diff --git a/swh/model/identifiers.py b/swh/model/identifiers.py
index 33e3afc1773922f361e69a3160f3ec8501e99c7a..70b82857e458a9c1a8ac870e2329dc5a5871ff6c 100644
--- a/swh/model/identifiers.py
+++ b/swh/model/identifiers.py
@@ -3,6 +3,8 @@
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information
+import binascii
+import datetime
from functools import lru_cache
from . import hashutil
@@ -40,6 +42,38 @@ def identifier_to_bytes(identifier):
identifier.__class__.__name__)
+@lru_cache()
+def identifier_to_str(identifier):
+ """Convert an identifier to an hexadecimal string.
+
+ Args:
+ identifier: an identifier, either a 40-char hexadecimal string or a
+ bytes object of length 20
+ Returns:
+ The length 40 string corresponding to the given identifier, hex encoded
+
+ Raises:
+ ValueError if the identifier is of an unexpected type or length.
+ """
+
+ if isinstance(identifier, str):
+ if len(identifier) != 40:
+ raise ValueError(
+ 'Wrong length for str identifier %s, expected 40' %
+ len(identifier))
+ return identifier
+
+ if isinstance(identifier, bytes):
+ if len(identifier) != 20:
+ raise ValueError(
+ 'Wrong length for bytes identifier %s, expected 20' %
+ len(identifier))
+ return binascii.hexlify(identifier).decode()
+
+ raise ValueError('Wrong type for identitfier %s, expected bytes or str' %
+ identifier.__class__.__name__)
+
+
def content_identifier(content):
"""Return the intrinsic identifier for a content.
@@ -121,3 +155,82 @@ def directory_identifier(directory):
])
return hashutil.hash_git_data(b''.join(components), 'tree')
+
+
+def format_date(date):
+ """Convert a date object into an UTC timestamp encoded as ascii bytes.
+
+ Git stores timestamps as an integer number of seconds since the UNIX epoch.
+
+ However, Software Heritage stores timestamps as an integer number of
+ microseconds (postgres type "datetime with timezone").
+
+ Therefore, we print timestamps with no microseconds as integers, and
+ timestamps with microseconds as floating point values.
+
+ """
+ if isinstance(date, datetime.datetime):
+ if date.microsecond == 0:
+ date = int(date.timestamp())
+ else:
+ date = date.timestamp()
+ return str(date).encode()
+ else:
+ if date == int(date):
+ date = int(date)
+ return str(date).encode()
+
+
+@lru_cache()
+def format_offset(offset):
+ """Convert an integer number of minutes into an offset representation.
+
+ The offset representation is [+-]hhmm where:
+ hh is the number of hours;
+ mm is the number of minutes.
+
+ A null offset is represented as +0000.
+ """
+ if offset >= 0:
+ sign = '+'
+ else:
+ sign = '-'
+
+ hours = abs(offset) // 60
+ minutes = abs(offset) % 60
+
+ t = '%s%02d%02d' % (sign, hours, minutes)
+ return t.encode()
+
+
+def format_author(author):
+ components = [
+ author['name'], b' <', author['email'], b'> ',
+ format_date(author['date']), b' ',
+ format_offset(author['date_offset']),
+ ]
+
+ return b''.join(components)
+
+
+def revision_identifier(revision):
+ """Return the intrinsic identifier for a revision.
+ """
+ components = [
+ b'tree ', identifier_to_str(revision['directory']).encode(), b'\n',
+ ]
+ for parent in revision['parents']:
+ if parent:
+ components.extend([
+ b'parent ', identifier_to_str(parent).encode(), b'\n',
+ ])
+
+ components.extend([
+ b'author ', format_author(revision['author']), b'\n',
+ b'committer ', format_author(revision['committer']), b'\n',
+ b'\n',
+ revision['message'],
+ ])
+
+ print(b''.join(components).decode('utf-8'))
+ return hashutil.hash_git_data(b''.join(components), 'commit')
diff --git a/swh/model/tests/test_identifiers.py b/swh/model/tests/test_identifiers.py
index 2dbd8ca2082b95eab2d0c4bf02074ca999457f4a..0ace24f1f7678a427caf502c7f10a2bd73beef35 100644
--- a/swh/model/tests/test_identifiers.py
+++ b/swh/model/tests/test_identifiers.py
@@ -138,3 +138,76 @@ class DirectoryIdentifier(unittest.TestCase):
self.assertEqual(
identifiers.directory_identifier(self.empty_directory),
self.empty_directory['id'])
+
+
+class RevisionIdentifier(unittest.TestCase):
+ def setUp(self):
+ self.revision = {
+ 'id': 'bc0195aad0daa2ad5b0d76cce22b167bc3435590',
+ 'directory': '85a74718d377195e1efd0843ba4f3260bad4fe07',
+ 'parents': ['01e2d0627a9a6edb24c37db45db5ecb31e9de808'],
+ 'author': {
+ 'name': b'Linus Torvalds',
+ 'email': b'torvalds@linux-foundation.org',
+ 'date': datetime.datetime(2015, 7, 12, 22, 10, 30,
+ tzinfo=datetime.timezone.utc),
+ 'date_offset': -420,
+
+ },
+ 'committer': {
+ 'name': b'Linus Torvalds',
+ 'email': b'torvalds@linux-foundation.org',
+ 'date': datetime.datetime(2015, 7, 12, 22, 10, 30,
+ tzinfo=datetime.timezone.utc),
+ 'date_offset': -420,
+
+ },
+ 'message': b'Linux 4.2-rc2\n',
+ }
+
+ self.synthetic_revision = {
+ 'id': b'\xb2\xa7\xe1&\x04\x92\xe3D\xfa\xb3\xcb\xf9\x1b\xc1<\x91'
+ b'\xe0T&\xfd',
+ 'author': {
+ 'name': b'Software Heritage',
+ 'email': b'robot@softwareheritage.org',
+ 'date': datetime.datetime(2015, 7, 16, 11, 51, 35,
+ tzinfo=datetime.timezone.utc),
+ 'date_offset': 0,
+ },
+ 'type': 'tar',
+ 'committer': {
+ 'name': b'Software Heritage',
+ 'date': datetime.datetime(2015, 7, 16, 11, 51, 35,
+ tzinfo=datetime.timezone.utc),
+ 'email': b'robot@softwareheritage.org',
+ 'date_offset': 0,
+ },
+ 'synthetic': True,
+ 'parents': [None],
+ 'message': b'synthetic revision message\n',
+ 'directory': b'\xd1\x1f\x00\xa6\xa0\xfe\xa6\x05SA\xd2U\x84\xb5\xa9'
+ b'e\x16\xc0\xd2\xb8',
+ 'metadata': {'original_artifact': [
+ {'archive_type': 'tar',
+ 'name': 'gcc-5.2.0.tar.bz2',
+ 'sha1_git': '39d281aff934d44b439730057e55b055e206a586',
+ 'sha1': 'fe3f5390949d47054b613edc36c557eb1d51c18e',
+ 'sha256': '5f835b04b5f7dd4f4d2dc96190ec1621b8d89f'
+ '2dc6f638f9f8bc1b1014ba8cad'}]},
+
+ }
+
+ @istest
+ def revision_identifier(self):
+ self.assertEqual(
+ identifiers.revision_identifier(self.revision),
+ identifiers.identifier_to_str(self.revision['id']),
+ )
+
+ @istest
+ def revision_identifier_synthetic(self):
+ self.assertEqual(
+ identifiers.revision_identifier(self.synthetic_revision),
+ identifiers.identifier_to_str(self.synthetic_revision['id']),
+ )