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view mercurial/branchmap.py @ 44192:d6d4170882cd
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On py3, stdout and stderr appear to be buffered and this causes my command's
output to be intermixed with the profiling output.
Differential Revision: https://phab.mercurial-scm.org/D8024
author | Kyle Lippincott <spectral@google.com> |
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date | Mon, 27 Jan 2020 18:16:05 -0800 |
parents | 7b14d649af1b |
children | a0ec05d93c8e |
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# branchmap.py - logic to computes, maintain and stores branchmap for local repo # # 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 version 2 or any later version. from __future__ import absolute_import import struct from .node import ( bin, hex, nullid, nullrev, ) from . import ( encoding, error, pycompat, scmutil, util, ) from .utils import ( repoviewutil, stringutil, ) if pycompat.TYPE_CHECKING: from typing import ( Any, Callable, Dict, Iterable, List, Optional, Set, Tuple, Union, ) assert any( (Any, Callable, Dict, Iterable, List, Optional, Set, Tuple, Union,) ) subsettable = repoviewutil.subsettable calcsize = struct.calcsize pack_into = struct.pack_into unpack_from = struct.unpack_from class BranchMapCache(object): """mapping of filtered views of repo with their branchcache""" def __init__(self): self._per_filter = {} def __getitem__(self, repo): self.updatecache(repo) return self._per_filter[repo.filtername] def updatecache(self, repo): """Update the cache for the given filtered view on a repository""" # This can trigger updates for the caches for subsets of the filtered # view, e.g. when there is no cache for this filtered view or the cache # is stale. cl = repo.changelog filtername = repo.filtername bcache = self._per_filter.get(filtername) if bcache is None or not bcache.validfor(repo): # cache object missing or cache object stale? Read from disk bcache = branchcache.fromfile(repo) revs = [] if bcache is None: # no (fresh) cache available anymore, perhaps we can re-use # the cache for a subset, then extend that to add info on missing # revisions. subsetname = subsettable.get(filtername) if subsetname is not None: subset = repo.filtered(subsetname) bcache = self[subset].copy() extrarevs = subset.changelog.filteredrevs - cl.filteredrevs revs.extend(r for r in extrarevs if r <= bcache.tiprev) else: # nothing to fall back on, start empty. bcache = branchcache() revs.extend(cl.revs(start=bcache.tiprev + 1)) if revs: bcache.update(repo, revs) assert bcache.validfor(repo), filtername self._per_filter[repo.filtername] = bcache def replace(self, repo, remotebranchmap): """Replace the branchmap cache for a repo with a branch mapping. This is likely only called during clone with a branch map from a remote. """ cl = repo.changelog clrev = cl.rev clbranchinfo = cl.branchinfo rbheads = [] closed = set() for bheads in pycompat.itervalues(remotebranchmap): rbheads += bheads for h in bheads: r = clrev(h) b, c = clbranchinfo(r) if c: closed.add(h) if rbheads: rtiprev = max((int(clrev(node)) for node in rbheads)) cache = branchcache( remotebranchmap, repo[rtiprev].node(), rtiprev, closednodes=closed, ) # Try to stick it as low as possible # filter above served are unlikely to be fetch from a clone for candidate in (b'base', b'immutable', b'served'): rview = repo.filtered(candidate) if cache.validfor(rview): self._per_filter[candidate] = cache cache.write(rview) return def clear(self): self._per_filter.clear() def _unknownnode(node): """ raises ValueError when branchcache found a node which does not exists """ raise ValueError('node %s does not exist' % pycompat.sysstr(hex(node))) def _branchcachedesc(repo): if repo.filtername is not None: return b'branch cache (%s)' % repo.filtername else: return b'branch cache' class branchcache(object): """A dict like object that hold branches heads cache. This cache is used to avoid costly computations to determine all the branch heads of a repo. The cache is serialized on disk in the following format: <tip hex node> <tip rev