view mercurial/subrepoutil.py @ 40030:62160d3077cd

cborutil: change buffering strategy

Profiling revealed that we were spending a lot of time on the
line that was concatenating the old buffer with the incoming data
when attempting to decode long byte strings, such as manifest
revisions.

Essentially, we were feeding N chunks of size len(X) << len(Y) into
decode() and continuously allocating a new, larger buffer to hold
the undecoded input. This created substantial memory churn and
slowed down execution.

Changing the code to aggregate pending chunks in a list until we
have enough data to fully decode the next atom makes things much
more efficient.

I don't have exact data, but I recall the old code spending >1s
on manifest fulltexts from the mozilla-unified repo. The new code
doesn't significantly appear in profile output.

Differential Revision: https://phab.mercurial-scm.org/D4854

# subrepoutil.py - sub-repository operations and substate handling
#
# Copyright 2009-2010 Matt Mackall <[e-mail]>
#
# 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

import errno
import os
import posixpath
import re

from .i18n import _
from . import (
    config,
    error,
    filemerge,
    pathutil,
    phases,
    util,
)
from .utils import (
    stringutil,
)

nullstate = ('', '', 'empty')

def state(ctx, ui):
    """return a state dict, mapping subrepo paths configured in .hgsub
    to tuple: (source from .hgsub, revision from .hgsubstate, kind
    (key in types dict))
    """
    p = config.config()
    repo = ctx.repo()
    def read(f, sections=None, remap=None):
        if f in ctx:
            try:
                data = ctx[f].data()
            except IOError as err:
                if err.errno != errno.ENOENT:
                    raise
                # handle missing subrepo spec files as removed
                ui.warn(_("warning: subrepo spec file \'%s\' not found\n") %
                        repo.pathto(f))
                return
            p.parse(f, data, sections, remap, read)
        else:
            raise error.Abort(_("subrepo spec file \'%s\' not found") %
                             repo.pathto(f))
    if '.hgsub' in ctx:
        read('.hgsub')

    for path, src in ui.configitems('subpaths'):
        p.set('subpaths', path, src, ui.configsource('subpaths', path))

    rev = {}
    if '.hgsubstate' in ctx:
        try:
            for i, l in enumerate(ctx['.hgsubstate'].data().splitlines()):
                l = l.lstrip()
                if not l:
                    continue
                try:
                    revision, path = l.split(" ", 1)
                except ValueError:
                    raise error.Abort(_("invalid subrepository revision "
                                       "specifier in \'%s\' line %d")
                                     % (repo.pathto('.hgsubstate'), (i + 1)))
                rev[path] = revision
        except IOError as err:
            if err.errno != errno.ENOENT:
                raise

    def remap(src):
        for pattern, repl in p.items('subpaths'):
            # Turn r'C:\foo\bar' into r'C:\\foo\\bar' since re.sub
            # does a string decode.
            repl = stringutil.escapestr(repl)
            # However, we still want to allow back references to go
            # through unharmed, so we turn r'\\1' into r'\1'. Again,
            # extra escapes are needed because re.sub string decodes.
            repl = re.sub(br'\\\\([0-9]+)', br'\\\1', repl)
            try:
                src = re.sub(pattern, repl, src, 1)
            except re.error as e:
                raise error.Abort(_("bad subrepository pattern in %s: %s")
                                 % (p.source('subpaths', pattern),
                                    stringutil.forcebytestr(e)))
        return src

    state = {}
    for path, src in p[''].items():
        kind = 'hg'
        if src.startswith('['):
            if ']' not in src:
                raise error.Abort(_('missing ] in subrepository source'))
            kind, src = src.split(']', 1)
            kind = kind[1:]
            src = src.lstrip() # strip any extra whitespace after ']'

        if not util.url(src).isabs():
            parent = _abssource(repo, abort=False)
            if parent:
                parent = util.url(parent)
                parent.path = posixpath.join(parent.path or '', src)
                parent.path = posixpath.normpath(parent.path)
                joined = bytes(parent)
                # Remap the full joined path and use it if it changes,
                # else remap the original source.
                remapped = remap(joined)
                if remapped == joined:
                    src = remap(src)
                else:
                    src = remapped

        src = remap(src)
        state[util.pconvert(path)] = (src.strip(), rev.get(path, ''), kind)

    return state

def writestate(repo, state):
    """rewrite .hgsubstate in (outer) repo with these subrepo states"""
    lines = ['%s %s\n' % (state[s][1], s) for s in sorted(state)
                                                if state[s][1] != nullstate[1]]
    repo.wwrite('.hgsubstate', ''.join(lines), '')

def submerge(repo, wctx, mctx, actx, overwrite, labels=None):
    """delegated from merge.applyupdates: merging of .hgsubstate file
    in working context, merging context and ancestor context"""
    if mctx == actx: # backwards?
        actx = wctx.p1()
    s1 = wctx.substate
    s2 = mctx.substate
    sa = actx.substate
    sm = {}

