##// END OF EJS Templates
wireprotov2peer: stream decoded responses...
wireprotov2peer: stream decoded responses Previously, wire protocol version 2 would buffer all response data. Only once all data was received did we CBOR decode it and resolve the future associated with the command. This was obviously not desirable. In future commits that introduce large response payloads, this caused significant memory bloat and slowed down client operations due to waiting on the server. This commit refactors the response handling code so that response data can be streamed. Command response objects now contain a buffered CBOR decoder. As new data arrives, it is fed into the decoder. Decoded objects are made available to the generator as they are decoded. Because there is a separate thread processing incoming frames and feeding data into the response object, there is the potential for race conditions when mutating response objects. So a lock has been added to guard access to critical state variables. Because the generator emitting decoded objects needs to wait on those objects to become available, we've added an Event for the generator to wait on so it doesn't busy loop. This does mean there is the potential for deadlocks. And I'm pretty sure they can occur in some scenarios. We already have a handful of TODOs around this. But I've added some more. Fixing this will likely require moving the background thread receiving frames into clienthandler. We likely would have done this anyway when implementing the client bits for the SSH transport. Test output changes because the initial CBOR map holding the overall response state is now always handled internally by the response object. Differential Revision: https://phab.mercurial-scm.org/D4474

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filelog.py
227 lines | 6.6 KiB | text/x-python | PythonLexer
# 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,
)
@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
self.filename = path
self.index = self._revlog.index
self.version = self._revlog.version
self._generaldelta = self._revlog._generaldelta
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 self._revlog.lookup(node)
def linkrev(self, rev):
return self._revlog.linkrev(rev)
def flags(self, rev):
return self._revlog.flags(rev)
def commonancestorsheads(self, node1, node2):
return self._revlog.commonancestorsheads(node1, node2)
def descendants(self, revs):
return self._revlog.descendants(revs)
def headrevs(self):
return self._revlog.headrevs()
def heads(self, start=None, stop=None):
return self._revlog.heads(start, stop)
def children(self, node):
return self._revlog.children(node)
def deltaparent(self, rev):
return self._revlog.deltaparent(rev)
def iscensored(self, rev):
return self._revlog.iscensored(rev)
def rawsize(self, rev):
return self._revlog.rawsize(rev)
def checkhash(self, text, node, p1=None, p2=None, rev=None):
return self._revlog.checkhash(text, node, p1=p1, p2=p2, rev=rev)
def revision(self, node, _df=None, raw=False):
return self._revlog.revision(node, _df=_df, raw=raw)
def revdiff(self, rev1, rev2):
return self._revlog.revdiff(rev1, rev2)
def emitrevisiondeltas(self, requests):
return self._revlog.emitrevisiondeltas(requests)
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 files(self):
return self._revlog.files()
def checksize(self):
return self._revlog.checksize()
def read(self, node):
t = self.revision(node)
if not t.startswith('\1\n'):
return t
s = t.index('\1\n', 2)
return t[s + 2:]
def add(self, text, meta, transaction, link, p1=None, p2=None):
if meta or text.startswith('\1\n'):
text = revlog.packmeta(meta, text)
return self.addrevision(text, transaction, link, p1, p2)
def renamed(self, node):
if self.parents(node)[0] != revlog.nullid:
return False
t = self.revision(node)
m = revlog.parsemeta(t)[0]
# copy and copyrev occur in pairs. In rare cases due to bugs,
# one can occur without the other.
if m and "copy" in m and "copyrev" in m:
return (m["copy"], revlog.bin(m["copyrev"]))
return False
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.
"""
t = text
if text.startswith('\1\n'):
t = '\1\n\1\n' + text
samehashes = not self._revlog.cmp(node, t)
if samehashes:
return False
# censored files compare against the empty file
if self.iscensored(self.rev(node)):
return text != ''
# renaming a file produces a different hash, even if the data
# remains unchanged. Check if it's the case (slow):
if self.renamed(node):
t2 = self.read(node)
return t2 != text
return True
@property
def filename(self):
return self._revlog.filename
@filename.setter
def filename(self, value):
self._revlog.filename = value
# TODO these aren't part of the interface and aren't internal methods.
# Callers should be fixed to not use them.
@property
def indexfile(self):
return self._revlog.indexfile
@indexfile.setter
def indexfile(self, value):
self._revlog.indexfile = value
@property
def datafile(self):
return self._revlog.datafile
@property
def opener(self):
return self._revlog.opener
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)
def start(self, rev):
return self._revlog.start(rev)
def end(self, rev):
return self._revlog.end(rev)
def length(self, rev):
return self._revlog.length(rev)
def compress(self, data):
return self._revlog.compress(data)
def _addrevision(self, *args, **kwargs):
return self._revlog._addrevision(*args, **kwargs)