view mercurial/hook.py @ 42043:1fac9b931d46

compression: introduce a `storage.revlog.zlib.level` configuration This option control the zlib compression level used when compression revlog chunk. This is also a good excuse to pave the way for a similar configuration option for the zstd compression engine. Having a dedicated option for each compression algorithm is useful because they don't support the same range of values. Using a higher zlib compression impact CPU consumption at compression time, but does not directly affected decompression time. However dealing with small compressed chunk can directly help decompression and indirectly help other revlog logic. I ran some basic test on repositories using different level. I am using the mercurial, pypy, netbeans and mozilla-central clone from our benchmark suite. All tested repository use sparse-revlog and got all their delta recomputed. The different compression level has a small effect on the repository size (about 10% variation in the total range). My quick analysis is that revlog mostly store small delta, that are not affected by the compression level much. So the variation probably mostly comes from better compression of the snapshots revisions, and snapshot revision only represent a small portion of the repository content. I also made some basic timings measurements. The "read" timings are gathered using simple run of `hg perfrevlogrevisions`, the "write" timings using `hg perfrevlogwrite` (restricted to the last 5000 revisions for netbeans and mozilla central). The timings are gathered on a generic machine, (not one of our performance locked machine), so small variation might not be meaningful. However large trend remains relevant. Keep in mind that these numbers are not pure compression/decompression time. They also involve the full revlog logic. In particular the difference in chunk size has an impact on the delta chain structure, affecting performance when writing or reading them. On read/write performance, the compression level has a bigger impact. Counter-intuitively, the higher compression levels improve "write" performance for the large repositories in our tested setting. Maybe because the last 5000 delta chain end up having a very different shape in this specific spot? Or maybe because of a more general trend of better delta chains thanks to the smaller chunk and snapshot. This series does not intend to change the default compression level. However, these result call for a deeper analysis of this performance difference in the future. Full data ========= repo level .hg/store size 00manifest.d read write ---------------------------------------------------------------- mercurial 1 49,402,813 5,963,475 0.170159 53.250304 mercurial 6 47,197,397 5,875,730 0.182820 56.264320 mercurial 9 47,121,596 5,849,781 0.189219 56.293612 pypy 1 370,830,572 28,462,425 2.679217 460.721984 pypy 6 340,112,317 27,648,747 2.768691 467.537158 pypy 9 338,360,736 27,639,003 2.763495 476.589918 netbeans 1 1,281,847,810 165,495,457 122.477027 520.560316 netbeans 6 1,205,284,353 159,161,207 139.876147 715.930400 netbeans 9 1,197,135,671 155,034,586 141.620281 678.297064 mozilla 1 2,775,497,186 298,527,987 147.867662 751.263721 mozilla 6 2,596,856,420 286,597,671 170.572118 987.056093 mozilla 9 2,587,542,494 287,018,264 163.622338 739.803002
author Pierre-Yves David <pierre-yves.david@octobus.net>
date Wed, 27 Mar 2019 18:35:27 +0100
parents 8c8fcb385c46
children 2372284d9457
line wrap: on
line source

# hook.py - hook support for mercurial
#
# Copyright 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

import os
import sys

from .i18n import _
from . import (
    demandimport,
    encoding,
    error,
    extensions,
    pycompat,
    util,
)
from .utils import (
    procutil,
    stringutil,
)

def pythonhook(ui, repo, htype, hname, funcname, args, throw):
    '''call python hook. hook is callable object, looked up as
    name in python module. if callable returns "true", hook
    fails, else passes. if hook raises exception, treated as
    hook failure. exception propagates if throw is "true".

    reason for "true" meaning "hook failed" is so that
    unmodified commands (e.g. mercurial.commands.update) can
    be run as hooks without wrappers to convert return values.'''

