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![Elijah Newren](/assets/img/avatar_default.png)
Commit25d5ea410f
("[PATCH] Redo rename/copy detection logic.", 2005-05-24) added a duplicate entry check on rename_src in order to avoid segfaults; the code at the time was prone to double free()s and an easy way to avoid it was just to turn off rename detection for any duplicate entries. Note that the form of the check was modified two commits ago in this series. Similarly, commit4d6be03b95
("diffcore-rename: avoid processing duplicate destinations", 2015-02-26) added a duplicate entry check on rename_dst for the exact same reason -- the code was prone to double free()s, and an easy way to avoid it was just to turn off rename detection entirely. Note that the form of the check was modified in the commit just before this one. In the original code in both places, the code was dealing with individual diff_filespecs and trying to match things up, instead of just keeping the original diff_filepairs around as we do now. The intervening change in structure has fixed the accounting problems and the associated double free()s that used to occur, and thus we already have a better fix. As such, we can remove the band-aid checks for duplicate entries. Due to the last two patches, the diffcore_rename() setup is no longer a sizeable chunk of overall runtime. Thus, in a large rebase of many commits with lots of renames and several optimizations to inexact rename detection, this patch only speeds up the overall code by about half a percent or so and is pretty close to the run-to-run variability making it hard to get an exact measurement. However, with some trace2 regions around the setup code in diffcore_rename() so that I can focus on just it, I measure that this patch consistently saves almost a third of the remaining time spent in diffcore_rename() setup. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
190 lines
5.8 KiB
Bash
Executable file
190 lines
5.8 KiB
Bash
Executable file
#!/bin/sh
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# NOTICE:
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# This testsuite does a number of diffs and checks that the output match.
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# However, it is a "garbage in, garbage out" situation; the trees have
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# duplicate entries for individual paths, and it results in diffs that do
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# not make much sense. As such, it is not clear that the diffs are
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# "correct". The primary purpose of these tests was to verify that
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# diff-tree does not segfault, but there is perhaps some value in ensuring
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# that the diff output isn't wildly unreasonable.
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test_description='test tree diff when trees have duplicate entries'
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. ./test-lib.sh
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# make_tree_entry <mode> <mode> <sha1>
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#
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# We have to rely on perl here because not all printfs understand
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# hex escapes (only octal), and xxd is not portable.
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make_tree_entry () {
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printf '%s %s\0' "$1" "$2" &&
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perl -e 'print chr(hex($_)) for ($ARGV[0] =~ /../g)' "$3"
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}
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# Like git-mktree, but without all of the pesky sanity checking.
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# Arguments come in groups of three, each group specifying a single
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# tree entry (see make_tree_entry above).
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make_tree () {
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while test $# -gt 2; do
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make_tree_entry "$1" "$2" "$3"
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shift; shift; shift
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done |
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git hash-object -w -t tree --stdin
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}
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# this is kind of a convoluted setup, but matches
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# a real-world case. Each tree contains four entries
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# for the given path, one with one sha1, and three with
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# the other. The first tree has them split across
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# two subtrees (which are themselves duplicate entries in
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# the root tree), and the second has them all in a single subtree.
