debugcommands: add debugwireproto command
We currently don't have a low-level mechanism for sending
arbitrary wire protocol commands. Having a generic and robust
mechanism for sending wire protocol commands, examining wire
data, etc would make it vastly easier to test the wire protocol
and debug server operation. This is a problem I've wanted a
solution for numerous times, especially recently as I've been
hacking on a new version of the wire protocol.
This commit establishes a `hg debugwireproto` command for sending
data to a peer.
The command invents a mini language for specifying actions to take.
This will enable a lot of flexibility for issuing commands and testing
variations for how commands are sent.
Right now, we only support low-level raw sends and receives. These
are probably the least valuable commands to intended users of this
command. But they are the most useful commands to implement to
bootstrap the feature (I've chosen to reimplement test-ssh-proto.t
using this command to prove its usefulness).
My eventual goal of `hg debugwireproto` is to allow calling wire
protocol commands with a human-friendly interface. Essentially,
people can type in a command name and arguments and
`hg debugwireproto` will figure out how to send that on the wire.
I'd love to eventually be able to save the server's raw response
to a file. This would allow us to e.g. call "getbundle" wire
protocol commands easily.
test-ssh-proto.t has been updated to use the new command in lieu
of piping directly to a server process. As part of the transition,
test behavior improved. Before, we piped all request data to the
server at once. Now, we have explicit control over the ordering of
operations. e.g. we can send one command, receive its response,
then send another command. This will allow us to more robustly
test race conditions, buffering behavior, etc.
There were some subtle changes in test behavior. For example,
previous behavior would often send trailing newlines to the server.
The new mechanism doesn't treat literal newlines specially and
requires newlines be escaped in the payload.
Because the new logging code is very low level, it is easy to
introduce race conditions in tests. For example, the number of bytes
returned by a read() may vary depending on load. This is why tests
make heavy use of "readline" for consuming data: the result of
that operation should be deterministic and not subject to race
conditions. There are still some uses of "readavailable." However,
those are only for reading from stderr. I was able to reproduce
timing issues with my system under load when using "readavailable"
globally. But if I "readline" to grab stdout, "readavailable"
appears to work deterministically for stderr. I think this is
because the server writes to stderr first. As long as the OS
delivers writes to pipes in the same order they were made, this
should work. If there are timing issues, we can introduce a
mechanism to readline from stderr.
Differential Revision: https://phab.mercurial-scm.org/D2392
""" Mercurial phases support code
---
Copyright 2011 Pierre-Yves David <pierre-yves.david@ens-lyon.org>
Logilab SA <contact@logilab.fr>
Augie Fackler <durin42@gmail.com>
This software may be used and distributed according to the terms
of the GNU General Public License version 2 or any later version.
---
This module implements most phase logic in mercurial.
Basic Concept
=============
A 'changeset phase' is an indicator that tells us how a changeset is
manipulated and communicated. The details of each phase is described
below, here we describe the properties they have in common.
Like bookmarks, phases are not stored in history and thus are not
permanent and leave no audit trail.
First, no changeset can be in two phases at once. Phases are ordered,
so they can be considered from lowest to highest. The default, lowest
phase is 'public' - this is the normal phase of existing changesets. A
child changeset can not be in a lower phase than its parents.
These phases share a hierarchy of traits:
immutable shared
public: X X
draft: X
secret:
Local commits are draft by default.
Phase Movement and Exchange
===========================
Phase data is exchanged by pushkey on pull and push. Some servers have
a publish option set, we call such a server a "publishing server".
Pushing a draft changeset to a publishing server changes the phase to
public.
A small list of fact/rules define the exchange of phase:
* old client never changes server states
* pull never changes server states
* publish and old server changesets are seen as public by client
* any secret changeset seen in another repository is lowered to at
least draft
Here is the final table summing up the 49 possible use cases of phase
exchange:
server
old publish non-publish
N X N D P N D P
old client
pull
N - X/X - X/D X/P - X/D X/P
X - X/X - X/D X/P - X/D X/P
push
X X/X X/X X/P X/P X/P X/D X/D X/P
new client
pull
N - P/X - P/D P/P - D/D P/P
D - P/X - P/D P/P - D/D P/P
P - P/X - P/D P/P - P/D P/P
push
D P/X P/X P/P P/P P/P D/D D/D P/P
P P/X P/X P/P P/P P/P P/P P/P P/P
Legend:
A/B = final state on client / state on server
* N = new/not present,
* P = public,
* D = draft,
* X = not tracked (i.e., the old client or server has no internal
way of recording the phase.)
passive = only pushes
A cell here can be read like this:
"When a new client pushes a draft changeset (D) to a publishing
server where it's not present (N), it's marked public on both
sides (P/P)."
