tests/test-hashutil.py

revlog: add a C implementation of `headrevsdiff`

Python implementation of `headrevsdiff` can be very slow in the worst
case compared with the `heads` computation it replaces, since the
latter is done in C.

Even the average case of this Python implementation is still
noticeable in the profiles.

This patch makes the computation much much faster by doing it in C.

# Tests to ensure that sha1dc.sha1 is exactly a drop-in for
# hashlib.sha1 for our needs.

import hashlib
import unittest

import silenttestrunner

try:
    from mercurial.thirdparty import sha1dc
except ImportError:
    sha1dc = None


class hashertestsbase:
    def test_basic_hash(self):
        h = self.hasher()
        h.update(b'foo')
        self.assertEqual(
            '0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33', h.hexdigest()
        )
        h.update(b'bar')
        self.assertEqual(
            '8843d7f92416211de9ebb963ff4ce28125932878', h.hexdigest()
        )

    def test_copy_hasher(self):
        h = self.hasher()
        h.update(b'foo')
        h2 = h.copy()
        h.update(b'baz')
        h2.update(b'bar')
        self.assertEqual(
            '21eb6533733a5e4763acacd1d45a60c2e0e404e1', h.hexdigest()
        )
        self.assertEqual(
            '8843d7f92416211de9ebb963ff4ce28125932878', h2.hexdigest()
        )

    def test_init_hasher(self):
        h = self.hasher(b'initial string')
        self.assertEqual(
            b'\xc9y|n\x1f3S\xa4:\xbaJ\xca,\xc1\x1a\x9e\xb8\xd8\xdd\x86',
            h.digest(),
        )

    def test_bytes_like_types(self):
        h = self.hasher()
        h.update(bytearray(b'foo'))
        h.update(memoryview(b'baz'))
        self.assertEqual(
            '21eb6533733a5e4763acacd1d45a60c2e0e404e1', h.hexdigest()
        )

        h = self.hasher(bytearray(b'foo'))
        h.update(b'baz')
        self.assertEqual(
            '21eb6533733a5e4763acacd1d45a60c2e0e404e1', h.hexdigest()
        )

        h = self.hasher(memoryview(b'foo'))
        h.update(b'baz')
        self.assertEqual(
            '21eb6533733a5e4763acacd1d45a60c2e0e404e1', h.hexdigest()
        )


class hashlibtests(unittest.TestCase, hashertestsbase):
    hasher = hashlib.sha1


if sha1dc:

    class sha1dctests(unittest.TestCase, hashertestsbase):
        hasher = sha1dc.sha1


if __name__ == '__main__':
    silenttestrunner.main(__name__)