Mercurial > hg
view mercurial/unionrepo.py @ 37052:8c3c47362934
wireproto: implement basic frame reading and processing
We just implemented support for writing frames. Now let's implement
support for reading them.
The bulk of the new code is for a class that maintains the state of
a server. Essentially, you construct an instance, feed frames to it,
and it tells you what you should do next. The design is inspired by
the "sans I/O" movement and the reactor pattern. We don't want to
perform I/O or any major blocking event during frame ingestion because
this arbitrarily limits ways that server pieces can be implemented.
For example, it makes it much harder to swap in an alternate
implementation based on asyncio or do crazy things like have requests
dispatch to other processes.
We do still implement readframe() which does I/O. But it is decoupled
from the server reactor. And important parsing of frame headers is
a standalone function. So I/O is only needed to obtain frame data.
Because testing server-side ingest is useful and difficult on running
servers, we create a new "debugreflect" endpoint that will echo back
to the client what was received and how it was interpreted. This could
be useful for a server admin, someone implementing a client. But
immediately, it is useful for testing: we're able to demonstrate that
frames are parsed correctly and turned into requests to run commands
without having to implement command dispatch on the server!
In addition, we implement Python level unit tests for the reactor.
This is vastly more efficient than sending requests to the
"debugreflect" endpoint and vastly more powerful for advanced
testing.
Differential Revision: https://phab.mercurial-scm.org/D2852
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 14 Mar 2018 15:25:06 -0700 |
parents | 21fc747e1bc5 |
children | 1541e1a8e87d |
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# unionrepo.py - repository class for viewing union of repository changesets # # Derived from bundlerepo.py # Copyright 2006, 2007 Benoit Boissinot <bboissin@gmail.com> # Copyright 2013 Unity Technologies, Mads Kiilerich <madski@unity3d.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Repository class for "in-memory pull" of one local repository to another, allowing operations like diff and log with revsets. """ from __future__ import absolute_import from .i18n import _ from .node import nullid from . import ( changelog, cmdutil, error, filelog, localrepo, manifest, mdiff, pathutil, pycompat, revlog, util, vfs as vfsmod, ) class unionrevlog(revlog.revlog): def __init__(self, opener, indexfile, revlog2, linkmapper): # How it works: # To retrieve a revision, we just need to know the node id so we can # look it up in revlog2. # # To differentiate a rev in the second revlog from a rev in the revlog, # we check revision against repotiprev. opener = vfsmod.readonlyvfs(opener) revlog.revlog.__init__(self, opener, indexfile) self.revlog2 = revlog2 n = len(self) self.repotiprev = n - 1 self.bundlerevs = set() # used by 'bundle()' revset expression for rev2 in self.revlog2: rev = self.revlog2.index[rev2] # rev numbers - in revlog2, very different from self.rev _start, _csize, _rsize, base, linkrev, p1rev, p2rev, node = rev flags = _start & 0xFFFF if linkmapper is None: # link is to same revlog assert linkrev == rev2 # we never link back link = n else: # rev must be mapped from repo2 cl to unified cl by linkmapper link = linkmapper(linkrev) if linkmapper is not None: # link is to same revlog base = linkmapper(base) if node in self.nodemap: # this happens for the common revlog revisions self.bundlerevs.add(self.nodemap[node]) continue p1node = self.revlog2.node(p1rev) p2node = self.revlog2.node(p2rev) e = (flags, None, None, base, link, self.rev(p1node), self.rev(p2node), node) self.index.insert(-1, e) self.nodemap[node] = n self.bundlerevs.add(n) n += 1 def _chunk(self, rev): if rev <= self.repotiprev: return revlog.revlog._chunk(self, rev) return self.revlog2._chunk(self.node(rev)) def revdiff(self, rev1, rev2): """return or calculate a delta between two revisions""" if rev1 > self.repotiprev and rev2 > self.repotiprev: return self.revlog2.revdiff( self.revlog2.rev(self.node(rev1)), self.revlog2.rev(self.node(rev2))) elif rev1 <= self.repotiprev and rev2 <= self.repotiprev: return self.baserevdiff(rev1, rev2) return mdiff.textdiff(self.revision(rev1), self.revision(rev2)) def revision(self, nodeorrev, raw=False): """return an uncompressed revision of a given node or revision number. """ if isinstance(nodeorrev, int): rev = nodeorrev node = self.node(rev) else: node = nodeorrev