1 files changed, 52 insertions, 0 deletions
diff --git a/pomu/util/git.py b/pomu/util/git.py
new file mode 100644
index 0000000..985087c
--- /dev/null
+++ b/pomu/util/git.py
@@ -0,0 +1,52 @@
+"""Miscellaneous utility functions for git structures"""
+
+from base64 import b16encode
+import zlib
+
+from pomu.util.result import Result
+
+def parse_tree(blob, path=b''):
+    """Parses a git tree"""
+    res = []
+    leng, _, tree = blob.partition(b'\0')
+    if path is str:
+        path = path.encode('utf-8')
+    if not tree:
+        return Result.Err('Invalid tree')
+    while len(tree) > 0:
+        mode, _, tree = tree.partition(b' ')
+        name, _, tree = tree.partition(b'\0')
+        sha = b16encode(tree[0:20]).decode('utf-8').lower()
+        tree = tree[20:]
+        if not name or not sha:
+            return Result.Err()
+        is_dir = mode[0:1] != b'1'
+        res.append((is_dir, sha, path + b'/' + name))
+    return Result.Ok(res)
+
+def parse_blob(blob):
+    """Parses a git blob"""
+    leng, _, data = blob.partition(b'\0')
+    if not leng or not data:
+        return Result.Err()
+    return Result.Ok(data)
+
+def commit_head(blob):
+    if not blob[7:] == 'commit ':
+        return Result.Err()
+    l = blob.split('\n')[0]
+    cid, _, tid = l.partition('\0')
+    if not tid[0:5] == 'tree ':
+        return Result.Err()
+    return tid[5:]
+
+def parse_object(obj, tpath=b''):
+    """Parses a git object"""
+    if tpath is str:
+        tpath = tpath.encode('utf-8')
+    data = zlib.decompress(obj)
+    if data[0:5] == b'blob ':
+        return parse_blob(data[5:])
+    elif data[0:5] == b'tree ':
+        return parse_tree(data[5:], tpath)
+    return Result.Err('Unsupported object type')