# procutil.py - utility for managing processes and executable environment

#

#  Copyright 2005 K. Thananchayan <thananck@yahoo.com>

#  Copyright 2005-2007 Matt Mackall <mpm@selenic.com>

#  Copyright 2006 Vadim Gelfer <vadim.gelfer@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.

from __future__ import absolute_import

import contextlib

import errno

import io

import os

import signal

import subprocess

import sys

import threading

import time

from ..i18n import _

from ..pycompat import (

    getattr,

    open,

)

from .. import (

    encoding,

    error,

    policy,

    pycompat,

)

# Import like this to keep import-checker happy

from ..utils import resourceutil

osutil = policy.importmod('osutil')

if pycompat.iswindows:

    from .. import windows as platform

else:

    from .. import posix as platform

def isatty(fp):

    try:

        return fp.isatty()

    except AttributeError:

        return False

class LineBufferedWrapper(object):

    def __init__(self, orig):

        self.orig = orig

    def __getattr__(self, attr):

        return getattr(self.orig, attr)

    def write(self, s):

        orig = self.orig

        res = orig.write(s)

        if s.endswith(b'\n'):

            orig.flush()

        return res

io.BufferedIOBase.register(LineBufferedWrapper)

def make_line_buffered(stream):

    if pycompat.ispy3 and not isinstance(stream, io.BufferedIOBase):

        # On Python 3, buffered streams can be expected to subclass

        # BufferedIOBase. This is definitively the case for the streams

        # initialized by the interpreter. For unbuffered streams, we don't need

        # to emulate line buffering.

        return stream

    if isinstance(stream, LineBufferedWrapper):

        return stream

    return LineBufferedWrapper(stream)

stderr = pycompat.stderr

stdin = pycompat.stdin

stdout = pycompat.stdout

if pycompat.iswindows:

    stdout = platform.winstdout(stdout)

# glibc determines buffering on first write to stdout - if we replace a TTY

# destined stdout with a pipe destined stdout (e.g. pager), we want line

# buffering.

if isatty(stdout):

    if pycompat.ispy3 or pycompat.iswindows:

        # On Python 3, buffered binary streams can't be set line-buffered.

        # On Python 2, Windows doesn't support line buffering.

        # Therefore we have a wrapper that implements line buffering.

        stdout = make_line_buffered(stdout)

    else:

        stdout = os.fdopen(stdout.fileno(), 'wb', 1)

findexe = platform.findexe

_gethgcmd = platform.gethgcmd

getuser = platform.getuser

getpid = os.getpid

hidewindow = platform.hidewindow

readpipe = platform.readpipe

setbinary = platform.setbinary

setsignalhandler = platform.setsignalhandler

shellquote = platform.shellquote

shellsplit = platform.shellsplit

spawndetached = platform.spawndetached

sshargs = platform.sshargs

testpid = platform.testpid

try:

    setprocname = osutil.setprocname

except AttributeError:

    pass

try:

    unblocksignal = osutil.unblocksignal

except AttributeError:

    pass

closefds = pycompat.isposix

def explainexit(code):

    """return a message describing a subprocess status

    (codes from kill are negative - not os.system/wait encoding)"""

    if code >= 0:

        return _(b"exited with status %d") % code

    return _(b"killed by signal %d") % -code

class _pfile(object):

    """File-like wrapper for a stream opened by subprocess.Popen()"""

    def __init__(self, proc, fp):

        self._proc = proc

        self._fp = fp

    def close(self):

        # unlike os.popen(), this returns an integer in subprocess coding

        self._fp.close()

        return self._proc.wait()

    def __iter__(self):

        return iter(self._fp)

    def __getattr__(self, attr):

        return getattr(self._fp, attr)

    def __enter__(self):

        return self

    def __exit__(self, exc_type, exc_value, exc_tb):

        self.close()

def popen(cmd, mode=b'rb', bufsize=-1):

    if mode == b'rb':

        return _popenreader(cmd, bufsize)

    elif mode == b'wb':

        return _popenwriter(cmd, bufsize)

    raise error.ProgrammingError(b'unsupported mode: %r' % mode)

def _popenreader(cmd, bufsize):

    p = subprocess.Popen(

        tonativestr(cmd),

        shell=True,

        bufsize=bufsize,

        close_fds=closefds,

        stdout=subprocess.PIPE,

    )

    return _pfile(p, p.stdout)

def _popenwriter(cmd, bufsize):

    p = subprocess.Popen(

        tonativestr(cmd),

        shell=True,

        bufsize=bufsize,

        close_fds=closefds,

        stdin=subprocess.PIPE,

    )

    return _pfile(p, p.stdin)

def popen2(cmd, env=None):

