--- a/mercurial/revlog.py Tue Sep 18 16:47:09 2018 -0700
+++ b/mercurial/revlog.py Tue Sep 18 17:51:43 2018 -0700
@@ -2492,3 +2492,92 @@
finally:
destrevlog._lazydeltabase = oldlazydeltabase
destrevlog._deltabothparents = oldamd
+
+ def censorrevision(self, node, tombstone=b''):
+ if (self.version & 0xFFFF) == REVLOGV0:
+ raise error.RevlogError(_('cannot censor with version %d revlogs') %
+ self.version)
+
+ rev = self.rev(node)
+ tombstone = packmeta({b'censored': tombstone}, b'')
+
+ if len(tombstone) > self.rawsize(rev):
+ raise error.Abort(_('censor tombstone must be no longer than '
+ 'censored data'))
+
+ # Using two files instead of one makes it easy to rewrite entry-by-entry
+ idxread = self.opener(self.indexfile, 'r')
+ idxwrite = self.opener(self.indexfile, 'wb', atomictemp=True)
+ if self.version & FLAG_INLINE_DATA:
+ dataread, datawrite = idxread, idxwrite
+ else:
+ dataread = self.opener(self.datafile, 'r')
+ datawrite = self.opener(self.datafile, 'wb', atomictemp=True)
+
+ # Copy all revlog data up to the entry to be censored.
+ offset = self.start(rev)
+
+ for chunk in util.filechunkiter(idxread, limit=rev * self._io.size):
+ idxwrite.write(chunk)
+ for chunk in util.filechunkiter(dataread, limit=offset):
+ datawrite.write(chunk)
+
+ def rewriteindex(r, newoffs, newdata=None):
+ """Rewrite the index entry with a new data offset and new data.
+
+ The newdata argument, if given, is a tuple of three positive
+ integers: (new compressed, new uncompressed, added flag bits).
+ """
+ offlags, comp, uncomp, base, link, p1, p2, nodeid = self.index[r]
+ flags = gettype(offlags)
+ if newdata:
+ comp, uncomp, nflags = newdata
+ flags |= nflags
+ offlags = offset_type(newoffs, flags)
+ e = (offlags, comp, uncomp, r, link, p1, p2, nodeid)
+ idxwrite.write(self._io.packentry(e, None, self.version, r))
+ idxread.seek(self._io.size, 1)
+
+ def rewrite(r, offs, data, nflags=REVIDX_DEFAULT_FLAGS):
+ """Write the given fulltext with the given data offset.
+
+ Returns:
+ The integer number of data bytes written, for tracking data
+ offsets.
+ """
+ flag, compdata = self.compress(data)
+ newcomp = len(flag) + len(compdata)
+ rewriteindex(r, offs, (newcomp, len(data), nflags))
+ datawrite.write(flag)
+ datawrite.write(compdata)
+ dataread.seek(self.length(r), 1)
+ return newcomp
+
+ # Rewrite censored entry with (padded) tombstone data.
+ pad = ' ' * (self.rawsize(rev) - len(tombstone))
+ offset += rewrite(rev, offset, tombstone + pad, REVIDX_ISCENSORED)
+
+ # Rewrite all following filelog revisions fixing up offsets and deltas.
+ for srev in pycompat.xrange(rev + 1, len(self)):
+ if rev in self.parentrevs(srev):
+ # Immediate children of censored node must be re-added as
+ # fulltext.
+ try:
+ revdata = self.revision(srev)
+ except error.CensoredNodeError as e:
+ revdata = e.tombstone
+ dlen = rewrite(srev, offset, revdata)
+ else:
+ # Copy any other revision data verbatim after fixing up the
+ # offset.
+ rewriteindex(srev, offset)
+ dlen = self.length(srev)
+ for chunk in util.filechunkiter(dataread, limit=dlen):
+ datawrite.write(chunk)
+ offset += dlen
+
+ idxread.close()
+ idxwrite.close()
+ if dataread is not idxread:
+ dataread.close()
+ datawrite.close()