# cmd.py

# Copyright (C) 2008, 2009 Michael Trier (mtrier@gmail.com) and contributors

#

# This module is part of GitPython and is released under

# the BSD License: http://www.opensource.org/licenses/bsd-license.php

from contextlib import contextmanager

import io

import logging

import os

import signal

from subprocess import (

call,

Popen,

PIPE

)

import subprocess

import sys

import threading

from git.compat import (

string_types,

defenc,

force_bytes,

PY3,

# just to satisfy flake8 on py3

unicode,

safe_decode,

is_posix,

is_win,

)

from git.exc import CommandError

from git.odict import OrderedDict

from git.util import is_cygwin_git, cygpath

from .exc import (

GitCommandError,

GitCommandNotFound

)

from .util import (

LazyMixin,

stream_copy,

)

execute_kwargs = set(('istream', 'with_extended_output',

'with_exceptions', 'as_process', 'stdout_as_string',

'output_stream', 'with_stdout', 'kill_after_timeout',

'universal_newlines', 'shell'))

log = logging.getLogger(__name__)

log.addHandler(logging.NullHandler())

__all__ = ('Git',)

# ==============================================================================

## @name Utilities

# ------------------------------------------------------------------------------

# Documentation

## @{

def handle_process_output(process, stdout_handler, stderr_handler,

finalizer=None, decode_streams=True):

"""Registers for notifications to lean that process output is ready to read, and dispatches lines to

the respective line handlers.

This function returns once the finalizer returns

:return: result of finalizer

:param process: subprocess.Popen instance

:param stdout_handler: f(stdout_line_string), or None

:param stderr_handler: f(stderr_line_string), or None

:param finalizer: f(proc) - wait for proc to finish

:param decode_streams:

Assume stdout/stderr streams are binary and decode them before pushing \

their contents to handlers.

Set it to False if `universal_newline == True` (then streams are in text-mode)

or if decoding must happen later (i.e. for Diffs).

"""

# Use 2 "pupm" threads and wait for both to finish.

def pump_stream(cmdline, name, stream, is_decode, handler):

try:

for line in stream:

if handler:

if is_decode:

line = line.decode(defenc)

handler(line)

except Exception as ex:

log.error("Pumping %r of cmd(%s) failed due to: %r", name, cmdline, ex)

raise CommandError(['<%s-pump>' % name] + cmdline, ex)

finally:

stream.close()

cmdline = getattr(process, 'args', '') # PY3+ only

if not isinstance(cmdline, (tuple, list)):

cmdline = cmdline.split()

pumps = []

if process.stdout:

pumps.append(('stdout', process.stdout, stdout_handler))

if process.stderr:

pumps.append(('stderr', process.stderr, stderr_handler))

threads = []

for name, stream, handler in pumps:

t = threading.Thread(target=pump_stream,

args=(cmdline, name, stream, decode_streams, handler))

t.setDaemon(True)

t.start()

threads.append(t)

## FIXME: Why Join?? Will block if `stdin` needs feeding...

#

for t in threads:

t.join()

if finalizer:

return finalizer(process)

def dashify(string):

return string.replace('_', '-')

def slots_to_dict(self, exclude=()):

return dict((s, getattr(self, s)) for s in self.__slots__ if s not in exclude)

def dict_to_slots_and__excluded_are_none(self, d, excluded=()):

for k, v in d.items():

setattr(self, k, v)

for k in excluded:

setattr(self, k, None)

## -- End Utilities -- @}

# value of Windows process creation flag taken from MSDN

CREATE_NO_WINDOW = 0x08000000

## CREATE_NEW_PROCESS_GROUP is needed to allow killing it afterwards,

# see https://docs.python.org/3/library/subprocess.html#subprocess.Popen.send_signal

PROC_CREATIONFLAGS = (CREATE_NO_WINDOW | subprocess.CREATE_NEW_PROCESS_GROUP

if is_win and sys.version_info >= (2, 7)

else 0)

class Git(LazyMixin):

"""

The Git class manages communication with the Git binary.

