# Copyright (C) 2006-2011 Canonical Ltd
#
# 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
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Tests for Knit data structure"""

import gzip
from io import BytesIO
from patiencediff import PatienceSequenceMatcher
import sys

from ... import (
    errors,
    multiparent,
    osutils,
    tests,
    transport,
    )
from .. import (
    knit,
    pack,
    )
from ..index import *
from ..knit import (
    AnnotatedKnitContent,
    KnitContent,
    KnitCorrupt,
    KnitDataStreamIncompatible,
    KnitDataStreamUnknown,
    KnitHeaderError,
    KnitIndexUnknownMethod,
    KnitVersionedFiles,
    PlainKnitContent,
    _VFContentMapGenerator,
    _KndxIndex,
    _KnitGraphIndex,
    _KnitKeyAccess,
    make_file_factory,
    )
from .. import (
    knitpack_repo,
    pack_repo,
    )
from ...tests import (
    TestCase,
    TestCaseWithMemoryTransport,
    TestCaseWithTransport,
    TestNotApplicable,
    )
from ..versionedfile import (
    AbsentContentFactory,
    ConstantMapper,
    network_bytes_to_kind_and_offset,
    RecordingVersionedFilesDecorator,
    )
from ...tests import (
    features,
    )


compiled_knit_feature = features.ModuleAvailableFeature(
    'breezy.bzr._knit_load_data_pyx')


class ErrorTests(TestCase):

    def test_knit_data_stream_incompatible(self):
        error = KnitDataStreamIncompatible(
            'stream format', 'target format')
        self.assertEqual('Cannot insert knit data stream of format '
                         '"stream format" into knit of format '
                         '"target format".', str(error))

    def test_knit_data_stream_unknown(self):
        error = KnitDataStreamUnknown(
            'stream format')
        self.assertEqual('Cannot parse knit data stream of format '
                         '"stream format".', str(error))

    def test_knit_header_error(self):
        error = KnitHeaderError('line foo\n', 'path/to/file')
        self.assertEqual("Knit header error: 'line foo\\n' unexpected"
                         " for file \"path/to/file\".", str(error))

    def test_knit_index_unknown_method(self):
        error = KnitIndexUnknownMethod('http://host/foo.kndx',
                                       ['bad', 'no-eol'])
        self.assertEqual("Knit index http://host/foo.kndx does not have a"
                         " known method in options: ['bad', 'no-eol']",
                         str(error))


class KnitContentTestsMixin(object):

    def test_constructor(self):
        content = self._make_content([])

    def test_text(self):
        content = self._make_content([])
        self.assertEqual(content.text(), [])

        content = self._make_content(
            [(b"origin1", b"text1"), (b"origin2", b"text2")])
        self.assertEqual(content.text(), [b"text1", b"text2"])

    def test_copy(self):
        content = self._make_content(
            [(b"origin1", b"text1"), (b"origin2", b"text2")])
        copy = content.copy()
        self.assertIsInstance(copy, content.__class__)
        self.assertEqual(copy.annotate(), content.annotate())

    def assertDerivedBlocksEqual(self, source, target, noeol=False):
        """Assert that the derived matching blocks match real output"""
        source_lines = source.splitlines(True)
        target_lines = target.splitlines(True)

        def nl(line):
            if noeol and not line.endswith('\n'):
                return line + '\n'
            else:
                return line
        source_content = self._make_content(
            [(None, nl(l)) for l in source_lines])
        target_content = self._make_content(
            [(None, nl(l)) for l in target_lines])
        line_delta = source_content.line_delta(target_content)
        delta_blocks = list(KnitContent.get_line_delta_blocks(line_delta,
                                                              source_lines, target_lines))
        matcher = PatienceSequenceMatcher(None, source_lines, target_lines)
        matcher_blocks = list(matcher.get_matching_blocks())
        self.assertEqual(matcher_blocks, delta_blocks)

    def test_get_line_delta_blocks(self):
        self.assertDerivedBlocksEqual('a\nb\nc\n', 'q\nc\n')
        self.assertDerivedBlocksEqual(TEXT_1, TEXT_1)
        self.assertDerivedBlocksEqual(TEXT_1, TEXT_1A)
        self.assertDerivedBlocksEqual(TEXT_1, TEXT_1B)
        self.assertDerivedBlocksEqual(TEXT_1B, TEXT_1A)
        self.assertDerivedBlocksEqual(TEXT_1A, TEXT_1B)
        self.assertDerivedBlocksEqual(TEXT_1A, '')
        self.assertDerivedBlocksEqual('', TEXT_1A)
        self.assertDerivedBlocksEqual('', '')
        self.assertDerivedBlocksEqual('a\nb\nc', 'a\nb\nc\nd')

    def test_get_line_delta_blocks_noeol(self):
        """Handle historical knit deltas safely

        Some existing knit deltas don't consider the last line to differ
        when the only difference whether it has a final newline.

