Mercurial > hg
view tests/test-merge1.t @ 47965:f9e6f2bb721d
rhg: Don’t compare ambiguous files one byte at a time
Even though the use of `BufReader` reduces the number of syscalls to read
the file from disk, `.bytes()` yields a separate `Result` for every byte.
Creating those results and dispatching on them is most likely costly.
Instead, this commit opts for simplicity by reading the entire file into memory
and comparing a single pair of byte strings. Note that memory already needs to
contain the entire previous contents of the file, as read from the filelog.
So with an extremely large file this doubles memory use but does not make it
grow by orders of magnitude.
At first I wrote code that still avoids reading the entire file into memory
and compares one buffer at a time with `BufReader`. Find this code below for
posterity. However its correctness is subtle. I ended up preferring the
simplicity of the obviously-correct single comparison.
```rust
let mut reader = BufReader::new(fobj);
let mut expected = &contents_in_p1[..];
loop {
let buf = reader.fill_buf().when_reading_file(&fs_path)?;
if buf.is_empty() {
// Found EOF
return Ok(expected.is_empty());
} else if let Some(rest) = expected.drop_prefix(buf) {
// What we read so far matches the expected content, continue reading
let buf_len = buf.len();
reader.consume(buf_len);
expected = rest
} else {
// Found different content
return Ok(false);
}
}
```
Differential Revision: https://phab.mercurial-scm.org/D11412
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Mon, 13 Sep 2021 18:48:48 +0200 |
parents | dc00324e80f4 |
children | 434de12918fd |
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$ cat <<EOF > merge > from __future__ import print_function > import sys, os > > try: > import msvcrt > msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) > msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY) > except ImportError: > pass > > print("merging for", os.path.basename(sys.argv[1])) > EOF $ HGMERGE="\"$PYTHON\" ../merge"; export HGMERGE $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ hg update 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test interrupted updates by having a non-empty dir with the same name as one of the files in a commit we're updating to $ mkdir b && touch b/nonempty $ hg up abort: Unlinking directory not permitted: *$TESTTMP/t/b* (glob) (windows !) abort: Directory not empty: '?\$TESTTMP/t/b'? (re) (no-windows !) [255] $ hg ci abort: last update was interrupted (use 'hg update' to get a consistent checkout) [20] $ hg sum parent: 0:538afb845929 commit #0 branch: default commit: 1 unknown (interrupted update) update: 1 new changesets (update) phases: 2 draft Detect interrupted update by hg status --verbose $ hg status -v ? b/nonempty # The repository is in an unfinished *update* state. # To continue: hg update . $ rm b/nonempty $ hg up 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg sum parent: 1:b8bb4a988f25 tip commit #1 branch: default commit: (clean) update: (current) phases: 2 draft Prepare a basic merge $ hg up 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #2" created new head $ echo This is file b1 > b no merges expected $ hg merge -P 1 changeset: 1:b8bb4a988f25 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: commit #1 $ hg merge 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 49035e18a8e6 b --- /dev/null +++ b/b @@ -0,0 +1,1 @@ +This is file b1 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ hg update 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #2" created new head $ echo This is file b2 > b merge should fail $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] #if symlink symlinks to directories should be treated as regular files (issue5027) $ rm b $ ln -s 'This is file b2' b $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] symlinks shouldn't be followed $ rm b $ echo This is file b1 > .hg/b $ ln -s .hg/b b $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ rm b $ echo This is file b2 > b #endif bad config $ hg merge 1 --config merge.checkunknown=x config error: merge.checkunknown not valid ('x' is none of 'abort', 'ignore', 'warn') [30] this merge should fail $ hg merge 1 --config merge.checkunknown=abort b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] this merge should warn $ hg merge 1 --config merge.checkunknown=warn b: replacing untracked file 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat b.orig This is file b2 $ hg up --clean 2 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ mv b.orig b this merge should silently ignore $ cat b This is file b2 $ hg merge 1 --config merge.checkunknown=ignore 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) merge.checkignored $ hg up --clean 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ cat >> .hgignore << EOF > remoteignored > EOF $ echo This is file localignored3 > localignored $ echo This is file remoteignored3 > remoteignored $ hg add .hgignore localignored remoteignored $ hg commit -m "commit #3" $ hg up 2 1 files updated, 0 