Mercurial > hg
view contrib/hgclient.py @ 27430:e240e914d226 stable
revlog: seek to end of file before writing (issue4943)
Revlogs were recently refactored to open file handles in "a+" and use a
persistent file handle for reading and writing. This drastically
reduced the number of file handles being opened.
Unfortunately, it appears that some versions of Solaris lose the file
offset when performing a write after the handle has been seeked.
The simplest workaround is to seek to EOF on files opened in a+ mode
before writing to them, which is what this patch does.
Ideally, this code would exist in the vfs layer. However, this would
require creating a proxy class for file objects in order to provide a
custom implementation of write(). This would add overhead. Since
revlogs are the only files we open in a+ mode, the one-off workaround
in revlog.py should be sufficient.
This patch appears to have little to no impact on performance on my
Linux machine.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 17 Dec 2015 17:16:02 -0800 |
parents | 24c5fd2894f8 |
children | 897a4bbd578b |
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# A minimal client for Mercurial's command server import os, sys, signal, struct, socket, subprocess, time, cStringIO def connectpipe(path=None): cmdline = ['hg', 'serve', '--cmdserver', 'pipe'] if path: cmdline += ['-R', path] server = subprocess.Popen(cmdline, stdin=subprocess.PIPE, stdout=subprocess.PIPE) return server class unixconnection(object): def __init__(self, sockpath): self.sock = sock = socket.socket(socket.AF_UNIX) sock.connect(sockpath) self.stdin = sock.makefile('wb') self.stdout = sock.makefile('rb') def wait(self): self.stdin.close() self.stdout.close() self.sock.close() class unixserver(object): def __init__(self, sockpath, logpath=None, repopath=None): self.sockpath = sockpath cmdline = ['hg', 'serve', '--cmdserver', 'unix', '-a', sockpath] if repopath: cmdline += ['-R', repopath] if logpath: stdout = open(logpath, 'a') stderr = subprocess.STDOUT else: stdout = stderr = None self.server = subprocess.Popen(cmdline, stdout=stdout, stderr=stderr) # wait for listen() while self.server.poll() is None: if os.path.exists(sockpath): break time.sleep(0.1) def connect(self): return unixconnection(self.sockpath) def shutdown(self): os.kill(self.server.pid, signal.SIGTERM) self.server.wait() def writeblock(server, data): server.stdin.write(struct.pack('>I', len(data))) server.stdin.write(data) server.stdin.flush() def readchannel(server): data = server.stdout.read(5) if not data: raise EOFError channel, length = struct.unpack('>cI', data) if channel in 'IL': return channel, length else: return channel, server.stdout.read(length) def sep(text): return text.replace('\\', '/') def runcommand(server, args, output=sys.stdout, error=sys.stderr, input=None, outfilter=lambda x: x): print '*** runcommand', ' '.join(args) sys.stdout.flush() server.stdin.write('runcommand\n') writeblock(server, '\0'.join(args)) if not input: input = cStringIO.StringIO() while True: ch, data = readchannel(server) if ch == 'o': output.write(outfilter(data)) output.flush() elif ch == 'e': error.write(data) error.flush() elif ch == 'I': writeblock(server, input.read(data)) elif ch == 'L': writeblock(server, input.readline(data)) elif ch == 'r': ret, = struct.unpack('>i', data) if ret != 0: print ' [%d]' % ret return ret else: print "unexpected channel %c: %r" % (ch, data) if ch.isupper(): return def check(func, connect=connectpipe): sys.stdout.flush() server = connect() try: return func(server) finally: server.stdin.close() server.wait()