        New knit deltas appear to always consider the last line to differ
        in this case.
        """
        self.assertDerivedBlocksEqual('a\nb\nc', 'a\nb\nc\nd\n', noeol=True)
        self.assertDerivedBlocksEqual('a\nb\nc\nd\n', 'a\nb\nc', noeol=True)
        self.assertDerivedBlocksEqual('a\nb\nc\n', 'a\nb\nc', noeol=True)
        self.assertDerivedBlocksEqual('a\nb\nc', 'a\nb\nc\n', noeol=True)


TEXT_1 = """\
Banana cup cakes:

- bananas
- eggs
- broken tea cups
"""

TEXT_1A = """\
Banana cup cake recipe
(serves 6)

- bananas
- eggs
- broken tea cups
- self-raising flour
"""

TEXT_1B = """\
Banana cup cake recipe

- bananas (do not use plantains!!!)
- broken tea cups
- flour
"""

delta_1_1a = """\
0,1,2
Banana cup cake recipe
(serves 6)
5,5,1
- self-raising flour
"""

TEXT_2 = """\
Boeuf bourguignon

- beef
- red wine
- small onions
- carrot
- mushrooms
"""


class TestPlainKnitContent(TestCase, KnitContentTestsMixin):

    def _make_content(self, lines):
        annotated_content = AnnotatedKnitContent(lines)
        return PlainKnitContent(annotated_content.text(), 'bogus')

    def test_annotate(self):
        content = self._make_content([])
        self.assertEqual(content.annotate(), [])

        content = self._make_content(
            [("origin1", "text1"), ("origin2", "text2")])
        self.assertEqual(content.annotate(),
                         [("bogus", "text1"), ("bogus", "text2")])

    def test_line_delta(self):
        content1 = self._make_content([("", "a"), ("", "b")])
        content2 = self._make_content([("", "a"), ("", "a"), ("", "c")])
        self.assertEqual(content1.line_delta(content2),
                         [(1, 2, 2, ["a", "c"])])

    def test_line_delta_iter(self):
        content1 = self._make_content([("", "a"), ("", "b")])
        content2 = self._make_content([("", "a"), ("", "a"), ("", "c")])
        it = content1.line_delta_iter(content2)
        self.assertEqual(next(it), (1, 2, 2, ["a", "c"]))
        self.assertRaises(StopIteration, next, it)


class TestAnnotatedKnitContent(TestCase, KnitContentTestsMixin):

    def _make_content(self, lines):
        return AnnotatedKnitContent(lines)

    def test_annotate(self):
        content = self._make_content([])
        self.assertEqual(content.annotate(), [])

        content = self._make_content(
            [(b"origin1", b"text1"), (b"origin2", b"text2")])
        self.assertEqual(content.annotate(),
                         [(b"origin1", b"text1"), (b"origin2", b"text2")])

    def test_line_delta(self):
        content1 = self._make_content([("", "a"), ("", "b")])
        content2 = self._make_content([("", "a"), ("", "a"), ("", "c")])
        self.assertEqual(content1.line_delta(content2),
                         [(1, 2, 2, [("", "a"), ("", "c")])])

    def test_line_delta_iter(self):
        content1 = self._make_content([("", "a"), ("", "b")])
        content2 = self._make_content([("", "a"), ("", "a"), ("", "c")])
        it = content1.line_delta_iter(content2)
        self.assertEqual(next(it), (1, 2, 2, [("", "a"), ("", "c")]))
        self.assertRaises(StopIteration, next, it)


class MockTransport(object):

    def __init__(self, file_lines=None):
        self.file_lines = file_lines
        self.calls = []
        # We have no base directory for the MockTransport
        self.base = ''

    def get(self, filename):
        if self.file_lines is None:
            raise errors.NoSuchFile(filename)
        else:
            return BytesIO(b"\n".join(self.file_lines))

    def readv(self, relpath, offsets):
        fp = self.get(relpath)
        for offset, size in offsets:
            fp.seek(offset)
            yield offset, fp.read(size)

    def __getattr__(self, name):
        def queue_call(*args, **kwargs):
            self.calls.append((name, args, kwargs))
        return queue_call


class MockReadvFailingTransport(MockTransport):
    """Fail in the middle of a readv() result.

