wireprotov2: define and use stream encoders
Now that we have basic support for defining stream encoding, it is
time to start doing something with it.
We define various classes implementing stream encoders/decoders for
the defined encoding profiles. This is relatively straightforward.
We teach the inputstream and outputstream classes how to encode,
decode, and flush data.
We then teach the clientreactor how to filter received data through
the inputstream decoder.
One of the features of the framing format is that streams can span
requests. This is a differentiating feature from say HTTP/2, which
associates streams with requests. By allowing streams to span requests,
we can reuse compression context data across requests/responses. But
in order to do this, we need a mechanism to "flush" the encoder at
logical boundaries so that receivers receive all data where it is
expected. And a "flush" event is distinct from a "finish" event from
the perspective of certain compressors because a "flush" will retain
compression context state whereas a "finish" operation will not. This
is why encoders have both a flush() and a finish() and each uses
specific flushing semantics on the underlying compressor.
The added tests verify various behavior of decoders via clientreactor.
These tests do test some compression behavior via use of outputstream.
But for all intents and purposes, server reactor support for encoding
is not yet implemented.
Differential Revision: https://phab.mercurial-scm.org/D4921
# filelog.py - file history class for mercurial
#
# 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
from . import (
error,
repository,
revlog,
)
from .utils import (
interfaceutil,
storageutil,
)
@interfaceutil.implementer(repository.ifilestorage)
class filelog(object):
def __init__(self, opener, path):
self._revlog = revlog.revlog(opener,
'/'.join(('data', path + '.i')),
censorable=True)
# Full name of the user visible file, relative to the repository root.
# Used by LFS.
self._revlog.filename = path
def __len__(self):
return len(self._revlog)
def __iter__(self):
return self._revlog.__iter__()
def revs(self, start=0, stop=None):
return self._revlog.revs(start=start, stop=stop)
def parents(self, node):
return self._revlog.parents(node)
def parentrevs(self, rev):
return self._revlog.parentrevs(rev)
def rev(self, node):
return self._revlog.rev(node)
def node(self, rev):
return self._revlog.node(rev)
def lookup(self, node):
return storageutil.fileidlookup(self._revlog, node,
self._revlog.indexfile)
def linkrev(self, rev):
return self._revlog.linkrev(rev)
def commonancestorsheads(self, node1, node2):
return self._revlog.commonancestorsheads(node1, node2)
# Used by dagop.blockdescendants().
def descendants(self, revs):
return self._revlog.descendants(revs)
def heads(self, start=None, stop=None):
return self._revlog.heads(start, stop)
# Used by hgweb, children extension.
def children(self, node):
return self._revlog.children(node)
def iscensored(self, rev):
return self._revlog.iscensored(rev)
def revision(self, node, _df=None, raw=False):
return self._revlog.revision(node, _df=_df, raw=raw)
def emitrevisions(self, nodes, nodesorder=None,
revisiondata=False, assumehaveparentrevisions=False,
deltaprevious=False):
return self._revlog.emitrevisions(
nodes, nodesorder=nodesorder, revisiondata=revisiondata,
assumehaveparentrevisions=assumehaveparentrevisions,
deltaprevious=deltaprevious)
def addrevision(self, revisiondata, transaction, linkrev, p1, p2,
node=None, flags=revlog.REVIDX_DEFAULT_FLAGS,
cachedelta=None):
return self._revlog.addrevision(revisiondata, transaction, linkrev,
p1, p2, node=node, flags=flags,
cachedelta=cachedelta)
def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None):
return self._revlog.addgroup(deltas, linkmapper, transaction,
addrevisioncb=addrevisioncb)
def getstrippoint(self, minlink):
return self._revlog.getstrippoint(minlink)
def strip(self, minlink, transaction):
return self._revlog.strip(minlink, transaction)
def censorrevision(self, tr, node, tombstone=b''):
return self._revlog.censorrevision(tr, node, tombstone=tombstone)
def files(self):
return self._revlog.files()
def read(self, node):
return storageutil.filtermetadata(self.revision(node))
def add(self, text, meta, transaction, link, p1=None, p2=None):
if meta or text.startswith('\1\n'):
text = storageutil.packmeta(meta, text)
return self.addrevision(text, transaction, link, p1, p2)
def renamed(self, node):
return storageutil.filerevisioncopied(self, node)
def size(self, rev):
"""return the size of a given revision"""
# for revisions with renames, we have to go the slow way
node = self.node(rev)
if self.renamed(node):
return len(self.read(node))
if self.iscensored(rev):
return 0
# XXX if self.read(node).startswith("\1\n"), this returns (size+4)
return self._revlog.size(rev)
def cmp(self, node, text):
"""compare text with a given file revision
returns True if text is different than what is stored.
"""
return not storageutil.filedataequivalent(self, node, text)
def verifyintegrity(self, state):
return self._revlog.verifyintegrity(state)
def storageinfo(self, exclusivefiles=False, sharedfiles=False,
revisionscount=False, trackedsize=False,
storedsize=False):
return self._revlog.storageinfo(
exclusivefiles=exclusivefiles, sharedfiles=sharedfiles,
revisionscount=revisionscount, trackedsize=trackedsize,
storedsize=storedsize)
# TODO these aren't part of the interface and aren't internal methods.
# Callers should be fixed to not use them.
# Used by bundlefilelog, unionfilelog.
@property
def indexfile(self):
return self._revlog.indexfile
@indexfile.setter
def indexfile(self, value):
self._revlog.indexfile = value
# Used by repo upgrade.
def clone(self, tr, destrevlog, **kwargs):
if not isinstance(destrevlog, filelog):
raise error.ProgrammingError('expected filelog to clone()')
return self._revlog.clone(tr, destrevlog._revlog, **kwargs)
class narrowfilelog(filelog):
"""Filelog variation to be used with narrow stores."""
def __init__(self, opener, path, narrowmatch):
super(narrowfilelog, self).__init__(opener, path)
self._narrowmatch = narrowmatch
def renamed(self, node):
res = super(narrowfilelog, self).renamed(node)
# Renames that come from outside the narrowspec are problematic
# because we may lack the base text for the rename. This can result
# in code attempting to walk the ancestry or compute a diff
# encountering a missing revision. We address this by silently
# removing rename metadata if the source file is outside the
# narrow spec.
#
# A better solution would be to see if the base revision is available,
# rather than assuming it isn't.
#
# An even better solution would be to teach all consumers of rename
# metadata that the base revision may not be available.
#
# TODO consider better ways of doing this.
if res and not self._narrowmatch(res[0]):
return None
return res
def size(self, rev):
# Because we have a custom renamed() that may lie, we need to call
# the base renamed() to report accurate results.
node = self.node(rev)
if super(narrowfilelog, self).renamed(node):
return len(self.read(node))
else:
return super(narrowfilelog, self).size(rev)
def cmp(self, node, text):
different = super(narrowfilelog, self).cmp(node, text)
# Because renamed() may lie, we may get false positives for
# different content. Check for this by comparing against the original
# renamed() implementation.
if different:
if super(narrowfilelog, self).renamed(node):
t2 = self.read(node)
return t2 != text
return different