Mercurial > hg
view mercurial/dagutil.py @ 25708:d3d32643c060
wireproto: correctly escape batched args and responses (issue4739)
This issue appears to be as old as wireproto batching itself: I can
reproduce the failure as far back as 08ef6b5f3715 trivially by
rebasing the test changes in this patch, which was back in the 1.9
era. I didn't test before that change, because prior to that the
testfile has a different name and I'm lazy.
Note that the test thought it was checking this case, but it actually
wasn't: it put a literal ; in the arg and response for its greet
command, but the mangle/unmangle step defined in the test meant that
instead of "Fo, =;o" going over the wire, "Gp-!><p" went instead,
which doesn't contain any special characters (those being [.=;]) and
thus not exercising the escaping. The test has been updated to use
pre-unmangled special characters, so the request is now "Fo+<:o",
which mangles to "Gp,=;p". I have confirmed that the test fails
without the adjustment to the escaping rules in wireproto.py.
No existing clients of RPC batching were depending on the old behavior
in any way. The only *actual* users of batchable RPCs in core were:
1) largefiles, wherein it batches up many statlfile calls. It sends
hexlified hashes over the wire and gets a 0, 1, or 2 back as a
response. No risk of special characters.
2) setdiscovery, which was using heads() and known(), both of which
communicate via hexlified nodes. Again, no risk of special characters.
Since the escaping functionality has been completely broken since it
was introduced, we know that it has no users. As such, we can change
the escaping mechanism without having to worry about backwards
compatibility issues.
For the curious, this was detected by chance: it happens that the
lz4-compressed text of a test file for remotefilelog compressed to
something containing a ;, which then caused the failure when I moved
remotefilelog to using batching for file content fetching.
author | Augie Fackler <augie@google.com> |
---|---|
date | Tue, 30 Jun 2015 19:19:17 -0400 |
parents | 6ddc86eedc3b |
children | 015ded095933 |
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# dagutil.py - dag utilities for mercurial # # Copyright 2010 Benoit Boissinot <bboissin@gmail.com> # and Peter Arrenbrecht <peter@arrenbrecht.ch> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from node import nullrev from i18n import _ class basedag(object): '''generic interface for DAGs terms: "ix" (short for index) identifies a nodes internally, "id" identifies one externally. All params are ixs unless explicitly suffixed otherwise. Pluralized params are lists or sets. ''' def __init__(self): self._inverse = None def nodeset(self): '''set of all node ixs''' raise NotImplementedError def heads(self): '''list of head ixs''' raise NotImplementedError def parents(self, ix): '''list of parents ixs of ix''' raise NotImplementedError def inverse(self): '''inverse DAG, where parents becomes children, etc.''' raise NotImplementedError def ancestorset(self, starts, stops=None): ''' set of all ancestors of starts (incl), but stop walk at stops (excl) ''' raise NotImplementedError def descendantset(self, starts, stops=None): ''' set of all descendants of starts (incl), but stop walk at stops (excl) ''' return self.inverse().ancestorset(starts, stops) def headsetofconnecteds(self, ixs): ''' subset of connected list of ixs so that no node has a descendant in it By "connected list" we mean that if an ancestor and a descendant are in the list, then so is at least one path connecting them. ''' raise NotImplementedError def externalize(self, ix): '''return a node id''' return self._externalize(ix) def externalizeall(self, ixs): '''return a list of (or set if given a set) of node ids''' ids = self._externalizeall(ixs) if isinstance(ixs, set): return set(ids) return list(ids) def internalize(self, id): '''return a node ix''' return self._internalize(id) def internalizeall(self, ids, filterunknown=False): '''return a list of (or set if given a set) of node ixs''' ixs = self._internalizeall(ids, filterunknown) if isinstance(ids, set): return set(ixs) return list(ixs) class genericdag(basedag): '''generic implementations for DAGs''' def ancestorset(self, starts, stops=None): if stops: stops = set(stops) else: stops = set() seen = set() pending = list(starts) while pending: n = pending.pop() if n not in seen and n not in stops: seen.add(n) pending.extend(self.parents(n)) return seen def headsetofconnecteds(self, ixs): hds = set(ixs) if not hds: return hds for n in ixs: for p in self.parents(n): hds.discard(p) assert hds return hds class revlogbaseddag(basedag): '''generic dag interface to a revlog''' def __init__(self, revlog, nodeset): basedag.