    This Transport will successfully yield the first two requested hunks, but
    raise NoSuchFile for the rest.
    """

    def readv(self, relpath, offsets):
        count = 0
        for result in MockTransport.readv(self, relpath, offsets):
            count += 1
            # we use 2 because the first offset is the pack header, the second
            # is the first actual content requset
            if count > 2:
                raise errors.NoSuchFile(relpath)
            yield result


class KnitRecordAccessTestsMixin(object):
    """Tests for getting and putting knit records."""

    def test_add_raw_records(self):
        """add_raw_records adds records retrievable later."""
        access = self.get_access()
        memos = access.add_raw_records([(b'key', 10)], [b'1234567890'])
        self.assertEqual([b'1234567890'], list(access.get_raw_records(memos)))

    def test_add_raw_record(self):
        """add_raw_record adds records retrievable later."""
        access = self.get_access()
        memos = access.add_raw_record(b'key', 10, [b'1234567890'])
        self.assertEqual([b'1234567890'], list(access.get_raw_records([memos])))

    def test_add_several_raw_records(self):
        """add_raw_records with many records and read some back."""
        access = self.get_access()
        memos = access.add_raw_records([(b'key', 10), (b'key2', 2), (b'key3', 5)],
                                       [b'12345678901234567'])
        self.assertEqual([b'1234567890', b'12', b'34567'],
                         list(access.get_raw_records(memos)))
        self.assertEqual([b'1234567890'],
                         list(access.get_raw_records(memos[0:1])))
        self.assertEqual([b'12'],
                         list(access.get_raw_records(memos[1:2])))
        self.assertEqual([b'34567'],
                         list(access.get_raw_records(memos[2:3])))
        self.assertEqual([b'1234567890', b'34567'],
                         list(access.get_raw_records(memos[0:1] + memos[2:3])))


class TestKnitKnitAccess(TestCaseWithMemoryTransport, KnitRecordAccessTestsMixin):
    """Tests for the .kndx implementation."""

    def get_access(self):
        """Get a .knit style access instance."""
        mapper = ConstantMapper("foo")
        access = _KnitKeyAccess(self.get_transport(), mapper)
        return access


class _TestException(Exception):
    """Just an exception for local tests to use."""


class TestPackKnitAccess(TestCaseWithMemoryTransport, KnitRecordAccessTestsMixin):
    """Tests for the pack based access."""

    def get_access(self):
        return self._get_access()[0]

    def _get_access(self, packname='packfile', index='FOO'):
        transport = self.get_transport()

        def write_data(bytes):
            transport.append_bytes(packname, bytes)
        writer = pack.ContainerWriter(write_data)
        writer.begin()
        access = pack_repo._DirectPackAccess({})
        access.set_writer(writer, index, (transport, packname))
        return access, writer

    def make_pack_file(self):
        """Create a pack file with 2 records."""
        access, writer = self._get_access(packname='packname', index='foo')
        memos = []
        memos.extend(access.add_raw_records([(b'key1', 10)], [b'1234567890']))
        memos.extend(access.add_raw_records([(b'key2', 5)], [b'12345']))
        writer.end()
        return memos

    def test_pack_collection_pack_retries(self):
        """An explicit pack of a pack collection succeeds even when a
        concurrent pack happens.
        """
        builder = self.make_branch_builder('.')
        builder.start_series()
        builder.build_snapshot(None, [
            ('add', ('', b'root-id', 'directory', None)),
            ('add', ('file', b'file-id', 'file', b'content\nrev 1\n')),
            ], revision_id=b'rev-1')
        builder.build_snapshot([b'rev-1'], [
            ('modify', ('file', b'content\nrev 2\n')),
            ], revision_id=b'rev-2')
        builder.build_snapshot([b'rev-2'], [
            ('modify', ('file', b'content\nrev 3\n')),
            ], revision_id=b'rev-3')
        self.addCleanup(builder.finish_series)
        b = builder.get_branch()
        self.addCleanup(b.lock_write().unlock)
        repo = b.repository
        collection = repo._pack_collection
        # Concurrently repack the repo.
        reopened_repo = repo.controldir.open_repository()
        reopened_repo.pack()
        # Pack the new pack.
        collection.pack()

    def make_vf_for_retrying(self):
        """Create 3 packs and a reload function.