Note: old client behave as a publishing server with draft only content
- other people see it as public
- content is pushed as draft
"""
from __future__ import absolute_import
import errno
import struct
from .i18n import _
from .node import (
bin,
hex,
nullid,
nullrev,
short,
)
from . import (
error,
pycompat,
smartset,
txnutil,
util,
)
_fphasesentry = struct.Struct('>i20s')
allphases = public, draft, secret = range(3)
trackedphases = allphases[1:]
phasenames = ['public', 'draft', 'secret']
def _readroots(repo, phasedefaults=None):
"""Read phase roots from disk
phasedefaults is a list of fn(repo, roots) callable, which are
executed if the phase roots file does not exist. When phases are
being initialized on an existing repository, this could be used to
set selected changesets phase to something else than public.
Return (roots, dirty) where dirty is true if roots differ from
what is being stored.
"""
repo = repo.unfiltered()
dirty = False
roots = [set() for i in allphases]
try:
f, pending = txnutil.trypending(repo.root, repo.svfs, 'phaseroots')
try:
for line in f:
phase, nh = line.split()
roots[int(phase)].add(bin(nh))
finally:
f.close()
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
if phasedefaults:
for f in phasedefaults:
roots = f(repo, roots)
dirty = True
return roots, dirty
def binaryencode(phasemapping):
"""encode a 'phase -> nodes' mapping into a binary stream
Since phases are integer the mapping is actually a python list:
[[PUBLIC_HEADS], [DRAFTS_HEADS], [SECRET_HEADS]]
"""
binarydata = []
for phase, nodes in enumerate(phasemapping):
for head in nodes:
binarydata.append(_fphasesentry.pack(phase, head))
return ''.join(binarydata)
def binarydecode(stream):
"""decode a binary stream into a 'phase -> nodes' mapping
Since phases are integer the mapping is actually a python list."""
headsbyphase = [[] for i in allphases]
entrysize = _fphasesentry.size
while True:
entry = stream.read(entrysize)
if len(entry) < entrysize:
if entry:
raise error.Abort(_('bad phase-heads stream'))
break
phase, node = _fphasesentry.unpack(entry)
headsbyphase[phase].append(node)
return headsbyphase
def _trackphasechange(data, rev, old, new):
"""add a phase move the <data> dictionnary
If data is None, nothing happens.
"""
if data is None:
return
existing = data.get(rev)
if existing is not None:
old = existing[0]
data[rev] = (old, new)
class phasecache(object):
def __init__(self, repo, phasedefaults, _load=True):
if _load:
# Cheap trick to allow shallow-copy without copy module
self.phaseroots, self.dirty = _readroots(repo, phasedefaults)
self._loadedrevslen = 0
self._phasesets = None
self.filterunknown(repo)
self.opener = repo.svfs
def getrevset(self, repo, phases, subset=None):
"""return a smartset for the given phases"""
self.loadphaserevs(repo) # ensure phase's sets are loaded
phases = set(phases)
if public not in phases:
# fast path: _phasesets contains the interesting sets,
# might only need a union and post-filtering.
if len(phases) == 1:
[p] = phases
revs = self._phasesets[p]
else:
revs = set.union(*[self._phasesets[p] for p in phases])
if repo.changelog.filteredrevs:
revs = revs - repo.changelog.filteredrevs
if subset is None:
return smartset.baseset(revs)
else:
return subset & smartset.baseset(revs)
else:
phases = set(allphases).difference(phases)
if not phases:
return smartset.fullreposet(repo)
if len(phases) == 1:
[p] = phases
revs = self._phasesets[p]
else:
revs = set.union(*[self._phasesets[p] for p in phases])
if subset is None:
subset = smartset.fullreposet(repo)
if not revs:
return subset
return subset.filter(lambda r: r not in revs)
def copy(self):