    if callable(funcname):
        obj = funcname
        funcname = pycompat.sysbytes(obj.__module__ + r"." + obj.__name__)
    else:
        d = funcname.rfind('.')
        if d == -1:
            raise error.HookLoadError(
                _('%s hook is invalid: "%s" not in a module')
                % (hname, funcname))
        modname = funcname[:d]
        oldpaths = sys.path
        if procutil.mainfrozen():
            # binary installs require sys.path manipulation
            modpath, modfile = os.path.split(modname)
            if modpath and modfile:
                sys.path = sys.path[:] + [modpath]
                modname = modfile
        with demandimport.deactivated():
            try:
                obj = __import__(pycompat.sysstr(modname))
            except (ImportError, SyntaxError):
                e1 = sys.exc_info()
                try:
                    # extensions are loaded with hgext_ prefix
                    obj = __import__(r"hgext_%s" % pycompat.sysstr(modname))
                except (ImportError, SyntaxError):
                    e2 = sys.exc_info()
                    if ui.tracebackflag:
                        ui.warn(_('exception from first failed import '
                                  'attempt:\n'))
                    ui.traceback(e1)
                    if ui.tracebackflag:
                        ui.warn(_('exception from second failed import '
                                  'attempt:\n'))
                    ui.traceback(e2)

                    if not ui.tracebackflag:
                        tracebackhint = _(
                            'run with --traceback for stack trace')
                    else:
                        tracebackhint = None
                    raise error.HookLoadError(
                        _('%s hook is invalid: import of "%s" failed') %
                        (hname, modname), hint=tracebackhint)
        sys.path = oldpaths
        try:
            for p in funcname.split('.')[1:]:
                obj = getattr(obj, p)
        except AttributeError:
            raise error.HookLoadError(
                _('%s hook is invalid: "%s" is not defined')
                % (hname, funcname))
        if not callable(obj):
            raise error.HookLoadError(
                _('%s hook is invalid: "%s" is not callable')
                % (hname, funcname))

    ui.note(_("calling hook %s: %s\n") % (hname, funcname))
    starttime = util.timer()

    try:
        r = obj(ui=ui, repo=repo, hooktype=htype, **pycompat.strkwargs(args))
    except Exception as exc:
        if isinstance(exc, error.Abort):
            ui.warn(_('error: %s hook failed: %s\n') %
                         (hname, exc.args[0]))
        else:
            ui.warn(_('error: %s hook raised an exception: '
                      '%s\n') % (hname, stringutil.forcebytestr(exc)))
        if throw:
            raise
        if not ui.tracebackflag:
            ui.warn(_('(run with --traceback for stack trace)\n'))
        ui.traceback()
        return True, True
    finally:
        duration = util.timer() - starttime
        ui.log('pythonhook', 'pythonhook-%s: %s finished in %0.2f seconds\n',
               htype, funcname, duration)
    if r:
        if throw:
            raise error.HookAbort(_('%s hook failed') % hname)
        ui.warn(_('warning: %s hook failed\n') % hname)
    return r, False

def _exthook(ui, repo, htype, name, cmd, args, throw):
    starttime = util.timer()
    env = {}

    # make in-memory changes visible to external process
    if repo is not None:
        tr = repo.currenttransaction()
        repo.dirstate.write(tr)
        if tr and tr.writepending():
            env['HG_PENDING'] = repo.root
    env['HG_HOOKTYPE'] = htype
    env['HG_HOOKNAME'] = name

    for k, v in args.iteritems():
        if callable(v):
            v = v()
        if isinstance(v, (dict, list)):
            v = stringutil.pprint(v)
        env['HG_' + k.upper()] = v

    if ui.configbool('hooks', 'tonative.%s' % name, False):
        oldcmd = cmd
        cmd = procutil.shelltonative(cmd, env)
        if cmd != oldcmd:
            ui.note(_('converting hook "%s" to native\n') % name)

    ui.note(_("running hook %s: %s\n") % (name, cmd))

    if repo:
        cwd = repo.root
    else:
        cwd = encoding.getcwd()
    r = ui.system(cmd, environ=env, cwd=cwd, blockedtag='exthook-%s' % (name,))

    duration = util.timer() - starttime
    ui.log('exthook', 'exthook-%s: %s finished in %0.2f seconds\n',
           name, cmd, duration)
    if r:
        desc = procutil.explainexit(r)
        if throw:
            raise error.HookAbort(_('%s hook %s') % (name, desc))
        ui.warn(_('warning: %s hook %s\n') % (name, desc))
    return r