        Originally, 2 pack files will have the data, but one will be missing.
        And then the third will be used in place of the first two if reload()
        is called.

        :return: (versioned_file, reload_counter)
            versioned_file  a KnitVersionedFiles using the packs for access
        """
        builder = self.make_branch_builder('.', format="1.9")
        builder.start_series()
        builder.build_snapshot(None, [
            ('add', ('', b'root-id', 'directory', None)),
            ('add', ('file', b'file-id', 'file', b'content\nrev 1\n')),
            ], revision_id=b'rev-1')
        builder.build_snapshot([b'rev-1'], [
            ('modify', ('file', b'content\nrev 2\n')),
            ], revision_id=b'rev-2')
        builder.build_snapshot([b'rev-2'], [
            ('modify', ('file', b'content\nrev 3\n')),
            ], revision_id=b'rev-3')
        builder.finish_series()
        b = builder.get_branch()
        b.lock_write()
        self.addCleanup(b.unlock)
        # Pack these three revisions into another pack file, but don't remove
        # the originals
        repo = b.repository
        collection = repo._pack_collection
        collection.ensure_loaded()
        orig_packs = collection.packs
        packer = knitpack_repo.KnitPacker(collection, orig_packs, '.testpack')
        new_pack = packer.pack()
        # forget about the new pack
        collection.reset()
        repo.refresh_data()
        vf = repo.revisions
        # Set up a reload() function that switches to using the new pack file
        new_index = new_pack.revision_index
        access_tuple = new_pack.access_tuple()
        reload_counter = [0, 0, 0]

        def reload():
            reload_counter[0] += 1
            if reload_counter[1] > 0:
                # We already reloaded, nothing more to do
                reload_counter[2] += 1
                return False
            reload_counter[1] += 1
            vf._index._graph_index._indices[:] = [new_index]
            vf._access._indices.clear()
            vf._access._indices[new_index] = access_tuple
            return True
        # Delete one of the pack files so the data will need to be reloaded. We
        # will delete the file with 'rev-2' in it
        trans, name = orig_packs[1].access_tuple()
        trans.delete(name)
        # We don't have the index trigger reloading because we want to test
        # that we reload when the .pack disappears
        vf._access._reload_func = reload
        return vf, reload_counter

    def make_reload_func(self, return_val=True):
        reload_called = [0]

        def reload():
            reload_called[0] += 1
            return return_val
        return reload_called, reload

    def make_retry_exception(self):
        # We raise a real exception so that sys.exc_info() is properly
        # populated
        try:
            raise _TestException('foobar')
        except _TestException as e:
            retry_exc = errors.RetryWithNewPacks(None, reload_occurred=False,
                                                 exc_info=sys.exc_info())
        # GZ 2010-08-10: Cycle with exc_info affects 3 tests
        return retry_exc

    def test_read_from_several_packs(self):
        access, writer = self._get_access()
        memos = []
        memos.extend(access.add_raw_records([(b'key', 10)], [b'1234567890']))
        writer.end()
        access, writer = self._get_access('pack2', 'FOOBAR')
        memos.extend(access.add_raw_records([(b'key', 5)], [b'12345']))
        writer.end()
        access, writer = self._get_access('pack3', 'BAZ')
        memos.extend(access.add_raw_records([(b'key', 5)], [b'alpha']))
        writer.end()
        transport = self.get_transport()
        access = pack_repo._DirectPackAccess({"FOO": (transport, 'packfile'),
                                              "FOOBAR": (transport, 'pack2'),
                                              "BAZ": (transport, 'pack3')})
        self.assertEqual([b'1234567890', b'12345', b'alpha'],
                         list(access.get_raw_records(memos)))
        self.assertEqual([b'1234567890'],
                         list(access.get_raw_records(memos[0:1])))
        self.assertEqual([b'12345'],
                         list(access.get_raw_records(memos[1:2])))
        self.assertEqual([b'alpha'],
                         list(access.get_raw_records(memos[2:3])))
        self.assertEqual([b'1234567890', b'alpha'],
                         list(access.get_raw_records(memos[0:1] + memos[2:3])))