# Shallow copy meant to ensure isolation in
# advance/retractboundary(), nothing more.
ph = self.__class__(None, None, _load=False)
ph.phaseroots = self.phaseroots[:]
ph.dirty = self.dirty
ph.opener = self.opener
ph._loadedrevslen = self._loadedrevslen
ph._phasesets = self._phasesets
return ph
def replace(self, phcache):
"""replace all values in 'self' with content of phcache"""
for a in ('phaseroots', 'dirty', 'opener', '_loadedrevslen',
'_phasesets'):
setattr(self, a, getattr(phcache, a))
def _getphaserevsnative(self, repo):
repo = repo.unfiltered()
nativeroots = []
for phase in trackedphases:
nativeroots.append(map(repo.changelog.rev, self.phaseroots[phase]))
return repo.changelog.computephases(nativeroots)
def _computephaserevspure(self, repo):
repo = repo.unfiltered()
cl = repo.changelog
self._phasesets = [set() for phase in allphases]
roots = pycompat.maplist(cl.rev, self.phaseroots[secret])
if roots:
ps = set(cl.descendants(roots))
for root in roots:
ps.add(root)
self._phasesets[secret] = ps
roots = pycompat.maplist(cl.rev, self.phaseroots[draft])
if roots:
ps = set(cl.descendants(roots))
for root in roots:
ps.add(root)
ps.difference_update(self._phasesets[secret])
self._phasesets[draft] = ps
self._loadedrevslen = len(cl)
def loadphaserevs(self, repo):
"""ensure phase information is loaded in the object"""
if self._phasesets is None:
try:
res = self._getphaserevsnative(repo)
self._loadedrevslen, self._phasesets = res
except AttributeError:
self._computephaserevspure(repo)
def invalidate(self):
self._loadedrevslen = 0
self._phasesets = None
def phase(self, repo, rev):
# We need a repo argument here to be able to build _phasesets
# if necessary. The repository instance is not stored in
# phasecache to avoid reference cycles. The changelog instance
# is not stored because it is a filecache() property and can
# be replaced without us being notified.
if rev == nullrev:
return public
if rev < nullrev:
raise ValueError(_('cannot lookup negative revision'))
if rev >= self._loadedrevslen:
self.invalidate()
self.loadphaserevs(repo)
for phase in trackedphases:
if rev in self._phasesets[phase]:
return phase
return public
def write(self):
if not self.dirty:
return
f = self.opener('phaseroots', 'w', atomictemp=True, checkambig=True)
try:
self._write(f)
finally:
f.close()
def _write(self, fp):
for phase, roots in enumerate(self.phaseroots):
for h in sorted(roots):
fp.write('%i %s\n' % (phase, hex(h)))
self.dirty = False
def _updateroots(self, phase, newroots, tr):
self.phaseroots[phase] = newroots
self.invalidate()
self.dirty = True
tr.addfilegenerator('phase', ('phaseroots',), self._write)
tr.hookargs['phases_moved'] = '1'
def registernew(self, repo, tr, targetphase, nodes):
repo = repo.unfiltered()
self._retractboundary(repo, tr, targetphase, nodes)
if tr is not None and 'phases' in tr.changes:
phasetracking = tr.changes['phases']
torev = repo.changelog.rev
phase = self.phase
for n in nodes:
rev = torev(n)
revphase = phase(repo, rev)
_trackphasechange(phasetracking, rev, None, revphase)
repo.invalidatevolatilesets()
def advanceboundary(self, repo, tr, targetphase, nodes):
"""Set all 'nodes' to phase 'targetphase'
Nodes with a phase lower than 'targetphase' are not affected.
"""
# Be careful to preserve shallow-copied values: do not update
# phaseroots values, replace them.
if tr is None:
phasetracking = None
else:
phasetracking = tr.changes.get('phases')
repo = repo.unfiltered()
delroots = [] # set of root deleted by this path
for phase in xrange(targetphase + 1, len(allphases)):
# filter nodes that are not in a compatible phase already
nodes = [n for n in nodes
if self.phase(repo, repo[n].rev()) >= phase]
if not nodes:
break # no roots to move anymore
olds = self.phaseroots[phase]
affected = repo.revs('%ln::%ln', olds, nodes)
for r in affected:
_trackphasechange(phasetracking, r, self.phase(repo, r),
targetphase)
roots = set(ctx.node() for ctx in repo.set(
'roots((%ln::) - %ld)', olds, affected))
if olds != roots:
self._updateroots(phase, roots, tr)
# some roots may need to be declared for lower phases
delroots.extend(olds - roots)
# declare deleted root in the target phase
if targetphase != 0:
self._retractboundary(repo, tr, targetphase, delroots)
repo.invalidatevolatilesets()
def retractboundary(self, repo, tr, targetphase, nodes):
oldroots = self.phaseroots[:targetphase + 1]
if tr is None:
phasetracking = None
else:
phasetracking = tr.changes.get('phases')
repo = repo.unfiltered()
if (self._retractboundary(repo, tr, targetphase, nodes)
and phasetracking is not None):
# find the affected revisions
new = self.phaseroots[targetphase]
old = oldroots[targetphase]
affected = set(repo.revs('(%ln::) - (%ln::)', new, old))
# find the phase of the affected revision
for phase in xrange(targetphase, -1, -1):
if phase:
roots = oldroots[phase]
revs = set(repo.revs('%ln::%ld', roots, affected))
affected -= revs
else: # public phase
revs = affected
for r in revs:
_trackphasechange(phasetracking, r, phase, targetphase)
repo.invalidatevolatilesets()
def _retractboundary(self, repo, tr, targetphase, nodes):