    repo.ui.debug("subrepo merge %s %s %s\n" % (wctx, mctx, actx))

    def debug(s, msg, r=""):
        if r:
            r = "%s:%s:%s" % r
        repo.ui.debug("  subrepo %s: %s %s\n" % (s, msg, r))

    promptssrc = filemerge.partextras(labels)
    for s, l in sorted(s1.iteritems()):
        prompts = None
        a = sa.get(s, nullstate)
        ld = l # local state with possible dirty flag for compares
        if wctx.sub(s).dirty():
            ld = (l[0], l[1] + "+")
        if wctx == actx: # overwrite
            a = ld

        prompts = promptssrc.copy()
        prompts['s'] = s
        if s in s2:
            r = s2[s]
            if ld == r or r == a: # no change or local is newer
                sm[s] = l
                continue
            elif ld == a: # other side changed
                debug(s, "other changed, get", r)
                wctx.sub(s).get(r, overwrite)
                sm[s] = r
            elif ld[0] != r[0]: # sources differ
                prompts['lo'] = l[0]
                prompts['ro'] = r[0]
                if repo.ui.promptchoice(
                    _(' subrepository sources for %(s)s differ\n'
                      'use (l)ocal%(l)s source (%(lo)s)'
                      ' or (r)emote%(o)s source (%(ro)s)?'
                      '$$ &Local $$ &Remote') % prompts, 0):
                    debug(s, "prompt changed, get", r)
                    wctx.sub(s).get(r, overwrite)
                    sm[s] = r
            elif ld[1] == a[1]: # local side is unchanged
                debug(s, "other side changed, get", r)
                wctx.sub(s).get(r, overwrite)
                sm[s] = r
            else:
                debug(s, "both sides changed")
                srepo = wctx.sub(s)
                prompts['sl'] = srepo.shortid(l[1])
                prompts['sr'] = srepo.shortid(r[1])
                option = repo.ui.promptchoice(
                    _(' subrepository %(s)s diverged (local revision: %(sl)s, '
                      'remote revision: %(sr)s)\n'
                      '(M)erge, keep (l)ocal%(l)s or keep (r)emote%(o)s?'
                      '$$ &Merge $$ &Local $$ &Remote')
                    % prompts, 0)
                if option == 0:
                    wctx.sub(s).merge(r)
                    sm[s] = l
                    debug(s, "merge with", r)
                elif option == 1:
                    sm[s] = l
                    debug(s, "keep local subrepo revision", l)
                else:
                    wctx.sub(s).get(r, overwrite)
                    sm[s] = r
                    debug(s, "get remote subrepo revision", r)
        elif ld == a: # remote removed, local unchanged
            debug(s, "remote removed, remove")
            wctx.sub(s).remove()
        elif a == nullstate: # not present in remote or ancestor
            debug(s, "local added, keep")
            sm[s] = l
            continue
        else:
            if repo.ui.promptchoice(
                _(' local%(l)s changed subrepository %(s)s'
                  ' which remote%(o)s removed\n'
                  'use (c)hanged version or (d)elete?'
                  '$$ &Changed $$ &Delete') % prompts, 0):
                debug(s, "prompt remove")
                wctx.sub(s).remove()

    for s, r in sorted(s2.items()):
        prompts = None
        if s in s1:
            continue
        elif s not in sa:
            debug(s, "remote added, get", r)
            mctx.sub(s).get(r)
            sm[s] = r
        elif r != sa[s]:
            prompts = promptssrc.copy()
            prompts['s'] = s
            if repo.ui.promptchoice(
                _(' remote%(o)s changed subrepository %(s)s'
                  ' which local%(l)s removed\n'
                  'use (c)hanged version or (d)elete?'
                  '$$ &Changed $$ &Delete') % prompts, 0) == 0:
                debug(s, "prompt recreate", r)
                mctx.sub(s).get(r)
                sm[s] = r

    # record merged .hgsubstate
    writestate(repo, sm)
    return sm

def precommit(ui, wctx, status, match, force=False):
    """Calculate .hgsubstate changes that should be applied before committing

    Returns (subs, commitsubs, newstate) where
    - subs: changed subrepos (including dirty ones)
    - commitsubs: dirty subrepos which the caller needs to commit recursively
    - newstate: new state dict which the caller must write to .hgsubstate

    This also updates the given status argument.
    """
    subs = []
    commitsubs = set()
    newstate = wctx.substate.copy()

    # only manage subrepos and .hgsubstate if .hgsub is present
    if '.hgsub' in wctx:
        # we'll decide whether to track this ourselves, thanks
        for c in status.modified, status.added, status.removed:
            if '.hgsubstate' in c:
                c.remove('.hgsubstate')

