mirror of
https://github.com/git/git
synced 2024-08-27 03:29:21 +00:00
94fcf0e852
Add a performance test comparing the execution times of 'prime_cache_tree()' and 'cache_tree_update(_, WRITE_TREE_SILENT | WRITE_TREE_REPAIR)'. The goal of comparing these two is to identify which is the faster method for rebuilding an invalid cache tree, ultimately to remove one when both are (reundantly) called in immediate succession. Both methods are fast, so the new tests in 'p0090-cache-tree.sh' must call each tested function multiple times to ensure the reported times (to 0.01s resolution) convey the differences between them. The tests compare the timing of a 'test-tool cache-tree' run as a no-op (to capture a baseline for the overhead associated with running the tool), 'cache_tree_update()', and 'prime_cache_tree()' on four scenarios: - A completely valid cache tree - A cache tree with 2 invalid paths - A cache tree with 50 invalid paths - A completely empty cache tree Example results: Test this tree ----------------------------------------------------------- 0090.2: no-op, clean 1.27(0.48+0.52) 0090.3: prime_cache_tree, clean 2.02(0.83+0.85) 0090.4: cache_tree_update, clean 1.30(0.49+0.54) 0090.5: no-op, invalidate 2 1.29(0.48+0.54) 0090.6: prime_cache_tree, invalidate 2 1.98(0.81+0.83) 0090.7: cache_tree_update, invalidate 2 2.12(0.94+0.86) 0090.8: no-op, invalidate 50 1.32(0.50+0.55) 0090.9: prime_cache_tree, invalidate 50 2.10(0.86+0.89) 0090.10: cache_tree_update, invalidate 50 2.35(1.14+0.90) 0090.11: no-op, empty 1.33(0.50+0.54) 0090.12: prime_cache_tree, empty 2.04(0.84+0.87) 0090.13: cache_tree_update, empty 2.51(1.27+0.92) These timings show that, while 'cache_tree_update()' is faster when the cache tree is completely valid, it is equal to or slower than 'prime_cache_tree()' when there are any invalid paths. Since the redundant calls are mostly in scenarios where the cache tree will be at least partially invalid (e.g., 'git reset --hard'), 'prime_cache_tree()' will likely perform better than 'cache_tree_update()' in typical cases. Helped-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Victoria Dye <vdye@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>
37 lines
770 B
Bash
Executable file
37 lines
770 B
Bash
Executable file
#!/bin/sh
|
|
|
|
test_description="Tests performance of cache tree update operations"
|
|
|
|
. ./perf-lib.sh
|
|
|
|
test_perf_large_repo
|
|
test_checkout_worktree
|
|
|
|
count=100
|
|
|
|
test_expect_success 'setup cache tree' '
|
|
git write-tree
|
|
'
|
|
|
|
test_cache_tree () {
|
|
test_perf "$1, $3" "
|
|
for i in \$(test_seq $count)
|
|
do
|
|
test-tool cache-tree $4 $2
|
|
done
|
|
"
|
|
}
|
|
|
|
test_cache_tree_update_functions () {
|
|
test_cache_tree 'no-op' 'control' "$1" "$2"
|
|
test_cache_tree 'prime_cache_tree' 'prime' "$1" "$2"
|
|
test_cache_tree 'cache_tree_update' 'update' "$1" "$2"
|
|
}
|
|
|
|
test_cache_tree_update_functions "clean" ""
|
|
test_cache_tree_update_functions "invalidate 2" "--invalidate 2"
|
|
test_cache_tree_update_functions "invalidate 50" "--invalidate 50"
|
|
test_cache_tree_update_functions "empty" "--empty"
|
|
|
|
test_done
|