Only check for upstream merges if not fast-forwarding

[stgit] / stgit / git.py

"""Python GIT interface
"""

__copyright__ = """
Copyright (C) 2005, Catalin Marinas <catalin.marinas@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""

import sys, os, popen2, re, gitmergeonefile

from stgit import basedir
from stgit.utils import *
from stgit.config import config
from sets import Set

# git exception class
class GitException(Exception):
    pass



#
# Classes
#

class Person:
    """An author, committer, etc."""
    def __init__(self, name = None, email = None, date = '',
                 desc = None):
        self.name = self.email = self.date = None
        if name or email or date:
            assert not desc
            self.name = name
            self.email = email
            self.date = date
        elif desc:
            assert not (name or email or date)
            def parse_desc(s):
                m = re.match(r'^(.+)<(.+)>(.*)$', s)
                assert m
                return [x.strip() or None for x in m.groups()]
            self.name, self.email, self.date = parse_desc(desc)
    def set_name(self, val):
        if val:
            self.name = val
    def set_email(self, val):
        if val:
            self.email = val
    def set_date(self, val):
        if val:
            self.date = val
    def __str__(self):
        if self.name and self.email:
            return '%s <%s>' % (self.name, self.email)
        else:
            raise GitException, 'not enough identity data'

class Commit:
    """Handle the commit objects
    """
    def __init__(self, id_hash):
        self.__id_hash = id_hash

        lines = _output_lines('git-cat-file commit %s' % id_hash)
        for i in range(len(lines)):
            line = lines[i]
            if line == '\n':
                break
            field = line.strip().split(' ', 1)
            if field[0] == 'tree':
                self.__tree = field[1]
            if field[0] == 'author':
                self.__author = field[1]
            if field[0] == 'committer':
                self.__committer = field[1]
        self.__log = ''.join(lines[i+1:])

    def get_id_hash(self):
        return self.__id_hash

    def get_tree(self):
        return self.__tree

    def get_parent(self):
        parents = self.get_parents()
        if parents:
            return parents[0]
        else:
            return None

    def get_parents(self):
        return _output_lines('git-rev-list --parents --max-count=1 %s'
                             % self.__id_hash)[0].split()[1:]

    def get_author(self):
        return self.__author

    def get_committer(self):
        return self.__committer

    def get_log(self):
        return self.__log

    def __str__(self):
        return self.get_id_hash()

# dictionary of Commit objects, used to avoid multiple calls to git
__commits = dict()

#
# Functions
#

def get_commit(id_hash):
    """Commit objects factory. Save/look-up them in the __commits
    dictionary
    """
    global __commits

    if id_hash in __commits:
        return __commits[id_hash]
    else:
        commit = Commit(id_hash)
        __commits[id_hash] = commit
        return commit

def get_conflicts():
    """Return the list of file conflicts
    """
    conflicts_file = os.path.join(basedir.get(), 'conflicts')
    if os.path.isfile(conflicts_file):
        f = file(conflicts_file)
        names = [line.strip() for line in f.readlines()]
        f.close()
        return names
    else:
        return None

def _input(cmd, file_desc):
    p = popen2.Popen3(cmd, True)
    while True:
        line = file_desc.readline()
        if not line:
            break
        p.tochild.write(line)
    p.tochild.close()
    if p.wait():
        raise GitException, '%s failed (%s)' % (str(cmd),
                                                p.childerr.read().strip())

def _input_str(cmd, string):
    p = popen2.Popen3(cmd, True)
    p.tochild.write(string)
    p.tochild.close()
    if p.wait():
        raise GitException, '%s failed (%s)' % (str(cmd),
                                                p.childerr.read().strip())

def _output(cmd):
    p=popen2.Popen3(cmd, True)
    output = p.fromchild.read()
    if p.wait():
        raise GitException, '%s failed (%s)' % (str(cmd),
                                                p.childerr.read().strip())
    return output

def _output_one_line(cmd, file_desc = None):
    p=popen2.Popen3(cmd, True)
    if file_desc != None:
        for line in file_desc:
            p.tochild.write(line)
        p.tochild.close()
    output = p.fromchild.readline().strip()
    if p.wait():
        raise GitException, '%s failed (%s)' % (str(cmd),
                                                p.childerr.read().strip())
    return output

def _output_lines(cmd):
    p=popen2.Popen3(cmd, True)
    lines = p.fromchild.readlines()
    if p.wait():
        raise GitException, '%s failed (%s)' % (str(cmd),
                                                p.childerr.read().strip())
    return lines

def __run(cmd, args=None):
    """__run: runs cmd using spawnvp.

    Runs cmd using spawnvp.  The shell is avoided so it won't mess up
    our arguments.  If args is very large, the command is run multiple
    times; args is split xargs style: cmd is passed on each
    invocation.  Unlike xargs, returns immediately if any non-zero
    return code is received.  
    """
    
    args_l=cmd.split()
    if args is None:
        args = []
    for i in range(0, len(args)+1, 100):
        r=os.spawnvp(os.P_WAIT, args_l[0], args_l + args[i:min(i+100, len(args))])
    if r:
        return r
    return 0

def __tree_status(files = None, tree_id = 'HEAD', unknown = False,
                  noexclude = True, verbose = False):
    """Returns a list of pairs - [status, filename]
    """
    if verbose and sys.stdout.isatty():
        print 'Checking for changes in the working directory...',
        sys.stdout.flush()

    refresh_index()

    if not files:
        files = []
    cache_files = []

    # unknown files
    if unknown:
        exclude_file = os.path.join(basedir.get(), 'info', 'exclude')
        base_exclude = ['--exclude=%s' % s for s in
                        ['*.[ao]', '*.pyc', '.*', '*~', '#*', 'TAGS', 'tags']]
        base_exclude.append('--exclude-per-directory=.gitignore')

        if os.path.exists(exclude_file):
            extra_exclude = ['--exclude-from=%s' % exclude_file]
        else:
            extra_exclude = []
        if noexclude:
            extra_exclude = base_exclude = []

        lines = _output_lines(['git-ls-files', '--others', '--directory']
                        + base_exclude + extra_exclude)
        cache_files += [('?', line.strip()) for line in lines]

    # conflicted files
    conflicts = get_conflicts()
    if not conflicts:
        conflicts = []
    cache_files += [('C', filename) for filename in conflicts]

    # the rest
    for line in _output_lines(['git-diff-index', tree_id, '--'] + files):
        fs = tuple(line.rstrip().split(' ',4)[-1].split('\t',1))
        if fs[1] not in conflicts:
            cache_files.append(fs)

    if verbose and sys.stdout.isatty():
        print 'done'

    return cache_files

def local_changes(verbose = True):
    """Return true if there are local changes in the tree
    """
    return len(__tree_status(verbose = verbose)) != 0

# HEAD value cached
__head = None

def get_head():
    """Verifies the HEAD and returns the SHA1 id that represents it
    """
    global __head

    if not __head:
        __head = rev_parse('HEAD')
    return __head

def get_head_file():
    """Returns the name of the file pointed to by the HEAD link
    """