Mercurial > hg
view tests/filterpyflakes.py @ 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 | cf339d6ac7c7 |
children | 046a7e828ea6 |
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#!/usr/bin/env python # Filter output by pyflakes to control which warnings we check from __future__ import absolute_import, print_function import re import sys def makekey(typeandline): """ for sorting lines by: msgtype, path/to/file, lineno, message typeandline is a sequence of a message type and the entire message line the message line format is path/to/file:line: message >>> makekey((3, 'example.py:36: any message')) (3, 'example.py', 36, ' any message') >>> makekey((7, 'path/to/file.py:68: dummy message')) (7, 'path/to/file.py', 68, ' dummy message') >>> makekey((2, 'fn:88: m')) > makekey((2, 'fn:9: m')) True """ msgtype, line = typeandline fname, line, message = line.split(":", 2) # line as int for ordering 9 before 88 return msgtype, fname, int(line), message lines = [] for line in sys.stdin: # We whitelist tests (see more messages in pyflakes.messages) pats = [ (r"imported but unused", None), (r"local variable '.*' is assigned to but never used", None), (r"unable to detect undefined names", None), (r"undefined name '.*'", r"undefined name '(WindowsError|memoryview)'") ] for msgtype, (pat, excl) in enumerate(pats): if re.search(pat, line) and (not excl or not re.search(excl, line)): break # pattern matches else: continue # no pattern matched, next line fn = line.split(':', 1)[0] f = open(fn) data = f.read() f.close() if 'no-' 'check-code' in data: continue lines.append((msgtype, line)) for msgtype, line in sorted(lines, key=makekey): sys.stdout.write(line) print() # self test of "undefined name" detection for other than 'memoryview' if False: print(undefinedname)