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
$ hg init t
$ cd t
$ mkdir a
$ echo foo > a/a
$ echo bar > a/b
$ hg ci -Am "0"
adding a/a
adding a/b
$ hg co -C 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg mv a b
moving a/a to b/a
moving a/b to b/b
$ hg ci -m "1 mv a/ b/"
$ hg co -C 0
2 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ echo baz > a/c
$ echo quux > a/d
$ hg add a/c
$ hg ci -m "2 add a/c"
created new head
$ hg merge --debug 1
searching for copies back to rev 1
unmatched files in local:
a/c
unmatched files in other:
b/a
b/b
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
src: 'a/a' -> dst: 'b/a'
src: 'a/b' -> dst: 'b/b'
checking for directory renames
discovered dir src: 'a/' -> dst: 'b/'
pending file src: 'a/c' -> dst: 'b/c'
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: f9b20c0d4c51, local: ce36d17b18fb+, remote: 397f8b00a740
a/a: other deleted -> r
removing a/a
a/b: other deleted -> r
removing a/b
b/a: remote created -> g
getting b/a
b/b: remote created -> g
getting b/b
b/c: remote directory rename - move from a/c -> dm
moving a/c to b/c
3 files updated, 0 files merged, 2 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ echo a/* b/*
a/d b/a b/b b/c
$ hg st -C
M b/a
M b/b
A b/c
a/c
R a/a
R a/b
R a/c
? a/d
$ hg ci -m "3 merge 2+1"
$ hg debugrename b/c
b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88
$ hg co -C 1
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge --debug 2
searching for copies back to rev 1
unmatched files in local:
b/a
b/b
unmatched files in other:
a/c
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
src: 'a/a' -> dst: 'b/a'
src: 'a/b' -> dst: 'b/b'
checking for directory renames
discovered dir src: 'a/' -> dst: 'b/'
pending file src: 'a/c' -> dst: 'b/c'
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: f9b20c0d4c51, local: 397f8b00a740+, remote: ce36d17b18fb
starting 4 threads for background file closing (?)
b/c: local directory rename - get from a/c -> dg
getting a/c to b/c
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ echo a/* b/*
a/d b/a b/b b/c
$ hg st -C
A b/c
a/c
? a/d
$ hg ci -m "4 merge 1+2"
created new head
$ hg debugrename b/c
b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88
Local directory rename with conflicting file added in remote source directory
and untracked in local target directory.
$ hg co -qC 1
$ echo target > b/c
$ hg merge 2
b/c: untracked file differs
abort: untracked files in working directory differ from files in requested revision
[255]
$ cat b/c
target
but it should succeed if the content matches
$ hg cat -r 2 a/c > b/c
$ hg merge 2
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st -C
A b/c
a/c
? a/d
Local directory rename with conflicting file added in remote source directory
and committed in local target directory.
$ hg co -qC 1
$ echo target > b/c
$ hg add b/c
$ hg commit -qm 'new file in target directory'
$ hg merge 2
merging b/c and a/c to b/c
warning: conflicts while merging b/c! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ hg st -A
M b/c
a/c
? a/d
? b/c.orig
C b/a
C b/b
$ cat b/c
<<<<<<< working copy: f1c50ca4f127 - test: new file in target directory
target
=======
baz
>>>>>>> merge rev: ce36d17b18fb - test: 2 add a/c
$ rm b/c.orig
Remote directory rename with conflicting file added in remote target directory
and committed in local source directory.
$ hg co -qC 2
$ hg st -A
? a/d
C a/a
C a/b
C a/c
$ hg merge 5
merging a/c and b/c to b/c
warning: conflicts while merging b/c! (edit, then use 'hg resolve --mark')
2 files updated, 0 files merged, 2 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ hg st -A
M b/a
M b/b
M b/c
a/c
R a/a
R a/b
R a/c
? a/d
? b/c.orig
$ cat b/c
<<<<<<< working copy: ce36d17b18fb - test: 2 add a/c
baz
=======
target
>>>>>>> merge rev: f1c50ca4f127 - test: new file in target directory
Second scenario with two repos:
$ cd ..
$ hg init r1
$ cd r1
$ mkdir a
$ echo foo > a/f
$ hg add a
adding a/f
$ hg ci -m "a/f == foo"
$ cd ..
$ hg clone r1 r2
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd r2
$ hg mv a b
moving a/f to b/f
$ echo foo1 > b/f
$ hg ci -m" a -> b, b/f == foo1"
$ cd ..
$ cd r1
$ mkdir a/aa
$ echo bar > a/aa/g
$ hg add a/aa
adding a/aa/g
$ hg ci -m "a/aa/g"
$ hg pull ../r2
pulling from ../r2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets 7d51ed18da25
1 local changesets published
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge
2 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st -C
M b/f
A b/aa/g
a/aa/g
R a/aa/g
R a/f
$ cd ..
Test renames to separate directories
$ hg init a
$ cd a
$ mkdir a
$ touch a/s
$ touch a/t
$ hg ci -Am0
adding a/s
adding a/t
Add more files
$ touch a/s2
$ touch a/t2
$ hg ci -Am1
adding a/s2
adding a/t2
Do moves on a branch
$ hg up 0
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ mkdir s
$ mkdir t
$ hg mv a/s s
$ hg mv a/t t
$ hg ci -Am2
created new head
$ hg st --copies --change .
A s/s
a/s
A t/t
a/t
R a/s
R a/t
Merge shouldn't move s2, t2
$ hg merge
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st --copies
M a/s2
M a/t2
Try the merge in the other direction. It may or may not be appropriate for
status to list copies here.
$ hg up -C 1
4 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ hg merge
2 files updated, 0 files merged, 2 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st --copies
M s/s
M t/t
R a/s
R a/t