    # Setting bufsize to -1 lets the system decide the buffer size.

    # The default for bufsize is 0, meaning unbuffered. This leads to

    # poor performance on Mac OS X: http://bugs.python.org/issue4194

    p = subprocess.Popen(

        tonativestr(cmd),

        shell=True,

        bufsize=-1,

        close_fds=closefds,

        stdin=subprocess.PIPE,

        stdout=subprocess.PIPE,

        env=tonativeenv(env),

    )

    return p.stdin, p.stdout

def popen3(cmd, env=None):

    stdin, stdout, stderr, p = popen4(cmd, env)

    return stdin, stdout, stderr

def popen4(cmd, env=None, bufsize=-1):

    p = subprocess.Popen(

        tonativestr(cmd),

        shell=True,

        bufsize=bufsize,

        close_fds=closefds,

        stdin=subprocess.PIPE,

        stdout=subprocess.PIPE,

        stderr=subprocess.PIPE,

        env=tonativeenv(env),

    )

    return p.stdin, p.stdout, p.stderr, p

def pipefilter(s, cmd):

    '''filter string S through command CMD, returning its output'''

    p = subprocess.Popen(

        tonativestr(cmd),

        shell=True,

        close_fds=closefds,

        stdin=subprocess.PIPE,

        stdout=subprocess.PIPE,

    )

    pout, perr = p.communicate(s)

    return pout

def tempfilter(s, cmd):

    '''filter string S through a pair of temporary files with CMD.

    CMD is used as a template to create the real command to be run,

    with the strings INFILE and OUTFILE replaced by the real names of

    the temporary files generated.'''

    inname, outname = None, None

    try:

        infd, inname = pycompat.mkstemp(prefix=b'hg-filter-in-')

        fp = os.fdopen(infd, 'wb')

        fp.write(s)

        fp.close()

        outfd, outname = pycompat.mkstemp(prefix=b'hg-filter-out-')

        os.close(outfd)

        cmd = cmd.replace(b'INFILE', inname)

        cmd = cmd.replace(b'OUTFILE', outname)

        code = system(cmd)

        if pycompat.sysplatform == b'OpenVMS' and code & 1:

            code = 0

        if code:

            raise error.Abort(

                _(b"command '%s' failed: %s") % (cmd, explainexit(code))

            )

        with open(outname, b'rb') as fp:

            return fp.read()

    finally:

        try:

            if inname:

                os.unlink(inname)

        except OSError:

            pass

        try:

            if outname:

                os.unlink(outname)

        except OSError:

            pass

_filtertable = {

    b'tempfile:': tempfilter,

    b'pipe:': pipefilter,

}

def filter(s, cmd):

    """filter a string through a command that transforms its input to its

    output"""

    for name, fn in pycompat.iteritems(_filtertable):

        if cmd.startswith(name):

            return fn(s, cmd[len(name) :].lstrip())

    return pipefilter(s, cmd)

_hgexecutable = None

def hgexecutable():

    """return location of the 'hg' executable.

    Defaults to $HG or 'hg' in the search path.

    """

    if _hgexecutable is None:

        hg = encoding.environ.get(b'HG')

        mainmod = sys.modules['__main__']

        if hg:

            _sethgexecutable(hg)

        elif resourceutil.mainfrozen():

            if getattr(sys, 'frozen', None) == 'macosx_app':

                # Env variable set by py2app

                _sethgexecutable(encoding.environ[b'EXECUTABLEPATH'])

            else:

                _sethgexecutable(pycompat.sysexecutable)

        elif (

            not pycompat.iswindows

            and os.path.basename(getattr(mainmod, '__file__', '')) == 'hg'

        ):

            _sethgexecutable(pycompat.fsencode(mainmod.__file__))

        else:

            _sethgexecutable(

                findexe(b'hg') or os.path.basename(pycompat.sysargv[0])

            )

    return _hgexecutable

def _sethgexecutable(path):

    """set location of the 'hg' executable"""

    global _hgexecutable

    _hgexecutable = path

def _testfileno(f, stdf):

    fileno = getattr(f, 'fileno', None)

    try:

        return fileno and fileno() == stdf.fileno()

    except io.UnsupportedOperation:

        return False  # fileno() raised UnsupportedOperation

def isstdin(f):

    return _testfileno(f, sys.__stdin__)

def isstdout(f):

    return _testfileno(f, sys.__stdout__)

def protectstdio(uin, uout):

    """Duplicate streams and redirect original if (uin, uout) are stdio

    If uin is stdin, it's redirected to /dev/null. If uout is stdout, it's

    redirected to stderr so the output is still readable.

    Returns (fin, fout) which point to the original (uin, uout) fds, but

    may be copy of (uin, uout). The returned streams can be considered

    "owned" in that print(), exec(), etc. never reach to them.

    """

    uout.flush()

    fin, fout = uin, uout

    if _testfileno(uin, stdin):

        newfd = os.dup(uin.fileno())

        nullfd = os.open(os.devnull, os.O_RDONLY)

        os.dup2(nullfd, uin.fileno())

        os.close(nullfd)

        fin = os.fdopen(newfd, 'rb')

    if _testfileno(uout, stdout):

        newfd = os.dup(uout.fileno())

        os.dup2(stderr.fileno(), uout.fileno())

        fout = os.fdopen(newfd, 'wb')

    return fin, fout

def restorestdio(uin, uout, fin, fout):

    """Restore (uin, uout) streams from possibly duplicated (fin, fout)"""

    uout.flush()

    for f, uif in [(fin, uin), (fout, uout)]:

        if f is not uif:

            os.dup2(f.fileno(), uif.fileno())