It provides a convenient interface to calling the Git binary, such as in::

g = Git( git_dir )

g.init() # calls 'git init' program

rval = g.ls_files() # calls 'git ls-files' program

``Debugging``

Set the GIT_PYTHON_TRACE environment variable print each invocation

of the command to stdout.

Set its value to 'full' to see details about the returned values.

"""

__slots__ = ("_working_dir", "cat_file_all", "cat_file_header", "_version_info",

"_git_options", "_persistent_git_options", "_environment")

_excluded_ = ('cat_file_all', 'cat_file_header', '_version_info')

def __getstate__(self):

return slots_to_dict(self, exclude=self._excluded_)

def __setstate__(self, d):

dict_to_slots_and__excluded_are_none(self, d, excluded=self._excluded_)

# CONFIGURATION

# The size in bytes read from stdout when copying git's output to another stream

max_chunk_size = io.DEFAULT_BUFFER_SIZE

git_exec_name = "git" # default that should work on linux and windows

# Enables debugging of GitPython's git commands

GIT_PYTHON_TRACE = os.environ.get("GIT_PYTHON_TRACE", False)

# Provide the full path to the git executable. Otherwise it assumes git is in the path

_git_exec_env_var = "GIT_PYTHON_GIT_EXECUTABLE"

GIT_PYTHON_GIT_EXECUTABLE = os.environ.get(_git_exec_env_var, git_exec_name)

# If True, a shell will be used when executing git commands.

# This should only be desirable on Windows, see https://github.com/gitpython-developers/GitPython/pull/126

# and check `git/test_repo.py:TestRepo.test_untracked_files()` TC for an example where it is required.

# Override this value using `Git.USE_SHELL = True`

USE_SHELL = False

@classmethod

def is_cygwin(cls):

return is_cygwin_git(cls.GIT_PYTHON_GIT_EXECUTABLE)

@classmethod

def polish_url(/sitelet?url=https%3A%2F%2Fgithub.com%2Fgitpython-developers%2FGitPython%2Fblob%2Fno_devnull_open%2Fgit%2Fcls%2C%2520url%2C%2520is_cygwin%3DNone):

if is_cygwin is None:

is_cygwin = cls.is_cygwin()

if is_cygwin:

url = cygpath(url)

else:

"""Remove any backslahes from urls to be written in config files.

Windows might create config-files containing paths with backslashed,

but git stops liking them as it will escape the backslashes.

Hence we undo the escaping just to be sure.

"""

url = url.replace("\\\\", "\\").replace("\\", "/")

return url

class AutoInterrupt(object):

"""Kill/Interrupt the stored process instance once this instance goes out of scope. It is

used to prevent processes piling up in case iterators stop reading.

Besides all attributes are wired through to the contained process object.

The wait method was overridden to perform automatic status code checking

and possibly raise."""

__slots__ = ("proc", "args")

def __init__(self, proc, args):

self.proc = proc

self.args = args

def __del__(self):

if self.proc is None:

return

proc = self.proc

self.proc = None

if proc.stdin:

proc.stdin.close()

if proc.stdout:

proc.stdout.close()

if proc.stderr:

proc.stderr.close()

# did the process finish already so we have a return code ?

if proc.poll() is not None:

return

# can be that nothing really exists anymore ...

if os is None or getattr(os, 'kill', None) is None:

return

# try to kill it

try:

proc.terminate()

proc.wait() # ensure process goes away

except OSError as ex:

log.info("Ignored error after process has dies: %r", ex)

pass # ignore error when process already died

except AttributeError:

# try windows

# for some reason, providing None for stdout/stderr still prints something. This is why

# we simply use the shell and redirect to nul. Its slower than CreateProcess, question

# is whether we really want to see all these messages. Its annoying no matter what.

call(("TASKKILL /F /T /PID %s 2>nul 1>nul" % str(proc.pid)), shell=True)

# END exception handling

def __getattr__(self, attr):

return getattr(self.proc, attr)

def wait(self, stderr=b''): # TODO: Bad choice to mimic `proc.wait()` but with different args.

"""Wait for the process and return its status code.

:param stderr: Previously read value of stderr, in case stderr is already closed.