# Be careful to preserve shallow-copied values: do not update
# phaseroots values, replace them.
repo = repo.unfiltered()
currentroots = self.phaseroots[targetphase]
finalroots = oldroots = set(currentroots)
newroots = [n for n in nodes
if self.phase(repo, repo[n].rev()) < targetphase]
if newroots:
if nullid in newroots:
raise error.Abort(_('cannot change null revision phase'))
currentroots = currentroots.copy()
currentroots.update(newroots)
# Only compute new roots for revs above the roots that are being
# retracted.
minnewroot = min(repo[n].rev() for n in newroots)
aboveroots = [n for n in currentroots
if repo[n].rev() >= minnewroot]
updatedroots = repo.set('roots(%ln::)', aboveroots)
finalroots = set(n for n in currentroots if repo[n].rev() <
minnewroot)
finalroots.update(ctx.node() for ctx in updatedroots)
if finalroots != oldroots:
self._updateroots(targetphase, finalroots, tr)
return True
return False
def filterunknown(self, repo):
"""remove unknown nodes from the phase boundary
Nothing is lost as unknown nodes only hold data for their descendants.
"""
filtered = False
nodemap = repo.changelog.nodemap # to filter unknown nodes
for phase, nodes in enumerate(self.phaseroots):
missing = sorted(node for node in nodes if node not in nodemap)
if missing:
for mnode in missing:
repo.ui.debug(
'removing unknown node %s from %i-phase boundary\n'
% (short(mnode), phase))
nodes.symmetric_difference_update(missing)
filtered = True
if filtered:
self.dirty = True
# filterunknown is called by repo.destroyed, we may have no changes in
# root but _phasesets contents is certainly invalid (or at least we
# have not proper way to check that). related to issue 3858.
#
# The other caller is __init__ that have no _phasesets initialized
# anyway. If this change we should consider adding a dedicated
# "destroyed" function to phasecache or a proper cache key mechanism
# (see branchmap one)
self.invalidate()
def advanceboundary(repo, tr, targetphase, nodes):
"""Add nodes to a phase changing other nodes phases if necessary.
This function move boundary *forward* this means that all nodes
are set in the target phase or kept in a *lower* phase.
Simplify boundary to contains phase roots only."""
phcache = repo._phasecache.copy()
phcache.advanceboundary(repo, tr, targetphase, nodes)
repo._phasecache.replace(phcache)
def retractboundary(repo, tr, targetphase, nodes):
"""Set nodes back to a phase changing other nodes phases if
necessary.
This function move boundary *backward* this means that all nodes
are set in the target phase or kept in a *higher* phase.
Simplify boundary to contains phase roots only."""
phcache = repo._phasecache.copy()
phcache.retractboundary(repo, tr, targetphase, nodes)
repo._phasecache.replace(phcache)
def registernew(repo, tr, targetphase, nodes):
"""register a new revision and its phase
Code adding revisions to the repository should use this function to
set new changeset in their target phase (or higher).
"""
phcache = repo._phasecache.copy()
phcache.registernew(repo, tr, targetphase, nodes)
repo._phasecache.replace(phcache)
def listphases(repo):
"""List phases root for serialization over pushkey"""
# Use ordered dictionary so behavior is deterministic.
keys = util.sortdict()
value = '%i' % draft
cl = repo.unfiltered().changelog
for root in repo._phasecache.phaseroots[draft]:
if repo._phasecache.phase(repo, cl.rev(root)) <= draft:
keys[hex(root)] = value
if repo.publishing():
