Mercurial > hg
view tests/test-treediscovery-legacy.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 | 9261f6c1d39b |
children |
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Tests discovery against servers without getbundle support: $ cat >> $HGRCPATH <<EOF > [ui] > logtemplate="{rev} {node|short}: {desc} {branches}\n" > EOF $ cp $HGRCPATH $HGRCPATH-withcap $ CAP="getbundle known changegroupsubset bundle2" $ . "$TESTDIR/notcapable" $ cp $HGRCPATH $HGRCPATH-nocap $ cp $HGRCPATH-withcap $HGRCPATH Prep for test server without branchmap support $ CAP="branchmap" $ . "$TESTDIR/notcapable" $ cp $HGRCPATH $HGRCPATH-nocap-branchmap $ cp $HGRCPATH-withcap $HGRCPATH Setup HTTP server control: $ remote=http://localhost:$HGPORT/ $ export remote $ tstart() { > echo '[web]' > $1/.hg/hgrc > echo 'push_ssl = false' >> $1/.hg/hgrc > echo 'allow_push = *' >> $1/.hg/hgrc > cp $HGRCPATH-nocap $HGRCPATH > hg serve -R $1 -p $HGPORT -d --pid-file=hg.pid -E errors.log > cat hg.pid >> $DAEMON_PIDS > } $ tstop() { > killdaemons.py > cp $HGRCPATH-withcap $HGRCPATH > } Both are empty: $ hg init empty1 $ hg init empty2 $ tstart empty2 $ hg incoming -R empty1 $remote comparing with http://localhost:$HGPORT/ no changes found [1] $ hg outgoing -R empty1 $remote comparing with http://localhost:$HGPORT/ no changes found [1] $ hg pull -R empty1 $remote pulling from http://localhost:$HGPORT/ no changes found $ hg push -R empty1 $remote pushing to http://localhost:$HGPORT/ no changes found [1] $ tstop Base repo: $ hg init main $ cd main $ hg debugbuilddag -mo '+2:tbase @name1 +3:thead1 <tbase @name2 +4:thead2 @both /thead1 +2:tmaintip' $ hg log -G o 11 a19bfa7e7328: r11 both | o 10 8b6bad1512e1: r10 both | o 9 025829e08038: r9 both |\ | o 8 d8f638ac69e9: r8 name2 | | | o 7 b6b4d315a2ac: r7 name2 | | | o 6 6c6f5d5f3c11: r6 name2 | | | o 5 70314b29987d: r5 name2 | | o | 4 e71dbbc70e03: r4 name1 | | o | 3 2c8d5d5ec612: r3 name1 | | o | 2 a7892891da29: r2 name1 |/ o 1 0019a3b924fd: r1 | o 0 d57206cc072a: r0 $ cd .. $ tstart main Full clone: $ hg clone main full updating to branch default 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd full $ hg incoming $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ hg outgoing $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ hg pull $remote pulling from http://localhost:$HGPORT/ searching for changes no changes found $ hg push $remote pushing to http://localhost:$HGPORT/ searching for changes no changes found [1] $ cd .. Local is empty: $ cd empty1 $ hg incoming $remote --rev name1 comparing with http://localhost:$HGPORT/ abort: cannot look up remote changes; remote repository does not support the 'changegroupsubset' capability [255] $ hg incoming $remote comparing with http://localhost:$HGPORT/ 0 d57206cc072a: r0 1 0019a3b924fd: r1 2 a7892891da29: r2 name1 3 2c8d5d5ec612: r3 name1 4 e71dbbc70e03: r4 name1 5 70314b29987d: r5 name2 6 6c6f5d5f3c11: r6 name2 7 b6b4d315a2ac: r7 name2 8 d8f638ac69e9: r8 name2 9 025829e08038: r9 both 10 8b6bad1512e1: r10 both 11 a19bfa7e7328: r11 both $ hg outgoing $remote comparing with http://localhost:$HGPORT/ no changes found [1] $ hg push $remote pushing to http://localhost:$HGPORT/ no changes found [1] $ hg pull $remote pulling from http://localhost:$HGPORT/ requesting all changes adding changesets adding manifests adding file changes added 12 changesets with 24 changes to 2 files new changesets d57206cc072a:a19bfa7e7328 (run 'hg update' to get a working copy) $ hg incoming $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ cd .. Local is subset: $ cp $HGRCPATH-withcap $HGRCPATH $ hg clone main subset --rev name2 ; cd subset adding changesets adding manifests adding file changes added 6 changesets with 12 changes to 2 files new changesets d57206cc072a:d8f638ac69e9 updating to branch name2 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cp $HGRCPATH-nocap $HGRCPATH $ hg incoming $remote comparing with http://localhost:$HGPORT/ searching for changes 6 a7892891da29: r2 name1 7 2c8d5d5ec612: r3 name1 8 e71dbbc70e03: r4 name1 9 