:warn: may deadlock if output or error pipes are used and not handled separately.

:raise GitCommandError: if the return status is not 0"""

if stderr is None:

stderr = b''

stderr = force_bytes(stderr)

status = self.proc.wait()

def read_all_from_possibly_closed_stream(stream):

try:

return stderr + force_bytes(stream.read())

except ValueError:

return stderr or b''

if status != 0:

errstr = read_all_from_possibly_closed_stream(self.proc.stderr)

log.debug('AutoInterrupt wait stderr: %r' % (errstr,))

raise GitCommandError(self.args, status, errstr)

# END status handling

return status

# END auto interrupt

class CatFileContentStream(object):

"""Object representing a sized read-only stream returning the contents of

an object.

It behaves like a stream, but counts the data read and simulates an empty

stream once our sized content region is empty.

If not all data is read to the end of the objects's lifetime, we read the

rest to assure the underlying stream continues to work"""

__slots__ = ('_stream', '_nbr', '_size')

def __init__(self, size, stream):

self._stream = stream

self._size = size

self._nbr = 0 # num bytes read

# special case: if the object is empty, has null bytes, get the

# final newline right away.

if size == 0:

stream.read(1)

# END handle empty streams

def read(self, size=-1):

bytes_left = self._size - self._nbr

if bytes_left == 0:

return b''

if size > -1:

# assure we don't try to read past our limit

size = min(bytes_left, size)

else:

# they try to read all, make sure its not more than what remains

size = bytes_left

# END check early depletion

data = self._stream.read(size)

self._nbr += len(data)

# check for depletion, read our final byte to make the stream usable by others

if self._size - self._nbr == 0:

self._stream.read(1) # final newline

# END finish reading

return data

def readline(self, size=-1):

if self._nbr == self._size:

return b''

# clamp size to lowest allowed value

bytes_left = self._size - self._nbr

if size > -1:

size = min(bytes_left, size)

else:

size = bytes_left

# END handle size

data = self._stream.readline(size)

self._nbr += len(data)

# handle final byte

if self._size - self._nbr == 0:

self._stream.read(1)

# END finish reading

return data

def readlines(self, size=-1):

if self._nbr == self._size:

return list()

# leave all additional logic to our readline method, we just check the size

out = list()

nbr = 0

while True:

line = self.readline()

if not line:

break

out.append(line)

if size > -1:

nbr += len(line)

if nbr > size:

break

# END handle size constraint

# END readline loop

return out

def __iter__(self):

return self

def next(self):

line = self.readline()

if not line:

raise StopIteration

return line

def __del__(self):

bytes_left = self._size - self._nbr

if bytes_left:

# read and discard - seeking is impossible within a stream

# includes terminating newline

self._stream.read(bytes_left + 1)

# END handle incomplete read

def __init__(self, working_dir=None):

"""Initialize this instance with:

:param working_dir:

Git directory we should work in. If None, we always work in the current

directory as returned by os.getcwd().

It is meant to be the working tree directory if available, or the

.git directory in case of bare repositories."""

super(Git, self).__init__()

self._working_dir = working_dir

self._git_options = ()

self._persistent_git_options = []

# Extra environment variables to pass to git commands

self._environment = {}

# cached command slots

self.cat_file_header = None

self.cat_file_all = None

def __getattr__(self, name):

"""A convenience method as it allows to call the command as if it was

an object.

:return: Callable object that will execute call _call_process with your arguments."""

if name[0] == '_':

return LazyMixin.__getattr__(self, name)

return lambda *args, **kwargs: self._call_process(name, *args, **kwargs)

def set_persistent_git_options(self, **kwargs):

"""Specify command line options to the git executable

for subsequent subcommand calls

:param kwargs:

is a dict of keyword arguments.

these arguments are passed as in _call_process

but will be passed to the git command rather than

the subcommand.