# Add an extra data to let remote know we are a publishing
# repo. Publishing repo can't just pretend they are old repo.
# When pushing to a publishing repo, the client still need to
# push phase boundary
#
# Push do not only push changeset. It also push phase data.
# New phase data may apply to common changeset which won't be
# push (as they are common). Here is a very simple example:
#
# 1) repo A push changeset X as draft to repo B
# 2) repo B make changeset X public
# 3) repo B push to repo A. X is not pushed but the data that
# X as now public should
#
# The server can't handle it on it's own as it has no idea of
# client phase data.
keys['publishing'] = 'True'
return keys
def pushphase(repo, nhex, oldphasestr, newphasestr):
"""List phases root for serialization over pushkey"""
repo = repo.unfiltered()
with repo.lock():
currentphase = repo[nhex].phase()
newphase = abs(int(newphasestr)) # let's avoid negative index surprise
oldphase = abs(int(oldphasestr)) # let's avoid negative index surprise
if currentphase == oldphase and newphase < oldphase:
with repo.transaction('pushkey-phase') as tr:
advanceboundary(repo, tr, newphase, [bin(nhex)])
return True
elif currentphase == newphase:
# raced, but got correct result
return True
else:
return False
def subsetphaseheads(repo, subset):
"""Finds the phase heads for a subset of a history
Returns a list indexed by phase number where each item is a list of phase
head nodes.
"""
cl = repo.changelog
headsbyphase = [[] for i in allphases]
# No need to keep track of secret phase; any heads in the subset that
# are not mentioned are implicitly secret.
for phase in allphases[:-1]:
revset = "heads(%%ln & %s())" % phasenames[phase]
headsbyphase[phase] = [cl.node(r) for r in repo.revs(revset, subset)]
return headsbyphase
def updatephases(repo, trgetter, headsbyphase):
"""Updates the repo with the given phase heads"""
# Now advance phase boundaries of all but secret phase
#
# run the update (and fetch transaction) only if there are actually things
# to update. This avoid creating empty transaction during no-op operation.
for phase in allphases[:-1]:
revset = '%%ln - %s()' % phasenames[phase]
heads = [c.node() for c in repo.set(revset, headsbyphase[phase])]
if heads:
advanceboundary(repo, trgetter(), phase, heads)
def analyzeremotephases(repo, subset, roots):
"""Compute phases heads and root in a subset of node from root dict
* subset is heads of the subset
* roots is {<nodeid> => phase} mapping. key and value are string.
Accept unknown element input
"""
repo = repo.unfiltered()
# build list from dictionary
draftroots = []
nodemap = repo.changelog.nodemap # to filter unknown nodes
for nhex, phase in roots.iteritems():
if nhex == 'publishing': # ignore data related to publish option
continue
node = bin(nhex)
phase = int(phase)
if phase == public:
if node != nullid:
repo.ui.warn(_('ignoring inconsistent public root'
' from remote: %s\n') % nhex)
elif phase == draft:
if node in nodemap:
draftroots.append(node)
else:
repo.ui.warn(_('ignoring unexpected root from remote: %i %s\n')
% (phase, nhex))
# compute heads
publicheads = newheads(repo, subset, draftroots)
return publicheads, draftroots
class remotephasessummary(object):
"""summarize phase information on the remote side
:publishing: True is the remote is publishing
:publicheads: list of remote public phase heads (nodes)
:draftheads: list of remote draft phase heads (nodes)
:draftroots: list of remote draft phase root (nodes)
"""
def __init__(self, repo, remotesubset, remoteroots):
unfi = repo.unfiltered()
self._allremoteroots = remoteroots
self.publishing = remoteroots.get('publishing', False)
ana = analyzeremotephases(repo, remotesubset, remoteroots)
self.publicheads, self.draftroots = ana
# Get the list of all "heads" revs draft on remote
dheads = unfi.set('heads(%ln::%ln)', self.draftroots, remotesubset)
self.draftheads = [c.node() for c in dheads]
def newheads(repo, heads, roots):
"""compute new head of a subset minus another
* `heads`: define the first subset
* `roots`: define the second we subtract from the first"""
repo = repo.unfiltered()
revset = repo.set('heads((%ln + parents(%ln)) - (%ln::%ln))',
heads, roots, roots, heads)
return [c.node() for c in revset]
def newcommitphase(ui):
"""helper to get the target phase of new commit
Handle all possible values for the phases.new-commit options.
"""
v = ui.config('phases', 'new-commit')
try:
return phasenames.index(v)
except ValueError:
try:
return int(v)
except ValueError:
msg = _("phases.new-commit: not a valid phase name ('%s')")
raise error.ConfigError(msg % v)
def hassecret(repo):
"""utility function that check if a repo have any secret changeset."""
return bool(repo._phasecache.phaseroots[2])
def preparehookargs(node, old, new):
if old is None:
old = ''
else:
old = phasenames[old]
return {'node': node,
'oldphase': old,
'phase': phasenames[new]}