Add write_tree_diff.

NEWS

@@ -6,13 +6,15 @@
 
   * Add eof() and unread_pkt_line() methods to Protocol. (Dave Borowitz)
 
+  * Add write_tree_diff(). (Jelmer Vernooij)
+
  BUG FIXES
 
   * Correct short-circuiting operation for no-op fetches in the server.
     (Dave Borowitz)
 
-  * Support parsing git mbox patches without a version tail, as generated by Mercurial. 
-    (Jelmer Vernooij)
+  * Support parsing git mbox patches without a version tail, as generated by
+    Mercurial.  (Jelmer Vernooij)
 
 0.6.2	2010-10-16
 

dulwich/patch.py

@@ -28,6 +28,7 @@ import subprocess
 import time
 
 from dulwich.objects import (
+    Blob,
     Commit,
     )
 
@@ -136,14 +137,37 @@ def write_blob_diff(f, (old_path, old_mode, old_blob),
             f.write("new mode %o\n" % new_mode)
         else:
             f.write("deleted mode %o\n" % old_mode)
-    f.write("index %s..%s %o\n" % (
-        blob_id(old_blob), blob_id(new_blob), new_mode))
+    f.write("index %s..%s" % (blob_id(old_blob), blob_id(new_blob)))
+    if new_mode is not None:
+        f.write(" %o" % new_mode)
+    f.write("\n")
     old_contents = lines(old_blob)
     new_contents = lines(new_blob)
     f.writelines(unified_diff(old_contents, new_contents,
         old_path, new_path))
 
 
+def write_tree_diff(f, store, old_tree, new_tree):
+    """Write tree diff.
+
+    :param f: File-like object to write to.
+    :param old_tree: Old tree id
+    :param new_tree: New tree id
+    """
+    changes = store.tree_changes(old_tree, new_tree)
+    for (oldpath, newpath), (oldmode, newmode), (oldsha, newsha) in changes:
+        if oldsha is None:
+            old_blob = Blob.from_string("")
+        else:
+            old_blob = store[oldsha]
+        if newsha is None:
+            new_blob = Blob.from_string("")
+        else:
+            new_blob = store[newsha]
+        write_blob_diff(f, (oldpath, oldmode, old_blob),
+                           (newpath, newmode, new_blob))
+
+
 def git_am_patch_split(f):
     """Parse a git-am-style patch and split it up into bits.
 

dulwich/tests/test_patch.py

@@ -21,12 +21,18 @@
 from cStringIO import StringIO
 
 from dulwich.objects import (
+    Blob,
     Commit,
     Tree,
     )
+from dulwich.object_store import (
+    MemoryObjectStore,
+    )
 from dulwich.patch import (
     git_am_patch_split,
+    write_blob_diff,
     write_commit_patch,
+    write_tree_diff,
     )
 from dulwich.tests import (
     TestCase,
@@ -153,3 +159,104 @@ From: Jelmer Vernooy <jelmer@debian.org>
 """
         c, diff, version = git_am_patch_split(StringIO(text))
         self.assertIs(None, version)
+
+
+class DiffTests(TestCase):
+    """Tests for write_blob_diff and write_tree_diff."""
+
+    def test_blob_diff(self):
+        f = StringIO()
+        write_blob_diff(f, ("foo.txt", 0644, Blob.from_string("old\nsame\n")),
+                           ("bar.txt", 0644, Blob.from_string("new\nsame\n")))
+        self.assertEquals([
+            "diff --git a/foo.txt b/bar.txt",
+            "index 3b0f961..a116b51 644",
+            "--- a/foo.txt",
+            "+++ b/bar.txt",
+            "@@ -1,2 +1,2 @@",
+            "-old",
+            "+new",
+            " same"
+            ], f.getvalue().splitlines())
+
+    def test_blob_add(self):
+        f = StringIO()
+        write_blob_diff(f, (None, None, None),
+                           ("bar.txt", 0644, Blob.from_string("new\nsame\n")))
+        self.assertEquals([
+            'diff --git /dev/null b/bar.txt',
+             'new mode 644',
+             'index 0000000..a116b51 644',
+             '--- /dev/null',
+             '+++ b/bar.txt',
+             '@@ -1,0 +1,2 @@',
+             '+new',
+             '+same'
+            ], f.getvalue().splitlines())
+
+    def test_blob_remove(self):
+        f = StringIO()
+        write_blob_diff(f, ("bar.txt", 0644, Blob.from_string("new\nsame\n")),
+                           (None, None, None))
+        self.assertEquals([
+            'diff --git a/bar.txt /dev/null',
+            'deleted mode 644',
+            'index a116b51..0000000',
+            '--- a/bar.txt',
+            '+++ /dev/null',
+            '@@ -1,2 +1,0 @@',
+            '-new',
+            '-same'
+            ], f.getvalue().splitlines())
+
+    def test_tree_diff(self):
+        f = StringIO()
+        store = MemoryObjectStore()
+        added = Blob.from_string("add\n")
+        removed = Blob.from_string("removed\n")
+        changed1 = Blob.from_string("unchanged\nremoved\n")
+        changed2 = Blob.from_string("unchanged\nadded\n")
+        unchanged = Blob.from_string("unchanged\n")
+        tree1 = Tree()
+        tree1.add(0644, "removed.txt", removed.id)
+        tree1.add(0644, "changed.txt", changed1.id)
+        tree1.add(0644, "unchanged.txt", changed1.id)
+        tree2 = Tree()
+        tree2.add(0644, "added.txt", added.id)
+        tree2.add(0644, "changed.txt", changed2.id)
+        tree1.add(0644, "unchanged.txt", changed1.id)
+        store.add_objects([(o, None) for o in [
+            tree1, tree2, added, removed, changed1, changed2, unchanged]])
+        write_tree_diff(f, store, tree1.id, tree2.id)
+        self.assertEquals([
+            'diff --git a/changed.txt b/changed.txt',
+            'index bf84e48..1be2436 644',
+            '--- a/changed.txt',
+            '+++ b/changed.txt',
+            '@@ -1,2 +1,2 @@',
+            ' unchanged',
+            '-removed',
+            '+added',
+            'diff --git a/removed.txt /dev/null',
+            'deleted mode 644',
+            'index 2c3f0b3..e69de29',
+            '--- a/removed.txt',
+            '+++ /dev/null',
+            '@@ -1,1 +1,0 @@',
+            '-removed',
+            'diff --git a/unchanged.txt /dev/null',
+            'deleted mode 644',
+            'index bf84e48..e69de29',
+            '--- a/unchanged.txt',
+            '+++ /dev/null',
+            '@@ -1,2 +1,0 @@',
+            '-unchanged',
+            '-removed',
+            'diff --git /dev/null b/added.txt',
+            'new mode 644',
+            'index e69de29..76d4bb8 644',
+            '--- /dev/null',
+            '+++ b/added.txt',
+            '@@ -1,0 +1,1 @@',
+            '+add'
+            ], f.getvalue().splitlines())