git-meld-commit

   1 #!/usr/bin/env python
   2
   3 # Copyright (c) 2009 James Ascroft-Leigh
   4 #
   5 # Permission is hereby granted, free of charge, to any person
   6 # obtaining a copy of this software and associated documentation
   7 # files (the "Software"), to deal in the Software without
   8 # restriction, including without limitation the rights to use,
   9 # copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 # copies of the Software, and to permit persons to whom the
  11 # Software is furnished to do so, subject to the following
  12 # conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be
  15 # included in all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  19 # OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  21 # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  22 # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24 # OTHER DEALINGS IN THE SOFTWARE.
  25
  26 """\
  27 %prog [options] COMMIT
  28
  29 Shows the difference between the tree from COMMIT and the tree from
  30 the parent of COMMIT.  Invokes meld once for each parent.
  31 """
  32
  33 # test cases:
  34 # initial: (cd ~/git/nacl-build && ~/git/git-meld-toys/git-meld-commit \
  35 #           8816f9f4ea28583d6dfa1fd96d3448977f6e2299)
  36 # commit: (cd ~/git/nacl-build && ~/git/git-meld-toys/git-meld-commit \
  37 #          707c127f621bf308f1e1a8526e79d5dc3888483c)
  38 # merge: (cd ~/git/git && ~/git/git-meld-toys/git-meld-commit \
  39 #         2d602e9179c7eb1a31a0abf41283c132e26a61af)
  40
  41 import optparse
  42 import os
  43 import subprocess
  44 import shutil
  45 import sys
  46 import tempfile
  47
  48
  49 def parse_argv(prog, argv):
  50     parser = optparse.OptionParser(__doc__, prog=prog)
  51     options, args = parser.parse_args(argv)
  52     if len(args) == 0:
  53         commit_spec = "HEAD"
  54     else:
  55         commit_spec = args.pop(0)
  56     if len(args) > 0:
  57         parser.error("Unexpected: %r" % (args,))
  58     return (commit_spec,)
  59
  60
  61 def dump_tree(tree_ish, destination):
  62     os.mkdir(destination)
  63     git = subprocess.Popen(["git", "archive", "--format=tar", tree_ish],
  64                            stdout=subprocess.PIPE)
  65     tar = subprocess.Popen(["tar", "-C", destination, "-x"],
  66                            stdin=git.stdout)
  67     tar.communicate()
  68     git.communicate()
  69     assert git.returncode == 0, git.returncode
  70     assert tar.returncode == 0, tar.returncode
  71
  72
  73 def meld(lhs, rhs):
  74     work_dir = tempfile.mkdtemp(prefix="git-meld-commit-")
  75     try:
  76         lhs_path = os.path.join(work_dir, "lhs", lhs)
  77         rhs_path = os.path.join(work_dir, "rhs", rhs)
  78         os.mkdir(os.path.dirname(lhs_path))
  79         os.mkdir(os.path.dirname(rhs_path))
  80         dump_tree(lhs, lhs_path)
  81         dump_tree(rhs, rhs_path)
  82         subprocess.check_call(["meld", lhs_path, rhs_path])
  83     finally:
  84         shutil.rmtree(work_dir)
  85
  86
  87 def main(commit_spec):
  88     cmd = ["git", "show", "--quiet", "--pretty=format:%P", commit_spec]
  89     git = subprocess.Popen(cmd, stdout=subprocess.PIPE)
  90     stdout, stderr = git.communicate()
  91     assert git.returncode == 0, git.returncode
  92     parents = stdout.rstrip("\n").split(" ")
  93     if parents == [""]:
  94         parents = []
  95     for parent in parents:
  96         meld(commit_spec, parent)
  97
  98
  99 if __name__ == "__main__":
 100     sys.exit(main(*parse_argv(sys.argv[0], sys.argv[1:])))
 101