    def test_set_writer(self):
        """The writer should be settable post construction."""
        access = pack_repo._DirectPackAccess({})
        transport = self.get_transport()
        packname = 'packfile'
        index = 'foo'

        def write_data(bytes):
            transport.append_bytes(packname, bytes)
        writer = pack.ContainerWriter(write_data)
        writer.begin()
        access.set_writer(writer, index, (transport, packname))
        memos = access.add_raw_records([(b'key', 10)], [b'1234567890'])
        writer.end()
        self.assertEqual([b'1234567890'], list(access.get_raw_records(memos)))

    def test_missing_index_raises_retry(self):
        memos = self.make_pack_file()
        transport = self.get_transport()
        reload_called, reload_func = self.make_reload_func()
        # Note that the index key has changed from 'foo' to 'bar'
        access = pack_repo._DirectPackAccess({'bar': (transport, 'packname')},
                                             reload_func=reload_func)
        e = self.assertListRaises(errors.RetryWithNewPacks,
                                  access.get_raw_records, memos)
        # Because a key was passed in which does not match our index list, we
        # assume that the listing was already reloaded
        self.assertTrue(e.reload_occurred)
        self.assertIsInstance(e.exc_info, tuple)
        self.assertIs(e.exc_info[0], KeyError)
        self.assertIsInstance(e.exc_info[1], KeyError)

    def test_missing_index_raises_key_error_with_no_reload(self):
        memos = self.make_pack_file()
        transport = self.get_transport()
        # Note that the index key has changed from 'foo' to 'bar'
        access = pack_repo._DirectPackAccess({'bar': (transport, 'packname')})
        e = self.assertListRaises(KeyError, access.get_raw_records, memos)

    def test_missing_file_raises_retry(self):
        memos = self.make_pack_file()
        transport = self.get_transport()
        reload_called, reload_func = self.make_reload_func()
        # Note that the 'filename' has been changed to 'different-packname'
        access = pack_repo._DirectPackAccess(
            {'foo': (transport, 'different-packname')},
            reload_func=reload_func)
        e = self.assertListRaises(errors.RetryWithNewPacks,
                                  access.get_raw_records, memos)
        # The file has gone missing, so we assume we need to reload
        self.assertFalse(e.reload_occurred)
        self.assertIsInstance(e.exc_info, tuple)
        self.assertIs(e.exc_info[0], errors.NoSuchFile)
        self.assertIsInstance(e.exc_info[1], errors.NoSuchFile)
        self.assertEqual('different-packname', e.exc_info[1].path)

    def test_missing_file_raises_no_such_file_with_no_reload(self):
        memos = self.make_pack_file()
        transport = self.get_transport()
        # Note that the 'filename' has been changed to 'different-packname'
        access = pack_repo._DirectPackAccess(
            {'foo': (transport, 'different-packname')})
        e = self.assertListRaises(errors.NoSuchFile,
                                  access.get_raw_records, memos)

    def test_failing_readv_raises_retry(self):
        memos = self.make_pack_file()
        transport = self.get_transport()
        failing_transport = MockReadvFailingTransport(
            [transport.get_bytes('packname')])
        reload_called, reload_func = self.make_reload_func()
        access = pack_repo._DirectPackAccess(
            {'foo': (failing_transport, 'packname')},
            reload_func=reload_func)
        # Asking for a single record will not trigger the Mock failure
        self.assertEqual([b'1234567890'],
                         list(access.get_raw_records(memos[:1])))
        self.assertEqual([b'12345'],
                         list(access.get_raw_records(memos[1:2])))
        # A multiple offset readv() will fail mid-way through
        e = self.assertListRaises(errors.RetryWithNewPacks,
                                  access.get_raw_records, memos)
        # The file has gone missing, so we assume we need to reload
        self.assertFalse(e.reload_occurred)
        self.assertIsInstance(e.exc_info, tuple)
        self.assertIs(e.exc_info[0], errors.NoSuchFile)
        self.assertIsInstance(e.exc_info[1], errors.NoSuchFile)
        self.assertEqual('packname', e.exc_info[1].path)

