Mercurial > hg
view hgext/remotefilelog/historypack.py @ 50916:98b8836d0e82
hgweb: use sysstr to set attribute on diff option
Attribute identifier should be `str` not `bytes`.
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
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date | Fri, 01 Sep 2023 12:09:54 +0200 |
parents | d44e3c45f0e4 |
children |
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import struct from mercurial.node import ( hex, sha1nodeconstants, ) from mercurial import ( util, ) from mercurial.utils import hashutil from . import ( basepack, constants, shallowutil, ) # (filename hash, offset, size) INDEXFORMAT2 = b'!20sQQII' INDEXENTRYLENGTH2 = struct.calcsize(INDEXFORMAT2) NODELENGTH = 20 NODEINDEXFORMAT = b'!20sQ' NODEINDEXENTRYLENGTH = struct.calcsize(NODEINDEXFORMAT) # (node, p1, p2, linknode) PACKFORMAT = b"!20s20s20s20sH" PACKENTRYLENGTH = 82 ENTRYCOUNTSIZE = 4 INDEXSUFFIX = b'.histidx' PACKSUFFIX = b'.histpack' ANC_NODE = 0 ANC_P1NODE = 1 ANC_P2NODE = 2 ANC_LINKNODE = 3 ANC_COPYFROM = 4 class historypackstore(basepack.basepackstore): INDEXSUFFIX = INDEXSUFFIX PACKSUFFIX = PACKSUFFIX def getpack(self, path): return historypack(path) def getancestors(self, name, node, known=None): for pack in self.packs: try: return pack.getancestors(name, node, known=known) except KeyError: pass for pack in self.refresh(): try: return pack.getancestors(name, node, known=known) except KeyError: pass raise KeyError((name, node)) def getnodeinfo(self, name, node): for pack in self.packs: try: return pack.getnodeinfo(name, node) except KeyError: pass for pack in self.refresh(): try: return pack.getnodeinfo(name, node) except KeyError: pass raise KeyError((name, node)) def add(self, filename, node, p1, p2, linknode, copyfrom): raise RuntimeError( b"cannot add to historypackstore (%s:%s)" % (filename, hex(node)) ) class historypack(basepack.basepack): INDEXSUFFIX = INDEXSUFFIX PACKSUFFIX = PACKSUFFIX SUPPORTED_VERSIONS = [2] def __init__(self, path): super(historypack, self).__init__(path) self.INDEXFORMAT = INDEXFORMAT2 self.INDEXENTRYLENGTH = INDEXENTRYLENGTH2 def getmissing(self, keys): missing = [] for name, node in keys: try: self._findnode(name, node) except KeyError: missing.append((name, node)) return missing def getancestors(self, name, node, known=None): """Returns as many ancestors as we're aware of. return value: { node: (p1, p2, linknode, copyfrom), ... } """ if known and node in known: return [] ancestors = self._getancestors(name, node, known=known) results = {} for ancnode, p1, p2, linknode, copyfrom in ancestors: results[ancnode] = (p1, p2, linknode, copyfrom) if not results: raise KeyError((name, node)) return results def getnodeinfo(self, name, node): # Drop the node from the tuple before returning, since the result should # just be (p1, p2, linknode, copyfrom) return self._findnode(name, node)[1:] def _getancestors(self, name, node, known=None): if known is None: known = set() section = self._findsection(name) filename, offset, size, nodeindexoffset, nodeindexsize = section pending = {node} o = 0 while o < size: if not pending: break entry, copyfrom = self._readentry(offset + o) o += PACKENTRYLENGTH if copyfrom: o += len(copyfrom) ancnode = entry[ANC_NODE] if ancnode in pending: pending.remove(ancnode) p1node = entry[ANC_P1NODE] p2node = entry[ANC_P2NODE] if p1node != sha1nodeconstants.nullid and p1node not in known: pending.add(p1node) if p2node != sha1nodeconstants.nullid and p2node not in known: pending.add(p2node) yield (ancnode, p1node, p2node, entry[ANC_LINKNODE], copyfrom) def _readentry(self, offset): data = self._data