store: speed up read and write of large fncache files
In my tests of an fncache containing 300,000 entries, this improves
read time from 567ms to 307, and write time from 1328ms to 533.
These numbers aren't so great, since the fncache file is only 17MB
in size, but they're an improvement.
--- a/mercurial/store.py Thu Apr 12 15:21:52 2012 -0700
+++ b/mercurial/store.py Thu Apr 12 15:21:54 2012 -0700
@@ -317,36 +317,36 @@
def _load(self):
'''fill the entries from the fncache file'''
- self.entries = set()
self._dirty = False
try:
fp = self.opener('fncache', mode='rb')
except IOError:
# skip nonexistent file
+ self.entries = set()
return
- for n, line in enumerate(fp):
- if (len(line) < 2) or (line[-1] != '\n'):
- t = _('invalid entry in fncache, line %s') % (n + 1)
- raise util.Abort(t)
- self.entries.add(decodedir(line[:-1]))
+ self.entries = set(map(decodedir, fp.read().splitlines()))
+ if '' in self.entries:
+ fp.seek(0)
+ for n, line in enumerate(fp):
+ if not line.rstrip('\n'):
+ t = _('invalid entry in fncache, line %s') % (n + 1)
+ raise util.Abort(t)
fp.close()
+ def _write(self, files, atomictemp):
+ fp = self.opener('fncache', mode='wb', atomictemp=atomictemp)
+ if files:
+ fp.write('\n'.join(map(encodedir, files)) + '\n')
+ fp.close()
+ self._dirty = False
+
def rewrite(self, files):
- fp = self.opener('fncache', mode='wb')
- for p in files:
- fp.write(encodedir(p) + '\n')
- fp.close()
+ self._write(files, False)
self.entries = set(files)
- self._dirty = False
def write(self):
- if not self._dirty:
- return
- fp = self.opener('fncache', mode='wb', atomictemp=True)
- for p in self.entries:
- fp.write(encodedir(p) + '\n')
- fp.close()
- self._dirty = False
+ if self._dirty:
+ self._write(self.entries, True)
def add(self, fn):
if self.entries is None: