Mercurial > hg
view tests/test-diff-unified.t @ 30212:260af19891f2
changegroup: increase write buffer size to 128k
By default, Python defers to the operating system for choosing the
default buffer size on opened files. On my Linux machine, the default
is 4k, which is really small for 2016.
This patch bumps the write buffer size when writing
changegroups/bundles to 128k. This matches the 128k read buffer
we already use on revlogs.
It's worth noting that this only impacts when writing to an explicit
file (such as during `hg bundle`). Buffers when writing to bundle
files via the repo vfs or to a temporary file are not impacted.
When producing a none-v2 bundle file of the mozilla-unified repository,
this change caused the number of write() system calls to drop from
952,449 to 29,788. After this change, the most frequent system
calls are fstat(), read(), lseek(), and open(). There were
2,523,672 system calls after this patch (so a net decrease of
~950k is statistically significant).
This change shows no performance change on my system. But I have a
high-end system with a fast SSD. It is quite possible this change
will have a significant impact on network file systems, where
extra network round trips due to excessive I/O system calls could
introduce significant latency.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sun, 16 Oct 2016 13:35:23 -0700 |
parents | e40343ce9c4c |
children | 6381a6dbc325 |
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$ hg init repo $ cd repo $ cat > a <<EOF > c > c > a > a > b > a > a > c > c > EOF $ hg ci -Am adda adding a $ cat > a <<EOF > c > c > a > a > dd > a > a > c > c > EOF default context $ hg diff --nodates diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -2,7 +2,7 @@ c a a -b +dd a a c invalid --unified $ hg diff --nodates -U foo abort: diff context lines count must be an integer, not 'foo' [255] $ hg diff --nodates -U 2 diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -3,5 +3,5 @@ a a -b +dd a a $ hg --config diff.unified=2 diff --nodates diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -3,5 +3,5 @@ a a -b +dd a a $ hg diff --nodates -U 1 diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -4,3 +4,3 @@ a -b +dd a invalid diff.unified $ hg --config diff.unified=foo diff --nodates abort: diff context lines count must be an integer, not 'foo' [255] noprefix config and option $ hg --config diff.noprefix=True diff --nodates diff -r cf9f4ba66af2 a --- a +++ a @@ -2,7 +2,7 @@ c a a -b +dd a a c $ hg diff --noprefix --nodates diff -r cf9f4ba66af2 a --- a +++ a @@ -2,7 +2,7 @@ c a a -b +dd a a c noprefix config disabled in plain mode, but option still enabled $ HGPLAIN=1 hg --config diff.noprefix=True diff --nodates diff -r cf9f4ba66af2 a --- a/a +++ b/a @@ -2,7 +2,7 @@ c a a -b +dd a a c $ HGPLAIN=1 hg diff --noprefix --nodates diff -r cf9f4ba66af2 a --- a +++ a @@ -2,7 +2,7 @@ c a a -b +dd a a c $ cd .. 0 lines of context hunk header matches gnu diff hunk header $ hg init diffzero $ cd diffzero $ cat > f1 << EOF > c2 > c4 > c5 > EOF $ hg commit -Am0 adding f1 $ cat > f2 << EOF > c1 > c2 > c3 > c4 > EOF $ mv f2 f1 $ hg diff -U0 --nodates diff -r 55d8ff78db23 f1 --- a/f1 +++ b/f1 @@ -0,0 +1,1 @@ +c1 @@ -1,0 +3,1 @@ +c3 @@ -3,1 +4,0 @@ -c5 $ hg diff -U0 --nodates --git diff --git a/f1 b/f1 --- a/f1 +++ b/f1 @@ -0,0 +1,1 @@ +c1 @@ -1,0 +3,1 @@ +c3 @@ -3,1 +4,0 @@ -c5 $ hg diff -U0 --nodates -p diff -r 55d8ff78db23 f1 --- a/f1 +++ b/f1 @@ -0,0 +1,1 @@ +c1 @@ -1,0 +3,1 @@ c2 +c3 @@ -3,1 +4,0 @@ c4 -c5 $ echo a > f1 $ hg ci -m movef2 Test diff headers terminating with TAB when necessary (issue3357) Regular diff --nodates, file creation $ hg mv f1 'f 1' $ echo b > 'f 1' $ hg diff --nodates 'f 1' diff -r 7574207d0d15 f 1 --- /dev/null +++ b/f 1 @@ -0,0 +1,1 @@ +b Git diff, adding space $ hg diff --git diff --git a/f1 b/f 1 rename from f1 rename to f 1 --- a/f1 +++ b/f 1 @@ -1,1 +1,1 @@ -a +b Git diff with noprefix $ hg --config diff.noprefix=True diff --git --nodates diff --git f1 f 1 rename from f1 rename to f 1 --- f1 +++ f 1 @@ -1,1 +1,1 @@ -a +b noprefix config disabled in plain mode, but option still enabled $ HGPLAIN=1 hg --config diff.noprefix=True diff --git --nodates diff --git a/f1 b/f 1 rename from f1 rename to f 1 --- a/f1 +++ b/f 1 @@ -1,1 +1,1 @@ -a +b $ HGPLAIN=1 hg diff --git --noprefix --nodates diff --git f1 f 1 rename from f1 rename to f 1 --- f1 +++ f 1 @@ -1,1 +1,1 @@ -a +b Regular diff --nodates, file deletion $ hg ci -m addspace $ hg mv 'f 1' f1 $ echo a > f1 $ hg diff --nodates 'f 1' diff -r ca50fe67c9c7 f 1 --- a/f 1 +++ /dev/null @@ -1,1 +0,0 @@ -b Git diff, removing space $ hg diff --git diff --git a/f 1 b/f1 rename from f 1 rename to f1 --- a/f 1 +++ b/f1 @@ -1,1 +1,1 @@ -b +a showfunc diff $ cat > f1 << EOF > int main() { > int a = 0; > int b = 1; > int c = 2; > int d = 3; > return a + b + c + d; > } > EOF $ hg commit -m addfunction $ cat > f1 << EOF > int main() { > int a = 0; > int b = 1; > int c = 2; > int e = 3; > return a + b + c + e; > } > EOF $ hg diff --git diff --git a/f1 b/f1 --- a/f1 +++ b/f1 @@ -2,6 +2,6 @@ int a = 0; int b = 1; int c = 2; - int d = 3; - return a + b + c + d; + int e = 3; + return a + b + c + e; } $ hg diff --config diff.showfunc=True --git diff --git a/f1 b/f1 --- a/f1 +++ b/f1 @@ -2,6 +2,6 @@ int main() { int a = 0; int b = 1; int c = 2; - int d = 3; - return a + b + c + d; + int e = 3; + return a + b + c + e; } If [diff] git is set to true, but the user says --no-git, we should *not* get git diffs $ hg diff --nodates --config diff.git=1 --no-git diff -r f2c7c817fa55 f1 --- a/f1 +++ b/f1 @@ -2,6 +2,6 @@ int a = 0; int b = 1; int c = 2; - int d = 3; - return a + b + c + d; + int e = 3; + return a + b + c + e; } $ cd ..