    def test_failing_readv_raises_no_such_file_with_no_reload(self):
        memos = self.make_pack_file()
        transport = self.get_transport()
        failing_transport = MockReadvFailingTransport(
            [transport.get_bytes('packname')])
        reload_called, reload_func = self.make_reload_func()
        access = pack_repo._DirectPackAccess(
            {'foo': (failing_transport, 'packname')})
        # Asking for a single record will not trigger the Mock failure
        self.assertEqual([b'1234567890'],
                         list(access.get_raw_records(memos[:1])))
        self.assertEqual([b'12345'],
                         list(access.get_raw_records(memos[1:2])))
        # A multiple offset readv() will fail mid-way through
        e = self.assertListRaises(errors.NoSuchFile,
                                  access.get_raw_records, memos)

    def test_reload_or_raise_no_reload(self):
        access = pack_repo._DirectPackAccess({}, reload_func=None)
        retry_exc = self.make_retry_exception()
        # Without a reload_func, we will just re-raise the original exception
        self.assertRaises(_TestException, access.reload_or_raise, retry_exc)

    def test_reload_or_raise_reload_changed(self):
        reload_called, reload_func = self.make_reload_func(return_val=True)
        access = pack_repo._DirectPackAccess({}, reload_func=reload_func)
        retry_exc = self.make_retry_exception()
        access.reload_or_raise(retry_exc)
        self.assertEqual([1], reload_called)
        retry_exc.reload_occurred = True
        access.reload_or_raise(retry_exc)
        self.assertEqual([2], reload_called)

    def test_reload_or_raise_reload_no_change(self):
        reload_called, reload_func = self.make_reload_func(return_val=False)
        access = pack_repo._DirectPackAccess({}, reload_func=reload_func)
        retry_exc = self.make_retry_exception()
        # If reload_occurred is False, then we consider it an error to have
        # reload_func() return False (no changes).
        self.assertRaises(_TestException, access.reload_or_raise, retry_exc)
        self.assertEqual([1], reload_called)
        retry_exc.reload_occurred = True
        # If reload_occurred is True, then we assume nothing changed because
        # it had changed earlier, but didn't change again
        access.reload_or_raise(retry_exc)
        self.assertEqual([2], reload_called)

    def test_annotate_retries(self):
        vf, reload_counter = self.make_vf_for_retrying()
        # It is a little bit bogus to annotate the Revision VF, but it works,
        # as we have ancestry stored there
        key = (b'rev-3',)
        reload_lines = vf.annotate(key)
        self.assertEqual([1, 1, 0], reload_counter)
        plain_lines = vf.annotate(key)
        self.assertEqual([1, 1, 0], reload_counter)  # No extra reloading
        if reload_lines != plain_lines:
            self.fail('Annotation was not identical with reloading.')
        # Now delete the packs-in-use, which should trigger another reload, but
        # this time we just raise an exception because we can't recover
        for trans, name in vf._access._indices.values():
            trans.delete(name)
        self.assertRaises(errors.NoSuchFile, vf.annotate, key)
        self.assertEqual([2, 1, 1], reload_counter)

    def test__get_record_map_retries(self):
        vf, reload_counter = self.make_vf_for_retrying()
        keys = [(b'rev-1',), (b'rev-2',), (b'rev-3',)]
        records = vf._get_record_map(keys)
        self.assertEqual(keys, sorted(records.keys()))
        self.assertEqual([1, 1, 0], reload_counter)
        # Now delete the packs-in-use, which should trigger another reload, but
        # this time we just raise an exception because we can't recover
        for trans, name in vf._access._indices.values():
            trans.delete(name)
        self.assertRaises(errors.NoSuchFile, vf._get_record_map, keys)
        self.assertEqual([2, 1, 1], reload_counter)