rev = self.rev(node) if node == nullid: return "" if rev > self.repotiprev: text = self.revlog2.revision(node) self._cache = (node, rev, text) else: text = self.baserevision(rev) # already cached return text def baserevision(self, nodeorrev): # Revlog subclasses may override 'revision' method to modify format of # content retrieved from revlog. To use unionrevlog with such class one # needs to override 'baserevision' and make more specific call here. return revlog.revlog.revision(self, nodeorrev) def baserevdiff(self, rev1, rev2): # Exists for the same purpose as baserevision. return revlog.revlog.revdiff(self, rev1, rev2) def addrevision(self, text, transaction, link, p1=None, p2=None, d=None): raise NotImplementedError def addgroup(self, deltas, transaction, addrevisioncb=None): raise NotImplementedError def strip(self, rev, minlink): raise NotImplementedError def checksize(self): raise NotImplementedError class unionchangelog(unionrevlog, changelog.changelog): def __init__(self, opener, opener2): changelog.changelog.__init__(self, opener) linkmapper = None changelog2 = changelog.changelog(opener2) unionrevlog.__init__(self, opener, self.indexfile, changelog2, linkmapper) def baserevision(self, nodeorrev): # Although changelog doesn't override 'revision' method, some extensions # may replace this class with another that does. Same story with # manifest and filelog classes. return changelog.changelog.revision(self, nodeorrev) def baserevdiff(self, rev1, rev2): return changelog.changelog.revdiff(self, rev1, rev2) class unionmanifest(unionrevlog, manifest.manifestrevlog): def __init__(self, opener, opener2, linkmapper): manifest.manifestrevlog.__init__(self, opener) manifest2 = manifest.manifestrevlog(opener2) unionrevlog.__init__(self, opener, self.indexfile, manifest2, linkmapper) def baserevision(self, nodeorrev): return manifest.manifestrevlog.revision(self, nodeorrev) def baserevdiff(self, rev1, rev2): return manifest.manifestrevlog.revdiff(self, rev1, rev2) class unionfilelog(unionrevlog, filelog.filelog): def __init__(self, opener, path, opener2, linkmapper, repo): filelog.filelog.__init__(self, opener, path) filelog2 = filelog.filelog(opener2, path) unionrevlog.__init__(self, opener, self.indexfile, filelog2, linkmapper) self._repo = repo def baserevision(self, nodeorrev): return filelog.filelog.revision(self, nodeorrev) def baserevdiff(self, rev1, rev2): return filelog.filelog.revdiff(self, rev1, rev2) def iscensored(self, rev): """Check if a revision is censored.""" if rev <= self.repotiprev: return filelog.filelog.iscensored(self, rev) node = self.node(rev) return self.revlog2.iscensored(self.revlog2.rev(node)) class unionpeer(localrepo.localpeer): def canpush(self): return False class unionrepository(localrepo.localrepository): def __init__(self, ui, path, path2): localrepo.localrepository.__init__(self, ui, path) self.ui.setconfig('phases', 'publish', False, 'unionrepo') self._url = 'union:%s+%s' % (util.expandpath(path), util.expandpath(path2)) self.repo2 = localrepo.localrepository(ui, path2) @localrepo.unfilteredpropertycache def changelog(self): return unionchangelog(self.svfs, self.repo2.svfs) def _clrev(self, rev2): """map from repo2 changelog rev to temporary rev in self.changelog""" node = self.repo2.changelog.node(rev2) return self.changelog.rev(node) def _constructmanifest(self): return unionmanifest(self.svfs, self.repo2.svfs, self.unfiltered()._clrev) def url(self): return self._url def file(self, f): return unionfilelog(self.svfs, f, self.repo2.svfs, self.unfiltered()._clrev, self) def close(self): self.repo2.close() def cancopy(self): return False def peer(self): return unionpeer(self) def getcwd(self): return pycompat.getcwd() # always outside the repo def instance(ui, path, create): if create: raise error.Abort(_('cannot create new union repository')) parentpath = ui.config("bundle", "mainreporoot") if not parentpath: # try to find the correct path to the working directory repo parentpath = cmdutil.findrepo(pycompat.getcwd()) if parentpath is None: parentpath = '' if parentpath: # Try to make the full path relative so we get a nice, short URL. # In particular, we don't want temp dir names in test outputs. cwd = pycompat.getcwd() if parentpath == cwd: parentpath = '' else: cwd = pathutil.normasprefix(cwd) if parentpath.startswith(cwd): parentpath = parentpath[len(cwd):] if path.startswith('union:'): s = path.split(":", 1)[1].split("+", 1) if len(s) == 1: repopath, repopath2 = parentpath, s[0] else: repopath, repopath2 = s else: repopath, repopath2 = parentpath, path return unionrepository(ui, repopath, repopath2)