Mercurial > hg
view tests/test-diff-ignore-whitespace.t @ 35793:4fb2bb61597c
bundle2: increase payload part chunk size to 32kb
Bundle2 payload parts are framed chunks. Esentially, we obtain
data in equal size chunks of size `preferedchunksize` and emit those
to a generator. That generator is fed into a compressor (which can
be the no-op compressor, which just re-emits the generator). And
the output from the compressor likely goes to a file descriptor
or socket.
What this means is that small chunk sizes create more Python objects
and Python function calls than larger chunk sizes. And as we know,
Python object and function call overhead in performance sensitive
code matters (at least with CPython).
This commit increases the bundle2 part payload chunk size from 4k
to 32k. Practically speaking, this means that the chunks we feed
into a compressor (implemented in C code) or feed directly into a
file handle or socket write() are larger. It's possible the chunks
might be larger than what the receiver can handle in one logical
operation. But at that point, we're in C code, which is much more
efficient at dealing with splitting up the chunk and making multiple
function calls than Python is.
A downside to larger chunks is that the receiver has to wait for that
much data to arrive (either raw or from a decompressor) before it
can process the chunk. But 32kb still feels like a small buffer to
have to wait for. And in many cases, the client will convert from
8 read(4096) to 1 read(32768). That's happening in Python land. So
we cut down on the number of Python objects and function calls,
making the client faster as well. I don't think there are any
significant concerns to increasing the payload chunk size to 32kb.
The impact of this change on performance significant. Using `curl`
to obtain a stream clone bundle2 payload from a server on localhost
serving the mozilla-unified repository:
before: 20.78 user; 7.71 system; 80.5 MB/s
after: 13.90 user; 3.51 system; 132 MB/s
legacy: 9.72 user; 8.16 system; 132 MB/s
bundle2 stream clone generation is still more resource intensive than
legacy stream clone (that's likely because of the use of a
util.chunkbuffer). But the throughput is the same. We might
be in territory we're this is effectively a benchmark of the
networking stack or Python's syscall throughput.
From the client perspective, `hg clone -U --stream`:
before: 33.50 user; 7.95 system; 53.3 MB/s
after: 22.82 user; 7.33 system; 72.7 MB/s
legacy: 29.96 user; 7.94 system; 58.0 MB/s
And for `hg clone --stream` with a working directory update of
~230k files:
after: 119.55 user; 26.47 system; 0:57.08 wall
legacy: 126.98 user; 26.94 system; 1:05.56 wall
So, it appears that bundle2's stream clone is now definitively faster
than legacy stream clone!
Differential Revision: https://phab.mercurial-scm.org/D1932
| author | Gregory Szorc <gregory.szorc@gmail.com> |
|---|---|
| date | Sat, 20 Jan 2018 22:55:42 -0800 |
| parents | da07367d683b |
| children | 55c6ebd11cb9 |
line wrap: on
line source
GNU diff is the reference for all of these results. Prepare tests: $ echo '[alias]' >> $HGRCPATH $ echo 'ndiff = diff --nodates' >> $HGRCPATH $ hg init $ printf 'hello world\ngoodbye world\n' >foo $ hg ci -Amfoo -ufoo adding foo Test added blank lines: $ printf '\nhello world\n\ngoodbye world\n\n' >foo >>> two diffs showing three added lines <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ + hello world + goodbye world + $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ + hello world + goodbye world + >>> no diffs <<< $ hg ndiff -B $ hg ndiff -Bb Test added horizontal space first on a line(): $ printf '\t hello world\ngoodbye world\n' >foo >>> four diffs showing added space first on the first line <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world + hello world goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world + hello world goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world + hello world goodbye world $ hg ndiff -Bb diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world + hello world goodbye world Test added horizontal space last on a line: $ printf 'hello world\t \ngoodbye world\n' >foo >>> two diffs showing space appended to the first line <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world +hello world goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world +hello world goodbye world >>> no diffs <<< $ hg ndiff -b $ hg ndiff -Bb Test added horizontal space in the middle of a word: $ printf 'hello world\ngood bye world\n' >foo >>> four diffs showing space inserted into "goodbye" <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +good bye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +good bye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +good bye world $ hg ndiff -Bb diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +good bye world Test increased horizontal whitespace amount: $ printf 'hello world\ngoodbye\t\t \tworld\n' >foo >>> two diffs showing changed whitespace amount in the last line <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ hello world -goodbye world +goodbye world >>> no diffs <<< $ hg ndiff -b $ hg ndiff -Bb Test added blank line with horizontal whitespace: $ printf 'hello world\n \t\ngoodbye world\n' >foo >>> three diffs showing added blank line with horizontal space <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world + goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world + goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world + goodbye world >>> no diffs <<< $ hg ndiff -Bb Test added blank line with other whitespace: $ printf 'hello world\n \t\ngoodbye world \n' >foo >>> three diffs showing added blank line with other space <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world -goodbye world +hello world + +goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world -goodbye world +hello world + +goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world + goodbye world >>> no diffs <<< $ hg ndiff -Bb Test whitespace changes: $ printf 'helloworld\ngoodbye\tworld \n' >foo >>> four diffs showing changed whitespace <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world -goodbye world +helloworld +goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world -goodbye world +helloworld +goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world +helloworld goodbye world $ hg ndiff -Bb diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,2 @@ -hello world +helloworld goodbye world >>> no diffs <<< $ hg ndiff -w Test whitespace changes and blank lines: $ printf 'helloworld\n\n\n\ngoodbye\tworld \n' >foo >>> five diffs showing changed whitespace <<< $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ -hello world -goodbye world +helloworld + + + +goodbye world $ hg ndiff -B diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ -hello world -goodbye world +helloworld + + + +goodbye world $ hg ndiff -b diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ -hello world +helloworld + + + goodbye world $ hg ndiff -Bb diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ -hello world +helloworld + + + goodbye world $ hg ndiff -w diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,5 @@ hello world + + + goodbye world >>> no diffs <<< $ hg ndiff -wB Test \r (carriage return) as used in "DOS" line endings: $ printf 'hello world\r\n\r\ngoodbye\rworld\n' >foo $ hg ndiff diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world -goodbye world +hello world\r (esc) +\r (esc) +goodbye\r (no-eol) (esc) world Test \r (carriage return) as used in "DOS" line endings: $ printf 'hello world \r\n\t\ngoodbye world\n' >foo $ hg ndiff --ignore-space-at-eol diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world +\t (esc) goodbye world No completely blank lines to ignore: $ printf 'hello world\r\n\r\ngoodbye\rworld\n' >foo $ hg ndiff --ignore-blank-lines diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world -goodbye world +hello world\r (esc) +\r (esc) +goodbye\r (no-eol) (esc) world Only new line noticed: $ hg ndiff --ignore-space-change diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world +\r (esc) goodbye world $ hg ndiff --ignore-all-space diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ hello world +\r (esc) goodbye world New line not noticed when space change ignored: $ hg ndiff --ignore-blank-lines --ignore-all-space Do not ignore all newlines, only blank lines $ printf 'hello \nworld\ngoodbye world\n' > foo $ hg ndiff --ignore-blank-lines diff -r 540c40a65b78 foo --- a/foo +++ b/foo @@ -1,2 +1,3 @@ -hello world +hello +world goodbye world Test hunk offsets adjustments with --ignore-blank-lines $ hg revert -aC reverting foo $ printf '\nb\nx\nd\n' > a $ printf 'b\ny\nd\n' > b $ hg add a b $ hg ci -m add $ hg cat -r . a > b $ hg cat -r . b > a $ hg diff -B --nodates a > ../diffa $ cat ../diffa diff -r 0e66aa54f318 a --- a/a +++ b/a @@ -1,4 +1,4 @@ b -x +y d $ hg diff -B --nodates b > ../diffb $ cat ../diffb diff -r 0e66aa54f318 b --- a/b +++ b/b @@ -1,3 +1,3 @@ b -y +x d $ hg revert -aC reverting a reverting b $ hg import --no-commit ../diffa applying ../diffa $ hg revert -aC reverting a $ hg import --no-commit ../diffb applying ../diffb $ hg revert -aC reverting b