entry = struct.unpack( PACKFORMAT, data[offset : offset + PACKENTRYLENGTH] ) copyfrom = None copyfromlen = entry[ANC_COPYFROM] if copyfromlen != 0: offset += PACKENTRYLENGTH copyfrom = data[offset : offset + copyfromlen] return entry, copyfrom def add(self, filename, node, p1, p2, linknode, copyfrom): raise RuntimeError( b"cannot add to historypack (%s:%s)" % (filename, hex(node)) ) def _findnode(self, name, node): if self.VERSION == 0: ancestors = self._getancestors(name, node) for ancnode, p1node, p2node, linknode, copyfrom in ancestors: if ancnode == node: return (ancnode, p1node, p2node, linknode, copyfrom) else: section = self._findsection(name) nodeindexoffset, nodeindexsize = section[3:] entry = self._bisect( node, nodeindexoffset, nodeindexoffset + nodeindexsize, NODEINDEXENTRYLENGTH, ) if entry is not None: node, offset = struct.unpack(NODEINDEXFORMAT, entry) entry, copyfrom = self._readentry(offset) # Drop the copyfromlen from the end of entry, and replace it # with the copyfrom string. return entry[:4] + (copyfrom,) raise KeyError(b"unable to find history for %s:%s" % (name, hex(node))) def _findsection(self, name): params = self.params namehash = hashutil.sha1(name).digest() fanoutkey = struct.unpack( params.fanoutstruct, namehash[: params.fanoutprefix] )[0] fanout = self._fanouttable start = fanout[fanoutkey] + params.indexstart indexend = self._indexend for i in range(fanoutkey + 1, params.fanoutcount): end = fanout[i] + params.indexstart if end != start: break else: end = indexend entry = self._bisect(namehash, start, end, self.INDEXENTRYLENGTH) if not entry: raise KeyError(name) rawentry = struct.unpack(self.INDEXFORMAT, entry) x, offset, size, nodeindexoffset, nodeindexsize = rawentry rawnamelen = self._index[ nodeindexoffset : nodeindexoffset + constants.FILENAMESIZE ] actualnamelen = struct.unpack(b'!H', rawnamelen)[0] nodeindexoffset += constants.FILENAMESIZE actualname = self._index[ nodeindexoffset : nodeindexoffset + actualnamelen ] if actualname != name: raise KeyError( b"found file name %s when looking for %s" % (actualname, name) ) nodeindexoffset += actualnamelen filenamelength = struct.unpack( b'!H', self._data[offset : offset + constants.FILENAMESIZE] )[0] offset += constants.FILENAMESIZE actualname = self._data[offset : offset + filenamelength] offset += filenamelength if name != actualname: raise KeyError( b"found file name %s when looking for %s" % (actualname, name) ) # Skip entry list size offset += ENTRYCOUNTSIZE nodelistoffset = offset nodelistsize = ( size - constants.FILENAMESIZE - filenamelength - ENTRYCOUNTSIZE ) return ( name, nodelistoffset, nodelistsize, nodeindexoffset, nodeindexsize, ) def _bisect(self, node, start, end, entrylen): # Bisect between start and end to find node origstart = start startnode = self._index[start : start + NODELENGTH] endnode = self._index[end : end + NODELENGTH] if startnode == node: return self._index[start : start + entrylen] elif endnode == node: return self._index[end : end + entrylen] else: while start < end - entrylen: mid = start + (end - start) // 2 mid = mid - ((mid - origstart) % entrylen) midnode = self._index[mid : mid + NODELENGTH] if midnode == node: return self._index[mid : mid + entrylen] if node > midnode: start = mid elif node < midnode: end = mid return None def markledger(self, ledger, options=None): for filename, node in self: ledger.markhistoryentry(self, filename, node) def cleanup(self, ledger): entries = ledger.sources.get(self, []) allkeys = set(self) repackedkeys = { (e.filename, e.node) for e in entries if e.historyrepacked } if len(allkeys - repackedkeys) == 