Another huge batch of registry v2 changes

Add patch support and resumeable sha
Implement all actual registry methods
Add a simple database generation option

digest/digest_tools.py

@@ -2,33 +2,61 @@ import re
 import os.path
 import hashlib
 
-from collections import namedtuple
-
-
-Digest = namedtuple('Digest', ['is_tarsum', 'tarsum_version', 'hash_alg', 'hash_bytes'])
-
 
 DIGEST_PATTERN = r'(tarsum\.(v[\w]+)\+)?([\w]+):([0-9a-f]+)'
-DIGEST_REGEX = re.compile(DIGEST_PATTERN)
 
 
 class InvalidDigestException(RuntimeError):
   pass
 
 
-def parse_digest(digest):
-  """ Returns the digest parsed out to its components. """
-  match = DIGEST_REGEX.match(digest)
-  if match is None or match.end() != len(digest):
-    raise InvalidDigestException('Not a valid digest: %s', digest)
+class Digest(object):
+  DIGEST_REGEX = re.compile(DIGEST_PATTERN)
 
-  is_tarsum = match.group(1) is not None
-  return Digest(is_tarsum, match.group(2), match.group(3), match.group(4))
+  def __init__(self, hash_alg, hash_bytes, is_tarsum=False, tarsum_version=None):
+    self._hash_alg = hash_alg
+    self._hash_bytes = hash_bytes
+    self._is_tarsum = is_tarsum
+    self._tarsum_version = tarsum_version
+
+  def __str__(self):
+    if self._is_tarsum:
+      return 'tarsum.{0}+{1}:{2}'.format(self._tarsum_version, self._hash_alg, self._hash_bytes)
+    return '{0}:{1}'.format(self._hash_alg, self._hash_bytes)
+
+  def __eq__(self, rhs):
+    return isinstance(rhs, Digest) and str(self) == str(rhs)
+
+  @staticmethod
+  def parse_digest(digest):
+    """ Returns the digest parsed out to its components. """
+    match = Digest.DIGEST_REGEX.match(digest)
+    if match is None or match.end() != len(digest):
+      raise InvalidDigestException('Not a valid digest: %s', digest)
+
+    is_tarsum = match.group(1) is not None
+    return Digest(match.group(3), match.group(4), is_tarsum, match.group(2))
+
+  @property
+  def is_tarsum(self):
+    return self._is_tarsum
+
+  @property
+  def tarsum_version(self):
+    return self._tarsum_version
+
+  @property
+  def hash_alg(self):
+    return self._hash_alg
+
+  @property
+  def hash_bytes(self):
+    return self._hash_bytes
 
 
 def content_path(digest):
   """ Returns a relative path to the parsed digest. """
-  parsed = parse_digest(digest)
+  parsed = Digest.parse_digest(digest)
   components = []
 
   if parsed.is_tarsum:
@@ -58,7 +86,11 @@ def sha256_digest_from_generator(content_generator):
   return 'sha256:{0}'.format(digest.hexdigest())
 
 
+def sha256_digest_from_hashlib(sha256_hash_obj):
+  return 'sha256:{0}'.format(sha256_hash_obj.hexdigest())
+
+
 def digests_equal(lhs_digest_string, rhs_digest_string):
   """ Parse and compare the two digests, returns True if the digests are equal, False otherwise.
   """
-  return parse_digest(lhs_digest_string) == parse_digest(rhs_digest_string)
+  return Digest.parse_digest(lhs_digest_string) == Digest.parse_digest(rhs_digest_string)