Add support for well-known objcts in blob stores

6 files changed, 65 insertions, 4 deletions

diff --git a/obnamlib/bag.py b/obnamlib/bag.py
index cf176b1b..87bec277 100644
--- a/obnamlib/bag.py
+++ b/obnamlib/bag.py
@@ -1,4 +1,4 @@
-# Copyright 2015  Lars Wirzenius
+# Copyright 2015-2016  Lars Wirzenius
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -30,6 +30,7 @@ class Bag(object):
         return self._bag_id
 
     def set_id(self, bag_id):
+        assert isinstance(bag_id, (int, long, str))
         self._bag_id = bag_id
 
     def append(self, blob):
@@ -55,6 +56,9 @@ class BagIdNotSetError(obnamlib.ObnamError):
 
 
 def make_object_id(bag_id, object_index):
+    if isinstance(bag_id, str):
+        assert object_index == 0
+        return '%s.%d' % (bag_id, object_index)
     return '%016x.%d' % (bag_id, object_index)
 
 
diff --git a/obnamlib/bag_store.py b/obnamlib/bag_store.py
index 0e1fe448..2246f232 100644
--- a/obnamlib/bag_store.py
+++ b/obnamlib/bag_store.py
@@ -32,6 +32,9 @@ class BagStore(object):
         self._id_inventor.set_filename_maker(self._make_bag_filename)
 
     def _make_bag_filename(self, bag_id):
+        if isinstance(bag_id, str):
+            return os.path.join(self._dirname, '%s.bag' % bag_id)
+
         basename = '%016x' % bag_id
         return os.path.join(
             self._dirname,
diff --git a/obnamlib/bag_store_tests.py b/obnamlib/bag_store_tests.py
index aa6e6740..49290d09 100644
--- a/obnamlib/bag_store_tests.py
+++ b/obnamlib/bag_store_tests.py
@@ -74,3 +74,9 @@ class BagStoreTests(unittest.TestCase):
         self.store.put_bag(self.bag)
         self.store.remove_bag(self.bag.get_id())
         self.assertEqual(list(self.store.get_bag_ids()), [])
+
+    def test_puts_bag_with_nonnumeric_id(self):
+        self.bag.set_id('well-known')
+        self.store.put_bag(self.bag)
+        returned = self.store.get_bag('well-known')
+        self.assertEqualBags(returned, self.bag)
diff --git a/obnamlib/bag_tests.py b/obnamlib/bag_tests.py
index 1465fc24..9bbffefe 100644
--- a/obnamlib/bag_tests.py
+++ b/obnamlib/bag_tests.py
@@ -1,4 +1,4 @@
-# Copyright 2015  Lars Wirzenius
+# Copyright 2015-2016  Lars Wirzenius
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -27,11 +27,16 @@ class BagTests(unittest.TestCase):
         bag = obnamlib.Bag()
         self.assertEqual(bag.get_id(), None)
 
-    def test_sets_bag_id(self):
+    def test_sets_bag_id_to_integer(self):
         bag = obnamlib.Bag()
         bag.set_id(123)
         self.assertEqual(bag.get_id(), 123)
 
+    def test_sets_bag_id_to_string(self):
+        bag = obnamlib.Bag()
+        bag.set_id('well-known')
+        self.assertEqual(bag.get_id(), 'well-known')
+
     def test_is_empty_initially(self):
         bag = obnamlib.Bag()
         self.assertEqual(len(bag), 0)
@@ -61,6 +66,12 @@ class BagTests(unittest.TestCase):
         object_id = bag.append('foo')
         self.assertEqual(object_id, obnamlib.make_object_id(1, 0))
 
+    def test_appending_returns_object_id_when_bag_id_is_a_string(self):
+        bag = obnamlib.Bag()
+        bag.set_id('well-known')
+        object_id = bag.append('foo')
+        self.assertEqual(object_id, obnamlib.make_object_id('well-known', 0))
+
 
 class ObjectIdTests(unittest.TestCase):
 
diff --git a/obnamlib/blob_store.py b/obnamlib/blob_store.py
index 8373fd32..219e585a 100644
--- a/obnamlib/blob_store.py
+++ b/obnamlib/blob_store.py
@@ -64,6 +64,19 @@ class BlobStore(object):
         bag.set_id(self._bag_store.reserve_bag_id())
         return bag
 
+    def get_well_known_blob(self, well_known_name):
+        if self._bag_store.has_bag(well_known_name):
+            bag = self._bag_store.get_bag(well_known_name)
+            if len(bag) > 0:
+                return bag[0]
+        return None
+
+    def put_well_known_blob(self, well_known_name, blob):
+        bag = obnamlib.Bag()
+        bag.set_id(well_known_name)
+        bag.append(blob)
+        self._bag_store.put_bag(bag)
+
     def flush(self):
         if self._bag is not None:
             self._bag_store.put_bag(self._bag)
diff --git a/obnamlib/blob_store_tests.py b/obnamlib/blob_store_tests.py
index 079c932b..fed20d14 100644
--- a/obnamlib/blob_store_tests.py
+++ b/obnamlib/blob_store_tests.py
@@ -1,4 +1,4 @@
-# Copyright 2015  Lars Wirzenius
+# Copyright 2015-2016  Lars Wirzenius
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -98,6 +98,30 @@ class BlobStoreTests(unittest.TestCase):
         retrieved = blob_store.get_blob(blob_id)
         self.assertEqual(blob, retrieved)
 
+    def test_returns_None_if_well_known_blog_does_not_exist(self):
+        bag_store = DummyBagStore()
+        well_known_id = 'bobby'
+
+        blob_store = obnamlib.BlobStore()
+        blob_store.set_bag_store(bag_store)
+        retrieved = blob_store.get_well_known_blob(well_known_id)
+        self.assertEqual(retrieved, None)
+
+    def test_puts_well_known_blob(self):
+        bag_store = DummyBagStore()
+        well_known_blob = 'Bob'
+        well_known_id = 'bobby'
+
+        blob_store = obnamlib.BlobStore()
+        blob_store.set_bag_store(bag_store)
+        blob_store.set_max_bag_size(len(well_known_blob) + 1)
+        returned_id = blob_store.put_well_known_blob(
+            well_known_id, well_known_blob)
+        self.assertEqual(returned_id, None)
+
+        retrieved = blob_store.get_well_known_blob(well_known_id)
+        self.assertEqual(well_known_blob, retrieved)
+
 
 class DummyBagStore(object):