# represent an untrusted hook command
_fromuntrusted = object()

def _allhooks(ui):
    """return a list of (hook-id, cmd) pairs sorted by priority"""
    hooks = _hookitems(ui)
    # Be careful in this section, propagating the real commands from untrusted
    # sources would create a security vulnerability, make sure anything altered
    # in that section uses "_fromuntrusted" as its command.
    untrustedhooks = _hookitems(ui, _untrusted=True)
    for name, value in untrustedhooks.items():
        trustedvalue = hooks.get(name, (None, None, name, _fromuntrusted))
        if value != trustedvalue:
            (lp, lo, lk, lv) = trustedvalue
            hooks[name] = (lp, lo, lk, _fromuntrusted)
    # (end of the security sensitive section)
    return [(k, v) for p, o, k, v in sorted(hooks.values())]

def _hookitems(ui, _untrusted=False):
    """return all hooks items ready to be sorted"""
    hooks = {}
    for name, cmd in ui.configitems('hooks', untrusted=_untrusted):
        if name.startswith('priority.') or name.startswith('tonative.'):
            continue

        priority = ui.configint('hooks', 'priority.%s' % name, 0)
        hooks[name] = (-priority, len(hooks), name, cmd)
    return hooks

_redirect = False
def redirect(state):
    global _redirect
    _redirect = state

def hashook(ui, htype):
    """return True if a hook is configured for 'htype'"""
    if not ui.callhooks:
        return False
    for hname, cmd in _allhooks(ui):
        if hname.split('.')[0] == htype and cmd:
            return True
    return False

def hook(ui, repo, htype, throw=False, **args):
    if not ui.callhooks:
        return False

    hooks = []
    for hname, cmd in _allhooks(ui):
        if hname.split('.')[0] == htype and cmd:
            hooks.append((hname, cmd))

    res = runhooks(ui, repo, htype, hooks, throw=throw, **args)
    r = False
    for hname, cmd in hooks:
        r = res[hname][0] or r
    return r

def runhooks(ui, repo, htype, hooks, throw=False, **args):
    args = pycompat.byteskwargs(args)
    res = {}
    oldstdout = -1

    try:
        for hname, cmd in hooks:
            if oldstdout == -1 and _redirect:
                try:
                    stdoutno = procutil.stdout.fileno()
                    stderrno = procutil.stderr.fileno()
                    # temporarily redirect stdout to stderr, if possible
                    if stdoutno >= 0 and stderrno >= 0:
                        procutil.stdout.flush()
                        oldstdout = os.dup(stdoutno)
                        os.dup2(stderrno, stdoutno)
                except (OSError, AttributeError):
                    # files seem to be bogus, give up on redirecting (WSGI, etc)
                    pass

            if cmd is _fromuntrusted:
                if throw:
                    raise error.HookAbort(
                        _('untrusted hook %s not executed') % hname,
                        hint = _("see 'hg help config.trusted'"))
                ui.warn(_('warning: untrusted hook %s not executed\n') % hname)
                r = 1
                raised = False
            elif callable(cmd):
                r, raised = pythonhook(ui, repo, htype, hname, cmd, args,
                                        throw)
            elif cmd.startswith('python:'):
                if cmd.count(':') >= 2:
                    path, cmd = cmd[7:].rsplit(':', 1)
                    path = util.expandpath(path)
                    if repo:
                        path = os.path.join(repo.root, path)
                    try:
                        mod = extensions.loadpath(path, 'hghook.%s' % hname)
                    except Exception:
                        ui.write(_("loading %s hook failed:\n") % hname)
                        raise
                    hookfn = getattr(mod, cmd)
                else:
                    hookfn = cmd[7:].strip()
                r, raised = pythonhook(ui, repo, htype, hname, hookfn, args,
                                        throw)
            else:
                r = _exthook(ui, repo, htype, hname, cmd, args, throw)
                raised = False

            res[hname] = r, raised
    finally:
        # The stderr is fully buffered on Windows when connected to a pipe.
        # A forcible flush is required to make small stderr data in the
        # remote side available to the client immediately.
        procutil.stderr.flush()

        if _redirect and oldstdout >= 0:
            procutil.stdout.flush()  # write hook output to stderr fd
            os.dup2(oldstdout, stdoutno)
            os.close(oldstdout)

    return res