"""

self._persistent_git_options = self.transform_kwargs(

split_single_char_options=True, **kwargs)

def _set_cache_(self, attr):

if attr == '_version_info':

# We only use the first 4 numbers, as everything else could be strings in fact (on windows)

version_numbers = self._call_process('version').split(' ')[2]

self._version_info = tuple(int(n) for n in version_numbers.split('.')[:4] if n.isdigit())

else:

super(Git, self)._set_cache_(attr)

# END handle version info

@property

def working_dir(self):

""":return: Git directory we are working on"""

return self._working_dir

@property

def version_info(self):

"""

:return: tuple(int, int, int, int) tuple with integers representing the major, minor

and additional version numbers as parsed from git version.

This value is generated on demand and is cached"""

return self._version_info

def execute(self, command,

istream=None,

with_extended_output=False,

with_exceptions=True,

as_process=False,

output_stream=None,

stdout_as_string=True,

kill_after_timeout=None,

with_stdout=True,

universal_newlines=False,

shell=None,

**subprocess_kwargs

):

"""Handles executing the command on the shell and consumes and returns

the returned information (stdout)

:param command:

The command argument list to execute.

It should be a string, or a sequence of program arguments. The

program to execute is the first item in the args sequence or string.

:param istream:

Standard input filehandle passed to subprocess.Popen.

:param with_extended_output:

Whether to return a (status, stdout, stderr) tuple.

:param with_exceptions:

Whether to raise an exception when git returns a non-zero status.

:param as_process:

Whether to return the created process instance directly from which

streams can be read on demand. This will render with_extended_output and

with_exceptions ineffective - the caller will have

to deal with the details himself.

It is important to note that the process will be placed into an AutoInterrupt

wrapper that will interrupt the process once it goes out of scope. If you

use the command in iterators, you should pass the whole process instance

instead of a single stream.

:param output_stream:

If set to a file-like object, data produced by the git command will be

output to the given stream directly.

This feature only has any effect if as_process is False. Processes will

always be created with a pipe due to issues with subprocess.

This merely is a workaround as data will be copied from the

output pipe to the given output stream directly.

Judging from the implementation, you shouldn't use this flag !

:param stdout_as_string:

if False, the commands standard output will be bytes. Otherwise, it will be

decoded into a string using the default encoding (usually utf-8).

The latter can fail, if the output contains binary data.

:param subprocess_kwargs:

Keyword arguments to be passed to subprocess.Popen. Please note that

some of the valid kwargs are already set by this method, the ones you

specify may not be the same ones.

:param with_stdout: If True, default True, we open stdout on the created process

:param universal_newlines:

if True, pipes will be opened as text, and lines are split at

all known line endings.

:param shell:

Whether to invoke commands through a shell (see `Popen(..., shell=True)`).

It overrides :attr:`USE_SHELL` if it is not `None`.

:param kill_after_timeout:

To specify a timeout in seconds for the git command, after which the process

should be killed. This will have no effect if as_process is set to True. It is

set to None by default and will let the process run until the timeout is

explicitly specified. This feature is not supported on Windows. It's also worth

noting that kill_after_timeout uses SIGKILL, which can have negative side

effects on a repository. For example, stale locks in case of git gc could

render the repository incapable of accepting changes until the lock is manually

removed.

:return:

* str(output) if extended_output = False (Default)

* tuple(int(status), str(stdout), str(stderr)) if extended_output = True

if ouput_stream is True, the stdout value will be your output stream:

* output_stream if extended_output = False

* tuple(int(status), output_stream, str(stderr)) if extended_output = True

Note git is executed with LC_MESSAGES="C" to ensure consistent

output regardless of system language.

:raise GitCommandError:

:note:

If you add additional keyword arguments to the signature of this method,

you must update the execute_kwargs tuple housed in this module."""

if self.GIT_PYTHON_TRACE and (self.GIT_PYTHON_TRACE != 'full' or as_process):

log.info(' '.join(command))

# Allow the user to have the command executed in their working dir.

cwd = self._working_dir or os.getcwd()

# Start the process

env = os.environ.copy()

# Attempt to force all output to plain ascii english, which is what some parsing code

# may expect.

# According to stackoverflow (http://goo.gl/l74GC8), we are setting LANGUAGE as well

# just to be sure.

env["LANGUAGE"] = "C"

env["LC_ALL"] = "C"

env.update(self._environment)

if is_win:

cmd_not_found_exception = OSError

if kill_after_timeout:

raise GitCommandError(command, '"kill_after_timeout" feature is not supported on Windows.')