files merged, 4 files removed, 0 files unresolved $ cat >> .hgignore << EOF > localignored > EOF $ hg add .hgignore $ hg commit -m "commit #4" remote .hgignore shouldn't be used for determining whether a file is ignored $ echo This is file remoteignored4 > remoteignored $ hg merge 3 --config merge.checkignored=ignore --config merge.checkunknown=abort remoteignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=ignore merging .hgignore merging for .hgignore 3 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat remoteignored This is file remoteignored3 $ cat remoteignored.orig This is file remoteignored4 $ rm remoteignored.orig local .hgignore should be used for that $ hg up --clean 4 1 files updated, 0 files merged, 3 files removed, 0 files unresolved $ echo This is file localignored4 > localignored also test other conflicting files to see we output the full set of warnings $ echo This is file b2 > b $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=abort b: untracked file differs localignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=ignore localignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ hg merge 3 --config merge.checkignored=warn --config merge.checkunknown=abort b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ hg merge 3 --config merge.checkignored=warn --config merge.checkunknown=warn b: replacing untracked file localignored: replacing untracked file merging .hgignore merging for .hgignore 3 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat localignored This is file localignored3 $ cat localignored.orig This is file localignored4 $ rm localignored.orig $ cat b.orig This is file b2 $ hg up --clean 2 0 files updated, 0 files merged, 4 files removed, 0 files unresolved $ mv b.orig b this merge of b should work $ cat b This is file b2 $ hg merge -f 1 merging b merging for b 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 49035e18a8e6 b --- /dev/null +++ b/b @@ -0,0 +1,1 @@ +This is file b2 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ echo This is file b22 > b $ hg commit -m "commit #2" $ hg update 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #3" created new head Contents of b should be "this is file b1" $ cat b This is file b1 $ echo This is file b22 > b merge fails $ hg merge 2 abort: uncommitted changes (use 'hg status' to list changes) [20] merge expected! $ hg merge -f 2 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 85de557015a8 b --- a/b +++ b/b @@ -1,1 +1,1 @@ -This is file b1 +This is file b22 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ echo This is file b22 > b $ hg commit -m "commit #2" $ hg update 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #3" created new head $ echo This is file b33 > b merge of b should fail $ hg merge 2 abort: uncommitted changes (use 'hg status' to list changes) [20] merge of b expected $ hg merge -f 2 merging b merging for b 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 85de557015a8 b --- a/b +++ b/b @@ -1,1 +1,1 @@ -This is file b1 +This is file b33 $ hg status M b Test for issue2364 $ hg up -qC . $ hg rm b $ hg ci -md $ hg revert -r -2 b $ hg up -q -- -2 Test that updated files are treated as "modified", when 'merge.update()' is aborted before 'merge.recordupdates()' (= parents aren't changed), even if none of mode, size and timestamp of them isn't changed on the filesystem (see also issue4583). $ cat > $TESTTMP/abort.py <<EOF > from __future__ import absolute_import > # emulate aborting before "recordupdates()". in this case, files > # are changed without updating dirstate > from mercurial import ( > error, > extensions, > merge, > ) > def applyupdates(orig, *args, **kwargs): > orig(*args, **kwargs) > raise error.Abort(b'intentional aborting') > def extsetup(ui): > extensions.wrapfunction(merge, "applyupdates", applyupdates) > EOF $ cat >> .hg/hgrc <<EOF > [fakedirstatewritetime] > # emulate invoking dirstate.write() via repo.status() > # at 2000-01-01 00:00 > fakenow = 200001010000 > EOF (file gotten from other revision) $ hg update -q -C 2 $ echo 'THIS IS FILE B5' > b $ hg commit -m 'commit #5' $ hg update -q -C 3 $ cat b This is file b1 $ touch -t 200001010000 b $ hg debugrebuildstate $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = $TESTDIR/fakedirstatewritetime.py > abort = $TESTTMP/abort.py > EOF $ hg merge 5 abort: intentional aborting [255] $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = ! > abort = ! > EOF $ cat b THIS IS FILE B5 $ touch -t 200001010000 b $ hg status -A b M b (file merged from other revision) $ hg update -q -C 3 $ echo 'this is file b6' > b $ hg commit -m 'commit #6' created new head $ cat b this is file b6 $ touch -t 200001010000 b $ hg debugrebuildstate $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = $TESTDIR/fakedirstatewritetime.py > abort = $TESTTMP/abort.py > EOF $ hg merge --tool internal:other 5 abort: intentional aborting [255] $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = ! > abort = ! > EOF $ cat b THIS IS FILE B5 $ touch -t 200001010000 b $ hg status -A b M b $ cd ..