Mercurial > public > mercurial-scm > hg
diff mercurial/branching/rev_cache.py @ 51971:76416b6e9d9b
rev-branch-cache: properly ignores unaligned trailing data
Previously, trailing data could lead to crash and would be written back to disk,
disaligning all new data?
This is no longer the cases.
This was detected while playing with branchmap-v3 that access the
rev-branch-cache much more aggressively.
| author | Pierre-Yves David <pierre-yves.david@octobus.net> |
|---|---|
| date | Fri, 27 Sep 2024 15:19:10 +0200 |
| parents | 4c885d5ff132 |
| children | db1980a361cb |
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--- a/mercurial/branching/rev_cache.py Fri Sep 27 15:01:43 2024 +0200 +++ b/mercurial/branching/rev_cache.py Fri Sep 27 15:19:10 2024 +0200 @@ -56,23 +56,28 @@ self._prefix = revs self._rest = bytearray() + @property + def len_prefix(self): + size = len(self._prefix) + return size - (size % _rbcrecsize) + def __len__(self): - return len(self._prefix) + len(self._rest) + return self.len_prefix + len(self._rest) def unpack_record(self, rbcrevidx): - if rbcrevidx < len(self._prefix): + if rbcrevidx < self.len_prefix: return unpack_from(_rbcrecfmt, util.buffer(self._prefix), rbcrevidx) else: return unpack_from( _rbcrecfmt, util.buffer(self._rest), - rbcrevidx - len(self._prefix), + rbcrevidx - self.len_prefix, ) def make_mutable(self): - if len(self._prefix) > 0: + if self.len_prefix > 0: entirety = bytearray() - entirety[:] = self._prefix + entirety[:] = self._prefix[: self.len_prefix] entirety.extend(self._rest) self._rest = entirety self._prefix = bytearray() @@ -82,10 +87,10 @@ del self._rest[pos:] def pack_into(self, rbcrevidx, node, branchidx): - if rbcrevidx < len(self._prefix): + if rbcrevidx < self.len_prefix: self.make_mutable() buf = self._rest - start_offset = rbcrevidx - len(self._prefix) + start_offset = rbcrevidx - self.len_prefix end_offset = start_offset + _rbcrecsize if len(self._rest) < end_offset: @@ -107,14 +112,14 @@ return self._rest.extend(extension) def slice(self, begin, end): - if begin < len(self._prefix): + if begin < self.len_prefix: acc = bytearray() - acc[:] = self._prefix[begin:end] + acc[:] = self._prefix[begin : min(end, self.len_prefix)] acc.extend( - self._rest[begin - len(self._prefix) : end - len(self._prefix)] + self._rest[begin - self.len_prefix : end - self.len_prefix] ) return acc - return self._rest[begin - len(self._prefix) : end - len(self._prefix)] + return self._rest[begin - self.len_prefix : end - self.len_prefix] class revbranchcache: @@ -388,6 +393,9 @@ if self._force_overwrite: start = 0 + # align start on entry boundary + start = _rbcrecsize * (start // _rbcrecsize) + with repo.cachevfs.open(_rbcrevs, b'a+b') as f: pass # this make sure the file exist… with repo.cachevfs.open(_rbcrevs, b'r+b') as f: