Rev 5081: Expose an api for getting a specifically named index out again. in http://bzr.arbash-meinel.com/branches/bzr/lp/2.2.0b2-contained-pack

[John Arbash Meinel]

At http://bzr.arbash-meinel.com/branches/bzr/lp/2.2.0b2-contained-pack

------------------------------------------------------------
revno: 5081
revision-id: john at arbash-meinel.com-20100304230418-xdt364o2rr5qitra
parent: john at arbash-meinel.com-20100304225223-hkgegogaj2vusvol
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: 2.2.0b2-contained-pack
timestamp: Thu 2010-03-04 17:04:18 -0600
message:
  Expose an api for getting a specifically named index out again.
-------------- next part --------------
=== modified file 'bzrlib/sack.py'
--- a/bzrlib/sack.py	2010-03-04 22:52:23 +0000
+++ b/bzrlib/sack.py	2010-03-04 23:04:18 +0000
@@ -129,11 +129,22 @@
         # This is a bootstrap method, if all you have is the sack file, read
         # its tail and figure out where the internal indices are.
         file_st = transport.stat(filename)
-        _,tail = transport.readv(filename, [(file_st.st_size-12, 12)]).next()
+        _, tail = transport.readv(filename, [(file_st.st_size-12, 12)]).next()
         ti = TrailingIndex.parse_tail_bytes(tail)
         ti._read_named_sections(transport, filename, file_st.st_size)
         return ti
 
+    def get_named_index(self, name, index_class, **kwargs):
+        """Create an Index using the content at the named location.
+        
+        :param name: The name of the given section
+        :param index_class: BTreeGraphIndex or GraphIndex, etc
+        :param **kwargs: Any other named arguments will be passed to the index
+            constructor
+        """
+        start, end = self._section_file_map[name]
+        return index_class(self._file_view, name, size=(end-start), **kwargs)
+
 
 class Sack(object):
     """A self-contained pack file.

=== modified file 'bzrlib/tests/test_sack.py'
--- a/bzrlib/tests/test_sack.py	2010-03-04 22:43:22 +0000
+++ b/bzrlib/tests/test_sack.py	2010-03-04 23:04:18 +0000
@@ -34,10 +34,7 @@
         pass
 
 
-def assert_btree_matches(test, a_dict, bytes):
-    t = memory.MemoryTransport('')
-    t.put_bytes('index', bytes)
-    index = btree_index.BTreeGraphIndex(t, 'index', len(bytes))
+def assert_index_content(test, a_dict, index):
     as_dict = {}
     for info in index.iter_all_entries():
         key = info[1]
@@ -46,6 +43,13 @@
     test.assertEqual(a_dict, as_dict)
 
 
+def assert_btree_matches(test, a_dict, bytes):
+    t = memory.MemoryTransport('')
+    t.put_bytes('index', bytes)
+    index = btree_index.BTreeGraphIndex(t, 'index', len(bytes))
+    assert_index_content(test, a_dict, index)
+
+
 class TestTrailingIndexBuilder(tests.TestCase):
 
     def assertAsBytes(self, index_content, ti):
@@ -108,3 +112,24 @@
         self.assertEqual({'root-index': (516, 500+len(content)-12),
                           'texts': (150, 500),
                          }, ti._section_file_map)
+
+    def test_get_named_index(self):
+        index_builder = btree_index.BTreeBuilder(0, 1)
+        index_builder.add_node(('key1',), 'value1')
+        index_builder.add_node(('key2',), 'value2')
+        text_idx_content = index_builder.finish().read()
+        trail_start = len(text_idx_content)
+        trailing_builder = sack.TrailingIndexBuilder(
+                                start_offset=trail_start)
+        trailing_builder.add_index_info('texts', 0, trail_start)
+        content = text_idx_content + trailing_builder.finish()
+        t = memory.MemoryTransport('')
+        t.put_bytes('test.sack', content)
+        ti = sack.TrailingIndex.from_transport(t, 'test.sack')
+        self.assertEqual({'root-index': (trail_start+16, len(content)-12),
+                          'texts': (0, trail_start),
+                         }, ti._section_file_map)
+        text_index = ti.get_named_index('texts', btree_index.BTreeGraphIndex)
+        assert_index_content(self, {('key1',): ('value1',),
+                                    ('key2',): ('value2',),
+                                   }, text_index)