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
Issue586: removing remote files after merge appears to corrupt the
dirstate
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Ama
adding a
$ hg init ../b
$ cd ../b
$ echo b > b
$ hg ci -Amb
adding b
$ hg pull -f ../a
pulling from ../a
searching for changes
warning: repository is unrelated
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets cb9a9f314b8b
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg rm -f a
$ hg ci -Amc
$ hg st -A
C b
$ cd ..
Issue1433: Traceback after two unrelated pull, two move, a merge and
a commit (related to issue586)
create test repos
$ hg init repoa
$ touch repoa/a
$ hg -R repoa ci -Am adda
adding a
$ hg init repob
$ touch repob/b
$ hg -R repob ci -Am addb
adding b
$ hg init repoc
$ cd repoc
$ hg pull ../repoa
pulling from ../repoa
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 7132ab4568ac
(run 'hg update' to get a working copy)
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ mkdir tst
$ hg mv * tst
$ hg ci -m "import a in tst"
$ hg pull -f ../repob
pulling from ../repob
searching for changes
warning: repository is unrelated
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets 5ddceb349652
(run 'hg heads' to see heads, 'hg merge' to merge)
merge both repos
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ mkdir src
move b content
$ hg mv b src
$ hg ci -m "import b in src"
$ hg manifest
src/b
tst/a
$ cd ..