Mercurial > hg
view hgext/convert/p4.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 | a0939666b836 |
children | fa2d2c8ac398 |
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# Perforce source for convert extension. # # Copyright 2009, Frank Kingswood <frank@kingswood-consulting.co.uk> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import marshal import re from mercurial.i18n import _ from mercurial import ( error, util, ) from . import common def loaditer(f): "Yield the dictionary objects generated by p4" try: while True: d = marshal.load(f) if not d: break yield d except EOFError: pass def decodefilename(filename): """Perforce escapes special characters @, #, *, or % with %40, %23, %2A, or %25 respectively >>> decodefilename('portable-net45%252Bnetcore45%252Bwp8%252BMonoAndroid') 'portable-net45%2Bnetcore45%2Bwp8%2BMonoAndroid' >>> decodefilename('//Depot/Directory/%2525/%2523/%23%40.%2A') '//Depot/Directory/%25/%23/#@.*' """ replacements = [('%2A', '*'), ('%23', '#'), ('%40', '@'), ('%25', '%')] for k, v in replacements: filename = filename.replace(k, v) return filename class p4_source(common.converter_source): def __init__(self, ui, path, revs=None): # avoid import cycle from . import convcmd super(p4_source, self).__init__(ui, path, revs=revs) if "/" in path and not path.startswith('//'): raise common.NoRepo(_('%s does not look like a P4 repository') % path) common.checktool('p4', abort=False) self.p4changes = {} self.heads = {} self.changeset = {} self.files = {} self.copies = {} self.tags = {} self.lastbranch = {} self.parent = {} self.encoding = self.ui.config('convert', 'p4.encoding', default=convcmd.orig_encoding) self.depotname = {} # mapping from local name to depot name self.localname = {} # mapping from depot name to local name self.re_type = re.compile( "([a-z]+)?(text|binary|symlink|apple|resource|unicode|utf\d+)" "(\+\w+)?$") self.re_keywords = re.compile( r"\$(Id|Header|Date|DateTime|Change|File|Revision|Author)" r":[^$\n]*\$") self.re_keywords_old = re.compile("\$(Id|Header):[^$\n]*\$") if revs and len(revs) > 1: raise error.Abort(_("p4 source does not support specifying " "multiple revisions")) self._parse(ui, path) def _parse_view(self, path): "Read changes affecting the path" cmd = 'p4 -G changes -s submitted %s' % util.shellquote(path) stdout = util.popen(cmd, mode='rb') for d in loaditer(stdout): c = d.get("change", None) if c: self.p4changes[c] = True def _parse(self, ui, path): "Prepare list of P4 filenames and revisions to import" ui.status(_('reading p4 views\n')) # read client spec or view if "/" in path: self._parse_view(path) if path.startswith("//") and path.endswith("/..."): views = {path[:-3]:""} else: views = {"//": ""} else: cmd = 'p4 -G client -o %s' % util.shellquote(path) clientspec = marshal.load(util.popen(cmd, mode='rb')) views = {} for client in clientspec: if client.startswith("View"): sview, cview = clientspec[client].split() self._parse_view(sview) if sview.endswith("...") and cview.endswith("..."): sview = sview[:-3] cview = cview[:-3] cview = cview[2:] cview = cview[cview.find("/") + 1:] views[sview] = cview # list of changes that affect our source files self.p4changes = self.p4changes.keys() self.p4changes.sort(key=int) # list with depot pathnames, longest first vieworder = views.keys() vieworder.sort(key=len, reverse=True) # handle revision limiting startrev = self.ui.config('convert', 'p4.startrev', default=0) self.p4changes = [x for x in self.p4changes if ((not startrev or int(x) >= int(startrev)) and (not self.revs or int(x) <= int(self.revs[0])))] # now read the full changelists to get the list of file revisions ui.status(_('collecting p4 changelists\n')) lastid = None for change in self.p4changes: cmd = "p4 -G describe -s %s" % change stdout = util.popen(cmd, mode='rb') d = marshal.load(stdout) desc = self.recode(d.get("desc", "")) shortdesc = desc.split("\n", 1)[0] t = '%s %s' % (d["change"], repr(shortdesc)[1:-1]) ui.status(util.ellipsis(t, 80) + '\n') if lastid: parents = [lastid] else: parents = [] date = (int(d["time"]), 0) # timezone not set c = common.commit(author=self.recode(d["user"]), date=util.datestr(date, '%Y-%m-%d %H:%M:%S %1%2'), parents=parents, desc=desc, branch=None, extra={"p4": change}) files = [] copies = {} copiedfiles = [] i = 0 while ("depotFile%d" % i) in d and ("rev%d" % i) in d: oldname = d["depotFile%d" % i] filename = None for v in vieworder: if oldname.lower().startswith(v.lower()): filename = decodefilename(views[v] + oldname[len(v):]) break if filename: files.append((filename, d["rev%d" % i])) self.depotname[filename] = oldname if (d.get("action%d" % i) == "move/add"): copiedfiles.append(filename) self.localname[oldname] = filename i += 1 # Collect information about copied files for filename in copiedfiles: oldname = self.depotname[filename] flcmd = 'p4 -G filelog %s' \ % util.shellquote(oldname) flstdout = util.popen(flcmd, mode='rb') copiedfilename = None for d in loaditer(flstdout): copiedoldname = None i = 0 while ("change%d" % i) in d: if (d["change%d" % i] == change and d["action%d" % i] == "move/add"): j = 0 while ("file%d,%d" % (i, j)) in d: if d["how%d,%d" % (i, j)] == "moved from": copiedoldname = d["file%d,%d" % (i, j)] break j += 1 i += 1 if copiedoldname and copiedoldname in self.localname: copiedfilename = self.localname[copiedoldname] break if copiedfilename: copies[filename] = copiedfilename else: ui.warn(_("cannot find source for copied file: %s@%s\n") % (filename, change)) self.changeset[change] = c self.files[change] = files self.copies[change] = copies lastid = change if lastid: self.heads = [lastid] def getheads(self): return self.heads def getfile(self, name, rev): cmd = 'p4 -G print %s' \ % util.shellquote("%s#%s" % (self.depotname[name], rev)) lasterror = None while True: stdout = util.popen(cmd, mode='rb') mode = None contents = [] keywords = None for d in loaditer(stdout): code = d["code"] data = d.get("data") if code == "error": # if this is the first time error happened # re-attempt getting the file if not lasterror: lasterror = IOError(d["generic"], data) # this will exit inner-most for-loop break else: raise lasterror elif code == "stat": action = d.get("action") if action in ["purge", "delete", "move/delete"]: return None, None p4type = self.re_type.match(d["type"]) if p4type: mode = "" flags = ((p4type.group(1) or "") + (p4type.group(3) or "")) if "x" in flags: mode = "x" if p4type.group(2) == "symlink": mode = "l" if "ko" in flags: keywords = self.re_keywords_old elif "k" in flags: keywords = self.re_keywords elif code == "text" or code == "binary": contents.append(data) lasterror = None if not lasterror: break if mode is None: return None, None contents = ''.join(contents) if keywords: contents = keywords.sub("$\\1$", contents) if mode == "l" and contents.endswith("\n"): contents = contents[:-1] return contents, mode def getchanges(self, rev, full): if full: raise error.Abort(_("convert from p4 does not support --full")) return self.files[rev], self.copies[rev], set() def getcommit(self, rev): return self.changeset[rev] def gettags(self): return self.tags def getchangedfiles(self, rev, i): return sorted([x[0] for x in self.files[rev]])