else:

if sys.version_info[0] > 2:

cmd_not_found_exception = FileNotFoundError # NOQA # exists, flake8 unknown @UndefinedVariable

else:

cmd_not_found_exception = OSError

# end handle

stdout_sink = (PIPE

if with_stdout

else getattr(subprocess, 'DEVNULL', None) or open(os.devnull, 'wb'))

log.debug("Popen(%s, cwd=%s, universal_newlines=%s, shell=%s)",

command, cwd, universal_newlines, shell)

try:

proc = Popen(command,

env=env,

cwd=cwd,

bufsize=-1,

stdin=istream,

stderr=PIPE,

stdout=stdout_sink,

shell=shell is not None and shell or self.USE_SHELL,

close_fds=is_posix, # unsupported on windows

universal_newlines=universal_newlines,

creationflags=PROC_CREATIONFLAGS,

**subprocess_kwargs

)

except cmd_not_found_exception as err:

raise GitCommandNotFound(command, err)

if as_process:

return self.AutoInterrupt(proc, command)

def _kill_process(pid):

""" Callback method to kill a process. """

p = Popen(['ps', '--ppid', str(pid)], stdout=PIPE,

creationflags=PROC_CREATIONFLAGS)

child_pids = []

for line in p.stdout:

if len(line.split()) > 0:

local_pid = (line.split())[0]

if local_pid.isdigit():

child_pids.append(int(local_pid))

try:

# Windows does not have SIGKILL, so use SIGTERM instead

sig = getattr(signal, 'SIGKILL', signal.SIGTERM)

os.kill(pid, sig)

for child_pid in child_pids:

try:

os.kill(child_pid, sig)

except OSError:

pass

kill_check.set() # tell the main routine that the process was killed

except OSError:

# It is possible that the process gets completed in the duration after timeout

# happens and before we try to kill the process.

pass

return

# end

if kill_after_timeout:

kill_check = threading.Event()

watchdog = threading.Timer(kill_after_timeout, _kill_process, args=(proc.pid,))

# Wait for the process to return

status = 0

stdout_value = b''

stderr_value = b''

try:

if output_stream is None:

if kill_after_timeout:

watchdog.start()

stdout_value, stderr_value = proc.communicate()

if kill_after_timeout:

watchdog.cancel()

if kill_check.isSet():

stderr_value = 'Timeout: the command "%s" did not complete in %d ' \

'secs.' % (" ".join(command), kill_after_timeout)

# strip trailing "\n"

if stdout_value.endswith(b"\n"):

stdout_value = stdout_value[:-1]

if stderr_value.endswith(b"\n"):

stderr_value = stderr_value[:-1]

status = proc.returncode

else:

stream_copy(proc.stdout, output_stream, self.max_chunk_size)

stdout_value = output_stream

stderr_value = proc.stderr.read()

# strip trailing "\n"

if stderr_value.endswith(b"\n"):

stderr_value = stderr_value[:-1]

status = proc.wait()

# END stdout handling

finally:

proc.stdout.close()

proc.stderr.close()

if self.GIT_PYTHON_TRACE == 'full':

cmdstr = " ".join(command)

def as_text(stdout_value):

return not output_stream and safe_decode(stdout_value) or '<OUTPUT_STREAM>'

# end

if stderr_value:

log.info("%s -> %d; stdout: '%s'; stderr: '%s'",

cmdstr, status, as_text(stdout_value), safe_decode(stderr_value))

elif stdout_value:

log.info("%s -> %d; stdout: '%s'", cmdstr, status, as_text(stdout_value))

else:

log.info("%s -> %d", cmdstr, status)

# END handle debug printing

if with_exceptions and status != 0:

raise GitCommandError(command, status, stderr_value, stdout_value)

if isinstance(stdout_value, bytes) and stdout_as_string: # could also be output_stream

stdout_value = safe_decode(stdout_value)

