mercurial/hook.py

copies: avoid instancing more changectx to access parent revisions

We just need to know the revision numbers of the parents, creating full context
is needlessly expensive.

This provide a small, but noticeable performance boost.

revision: large amount; added files: large amount; rename small amount; c3b14617fbd7 9ba6ab77fd29
before: ! wall 2.885636 comb 2.900000 user 2.870000 sys 0.030000 (median of 10)
after:  ! wall 2.702270 comb 2.710000 user 2.690000 sys 0.020000 (median of 10)
revision: large amount; added files: small amount; rename small amount; c3b14617fbd7 f650a9b140d2
before: ! wall 4.298271 comb 4.290000 user 4.240000 sys 0.050000 (median of 10)
after:  ! wall 3.976610 comb 3.970000 user 3.920000 sys 0.050000 (median of 10)
revision: large amount; added files: large amount; rename large amount; 08ea3258278e d9fa043f30c0
before: ! wall 0.773397 comb 0.770000 user 0.770000 sys 0.000000 (median of 11)
after:  ! wall 0.701634 comb 0.700000 user 0.700000 sys 0.000000 (median of 13)
revision: small amount; added files: large amount; rename large amount; df6f7a526b60 a83dc6a2d56f
before: ! wall 0.013585 comb 0.010000 user 0.010000 sys 0.000000 (median of 217)
after:  ! wall 0.013550 comb 0.010000 user 0.010000 sys 0.000000 (median of 218)
revision: small amount; added files: large amount; rename small amount; 4aa4e1f8e19a 169138063d63
before: ! wall 0.003202 comb 0.000000 user 0.000000 sys 0.000000 (median of 929)
after:  ! wall 0.002993 comb 0.010000 user 0.010000 sys 0.000000 (median of 992)
revision: small amount; added files: small amount; rename small amount; 4bc173b045a6 964879152e2e
before: ! wall 0.000077 comb 0.000000 user 0.000000 sys 0.000000 (median of 12060)
after:  ! wall 0.000072 comb 0.000000 user 0.000000 sys 0.000000 (median of 12804)
revision: medium amount; added files: large amount; rename medium amount; c95f1ced15f2 2c68e87c3efe
before: ! wall 0.510614 comb 0.500000 user 0.500000 sys 0.000000 (median of 18)
after:  ! wall 0.473681 comb 0.470000 user 0.470000 sys 0.000000 (median of 20)
revision: medium amount; added files: medium amount; rename small amount; d343da0c55a8 d7746d32bf9d
before: ! wall 0.126552 comb 0.130000 user 0.130000 sys 0.000000 (median of 77)
after:  ! wall 0.115240 comb 0.110000 user 0.110000 sys 0.000000 (median of 85)

Differential Revision: https://phab.mercurial-scm.org/D7122

# hook.py - hook support for mercurial
#
# Copyright 2007 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 os
import sys

from .i18n import _
from .pycompat import getattr
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(b'.')
        if d == -1:
            raise error.HookLoadError(
                _(b'%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(
                            _(
                                b'exception from first failed import '
                                b'attempt:\n'
                            )
                        )
                    ui.traceback(e1)
                    if ui.tracebackflag:
                        ui.warn(
                            _(
                                b'exception from second failed import '
                                b'attempt:\n'
                            )
                        )
                    ui.traceback(e2)

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

    ui.note(_(b"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(_(b'error: %s hook failed: %s\n') % (hname, exc.args[0]))
        else:
            ui.warn(
                _(b'error: %s hook raised an exception: %s\n')
                % (hname, stringutil.forcebytestr(exc))
            )
        if throw:
            raise
        if not ui.tracebackflag:
            ui.warn(_(b'(run with --traceback for stack trace)\n'))
        ui.traceback()
        return True, True
    finally:
        duration = util.timer() - starttime
        ui.log(
            b'pythonhook',
            b'pythonhook-%s: %s finished in %0.2f seconds\n',
            htype,
            funcname,
            duration,
        )
    if r:
        if throw:
            raise error.HookAbort(_(b'%s hook failed') % hname)
        ui.warn(_(b'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[b'HG_PENDING'] = repo.root
    env[b'HG_HOOKTYPE'] = htype
    env[b'HG_HOOKNAME'] = name

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

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

    ui.note(_(b"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=b'exthook-%s' % (name,))

    duration = util.timer() - starttime
    ui.log(
        b'exthook',
        b'exthook-%s: %s finished in %0.2f seconds\n',
        name,
        cmd,
        duration,
    )
    if r:
        desc = procutil.explainexit(r)
        if throw:
            raise error.HookAbort(_(b'%s hook %s') % (name, desc))
        ui.warn(_(b'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(b'hooks', untrusted=_untrusted):
        if name.startswith(b'priority.') or name.startswith(b'tonative.'):
            continue

        priority = ui.configint(b'hooks', b'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(b'.')[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(b'.')[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(
                        _(b'untrusted hook %s not executed') % hname,
                        hint=_(b"see 'hg help config.trusted'"),
                    )
                ui.warn(_(b'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(b'python:'):
                if cmd.count(b':') >= 2:
                    path, cmd = cmd[7:].rsplit(b':', 1)
                    path = util.expandpath(path)
                    if repo:
                        path = os.path.join(repo.root, path)
                    try:
                        mod = extensions.loadpath(path, b'hghook.%s' % hname)
                    except Exception:
                        ui.write(_(b"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