025829e08038: r9 both 10 8b6bad1512e1: r10 both 11 a19bfa7e7328: r11 both $ hg outgoing $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ hg push $remote pushing to http://localhost:$HGPORT/ searching for changes no changes found [1] $ hg pull $remote pulling from http://localhost:$HGPORT/ searching for changes adding changesets adding manifests adding file changes added 6 changesets with 12 changes to 2 files new changesets a7892891da29:a19bfa7e7328 (run 'hg update' to get a working copy) $ hg incoming $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ cd .. Remote is empty: $ tstop ; tstart empty2 $ cd main $ hg incoming $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ hg outgoing $remote comparing with http://localhost:$HGPORT/ searching for changes 0 d57206cc072a: r0 1 0019a3b924fd: r1 2 a7892891da29: r2 name1 3 2c8d5d5ec612: r3 name1 4 e71dbbc70e03: r4 name1 5 70314b29987d: r5 name2 6 6c6f5d5f3c11: r6 name2 7 b6b4d315a2ac: r7 name2 8 d8f638ac69e9: r8 name2 9 025829e08038: r9 both 10 8b6bad1512e1: r10 both 11 a19bfa7e7328: r11 both $ hg pull $remote pulling from http://localhost:$HGPORT/ searching for changes no changes found $ hg push $remote pushing to http://localhost:$HGPORT/ searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 12 changesets with 24 changes to 2 files $ hg outgoing $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ cd .. Local is superset: $ tstop $ hg clone main subset2 --rev name2 adding changesets adding manifests adding file changes added 6 changesets with 12 changes to 2 files new changesets d57206cc072a:d8f638ac69e9 updating to branch name2 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ tstart subset2 $ cd main $ hg incoming $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ hg outgoing $remote comparing with http://localhost:$HGPORT/ searching for changes 2 a7892891da29: r2 name1 3 2c8d5d5ec612: r3 name1 4 e71dbbc70e03: r4 name1 9 025829e08038: r9 both 10 8b6bad1512e1: r10 both 11 a19bfa7e7328: r11 both $ hg pull $remote pulling from http://localhost:$HGPORT/ searching for changes no changes found $ hg push $remote pushing to http://localhost:$HGPORT/ searching for changes abort: push creates new remote branches: both, name1 (use 'hg push --new-branch' to create new remote branches) [20] $ hg push $remote --new-branch pushing to http://localhost:$HGPORT/ searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 6 changesets with 12 changes to 2 files $ hg outgoing $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ cd .. Partial pull: $ tstop ; tstart main $ hg clone $remote partial --rev name2 abort: partial pull cannot be done because other repository doesn't support changegroupsubset. [255] $ hg init partial; cd partial $ hg incoming $remote --rev name2 comparing with http://localhost:$HGPORT/ abort: cannot look up remote changes; remote repository does not support the 'changegroupsubset' capability [255] $ hg pull $remote --rev name2 pulling from http://localhost:$HGPORT/ abort: partial pull cannot be done because other repository doesn't support changegroupsubset. [255] $ cd .. $ tstop Exercise pushing to server without branchmap capability $ cp $HGRCPATH-nocap-branchmap $HGRCPATH-nocap $ hg init rlocal $ cd rlocal $ echo A > A $ hg ci -Am A adding A $ cd .. $ hg clone rlocal rremote updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd rlocal $ echo B > B $ hg ci -Am B adding B $ cd .. $ tstart rremote $ cd rlocal $ hg incoming $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ hg outgoing $remote comparing with http://localhost:$HGPORT/ searching for changes 1 27547f69f254: B $ hg pull $remote pulling from http://localhost:$HGPORT/ searching for changes no changes found 1 local changesets published $ hg push $remote pushing to http://localhost:$HGPORT/ searching for changes remote: adding changesets remote: adding manifests remote: adding file changes remote: added 1 changesets with 1 changes to 1 files $ hg outgoing $remote comparing with http://localhost:$HGPORT/ searching for changes no changes found [1] $ cd .. $ tstop