# Allow access to the command's status code

if with_extended_output:

return (status, stdout_value, safe_decode(stderr_value))

else:

return stdout_value

def environment(self):

return self._environment

def update_environment(self, **kwargs):

"""

Set environment variables for future git invocations. Return all changed

values in a format that can be passed back into this function to revert

the changes:

``Examples``::

old_env = self.update_environment(PWD='/tmp')

self.update_environment(**old_env)

:param kwargs: environment variables to use for git processes

:return: dict that maps environment variables to their old values

"""

old_env = {}

for key, value in kwargs.items():

# set value if it is None

if value is not None:

old_env[key] = self._environment.get(key)

self._environment[key] = value

# remove key from environment if its value is None

elif key in self._environment:

old_env[key] = self._environment[key]

del self._environment[key]

return old_env

@contextmanager

def custom_environment(self, **kwargs):

"""

A context manager around the above ``update_environment`` method to restore the

environment back to its previous state after operation.

``Examples``::

with self.custom_environment(GIT_SSH='/bin/ssh_wrapper'):

repo.remotes.origin.fetch()

:param kwargs: see update_environment

"""

old_env = self.update_environment(**kwargs)

try:

yield

finally:

self.update_environment(**old_env)

def transform_kwarg(self, name, value, split_single_char_options):

if len(name) == 1:

if value is True:

return ["-%s" % name]

elif type(value) is not bool:

if split_single_char_options:

return ["-%s" % name, "%s" % value]

else:

return ["-%s%s" % (name, value)]

else:

if value is True:

return ["--%s" % dashify(name)]

elif type(value) is not bool:

return ["--%s=%s" % (dashify(name), value)]

return []

def transform_kwargs(self, split_single_char_options=True, **kwargs):

"""Transforms Python style kwargs into git command line options."""

args = list()

kwargs = OrderedDict(sorted(kwargs.items(), key=lambda x: x[0]))

for k, v in kwargs.items():

if isinstance(v, (list, tuple)):

for value in v:

args += self.transform_kwarg(k, value, split_single_char_options)

else:

args += self.transform_kwarg(k, v, split_single_char_options)

return args

@classmethod

def __unpack_args(cls, arg_list):

if not isinstance(arg_list, (list, tuple)):

# This is just required for unicode conversion, as subprocess can't handle it

# However, in any other case, passing strings (usually utf-8 encoded) is totally fine

if not PY3 and isinstance(arg_list, unicode):

return [arg_list.encode(defenc)]

return [str(arg_list)]

outlist = list()

for arg in arg_list:

if isinstance(arg_list, (list, tuple)):

outlist.extend(cls.__unpack_args(arg))

elif not PY3 and isinstance(arg_list, unicode):

outlist.append(arg_list.encode(defenc))

# END recursion

else:

outlist.append(str(arg))

# END for each arg

return outlist

def __call__(self, **kwargs):

"""Specify command line options to the git executable

for a subcommand call

:param kwargs:

is a dict of keyword arguments.

these arguments are passed as in _call_process

but will be passed to the git command rather than

the subcommand.

``Examples``::

git(work_tree='/tmp').difftool()"""

self._git_options = self.transform_kwargs(

split_single_char_options=True, **kwargs)

return self

def _call_process(self, method, *args, **kwargs):

"""Run the given git command with the specified arguments and return

the result as a String

:param method:

is the command. Contained "_" characters will be converted to dashes,

such as in 'ls_files' to call 'ls-files'.

:param args:

is the list of arguments. If None is included, it will be pruned.

This allows your commands to call git more conveniently as None

is realized as non-existent

:param kwargs:

is a dict of keyword arguments.

This function accepts the same optional keyword arguments

as execute().

