# HG changeset patch # User Mads Kiilerich <mad...@unity3d.com> # Date 1476837995 -7200 # Wed Oct 19 02:46:35 2016 +0200 # Node ID 023b6f7456b3622cc81332ae9d6e30b7ecc37415 # Parent 1c3352d7eaf24533ad52d4b8a024211e9189fb0b rbc: use struct unpack_from and pack_into instead of unpack and pack
These functions were introduced in Python 2.5 and are faster and simpler than the old ones ... mainly because we can avoid intermediate buffers: $ python -m timeit -s "_rbcrecfmt='>4sI'" -s 's = "x"*10000' -s 'from struct import unpack' 'unpack(_rbcrecfmt, buffer(s, 16, 8))' 1000000 loops, best of 3: 0.543 usec per loop $ python -m timeit -s "_rbcrecfmt='>4sI'" -s 's = "x"*10000' -s 'from struct import unpack_from' 'unpack_from(_rbcrecfmt, s, 16)' 1000000 loops, best of 3: 0.323 usec per loop $ python -m timeit -s "from array import array" -s "_rbcrecfmt='>4sI'" -s "s = array('c')" -s 's.fromstring("x"*10000)' -s 'from struct import pack' -s "rec = array('c')" 'rec.fromstring(pack(_rbcrecfmt, "asdf", 7))' 1000000 loops, best of 3: 0.364 usec per loop $ python -m timeit -s "from array import array" -s "_rbcrecfmt='>4sI'" -s "s = array('c')" -s 's.fromstring("x"*10000)' -s 'from struct import pack_into' -s "rec = array('c')" -s 'rec.fromstring("x"*100)' 'pack_into(_rbcrecfmt, rec, 0, "asdf", 7)' 1000000 loops, best of 3: 0.229 usec per loop diff --git a/mercurial/branchmap.py b/mercurial/branchmap.py --- a/mercurial/branchmap.py +++ b/mercurial/branchmap.py @@ -25,8 +25,8 @@ from . import ( array = array.array calcsize = struct.calcsize -pack = struct.pack -unpack = struct.unpack +pack_into = struct.pack_into +unpack_from = struct.unpack_from def _filename(repo): """name of a branchcache file for a given repo or repoview""" @@ -409,8 +409,7 @@ class revbranchcache(object): # fast path: extract data from cache, use it if node is matching reponode = changelog.node(rev)[:_rbcnodelen] - cachenode, branchidx = unpack( - _rbcrecfmt, buffer(self._rbcrevs, rbcrevidx, _rbcrecsize)) + cachenode, branchidx = unpack_from(_rbcrecfmt, self._rbcrevs, rbcrevidx) close = bool(branchidx & _rbccloseflag) if close: branchidx &= _rbcbranchidxmask @@ -454,13 +453,11 @@ class revbranchcache(object): def _setcachedata(self, rev, node, branchidx): """Writes the node's branch data to the in-memory cache data.""" rbcrevidx = rev * _rbcrecsize - rec = array('c') - rec.fromstring(pack(_rbcrecfmt, node, branchidx)) if len(self._rbcrevs) < rbcrevidx + _rbcrecsize: self._rbcrevs.extend('\0' * (len(self._repo.changelog) * _rbcrecsize - len(self._rbcrevs))) - self._rbcrevs[rbcrevidx:rbcrevidx + _rbcrecsize] = rec + pack_into(_rbcrecfmt, self._rbcrevs, rbcrevidx, node, branchidx) self._rbcrevslen = min(self._rbcrevslen, rev) tr = self._repo.currenttransaction() _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel