Add support for branch description files

[stgit] / stgit / git.py

diff --git a/stgit/git.py b/stgit/git.py
index a118140..55f06c1 100644 (file)
--- a/stgit/git.py
+++ b/stgit/git.py
@@ -264,6 +264,71 @@ def rev_parse(git_id):
     except GitException:
         raise GitException, 'Unknown revision: %s' % git_id
 
+def branch_exists(branch):
+    """Existance check for the named branch
+    """
+    for line in _output_lines(['git-rev-parse', '--symbolic', '--all']):
+        if line.strip() == branch:
+            return True
+    return False
+
+def create_branch(new_branch, tree_id = None):
+    """Create a new branch in the git repository
+    """
+    new_head = os.path.join('refs', 'heads', new_branch)
+    if branch_exists(new_head):
+        raise GitException, 'Branch "%s" already exists' % new_branch
+
+    current_head = get_head()
+    set_head_file(new_head)
+    __set_head(current_head)
+
+    # a checkout isn't needed if new branch points to the current head
+    if tree_id:
+        git.switch(tree_id)
+
+    if os.path.isfile(os.path.join(base_dir, 'MERGE_HEAD')):
+        os.remove(os.path.join(base_dir, 'MERGE_HEAD'))
+
+def switch_branch(name):
+    """Switch to a git branch
+    """
+    new_head = os.path.join('refs', 'heads', name)
+    if not branch_exists(new_head):
+        raise GitException, 'Branch "%s" does not exist' % name
+
+    tree_id = rev_parse(new_head + '^0')
+    if tree_id != get_head():
+        if __run('git-read-tree -u -m', [get_head(), tree_id]) != 0:
+            raise GitException, 'git-read-tree failed (local changes maybe?)'
+        __head = tree_id
+    set_head_file(new_head)
+
+    if os.path.isfile(os.path.join(base_dir, 'MERGE_HEAD')):
+        os.remove(os.path.join(base_dir, 'MERGE_HEAD'))
+
+def delete_branch(name):
+    """Delete a git branch
+    """
+    branch_head = os.path.join('refs', 'heads', name)
+    if not branch_exists(branch_head):
+        raise GitException, 'Branch "%s" does not exist' % name
+    os.remove(os.path.join(base_dir, branch_head))
+
+def rename_branch(from_name, to_name):
+    """Rename a git branch
+    """
+    from_head = os.path.join(base_dir, 'refs', 'heads', from_name)
+    if not branch_exists(from_head):
+        raise GitException, 'Branch "%s" does not exist' % from_name
+    to_head = os.path.join(base_dir, 'refs', 'heads', to_name)
+    if branch_exists(to_head):
+        raise GitException, 'Branch "%s" already exists' % to_name
+
+    if get_head_file() == from_name:
+        set_head_file(os.path.join('refs', 'heads', to_name))
+    os.rename(from_head, to_head)
+
 def add(names):
     """Add the files or recursively add the directory contents
     """