--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/treepkg/git.py	Fri Mar 12 09:13:33 2010 +0000
@@ -0,0 +1,124 @@
+# Copyright (C) 2010 by Intevation GmbHi
+# Authors:
+# Andre Heinecke <aheinecke@intevation.de>
+#
+# This program is free software under the GPL (>=v2)
+# Read the file COPYING coming with the software for details.
+
+"""Collection of Git utility code"""
+
+import os
+import shutil
+import re
+import StringIO
+
+import run
+from cmdexpand import cmdexpand
+from util import extract_value_for_key
+
+
+class GitError(Exception):
+
+    """Base class for Git specific errors raised by TreePKG"""
+
+def checkout(url, localdir, branch=None):
+    """Clones the repository at url into the localdir"""
+    run.call(cmdexpand("git clone $url $localdir", **locals()))        
+    if branch:
+        run.call(cmdexpand("/bin/bash -c \"cd $localdir && git checkout --track -b local $branch\"",
+                            **locals()))
+    else:
+        run.call(cmdexpand("/bin/bash -c \"cd $localdir && git checkout --track -b local master\"",
+                            **locals()))
+
+def update(localdir, revision=None):
+    """Runs git pull on the localdir."""
+    run.call(cmdexpand("/bin/bash -c \"cd $localdir && git pull -q\"", **locals()))
+
+def export(src, dest):
+    """Exports the local branch from src to dest"""
+    run.call(cmdexpand("/bin/bash -c \"cd $src && git checkout-index -a -f --prefix=$dest\"", **locals()))
+
+def last_changed_revision(git_working_copy):
+    """return the last changed revision of a Git branch as a incrementing Number"""
+    output = run.capture_output(cmdexpand("/bin/bash -c \"cd $git_working_copy && git rev-list local | nl | tail -n 1 | awk \'{print $$1}\'\"", **locals()))
+    if output is None:
+        raise GitError("Cannot determine last changed revision for %r"
+                              % git_working_copy)
+    return int(output)
+
+class GitRepository(object):
+
+    """Describes a git repository"""
+
+    def __init__(self, url, branch=None):
+        """Initialize the git repository description
+        Parameters:
+          url -- The url of the repository
+
+          branch -- The name of the remote Branch to track
+                    defaults to master
+        """
+        self.url = url
+        self.branch = branch
+
+    def checkout(self, localdir):
+        """Checks out the repository into localdir."""
+        checkout(self.url , localdir, self.branch)
+        update(localdir)
+
+    def export(self, localdir, destdir):
+        """Exports the working copy in localdir to destdir"""
+        export(localdir, destdir)
+
+    def last_changed_revision(self, localdir):
+        """Returns the last changed revision of the working copy in localdir"""
+        return last_changed_revision(localdir)
+
+    def check_working_copy(self, localdir):
+        """
+	FIXME STUB: Not implemented for git
+        """
+        return None  
+
+class GitWorkingCopy(object):
+
+    """Represents a checkout of a git repository"""
+
+    def __init__(self, repository, localdir, logger=None):
+        """
+        Initialize the working copy.
+        Parameters:
+          repository -- The GitRepository instance describing the
+                        repository
+          localdir -- The directory for the working copy
+          logger -- logging object to use for some info/debug messages
+        """
+        self.repository = repository
+        self.localdir = localdir
+        self.logger = logger
+
+    def log_info(self, *args):
+        if self.logger is not None:
+            self.logger.info(*args)
+
+    def update_or_checkout(self, revision=0):
+        """Updates the working copy or creates by checking out the repository.
+           Revision number included for compatibility
+        """
+        if os.path.exists(self.localdir):
+            self.log_info("Updating the working copy in %r", self.localdir)
+            update(self.localdir, self.repository.branch)
+        else:
+            self.log_info("The working copy in %r doesn't exist yet."
+                          "  Checking out from %r",
+                          self.localdir, self.repository.url)
+            self.repository.checkout(self.localdir)
+
+    def export(self, destdir):
+        """Exports the working copy to destdir"""
+        self.repository.export(self.localdir, destdir)
+
+    def last_changed_revision(self):
+        """Returns the last changed rev of the working copy"""
+        return self.repository.last_changed_revision(self.localdir)