``Examples``::

git.rev_list('master', max_count=10, header=True)

:return: Same as ``execute``"""

# Handle optional arguments prior to calling transform_kwargs

# otherwise these'll end up in args, which is bad.

_kwargs = dict()

for kwarg in execute_kwargs:

try:

_kwargs[kwarg] = kwargs.pop(kwarg)

except KeyError:

pass

insert_after_this_arg = kwargs.pop('insert_kwargs_after', None)

# Prepare the argument list

opt_args = self.transform_kwargs(**kwargs)

ext_args = self.__unpack_args([a for a in args if a is not None])

if insert_after_this_arg is None:

args = opt_args + ext_args

else:

try:

index = ext_args.index(insert_after_this_arg)

except ValueError:

raise ValueError("Couldn't find argument '%s' in args %s to insert kwargs after"

% (insert_after_this_arg, str(ext_args)))

# end handle error

args = ext_args[:index + 1] + opt_args + ext_args[index + 1:]

# end handle kwargs

call = [self.GIT_PYTHON_GIT_EXECUTABLE]

# add persistent git options

call.extend(self._persistent_git_options)

# add the git options, then reset to empty

# to avoid side_effects

call.extend(self._git_options)

self._git_options = ()

call.append(dashify(method))

call.extend(args)

return self.execute(call, **_kwargs)

def _parse_object_header(self, header_line):

"""

:param header_line:

<hex_sha> type_string size_as_int

:return: (hex_sha, type_string, size_as_int)

:raise ValueError: if the header contains indication for an error due to

incorrect input sha"""

tokens = header_line.split()

if len(tokens) != 3:

if not tokens:

raise ValueError("SHA could not be resolved, git returned: %r" % (header_line.strip()))

else:

raise ValueError("SHA %s could not be resolved, git returned: %r" % (tokens[0], header_line.strip()))

# END handle actual return value

# END error handling

if len(tokens[0]) != 40:

raise ValueError("Failed to parse header: %r" % header_line)

return (tokens[0], tokens[1], int(tokens[2]))

def _prepare_ref(self, ref):

# required for command to separate refs on stdin, as bytes

refstr = ref

if isinstance(ref, bytes):

# Assume 40 bytes hexsha - bin-to-ascii for some reason returns bytes, not text

refstr = ref.decode('ascii')

elif not isinstance(ref, string_types):

refstr = str(ref) # could be ref-object

if not refstr.endswith("\n"):

refstr += "\n"

return refstr.encode(defenc)

def _get_persistent_cmd(self, attr_name, cmd_name, *args, **kwargs):

cur_val = getattr(self, attr_name)

if cur_val is not None:

return cur_val

options = {"istream": PIPE, "as_process": True}

options.update(kwargs)

cmd = self._call_process(cmd_name, *args, **options)

setattr(self, attr_name, cmd)

return cmd

def __get_object_header(self, cmd, ref):

cmd.stdin.write(self._prepare_ref(ref))

cmd.stdin.flush()

return self._parse_object_header(cmd.stdout.readline())

def get_object_header(self, ref):

""" Use this method to quickly examine the type and size of the object behind

the given ref.

:note: The method will only suffer from the costs of command invocation

once and reuses the command in subsequent calls.

:return: (hexsha, type_string, size_as_int)"""

cmd = self._get_persistent_cmd("cat_file_header", "cat_file", batch_check=True)

return self.__get_object_header(cmd, ref)

def get_object_data(self, ref):

""" As get_object_header, but returns object data as well

:return: (hexsha, type_string, size_as_int,data_string)

:note: not threadsafe"""

hexsha, typename, size, stream = self.stream_object_data(ref)

data = stream.read(size)

del(stream)

return (hexsha, typename, size, data)

def stream_object_data(self, ref):

""" As get_object_header, but returns the data as a stream

:return: (hexsha, type_string, size_as_int, stream)

:note: This method is not threadsafe, you need one independent Command instance per thread to be safe !"""

cmd = self._get_persistent_cmd("cat_file_all", "cat_file", batch=True)

hexsha, typename, size = self.__get_object_header(cmd, ref)

return (hexsha, typename, size, self.CatFileContentStream(size, cmd.stdout))

def clear_cache(self):

"""Clear all kinds of internal caches to release resources.

Currently persistent commands will be interrupted.

:return: self"""

for cmd in (self.cat_file_all, self.cat_file_header):

if cmd:

cmd.__del__()

self.cat_file_all = None

self.cat_file_header = None

return self