0: if self.path not in ledger.created: util.unlinkpath(self.indexpath, ignoremissing=True) util.unlinkpath(self.packpath, ignoremissing=True) def __iter__(self): for f, n, x, x, x, x in self.iterentries(): yield f, n def iterentries(self): # Start at 1 to skip the header offset = 1 while offset < self.datasize: data = self._data # <2 byte len> + <filename> filenamelen = struct.unpack( b'!H', data[offset : offset + constants.FILENAMESIZE] )[0] offset += constants.FILENAMESIZE filename = data[offset : offset + filenamelen] offset += filenamelen revcount = struct.unpack( b'!I', data[offset : offset + ENTRYCOUNTSIZE] )[0] offset += ENTRYCOUNTSIZE for i in range(revcount): entry = struct.unpack( PACKFORMAT, data[offset : offset + PACKENTRYLENGTH] ) offset += PACKENTRYLENGTH copyfrom = data[offset : offset + entry[ANC_COPYFROM]] offset += entry[ANC_COPYFROM] yield ( filename, entry[ANC_NODE], entry[ANC_P1NODE], entry[ANC_P2NODE], entry[ANC_LINKNODE], copyfrom, ) self._pagedin += PACKENTRYLENGTH # If we've read a lot of data from the mmap, free some memory. self.freememory() class mutablehistorypack(basepack.mutablebasepack): """A class for constructing and serializing a histpack file and index. A history pack is a pair of files that contain the revision history for various file revisions in Mercurial. It contains only revision history (like parent pointers and linknodes), not any revision content information. It consists of two files, with the following format: .histpack The pack itself is a series of file revisions with some basic header information on each. datapack = <version: 1 byte> [<filesection>,...] filesection = <filename len: 2 byte unsigned int> <filename> <revision count: 4 byte unsigned int> [<revision>,...] revision = <node: 20 byte> <p1node: 20 byte> <p2node: 20 byte> <linknode: 20 byte> <copyfromlen: 2 byte> <copyfrom> The revisions within each filesection are stored in topological order (newest first). If a given entry has a parent from another file (a copy) then p1node is the node from the other file, and copyfrom is the filepath of the other file. .histidx The index file provides a mapping from filename to the file section in the histpack. In V1 it also contains sub-indexes for specific nodes within each file. It consists of three parts, the fanout, the file index and the node indexes. The file index is a list of index entries, sorted by filename hash (one per file section in the pack). Each entry has: - node (The 20 byte hash of the filename) - pack entry offset (The location of this file section in the histpack) - pack content size (The on-disk length of this file section's pack data) - node index offset (The location of the file's node index in the index file) [1] - node index size (the on-disk length of this file's node index) [1] The fanout is a quick lookup table to reduce the number of steps for bisecting the index. It is a series of 4 byte pointers to positions within the index. It has 2^16 entries, which corresponds to hash prefixes [00, 01, 02,..., FD, FE, FF]. Example: the pointer in slot 4F points to the index position of the first revision whose node starts with 4F. This saves log(2^16) bisect steps. dataidx = <fanouttable> <file count: 8 byte unsigned> [1] <fileindex> <node count: 8 byte unsigned> [1] [<nodeindex>,...] [1] fanouttable = [<index offset: 4 byte unsigned int>,...] (2^16 entries) fileindex = [<file index entry>,...] fileindexentry = <node: 20 byte> <pack file section offset: 8 byte unsigned int> <pack file section size: 8 byte unsigned int> <node index offset: 4 byte unsigned int> [1] <node index size: 4 byte unsigned int> [1] nodeindex = <filename>[<node index entry>,...] [1] filename = <filename len : 2 byte unsigned int><filename value> [1] nodeindexentry = <node: 20 byte> [1] <pack file node offset: 8 byte unsigned int> [1] [1]: new in version 1. """ INDEXSUFFIX = INDEXSUFFIX PACKSUFFIX = PACKSUFFIX SUPPORTED_VERSIONS = [2] def __init__(self, ui, packpath, version=2): super(mutablehistorypack, self).