number> [optional filtered repo hex hash] <branch head hex node> <open/closed state> <branch name> <branch head hex node> <open/closed state> <branch name> ... The first line is used to check if the cache is still valid. If the branch cache is for a filtered repo view, an optional third hash is included that hashes the hashes of all filtered revisions. The open/closed state is represented by a single letter 'o' or 'c'. This field can be used to avoid changelog reads when determining if a branch head closes a branch or not. """ def __init__( self, entries=(), tipnode=nullid, tiprev=nullrev, filteredhash=None, closednodes=None, hasnode=None, ): # type: (Union[Dict[bytes, List[bytes]], Iterable[Tuple[bytes, List[bytes]]]], bytes, int, Optional[bytes], Optional[Set[bytes]], Optional[Callable[[bytes], bool]]) -> None """ hasnode is a function which can be used to verify whether changelog has a given node or not. If it's not provided, we assume that every node we have exists in changelog """ self.tipnode = tipnode self.tiprev = tiprev self.filteredhash = filteredhash # closednodes is a set of nodes that close their branch. If the branch # cache has been updated, it may contain nodes that are no longer # heads. if closednodes is None: self._closednodes = set() else: self._closednodes = closednodes self._entries = dict(entries) # whether closed nodes are verified or not self._closedverified = False # branches for which nodes are verified self._verifiedbranches = set() self._hasnode = hasnode if self._hasnode is None: self._hasnode = lambda x: True def _verifyclosed(self): """ verify the closed nodes we have """ if self._closedverified: return for node in self._closednodes: if not self._hasnode(node): _unknownnode(node) self._closedverified = True def _verifybranch(self, branch): """ verify head nodes for the given branch. """ if branch not in self._entries or branch in self._verifiedbranches: return for n in self._entries[branch]: if not self._hasnode(n): _unknownnode(n) self._verifiedbranches.add(branch) def _verifyall(self): """ verifies nodes of all the branches """ needverification = set(self._entries.keys()) - self._verifiedbranches for b in needverification: self._verifybranch(b) def __iter__(self): return iter(self._entries) def __setitem__(self, key, value): self._entries[key] = value def __getitem__(self, key): self._verifybranch(key) return self._entries[key] def __contains__(self, key): self._verifybranch(key) return key in self._entries def iteritems(self): for k, v in pycompat.iteritems(self._entries): self._verifybranch(k) yield k, v items = iteritems def hasbranch(self, label): """ checks whether a branch of this name exists or not """ self._verifybranch(label) return label in self._entries @classmethod def fromfile(cls, repo): f = None try: f = repo.cachevfs(cls._filename(repo)) lineiter = iter(f) cachekey = next(lineiter).rstrip(b'\n').split(b" ", 2) last, lrev = cachekey[:2] last, lrev = bin(last), int(lrev) filteredhash = None hasnode = repo.changelog.hasnode if len(cachekey) > 2: filteredhash = bin(cachekey[2]) bcache = cls( tipnode=last, tiprev=lrev, filteredhash=filteredhash, hasnode=hasnode, ) if not bcache.validfor(repo): # invalidate the cache raise ValueError('tip differs') bcache.load(repo, lineiter) except (IOError, OSError): return None except Exception as inst: if repo.ui.debugflag: msg = b'invalid %s: %s\n' repo.ui.debug( msg % ( _branchcachedesc(repo), pycompat.bytestr( inst # pytype: disable=wrong-arg-types ), ) ) bcache = None finally: if f: f.close() return bcache def load(self, repo, lineiter): """ fully loads the branchcache by reading from the file using the line iterator passed""" for line in lineiter: line = line.rstrip(b'\n') if not line: continue node, state, label = line.split(b" ", 2) if state not in b'oc': raise ValueError('invalid branch state') label = encoding.tolocal(label.strip()) node = bin(node) self._entries.setdefault(label, []).append(node) if state == b'c': self._closednodes.add(node) @staticmethod def _filename(repo): """name of a branchcache file for a given repo or repoview""" filename = b"branch2" if repo.filtername: filename = b'%s-%s' % (filename, repo.filtername) return filename def validfor(self, repo): """Is the cache content valid regarding a repo - False when cached tipnode is unknown or if we detect a strip. - True when cache is up to date or a subset of current repo.""" try: return (self.tipnode == repo.changelog.node(self.tiprev)) and ( self.filteredhash == scmutil.filteredhash(repo, self.tiprev) ) except IndexError: return False def _branchtip(self, heads): '''Return tuple with last open head in heads and false, otherwise return last closed head and true.''' tip = heads[-1] closed = True for h in reversed(heads): if h not in self._closednodes: tip = h closed = False break return tip, closed def branchtip(self, branch): '''Return the tipmost open head on branch head, otherwise return the tipmost closed head on branch. Raise KeyError for unknown branch.''' return self._branchtip(self[branch])[0] def iteropen(self, nodes): return (n for n in nodes if n not in self._closednodes) def branchheads(self, branch, closed=False): self._verifybranch(branch) heads = self._entries[branch] if not closed: heads = list(self.iteropen(heads)) return heads def iterbranches(self): for bn, heads in pycompat.iteritems(self): yield (bn, heads) + self._branchtip(heads) def iterheads(self): """ returns all the heads """ self._verifyall() return pycompat.itervalues(self._entries) def copy(self): """return an deep copy of the branchcache object""" return type(self)( self._entries, self.tipnode, self.tiprev, self.filteredhash, self._closednodes, ) def write(self, repo): try: f = repo.cachevfs(self._filename(repo), b"w", atomictemp=True) cachekey = [hex(self.tipnode), b'%d' % self.tiprev] if self.filteredhash is not None: cachekey.append(hex(self.filteredhash)) f.write(b" ".join(cachekey) + b'\n') nodecount = 0 for label, nodes in sorted(pycompat.iteritems(self._entries)): label = encoding.fromlocal(label) for node in nodes: nodecount += 1 if node in self._closednodes: state = b'c' else: state = b'o' f.write(b"%s %s %s\n" % (hex(node), state, label)) f.close() repo.ui.log( b'branchcache', b'wrote %s with %d labels and %d nodes\n', _branchcachedesc(repo), len(self._entries), nodecount, ) except (IOError, OSError, error.Abort) as inst: # Abort may be raised by read only opener, so log and continue repo.ui.debug( b"couldn't write branch cache: %s\n" % stringutil.forcebytestr(inst) ) def update(self, repo, revgen): """Given a branchhead cache, self, that may have extra nodes or be missing heads, and a generator of nodes that are strictly a superset of heads missing, this function updates self to be correct. """ starttime = util.timer() cl = repo.changelog # collect new branch entries newbranches = {} getbranchinfo = repo.revbranchcache().branchinfo for r in revgen: branch, closesbranch = getbranchinfo(r) newbranches.setdefault(branch, []).append(r) if closesbranch: self._closednodes.add(cl.node(r)) # fetch current topological heads to speed up filtering topoheads = set(cl.headrevs()) # new tip revision which we found after iterating items from new # branches ntiprev = self.tiprev # if older branchheads are reachable from new ones, they aren't # really branchheads. Note checking parents is insufficient: # 1 (branch a) -> 2 (branch b) -> 3 (branch a) for branch, newheadrevs in pycompat.iteritems(newbranches): bheads = self._entries.setdefault(branch, []) bheadset = set(cl.rev(node) for node in bheads) # This have been tested True on all internal usage of this function. # run it again in case of doubt # assert not (set(bheadrevs) & set(newheadrevs)) bheadset.update(newheadrevs) # This prunes out two kinds of heads - heads that are superseded by # a head in newheadrevs, and newheadrevs that are not heads because # an existing head is their descendant. uncertain = bheadset - topoheads if uncertain: floorrev = min(uncertain) ancestors = set(cl.ancestors(newheadrevs, floorrev)) bheadset -= ancestors bheadrevs = sorted(bheadset) self[branch] = [cl.node(rev) for rev in bheadrevs] tiprev = bheadrevs[-1] if tiprev > ntiprev: ntiprev = tiprev if ntiprev > self.tiprev: self.tiprev = ntiprev self.tipnode = cl.node(ntiprev) if not self.validfor(repo): # cache key are not valid anymore self.tipnode = nullid self.tiprev = nullrev for heads in self.iterheads(): tiprev = max(cl.rev(node) for node in heads) if tiprev > self.tiprev: self.tipnode = cl.node(tiprev) self.tiprev = tiprev self.filteredhash = scmutil.filteredhash(repo, self.tiprev) duration = util.timer() - starttime repo.ui.log( b'branchcache', b'updated %s in %.4f seconds\n', _branchcachedesc(repo), duration, ) self.write(repo) class remotebranchcache(branchcache): """Branchmap info for a remote connection, should not write locally""" def write(self, repo): pass # Revision branch info cache _rbcversion = b'-v1' _rbcnames = b'rbc-names' + _rbcversion _rbcrevs = b'rbc-revs' + _rbcversion # [4 byte hash prefix][4 byte branch name number with sign bit indicating open] _rbcrecfmt = b'>4sI' _rbcrecsize = calcsize(_rbcrecfmt) _rbcnodelen = 4 _rbcbranchidxmask = 0x7FFFFFFF _rbccloseflag = 0x80000000 class revbranchcache(object): """Persistent cache, mapping from revision number to branch name and close. This is a low level cache, independent of filtering. Branch names are stored in rbc-names in internal encoding separated by 0. rbc-names is append-only, and each branch name is only stored once and will thus have a unique index. The branch info for each revision is stored in rbc-revs as constant size records. The whole file is read into memory, but it is only 'parsed' on demand. The file is usually append-only but will be truncated if repo modification is detected. The record for each revision contains the first 4 bytes of the corresponding node hash, and the record is only used if it still matches. Even a completely trashed rbc-revs fill thus still give the right result while converging towards full recovery ... assuming no incorrectly matching node hashes. The record also contains 4 bytes where 31 bits contains the index of the branch and the last bit indicate that it is a branch close commit. The usage pattern for rbc-revs is thus somewhat similar to 00changelog.i and will grow with it but be 1/8th of its size. """ def __init__(self, repo, readonly=True): assert repo.filtername is None self._repo = repo self._names = [] # branch names in local encoding with static index self._rbcrevs = bytearray() self._rbcsnameslen = 0 # length of names read at _rbcsnameslen try: bndata = repo.cachevfs.read(_rbcnames) self._rbcsnameslen = len(bndata) # for verification before writing if bndata: self._names = [ encoding.tolocal(bn) for bn in bndata.split(b'\0') ] except (IOError, OSError): if readonly: # don't try to use cache - fall back to the slow path self.branchinfo = self._branchinfo if self._names: try: data = repo.cachevfs.read(_rbcrevs) self._rbcrevs[:] = data except (IOError, OSError) as inst: repo.ui.debug( b"couldn't read revision branch cache: %s\n" % stringutil.forcebytestr(inst) ) # remember number of good records on disk self._rbcrevslen = min( len(self._rbcrevs) // _rbcrecsize, len(repo.changelog) ) if self._rbcrevslen == 0: self._names = [] self._rbcnamescount = len(self._names) # number of names read at # _rbcsnameslen def _clear(self): self._rbcsnameslen = 0 del self._names[:] self._rbcnamescount = 0 self._rbcrevslen = len(self._repo.changelog) self._rbcrevs = bytearray(self._rbcrevslen * _rbcrecsize) util.clearcachedproperty(self, b'_namesreverse') @util.propertycache def _namesreverse(self): return dict((b, r) for r, b in enumerate(self._names)) def branchinfo(self, rev): """Return branch name and close flag for rev, using and updating persistent cache.""" changelog = self._repo.changelog rbcrevidx = rev * _rbcrecsize # avoid negative index, changelog.read(nullrev) is fast without cache if rev == nullrev: return changelog.branchinfo(rev) # if requested rev isn't allocated, grow and cache the rev info if len(self._rbcrevs) < rbcrevidx + _rbcrecsize: return self._branchinfo(rev) # fast path: extract data from cache, use it if node is matching reponode = changelog.node(rev)[:_rbcnodelen] cachenode, branchidx = unpack_from( _rbcrecfmt, util.buffer(self._rbcrevs), rbcrevidx ) close = bool(branchidx & _rbccloseflag) if close: branchidx &= _rbcbranchidxmask if cachenode == b'\0\0\0\0': pass elif cachenode == reponode: try: return self._names[branchidx], close except IndexError: # recover from invalid reference to unknown branch self._repo.ui.debug( b"referenced branch names not found" b" - rebuilding revision branch cache from scratch\n" ) self._clear() else: # rev/node map has changed, invalidate the cache from here up self._repo.ui.debug( b"history modification detected - truncating " b"revision branch cache to revision %d\n" % rev ) truncate = rbcrevidx + _rbcrecsize del self._rbcrevs[truncate:] self._rbcrevslen = min(self._rbcrevslen, truncate) # fall back to slow path and make sure it will be written to disk return self._branchinfo(rev) def _branchinfo(self, rev): """Retrieve branch info from changelog and update _rbcrevs""" changelog = self._repo.changelog b, close = changelog.branchinfo(rev) if b in self._namesreverse: branchidx = self._namesreverse[b] else: branchidx = len(self._names) self._names.append(b) self._namesreverse[b] = branchidx reponode = changelog.node(rev) if close: branchidx |= _rbccloseflag self._setcachedata(rev, reponode, branchidx) return b, close def setdata(self, branch, rev, node, close): """add new data information to the cache""" if branch in self._namesreverse: branchidx = self._namesreverse[branch] else: branchidx = len(self._names) self._names.append(branch) self._namesreverse[branch] = branchidx if close: branchidx |= _rbccloseflag self._setcachedata(rev, node, branchidx) # If no cache data were readable (non exists, bad permission, etc) # the cache was bypassing itself by setting: # # self.branchinfo = self._branchinfo # # Since we now have data in the cache, we need to drop this bypassing. if 'branchinfo' in vars(self): del self.branchinfo def _setcachedata(self, rev, node, branchidx): """Writes the node's branch data to the in-memory cache data.""" if rev == nullrev: return rbcrevidx = rev * _rbcrecsize if len(self._rbcrevs) < rbcrevidx + _rbcrecsize: self._rbcrevs.extend( b'\0' * (len(self._repo.changelog) * _rbcrecsize - len(self._rbcrevs)) ) pack_into(_rbcrecfmt, self._rbcrevs, rbcrevidx, node, branchidx) self._rbcrevslen = min(self._rbcrevslen, rev) tr = self._repo.currenttransaction() if tr: tr.addfinalize(b'write-revbranchcache', self.write) def write(self, tr=None): """Save branch cache if it is dirty.""" repo = self._repo wlock = None step = b'' try: # write the new names if self._rbcnamescount < len(self._names): wlock = repo.wlock(wait=False) step = b' names' self._writenames(repo) # write the new revs start = self._rbcrevslen * _rbcrecsize if start != len(self._rbcrevs): step = b'' if wlock is None: wlock = repo.wlock(wait=False) self._writerevs(repo, start) except (IOError, OSError, error.Abort, error.LockError) as inst: repo.ui.debug( b"couldn't write revision branch cache%s: %s\n" % (step, stringutil.forcebytestr(inst)) ) finally: if wlock is not None: wlock.release() def _writenames(self, repo): """ write the new branch names to revbranchcache """ if self._rbcnamescount != 0: f = repo.cachevfs.open(_rbcnames, b'ab') if f.tell() == self._rbcsnameslen: f.write(b'\0') else: f.close() repo.ui.debug(b"%s changed - rewriting it\n" % _rbcnames) self._rbcnamescount = 0 self._rbcrevslen = 0 if self._rbcnamescount == 0: # before rewriting names, make sure references are removed repo.cachevfs.unlinkpath(_rbcrevs, ignoremissing=True) f = repo.cachevfs.open(_rbcnames, b'wb') f.write( b'\0'.join( encoding.fromlocal(b) for b in self._names[self._rbcnamescount :] ) ) self._rbcsnameslen = f.tell() f.close() self._rbcnamescount = len(self._names) def _writerevs(self, repo, start): """ write the new revs to revbranchcache """ revs = min(len(repo.changelog), len(self._rbcrevs) // _rbcrecsize) with repo.cachevfs.open(_rbcrevs, b'ab') as f: if f.tell() != start: repo.ui.debug( b"truncating cache/%s to %d\n" % (_rbcrevs, start) ) f.seek(start) if f.tell() != start: start = 0 f.seek(start) f.truncate() end = revs * _rbcrecsize f.write(self._rbcrevs[start:end]) self._rbcrevslen = revs