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test_expect_success 'create trees with duplicate entries' '
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blob_one=$(echo one | git hash-object -w --stdin) &&
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blob_two=$(echo two | git hash-object -w --stdin) &&
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inner_one_a=$(make_tree \
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100644 inner $blob_one
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) &&
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inner_one_b=$(make_tree \
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100644 inner $blob_two \
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100644 inner $blob_two \
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100644 inner $blob_two
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) &&
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outer_one=$(make_tree \
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040000 outer $inner_one_a \
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040000 outer $inner_one_b
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) &&
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inner_two=$(make_tree \
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100644 inner $blob_one \
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100644 inner $blob_two \
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100644 inner $blob_two \
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100644 inner $blob_two
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) &&
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outer_two=$(make_tree \
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040000 outer $inner_two
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) &&
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git tag one $outer_one &&
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git tag two $outer_two
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'
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test_expect_success 'create tree without duplicate entries' '
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blob_one=$(echo one | git hash-object -w --stdin) &&
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outer_three=$(make_tree \
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100644 renamed $blob_one
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) &&
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git tag three $outer_three
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'
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test_expect_success 'diff-tree between duplicate trees' '
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# See NOTICE at top of file
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{
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printf ":000000 100644 $ZERO_OID $blob_two A\touter/inner\n" &&
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printf ":000000 100644 $ZERO_OID $blob_two A\touter/inner\n" &&
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printf ":000000 100644 $ZERO_OID $blob_two A\touter/inner\n" &&
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n"
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} >expect &&
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git diff-tree -r --no-abbrev one two >actual &&
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test_cmp expect actual
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'
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test_expect_success 'diff-tree with renames' '
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# See NOTICE at top of file.
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git diff-tree -M -r --no-abbrev one two >actual &&
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test_must_be_empty actual
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'
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test_expect_success 'diff-tree FROM duplicate tree' '
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# See NOTICE at top of file.
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{
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printf ":100644 000000 $blob_one $ZERO_OID D\touter/inner\n" &&
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
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printf ":000000 100644 $ZERO_OID $blob_one A\trenamed\n"
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} >expect &&
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git diff-tree -r --no-abbrev one three >actual &&
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test_cmp expect actual
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'
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test_expect_success 'diff-tree FROM duplicate tree, with renames' '
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# See NOTICE at top of file.
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{
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
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printf ":100644 000000 $blob_two $ZERO_OID D\touter/inner\n" &&
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printf ":100644 100644 $blob_one $blob_one R100\touter/inner\trenamed\n"
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} >expect &&
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git diff-tree -M -r --no-abbrev one three >actual &&
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test_cmp expect actual
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'
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test_expect_success 'create a few commits' '
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git commit-tree -m "Duplicate Entries" two^{tree} >commit_id &&
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git branch base $(cat commit_id) &&
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git commit-tree -p $(cat commit_id) -m "Just one" three^{tree} >up &&
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git branch update $(cat up) &&
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git commit-tree -p $(cat up) -m "Back to weird" two^{tree} >final &&
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git branch final $(cat final) &&
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rm commit_id up final
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'
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test_expect_failure 'git read-tree does not segfault' '
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test_when_finished rm .git/index.lock &&
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test_might_fail git read-tree --reset base
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'
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test_expect_failure 'reset --hard does not segfault' '
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test_when_finished rm .git/index.lock &&
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git checkout base &&
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test_might_fail git reset --hard
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'
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test_expect_failure 'git diff HEAD does not segfault' '
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git checkout base &&
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GIT_TEST_CHECK_CACHE_TREE=false &&
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git reset --hard &&
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test_might_fail git diff HEAD
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'
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test_expect_failure 'can switch to another branch when status is empty' '
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git clean -ffdqx &&
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git status --porcelain -uno >actual &&
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test_must_be_empty actual &&
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git checkout update
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'
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test_expect_success 'forcibly switch to another branch, verify status empty' '
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git checkout -f update &&
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git status --porcelain -uno >actual &&
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test_must_be_empty actual
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'
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test_expect_success 'fast-forward from non-duplicate entries to duplicate' '
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git merge final
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'
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test_expect_failure 'clean status, switch branches, status still clean' '
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git status --porcelain -uno >actual &&
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test_must_be_empty actual &&
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git checkout base &&
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git status --porcelain -uno >actual &&
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test_must_be_empty actual
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'
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test_expect_success 'switch to base branch and force status to be clean' '
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git checkout base &&
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GIT_TEST_CHECK_CACHE_TREE=false git reset --hard &&
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git status --porcelain -uno >actual &&
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test_must_be_empty actual
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'
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test_expect_failure 'fast-forward from duplicate entries to non-duplicate' '
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git merge update
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'
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test_done
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