cborutil: change buffering strategy
Profiling revealed that we were spending a lot of time on the
line that was concatenating the old buffer with the incoming data
when attempting to decode long byte strings, such as manifest
revisions.
Essentially, we were feeding N chunks of size len(X) << len(Y) into
decode() and continuously allocating a new, larger buffer to hold
the undecoded input. This created substantial memory churn and
slowed down execution.
Changing the code to aggregate pending chunks in a list until we
have enough data to fully decode the next atom makes things much
more efficient.
I don't have exact data, but I recall the old code spending >1s
on manifest fulltexts from the mozilla-unified repo. The new code
doesn't significantly appear in profile output.
Differential Revision: https://phab.mercurial-scm.org/D4854
Path conflict checking is currently disabled by default because of issue5716.
Turn it on for this test.
$ cat >> $HGRCPATH << EOF
> [experimental]
> merge.checkpathconflicts=True
> EOF
$ hg init repo
$ cd repo
$ echo base > base
$ hg add base
$ hg commit -m "base"
$ hg bookmark -i base
$ mkdir a
$ echo 1 > a/b
$ hg add a/b
$ hg commit -m "file"
$ hg bookmark -i file
$ echo 2 > a/b
$ hg commit -m "file2"
$ hg bookmark -i file2
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mkdir a
#if symlink
$ ln -s c a/b
#else
$ touch a/b
#endif
$ hg add a/b
$ hg commit -m "link"
created new head
$ hg bookmark -i link
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mkdir -p a/b/c
$ echo 2 > a/b/c/d
$ hg add a/b/c/d
$ hg commit -m "dir"
created new head
$ hg bookmark -i dir
Update - local file conflicts with remote directory:
$ hg up -q 0
$ mkdir a
$ echo 9 > a/b
$ hg up dir
a/b: untracked file conflicts with directory
abort: untracked files in working directory differ from files in requested revision
[255]
$ hg up dir --config merge.checkunknown=warn
a/b: replacing untracked file
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark dir)
$ cat a/b.orig
9
$ rm a/b.orig
Update - local symlink conflicts with remote directory:
$ hg up -q 0
$ mkdir a
#if symlink
$ ln -s x a/b
#else
$ touch a/b
#endif
$ hg up dir
a/b: untracked file conflicts with directory
abort: untracked files in working directory differ from files in requested revision
[255]
$ hg up dir --config merge.checkunknown=warn
a/b: replacing untracked file
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark dir)
#if symlink
$ readlink.py a/b.orig
a/b.orig -> x
#endif
$ rm a/b.orig
Update - local directory conflicts with remote file
$ hg up -q 0
$ mkdir -p a/b/c
$ echo 9 > a/b/c/d
$ hg up file
a/b: untracked directory conflicts with file
abort: untracked files in working directory differ from files in requested revision
[255]
$ hg up file --config merge.checkunknown=warn
a/b: replacing untracked files in directory
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark file)
$ cat a/b
1
$ test -d a/b.orig
$ rm -rf a/b.orig
Update - local directory conflicts with remote symlink
$ hg up -q 0
$ mkdir -p a/b/c
$ echo 9 > a/b/c/d
$ hg up link
a/b: untracked directory conflicts with file
abort: untracked files in working directory differ from files in requested revision
[255]
$ hg up link --config merge.checkunknown=warn
a/b: replacing untracked files in directory
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark link)
#if symlink
$ readlink.py a/b
a/b -> c
#endif
$ test -d a/b.orig
$ rm -rf a/b.orig
Update - local renamed file conflicts with remote directory
$ hg up -q 0
$ hg mv base a
$ hg status -C
A a
base
R base
$ hg up --check dir
abort: uncommitted changes
[255]
$ hg up dir
a: path conflict - a file or link has the same name as a directory
the local file has been renamed to a~d20a80d4def3
resolve manually then use 'hg resolve --mark a'
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges
(activating bookmark dir)
[1]
$ hg status -C
A a~d20a80d4def3
base
R base
$ hg resolve --list
P a
$ hg up --clean -q 0
Update clean - local directory conflicts with changed remote file
$ hg up -q file
$ rm a/b
$ mkdir a/b
$ echo 9 > a/b/c
$ hg up file2 --check --config merge.checkunknown=warn
abort: uncommitted changes
[255]
$ hg up file2 --clean
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark file2)