Merge branch 'glacier-tree-hash' into develop

Fixes #1083.

* glacier-tree-hash:
  Account for empty archives in hash calculations

boto/glacier/utils.py

@@ -56,6 +56,8 @@ def chunk_hashes(bytestring, chunk_size=_MEGABYTE):
         start = i * chunk_size
         end = (i + 1) * chunk_size
         hashes.append(hashlib.sha256(bytestring[start:end]).digest())
+    if not hashes:
+        return [hashlib.sha256('').digest()]
     return hashes
 
 
@@ -107,6 +109,8 @@ def compute_hashes_from_fileobj(fileobj, chunk_size=1024 * 1024):
         linear_hash.update(chunk)
         chunks.append(hashlib.sha256(chunk).digest())
         chunk = fileobj.read(chunk_size)
+    if not chunks:
+        chunks = [hashlib.sha256('').digest()]
     return linear_hash.hexdigest(), bytes_to_hex(tree_hash(chunks))
 
 

tests/unit/glacier/test_utils.py

@@ -19,53 +19,93 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 # IN THE SOFTWARE.
 #
+import time
+import logging
 from hashlib import sha256
 from tests.unit import unittest
 
-from boto.glacier import utils
+from boto.glacier.utils import minimum_part_size, chunk_hashes, tree_hash, \
+        bytes_to_hex
 
 
 class TestPartSizeCalculations(unittest.TestCase):
     def test_small_values_still_use_default_part_size(self):
-        self.assertEqual(utils.minimum_part_size(1), 4 * 1024 * 1024)
+        self.assertEqual(minimum_part_size(1), 4 * 1024 * 1024)
 
     def test_under_the_maximum_value(self):
         # If we're under the maximum, we can use 4MB part sizes.
-        self.assertEqual(utils.minimum_part_size(8 * 1024 * 1024),
+        self.assertEqual(minimum_part_size(8 * 1024 * 1024),
                          4 * 1024 * 1024)
 
     def test_gigabyte_size(self):
         # If we're over the maximum default part size, we go up to the next
         # power of two until we find a part size that keeps us under 10,000
         # parts.
-        self.assertEqual(utils.minimum_part_size(8 * 1024 * 1024 * 10000),
+        self.assertEqual(minimum_part_size(8 * 1024 * 1024 * 10000),
                          8 * 1024 * 1024)
 
     def test_terabyte_size(self):
         # For a 4 TB file we need at least a 512 MB part size.
-        self.assertEqual(utils.minimum_part_size(4 * 1024 * 1024 * 1024 * 1024),
+        self.assertEqual(minimum_part_size(4 * 1024 * 1024 * 1024 * 1024),
                          512 * 1024 * 1024)
 
     def test_file_size_too_large(self):
         with self.assertRaises(ValueError):
-            utils.minimum_part_size((40000 * 1024 * 1024 * 1024) + 1)
+            minimum_part_size((40000 * 1024 * 1024 * 1024) + 1)
 
 
 class TestChunking(unittest.TestCase):
     def test_chunk_hashes_exact(self):
-        chunks = utils.chunk_hashes('a' * (2 * 1024 * 1024))
+        chunks = chunk_hashes('a' * (2 * 1024 * 1024))
         self.assertEqual(len(chunks), 2)
         self.assertEqual(chunks[0], sha256('a' * 1024 * 1024).digest())
 
     def test_chunks_with_leftovers(self):
         bytestring = 'a' * (2 * 1024 * 1024 + 20)
-        chunks = utils.chunk_hashes(bytestring)
+        chunks = chunk_hashes(bytestring)
         self.assertEqual(len(chunks), 3)
         self.assertEqual(chunks[0], sha256('a' * 1024 * 1024).digest())
         self.assertEqual(chunks[1], sha256('a' * 1024 * 1024).digest())
         self.assertEqual(chunks[2], sha256('a' * 20).digest())
 
     def test_less_than_one_chunk(self):
-        chunks = utils.chunk_hashes('aaaa')
+        chunks = chunk_hashes('aaaa')
         self.assertEqual(len(chunks), 1)
         self.assertEqual(chunks[0], sha256('aaaa').digest())
+
+
+class TestTreeHash(unittest.TestCase):
+    # For these tests, a set of reference tree hashes were computed.
+    # This will at least catch any regressions to the tree hash
+    # calculations.
+    def calculate_tree_hash(self, bytestring):
+        start = time.time()
+        calculated = bytes_to_hex(tree_hash(chunk_hashes(bytestring)))
+        end = time.time()
+        logging.debug("Tree hash calc time for length %s: %s",
+                      len(bytestring), end - start)
+        return calculated
+
+    def test_tree_hash_calculations(self):
+        one_meg_bytestring = 'a' * (1 * 1024 * 1024)
+        two_meg_bytestring = 'a' * (2 * 1024 * 1024)
+        four_meg_bytestring = 'a' * (4 * 1024 * 1024)
+        bigger_bytestring = four_meg_bytestring + 'a' * 20
+
+        self.assertEqual(
+            self.calculate_tree_hash(one_meg_bytestring),
+            '9bc1b2a288b26af7257a36277ae3816a7d4f16e89c1e7e77d0a5c48bad62b360')
+        self.assertEqual(
+            self.calculate_tree_hash(two_meg_bytestring),
+            '560c2c9333c719cb00cfdffee3ba293db17f58743cdd1f7e4055373ae6300afa')
+        self.assertEqual(
+            self.calculate_tree_hash(four_meg_bytestring),
+            '9491cb2ed1d4e7cd53215f4017c23ec4ad21d7050a1e6bb636c4f67e8cddb844')
+        self.assertEqual(
+            self.calculate_tree_hash(bigger_bytestring),
+            '12f3cbd6101b981cde074039f6f728071da8879d6f632de8afc7cdf00661b08f')
+
+    def test_empty_tree_hash(self):
+        self.assertEqual(
+            self.calculate_tree_hash(''),
+            'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855')