Mercurial > hg
view tests/test-no-symlinks.t @ 49568:da48f170d203
rust-status: query fs traversal metadata lazily
Currently, any time the status algorithm needs to read a directory from the
filesystem (because the stat-only optimization is not available), it also
stats each directory entry eagerly.
Stat'ing the entries is only needed in a few cases (like when checking
the mtime of a directory for caching): this patch creates a wrapper struct
`DirEntry` that only stats the directory entry it represents when needed.
Excerpt of an `strace` before this change on Mozilla Central:
```
openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3
newfstatat(3, "", {st_mode=S_IFDIR|0755, st_size=3540, ...}, AT_EMPTY_PATH) = 0
getdents64(3, 0x55dc970bd440 /* 139 entries */, 32768) = 5072
statx(3, ".hg", AT_STATX_SYNC_AS_STAT|AT_SYMLINK_NOFOLLOW, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFDIR|0755, stx_size=772, ...}) = 0
[... 135 other successful `statx` calls]
getdents64(3, 0x55dc970bd440 /* 0 entries */, 32768) = 0
close(3) = 0
```
After this change:
```
openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3
newfstatat(3, "", {st_mode=S_IFDIR|0755, st_size=3540, ...}, AT_EMPTY_PATH) = 0
getdents64(3, 0x561567c10190 /* 139 entries */, 32768) = 5072
getdents64(3, 0x561567c10190 /* 0 entries */, 32768) = 0
close(3) = 0
```
author | Raphaël Gomès <rgomes@octobus.net> |
---|---|
date | Wed, 19 Oct 2022 12:38:06 +0200 |
parents | 0612e4c6fda0 |
children |
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#require no-symlink # The following script was used to create the bundle: # # hg init symlinks # cd symlinks # echo a > a # mkdir d # echo b > d/b # ln -s a a.lnk # ln -s d/b d/b.lnk # hg ci -Am t # hg bundle --base null ../test-no-symlinks.hg Extract a symlink on a platform not supporting them $ hg init t $ cd t $ hg pull -q "$TESTDIR/bundles/test-no-symlinks.hg" $ hg update 4 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cat a.lnk && echo a $ cat d/b.lnk && echo d/b Copy a symlink and move another $ hg copy a.lnk d/a2.lnk $ hg mv d/b.lnk b2.lnk $ hg ci -Am copy $ cat d/a2.lnk && echo a $ cat b2.lnk && echo d/b Bundle and extract again $ hg bundle --base null ../symlinks.hg 2 changesets found $ cd .. $ hg init t2 $ cd t2 $ hg pull ../symlinks.hg pulling from ../symlinks.hg requesting all changes adding changesets adding manifests adding file changes added 2 changesets with 6 changes to 6 files new changesets d326ae2d01ee:71d85cf3ba90 (2 drafts) (run 'hg update' to get a working copy) $ hg update 5 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cat a.lnk && echo a $ cat d/a2.lnk && echo a $ cat b2.lnk && echo d/b