__init__(ui, packpath, version=version) self.files = {} self.entrylocations = {} self.fileentries = {} self.INDEXFORMAT = INDEXFORMAT2 self.INDEXENTRYLENGTH = INDEXENTRYLENGTH2 self.NODEINDEXFORMAT = NODEINDEXFORMAT self.NODEINDEXENTRYLENGTH = NODEINDEXENTRYLENGTH def add(self, filename, node, p1, p2, linknode, copyfrom): copyfrom = copyfrom or b'' copyfromlen = struct.pack(b'!H', len(copyfrom)) self.fileentries.setdefault(filename, []).append( (node, p1, p2, linknode, copyfromlen, copyfrom) ) def _write(self): for filename in sorted(self.fileentries): entries = self.fileentries[filename] sectionstart = self.packfp.tell() # Write the file section content entrymap = {e[0]: e for e in entries} def parentfunc(node): x, p1, p2, x, x, x = entrymap[node] parents = [] if p1 != sha1nodeconstants.nullid: parents.append(p1) if p2 != sha1nodeconstants.nullid: parents.append(p2) return parents sortednodes = list( reversed( shallowutil.sortnodes((e[0] for e in entries), parentfunc) ) ) # Write the file section header self.writeraw( b"%s%s%s" % ( struct.pack(b'!H', len(filename)), filename, struct.pack(b'!I', len(sortednodes)), ) ) sectionlen = constants.FILENAMESIZE + len(filename) + 4 rawstrings = [] # Record the node locations for the index locations = self.entrylocations.setdefault(filename, {}) offset = sectionstart + sectionlen for node in sortednodes: locations[node] = offset raw = b'%s%s%s%s%s%s' % entrymap[node] rawstrings.append(raw) offset += len(raw) rawdata = b''.join(rawstrings) sectionlen += len(rawdata) self.writeraw(rawdata) # Record metadata for the index self.files[filename] = (sectionstart, sectionlen) node = hashutil.sha1(filename).digest() self.entries[node] = node def close(self, ledger=None): if self._closed: return self._write() return super(mutablehistorypack, self).close(ledger=ledger) def createindex(self, nodelocations, indexoffset): fileindexformat = self.INDEXFORMAT fileindexlength = self.INDEXENTRYLENGTH nodeindexformat = self.NODEINDEXFORMAT nodeindexlength = self.NODEINDEXENTRYLENGTH files = ( (hashutil.sha1(filename).digest(), filename, offset, size) for filename, (offset, size) in self.files.items() ) files = sorted(files) # node index is after file index size, file index, and node index size indexlensize = struct.calcsize(b'!Q') nodeindexoffset = ( indexoffset + indexlensize + (len(files) * fileindexlength) + indexlensize ) fileindexentries = [] nodeindexentries = [] nodecount = 0 for namehash, filename, offset, size in files: # File section index nodelocations = self.entrylocations[filename] nodeindexsize = len(nodelocations) * nodeindexlength rawentry = struct.pack( fileindexformat, namehash, offset, size, nodeindexoffset, nodeindexsize, ) # Node index nodeindexentries.append( struct.pack(constants.FILENAMESTRUCT, len(filename)) + filename ) nodeindexoffset += constants.FILENAMESIZE + len(filename) for node, location in sorted(nodelocations.items()): nodeindexentries.append( struct.pack(nodeindexformat, node, location) ) nodecount += 1 nodeindexoffset += len(nodelocations) * nodeindexlength fileindexentries.append(rawentry) nodecountraw = struct.pack(b'!Q', nodecount) return ( b''.join(fileindexentries) + nodecountraw + b''.join(nodeindexentries) )