Added a RemoteRepo object for remote fetching

Added utility functions for git data structures

2 files changed, 74 insertions, 0 deletions

diff --git a/pomu/repo/remote/remote.py b/pomu/repo/remote/remote.py
new file mode 100644
index 0000000..e177f68
--- /dev/null
+++ b/pomu/repo/remote/remote.py
@@ -0,0 +1,28 @@
+"""A template class for remote repos"""
+
+
+class RemoteRepo():
+    """A class responsible for remotes"""
+    def __init__(self, url):
+        self.uri = uri
+        raise NotImplementedError()
+
+    def fetch_package(self, name, category=None, version=None):
+        """Fetches a package, determined by the parametres"""
+        raise NotImplementedError()
+
+    def list_cpvs(self):
+        """Gets a list of all pebuilds in the repo"""
+        raise NotImplementedError()
+
+    def fetch_tree(self):
+        """Returns repos hierarchy"""
+        raise NotImplementedError()
+
+    def fetch_subtree(self, key):
+        """Lists a subtree"""
+        raise NotImplementedError()
+
+    def fetch_file(self, key):
+        """Fetches a file from the repo"""
+        raise NotImplementedError()
diff --git a/pomu/util/git.py b/pomu/util/git.py
new file mode 100644
index 0000000..4c3e2ed
--- /dev/null
+++ b/pomu/util/git.py
@@ -0,0 +1,46 @@
+"""Miscellaneous utility functions for git structures"""
+
+from base64 import b16encode
+
+from pomu.util.result import Result
+
+def parse_tree(blob):
+    """Parses a git tree"""
+    res = []
+    leng, _, tree = blob.partition('\0')
+    if not tree:
+        return Result.Err('Invalid tree')
+    while len(data) > 0:
+        data = data[7:] # strip access code
+        name, _, data = data.partition('\0')
+        sha = b16encode(data[0:20]).decode('utf-8')
+        data = data[20:]
+        if not name or not sha:
+            return Result.Err()
+        res.append((sha, name))
+    return Result.Ok(res)
+
+def parse_blob(blob):
+    """Parses a git blob"""
+    data = zlib.decompress(blob)
+    leng, _, data = data.partition('\0')
+    if not leng or not data:
+        return Result.Err()
+
+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):
+    """Parses a git object"""
+    data = zlib.decompress(obj)
+    if data[0:5] == 'blob ':
+        return parse_blob(data[5:])
+    elif data[0:5] == 'tree ':
+        return parse_tree(data[5:])
+    return Result.Err('Unsupported object type')