        # compare current state to last committed state
        # build new substate based on last committed state
        oldstate = wctx.p1().substate
        for s in sorted(newstate.keys()):
            if not match(s):
                # ignore working copy, use old state if present
                if s in oldstate:
                    newstate[s] = oldstate[s]
                    continue
                if not force:
                    raise error.Abort(
                        _("commit with new subrepo %s excluded") % s)
            dirtyreason = wctx.sub(s).dirtyreason(True)
            if dirtyreason:
                if not ui.configbool('ui', 'commitsubrepos'):
                    raise error.Abort(dirtyreason,
                        hint=_("use --subrepos for recursive commit"))
                subs.append(s)
                commitsubs.add(s)
            else:
                bs = wctx.sub(s).basestate()
                newstate[s] = (newstate[s][0], bs, newstate[s][2])
                if oldstate.get(s, (None, None, None))[1] != bs:
                    subs.append(s)

        # check for removed subrepos
        for p in wctx.parents():
            r = [s for s in p.substate if s not in newstate]
            subs += [s for s in r if match(s)]
        if subs:
            if (not match('.hgsub') and
                '.hgsub' in (wctx.modified() + wctx.added())):
                raise error.Abort(_("can't commit subrepos without .hgsub"))
            status.modified.insert(0, '.hgsubstate')

    elif '.hgsub' in status.removed:
        # clean up .hgsubstate when .hgsub is removed
        if ('.hgsubstate' in wctx and
            '.hgsubstate' not in (status.modified + status.added +
                                  status.removed)):
            status.removed.insert(0, '.hgsubstate')

    return subs, commitsubs, newstate

def reporelpath(repo):
    """return path to this (sub)repo as seen from outermost repo"""
    parent = repo
    while util.safehasattr(parent, '_subparent'):
        parent = parent._subparent
    return repo.root[len(pathutil.normasprefix(parent.root)):]

def subrelpath(sub):
    """return path to this subrepo as seen from outermost repo"""
    return sub._relpath

def _abssource(repo, push=False, abort=True):
    """return pull/push path of repo - either based on parent repo .hgsub info
    or on the top repo config. Abort or return None if no source found."""
    if util.safehasattr(repo, '_subparent'):
        source = util.url(repo._subsource)
        if source.isabs():
            return bytes(source)
        source.path = posixpath.normpath(source.path)
        parent = _abssource(repo._subparent, push, abort=False)
        if parent:
            parent = util.url(util.pconvert(parent))
            parent.path = posixpath.join(parent.path or '', source.path)
            parent.path = posixpath.normpath(parent.path)
            return bytes(parent)
    else: # recursion reached top repo
        path = None
        if util.safehasattr(repo, '_subtoppath'):
            path = repo._subtoppath
        elif push and repo.ui.config('paths', 'default-push'):
            path = repo.ui.config('paths', 'default-push')
        elif repo.ui.config('paths', 'default'):
            path = repo.ui.config('paths', 'default')
        elif repo.shared():
            # chop off the .hg component to get the default path form.  This has
            # already run through vfsmod.vfs(..., realpath=True), so it doesn't
            # have problems with 'C:'
            return os.path.dirname(repo.sharedpath)
        if path:
            # issue5770: 'C:\' and 'C:' are not equivalent paths.  The former is
            # as expected: an absolute path to the root of the C: drive.  The
            # latter is a relative path, and works like so:
            #
            #   C:\>cd C:\some\path
            #   C:\>D:
            #   D:\>python -c "import os; print os.path.abspath('C:')"
            #   C:\some\path
            #
            #   D:\>python -c "import os; print os.path.abspath('C:relative')"
            #   C:\some\path\relative
            if util.hasdriveletter(path):
                if len(path) == 2 or path[2:3] not in br'\/':
                    path = os.path.abspath(path)
            return path

    if abort:
        raise error.Abort(_("default path for subrepository not found"))

def newcommitphase(ui, ctx):
    commitphase = phases.newcommitphase(ui)
    substate = getattr(ctx, "substate", None)
    if not substate:
        return commitphase
    check = ui.config('phases', 'checksubrepos')
    if check not in ('ignore', 'follow', 'abort'):
        raise error.Abort(_('invalid phases.checksubrepos configuration: %s')
                         % (check))
    if check == 'ignore':
        return commitphase
    maxphase = phases.public
    maxsub = None
    for s in sorted(substate):
        sub = ctx.sub(s)
        subphase = sub.phase(substate[s][1])
        if maxphase < subphase:
            maxphase = subphase
            maxsub = s
    if commitphase < maxphase:
        if check == 'abort':
            raise error.Abort(_("can't commit in %s phase"
                               " conflicting %s from subrepository %s") %
                             (phases.phasenames[commitphase],
                              phases.phasenames[maxphase], maxsub))
        ui.warn(_("warning: changes are committed in"
                  " %s phase from subrepository %s\n") %
                (phases.phasenames[maxphase], maxsub))
        return maxphase
    return commitphase