Mercurial > hg
view mercurial/pure/parsers.py @ 47142:4292bed8da7c
revlog: make the index always return the same tuple
It is simpler to manage the diferrence in on disk format in the internal index
code itself and lets the rest of the code always handle the same object.
This will become even more important when the data we store will be entirely
different (for example the changelog does not need the "linkrev" field.
We start with item reading, we will deal with item writing in the next
changesets.
Differential Revision: https://phab.mercurial-scm.org/D10568
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Mon, 03 May 2021 12:21:15 +0200 |
parents | 223b47235d1c |
children | 47ffc754989a |
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# parsers.py - Python implementation of parsers.c # # Copyright 2009 Olivia Mackall <olivia@selenic.com> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import struct import zlib from ..node import ( nullrev, sha1nodeconstants, ) from .. import ( pycompat, util, ) from ..revlogutils import nodemap as nodemaputil from ..revlogutils import constants as revlog_constants stringio = pycompat.bytesio _pack = struct.pack _unpack = struct.unpack _compress = zlib.compress _decompress = zlib.decompress # Some code below makes tuples directly because it's more convenient. However, # code outside this module should always use dirstatetuple. def dirstatetuple(*x): # x is a tuple return x def gettype(q): return int(q & 0xFFFF) def offset_type(offset, type): return int(int(offset) << 16 | type) class BaseIndexObject(object): # Format of an index entry according to Python's `struct` language index_format = revlog_constants.INDEX_ENTRY_V1 # Size of a C unsigned long long int, platform independent big_int_size = struct.calcsize(b'>Q') # Size of a C long int, platform independent int_size = struct.calcsize(b'>i') # An empty index entry, used as a default value to be overridden, or nullrev null_item = (0, 0, 0, -1, -1, -1, -1, sha1nodeconstants.nullid, 0, 0) @util.propertycache def entry_size(self): return self.index_format.size @property def nodemap(self): msg = b"index.nodemap is deprecated, use index.[has_node|rev|get_rev]" util.nouideprecwarn(msg, b'5.3', stacklevel=2) return self._nodemap @util.propertycache def _nodemap(self): nodemap = nodemaputil.NodeMap({sha1nodeconstants.nullid: nullrev}) for r in range(0, len(self)): n = self[r][7] nodemap[n] = r return nodemap def has_node(self, node): """return True if the node exist in the index""" return node in self._nodemap def rev(self, node): """return a revision for a node If the node is unknown, raise a RevlogError""" return self._nodemap[node] def get_rev(self, node): """return a revision for a node If the node is unknown, return None""" return self._nodemap.get(node) def _stripnodes(self, start): if '_nodemap' in vars(self): for r in range(start, len(self)): n = self[r][7] del self._nodemap[n] def clearcaches(self): self.__dict__.pop('_nodemap', None) def __len__(self): return self._lgt + len(self._extra) def append(self, tup): if '_nodemap' in vars(self): self._nodemap[tup[7]] = len(self) data = self.index_format.pack(*tup) self._extra.append(data) def _check_index(self, i): if not isinstance(i, int): raise TypeError(b"expecting int indexes") if i < 0 or i >= len(self): raise IndexError def __getitem__(self, i): if i == -1: return self.null_item self._check_index(i) if i >= self._lgt: data = self._extra[i - self._lgt] else: index = self._calculate_index(i) data = self._data[index : index + self.entry_size] r = self._unpack_entry(data) if self._lgt and i == 0: r = (offset_type(0, gettype(r[0])),) + r[1:] return r def _unpack_entry(self, data): r = self.index_format.unpack(data) r = r + (0, 0) return r def pack_header(self, header): """pack header information as binary""" v_fmt = revlog_constants.INDEX_HEADER return v_fmt.pack(header) def entry_binary(self, rev): """return the raw binary string representing a revision""" entry = self[rev] p = revlog_constants.INDEX_ENTRY_V1.pack(*entry[:8]) if rev == 0: p = p[revlog_constants.INDEX_HEADER.size :] return p class IndexObject(BaseIndexObject): def __init__(self, data): assert len(data) % self.entry_size == 0, ( len(data), self.entry_size, len(data) % self.entry_size, ) self._data = data self._lgt = len(data) // self.entry_size self._extra = [] def _calculate_index(self, i): return i * self.entry_size def __delitem__(self, i): if not isinstance(i, slice) or not i.stop == -1 or i.step is not None: raise ValueError(b"deleting slices only supports a:-1 with step 1") i = i.start self._check_index(i) self._stripnodes(i) if i < self._lgt: self._data = self._data[: i * self.entry_size] self._lgt = i self._extra = [] else: self._extra = self._extra[: i - self._lgt] class PersistentNodeMapIndexObject(IndexObject): """a Debug oriented class to test persistent nodemap We need a simple python object to test API and higher level behavior. See the Rust implementation for more serious usage. This should be used only through the dedicated `devel.persistent-nodemap` config. """ def nodemap_data_all(self): """Return bytes containing a full serialization of a nodemap The nodemap should be valid for the full set of revisions in the index.""" return nodemaputil.persistent_data(self) def nodemap_data_incremental(self): """Return bytes containing a incremental update to persistent nodemap This containst the data for an append-only update of the data provided in the last call to `update_nodemap_data`. """ if self._nm_root is None: return None docket = self._nm_docket changed, data = nodemaputil.update_persistent_data( self, self._nm_root, self._nm_max_idx, self._nm_docket.tip_rev ) self._nm_root = self._nm_max_idx = self._nm_docket = None return docket, changed, data def update_nodemap_data(self, docket, nm_data): """provide full block of persisted binary data for a nodemap The data are expected to come from disk. See `nodemap_data_all` for a produceur of such data.""" if nm_data is not None: self._nm_root, self._nm_max_idx = nodemaputil.parse_data(nm_data) if self._nm_root: self._nm_docket = docket else: self._nm_root = self._nm_max_idx = self._nm_docket = None class InlinedIndexObject(BaseIndexObject): def __init__(self, data, inline=0): self._data = data self._lgt = self._inline_scan(None) self._inline_scan(self._lgt) self._extra = [] def _inline_scan(self, lgt): off = 0 if lgt is not None: self._offsets = [0] * lgt count = 0 while off <= len(self._data) - self.entry_size: start = off + self.big_int_size (s,) = struct.unpack( b'>i', self._data[start : start + self.int_size], ) if lgt is not None: self._offsets[count] = off count += 1 off += self.entry_size + s if off != len(self._data): raise ValueError(b"corrupted data") return count def __delitem__(self, i): if not isinstance(i, slice) or not i.stop == -1 or i.step is not None: raise ValueError(b"deleting slices only supports a:-1 with step 1") i = i.start self._check_index(i) self._stripnodes(i) if i < self._lgt: self._offsets = self._offsets[:i] self._lgt = i self._extra = [] else: self._extra = self._extra[: i - self._lgt] def _calculate_index(self, i): return self._offsets[i] def parse_index2(data, inline, revlogv2=False): if not inline: cls = IndexObject2 if revlogv2 else IndexObject return cls(data), None cls = InlinedIndexObject2 if revlogv2 else InlinedIndexObject return cls(data, inline), (0, data) class Index2Mixin(object): index_format = revlog_constants.INDEX_ENTRY_V2 def replace_sidedata_info( self, i, sidedata_offset, sidedata_length, offset_flags ): """ Replace an existing index entry's sidedata offset and length with new ones. This cannot be used outside of the context of sidedata rewriting, inside the transaction that creates the revision `i`. """ if i < 0: raise KeyError self._check_index(i) sidedata_format = b">Qi" packed_size = struct.calcsize(sidedata_format) if i >= self._lgt: packed = _pack(sidedata_format, sidedata_offset, sidedata_length) old = self._extra[i - self._lgt] offset_flags = struct.pack(b">Q", offset_flags) new = offset_flags + old[8:64] + packed + old[64 + packed_size :] self._extra[i - self._lgt] = new else: msg = b"cannot rewrite entries outside of this transaction" raise KeyError(msg) def _unpack_entry(self, data): return self.index_format.unpack(data) def entry_binary(self, rev): """return the raw binary string representing a revision""" entry = self[rev] p = revlog_constants.INDEX_ENTRY_V2.pack(*entry) if rev == 0: p = p[revlog_constants.INDEX_HEADER.size :] return p class IndexObject2(Index2Mixin, IndexObject): pass class InlinedIndexObject2(Index2Mixin, InlinedIndexObject): def _inline_scan(self, lgt): sidedata_length_pos = 72 off = 0 if lgt is not None: self._offsets = [0] * lgt count = 0 while off <= len(self._data) - self.entry_size: start = off + self.big_int_size (data_size,) = struct.unpack( b'>i', self._data[start : start + self.int_size], ) start = off + sidedata_length_pos (side_data_size,) = struct.unpack( b'>i', self._data[start : start + self.int_size] ) if lgt is not None: self._offsets[count] = off count += 1 off += self.entry_size + data_size + side_data_size if off != len(self._data): raise ValueError(b"corrupted data") return count def parse_index_devel_nodemap(data, inline): """like parse_index2, but alway return a PersistentNodeMapIndexObject""" return PersistentNodeMapIndexObject(data), None def parse_dirstate(dmap, copymap, st): parents = [st[:20], st[20:40]] # dereference fields so they will be local in loop format = b">cllll" e_size = struct.calcsize(format) pos1 = 40 l = len(st) # the inner loop while pos1 < l: pos2 = pos1 + e_size e = _unpack(b">cllll", st[pos1:pos2]) # a literal here is faster pos1 = pos2 + e[4] f = st[pos2:pos1] if b'\0' in f: f, c = f.split(b'\0') copymap[f] = c dmap[f] = e[:4] return parents def pack_dirstate(dmap, copymap, pl, now): now = int(now) cs = stringio() write = cs.write write(b"".join(pl)) for f, e in pycompat.iteritems(dmap): if e[0] == b'n' and e[3] == now: # The file was last modified "simultaneously" with the current # write to dirstate (i.e. within the same second for file- # systems with a granularity of 1 sec). This commonly happens # for at least a couple of files on 'update'. # The user could change the file without changing its size # within the same second. Invalidate the file's mtime in # dirstate, forcing future 'status' calls to compare the # contents of the file if the size is the same. This prevents # mistakenly treating such files as clean. e = dirstatetuple(e[0], e[1], e[2], -1) dmap[f] = e if f in copymap: f = b"%s\0%s" % (f, copymap[f]) e = _pack(b">cllll", e[0], e[1], e[2], e[3], len(f)) write(e) write(f) return cs.getvalue()