) have special meta-characters in them. For a pattern like "refs/foo[ac]", the excluded regions ("refs/fooa", "refs/fooc", and everything underneath them) are not connected. A future implementation that handles this case may split the character class (pretending as if two patterns were excluded: "refs/fooa", and "refs/fooc"). There are a few other gotchas worth considering. First, note that the jump list is sorted, so once we jump past a region, we can avoid considering it (or any regions preceding it) again. The member `jump_pos` is used to track the first next-possible region to jump through. Second, note that the jump list is best-effort, since we do not handle loose references, and because of the meta-character issue above. The jump list may not skip past all references which won't appear in the results, but will never skip over a reference which does appear in the result set. In repositories with a large number of hidden references, the speed-up can be significant. Tests here are done with a copy of linux.git with a reference "refs/pull/N" pointing at every commit, as in: $ git rev-list HEAD | awk '{ print "create refs/pull/" NR " " $0 }' | git update-ref --stdin $ git pack-refs --all , it is significantly faster to have `for-each-ref` jump over the excluded references, as opposed to filtering them out after the fact: $ hyperfine \ 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' \ 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' \ 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' Benchmark 1: git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/" Time (mean ± σ): 798.1 ms ± 3.3 ms [User: 687.6 ms, System: 146.4 ms] Range (min … max): 794.5 ms … 805.5 ms 10 runs Benchmark 2: git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 98.9 ms ± 1.4 ms [User: 93.1 ms, System: 5.7 ms] Range (min … max): 97.0 ms … 104.0 ms 29 runs Benchmark 3: git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull" Time (mean ± σ): 4.5 ms ± 0.2 ms [User: 0.7 ms, System: 3.8 ms] Range (min … max): 4.1 ms … 5.8 ms 524 runs Summary 'git.compile for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' ran 21.87 ± 1.05 times faster than 'git.prev for-each-ref --format="%(objectname) %(refname)" --exclude="refs/pull"' 176.52 ± 8.19 times faster than 'git for-each-ref --format="%(objectname) %(refname)" | grep -vE "^[0-9a-f]{40} refs/pull/"' (Comparing stock git and this patch isn't quite fair, since an earlier commit in this series adds a naive implementation of the `--exclude` option. `git.prev` is built from the previous commit and includes this naive implementation). Using the jump list is fairly straightforward (see the changes to `refs/packed-backend.c::next_record()`), but constructing the list is not. To ensure that the construction is correct, add a new suite of tests in t1419 covering various corner cases (overlapping regions, partially overlapping regions, adjacent regions, etc.). Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-11 00:12:28 +03:00
'
test_done