Mercurial > hg > mercurial-crew-with-dirclash
view mercurial/filelog.py @ 5369:7530334bf301
revlog: generate trivial deltas against null revision
To avoid extra memory usage and performance issues with large files,
generate a trivial delta header for deltas against the null revision
rather than calling the usual delta generator.
We append the delta header to meta rather than prepending it to data
to avoid a large allocate and copy.
author | Matt Mackall <mpm@selenic.com> |
---|---|
date | Wed, 03 Oct 2007 17:17:27 -0500 |
parents | 63b9d2deed48 |
children |
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# filelog.py - file history class for mercurial # # Copyright 2005-2007 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms # of the GNU General Public License, incorporated herein by reference. from revlog import * import os class filelog(revlog): def __init__(self, opener, path): revlog.__init__(self, opener, "/".join(("data", self.encodedir(path + ".i")))) # This avoids a collision between a file named foo and a dir named # foo.i or foo.d def encodedir(self, path): return (path .replace(".hg/", ".hg.hg/") .replace(".i/", ".i.hg/") .replace(".d/", ".d.hg/")) def decodedir(self, path): return (path .replace(".d.hg/", ".d/") .replace(".i.hg/", ".i/") .replace(".hg.hg/", ".hg/")) def read(self, node): t = self.revision(node) if not t.startswith('\1\n'): return t s = t.index('\1\n', 2) return t[s+2:] def _readmeta(self, node): t = self.revision(node) if not t.startswith('\1\n'): return {} s = t.index('\1\n', 2) mt = t[2:s] m = {} for l in mt.splitlines(): k, v = l.split(": ", 1) m[k] = v return m def add(self, text, meta, transaction, link, p1=None, p2=None): if meta or text.startswith('\1\n'): mt = "" if meta: mt = [ "%s: %s\n" % (k, v) for k,v in meta.items() ] text = "\1\n%s\1\n%s" % ("".join(mt), text) return self.addrevision(text, transaction, link, p1, p2) def renamed(self, node): if self.parents(node)[0] != nullid: return False m = self._readmeta(node) if m and m.has_key("copy"): return (m["copy"], bin(m["copyrev"])) return False def size(self, rev): """return the size of a given revision""" # for revisions with renames, we have to go the slow way node = self.node(rev) if self.renamed(node): return len(self.read(node)) return revlog.size(self, rev) def cmp(self, node, text): """compare text with a given file revision""" # for renames, we have to go the slow way if self.renamed(node): t2 = self.read(node) return t2 != text return revlog.cmp(self, node, text)