__init__(self) self._revlog = revlog self._heads = None self._nodeset = nodeset def nodeset(self): return self._nodeset def heads(self): if self._heads is None: self._heads = self._getheads() return self._heads def _externalize(self, ix): return self._revlog.index[ix][7] def _externalizeall(self, ixs): idx = self._revlog.index return [idx[i][7] for i in ixs] def _internalize(self, id): ix = self._revlog.rev(id) if ix == nullrev: raise LookupError(id, self._revlog.indexfile, _('nullid')) return ix def _internalizeall(self, ids, filterunknown): rl = self._revlog if filterunknown: return [r for r in map(rl.nodemap.get, ids) if (r is not None and r != nullrev and r not in rl.filteredrevs)] return map(self._internalize, ids) class revlogdag(revlogbaseddag): '''dag interface to a revlog''' def __init__(self, revlog): revlogbaseddag.__init__(self, revlog, set(revlog)) def _getheads(self): return [r for r in self._revlog.headrevs() if r != nullrev] def parents(self, ix): rlog = self._revlog idx = rlog.index revdata = idx[ix] prev = revdata[5] if prev != nullrev: prev2 = revdata[6] if prev2 == nullrev: return [prev] return [prev, prev2] prev2 = revdata[6] if prev2 != nullrev: return [prev2] return [] def inverse(self): if self._inverse is None: self._inverse = inverserevlogdag(self) return self._inverse def ancestorset(self, starts, stops=None): rlog = self._revlog idx = rlog.index if stops: stops = set(stops) else: stops = set() seen = set() pending = list(starts) while pending: rev = pending.pop() if rev not in seen and rev not in stops: seen.add(rev) revdata = idx[rev] for i in [5, 6]: prev = revdata[i] if prev != nullrev: pending.append(prev) return seen def headsetofconnecteds(self, ixs): if not ixs: return set() rlog = self._revlog idx = rlog.index headrevs = set(ixs) for rev in ixs: revdata = idx[rev] for i in [5, 6]: prev = revdata[i] if prev != nullrev: headrevs.discard(prev) assert headrevs return headrevs def linearize(self, ixs): '''linearize and topologically sort a list of revisions The linearization process tries to create long runs of revs where a child rev comes immediately after its first parent. This is done by visiting the heads of the given revs in inverse topological order, and for each visited rev, visiting its second parent, then its first parent, then adding the rev itself to the output list. ''' sorted = [] visit = list(self.headsetofconnecteds(ixs)) visit.sort(reverse=True) finished = set() while visit: cur = visit.pop() if cur < 0: cur = -cur - 1 if cur not in finished: sorted.append(cur) finished.add(cur) else: visit.append(-cur - 1) visit += [p for p in self.parents(cur) if p in ixs and p not in finished] assert len(sorted) == len(ixs) return sorted class inverserevlogdag(revlogbaseddag, genericdag): '''inverse of an existing revlog dag; see revlogdag.inverse()''' def __init__(self, orig): revlogbaseddag.__init__(self, orig._revlog, orig._nodeset) self._orig = orig self._children = {} self._roots = [] self._walkfrom = len(self._revlog) - 1 def _walkto(self, walkto): rev = self._walkfrom cs = self._children roots = self._roots idx = self._revlog.index while rev >= walkto: data = idx[rev] isroot = True for prev in [data[5], data[6]]: # parent revs if prev != nullrev: cs.setdefault(prev, []).append(rev) isroot = False if isroot: roots.append(rev) rev -= 1 self._walkfrom = rev def _getheads(self): self._walkto(nullrev) return self._roots def parents(self, ix): if ix is None: return [] if ix <= self._walkfrom: self._walkto(ix) return self._children.get(ix, []) def inverse(self): return self._orig