    def test_get_record_stream_retries(self):
        vf, reload_counter = self.make_vf_for_retrying()
        keys = [(b'rev-1',), (b'rev-2',), (b'rev-3',)]
        record_stream = vf.get_record_stream(keys, 'topological', False)
        record = next(record_stream)
        self.assertEqual((b'rev-1',), record.key)
        self.assertEqual([0, 0, 0], reload_counter)
        record = next(record_stream)
        self.assertEqual((b'rev-2',), record.key)
        self.assertEqual([1, 1, 0], reload_counter)
        record = next(record_stream)
        self.assertEqual((b'rev-3',), record.key)
        self.assertEqual([1, 1, 0], reload_counter)
        # Now delete all pack files, and see that we raise the right error
        for trans, name in vf._access._indices.values():
            trans.delete(name)
        self.assertListRaises(errors.NoSuchFile,
                              vf.get_record_stream, keys, 'topological', False)

    def test_iter_lines_added_or_present_in_keys_retries(self):
        vf, reload_counter = self.make_vf_for_retrying()
        keys = [(b'rev-1',), (b'rev-2',), (b'rev-3',)]
        # Unfortunately, iter_lines_added_or_present_in_keys iterates the
        # result in random order (determined by the iteration order from a
        # set()), so we don't have any solid way to trigger whether data is
        # read before or after. However we tried to delete the middle node to
        # exercise the code well.
        # What we care about is that all lines are always yielded, but not
        # duplicated
        count = 0
        reload_lines = sorted(vf.iter_lines_added_or_present_in_keys(keys))
        self.assertEqual([1, 1, 0], reload_counter)
        # Now do it again, to make sure the result is equivalent
        plain_lines = sorted(vf.iter_lines_added_or_present_in_keys(keys))
        self.assertEqual([1, 1, 0], reload_counter)  # No extra reloading
        self.assertEqual(plain_lines, reload_lines)
        self.assertEqual(21, len(plain_lines))
        # Now delete all pack files, and see that we raise the right error
        for trans, name in vf._access._indices.values():
            trans.delete(name)
        self.assertListRaises(errors.NoSuchFile,
                              vf.iter_lines_added_or_present_in_keys, keys)
        self.assertEqual([2, 1, 1], reload_counter)

    def test_get_record_stream_yields_disk_sorted_order(self):
        # if we get 'unordered' pick a semi-optimal order for reading. The
        # order should be grouped by pack file, and then by position in file
        repo = self.make_repository('test', format='pack-0.92')
        repo.lock_write()
        self.addCleanup(repo.unlock)
        repo.start_write_group()
        vf = repo.texts
        vf.add_lines((b'f-id', b'rev-5'), [(b'f-id', b'rev-4')], [b'lines\n'])
        vf.add_lines((b'f-id', b'rev-1'), [], [b'lines\n'])
        vf.add_lines((b'f-id', b'rev-2'), [(b'f-id', b'rev-1')], [b'lines\n'])
        repo.commit_write_group()
        # We inserted them as rev-5, rev-1, rev-2, we should get them back in
        # the same order
        stream = vf.get_record_stream([(b'f-id', b'rev-1'), (b'f-id', b'rev-5'),
                                       (b'f-id', b'rev-2')], 'unordered', False)
        keys = [r.key for r in stream]
        self.assertEqual([(b'f-id', b'rev-5'), (b'f-id', b'rev-1'),
                          (b'f-id', b'rev-2')], keys)
        repo.start_write_group()
        vf.add_lines((b'f-id', b'rev-4'), [(b'f-id', b'rev-3')], [b'lines\n'])
        vf.add_lines((b'f-id', b'rev-3'), [(b'f-id', b'rev-2')], [b'lines\n'])
        vf.add_lines((b'f-id', b'rev-6'), [(b'f-id', b'rev-5')], [b'lines\n'])
        repo.commit_write_group()
        # Request in random order, to make sure the output order isn't based on
        # the request
        request_keys = set((b'f-id', b'rev-%d' % i) for i in range(1, 7))
        stream = vf.get_record_stream(request_keys, 'unordered', False)
        keys = [r.key for r in stream]
        # We want to get the keys back in disk order, but it doesn't matter
        # which pack we read from first. So this can come back in 2 orders
        alt1 = [(b'f-id', b'rev-%d' % i) for i in [4, 3, 6, 5, 1, 2]]
        alt2 = [(b'f-id', b'rev-%d' % i) for i in [5, 1, 2, 4, 3, 6]]
        if keys != alt1 and keys != alt2:
            self.fail('Returned key order did not match either expected order.'
                      ' expected %s or %s, not %s'
                      % (alt1, alt2, keys))


class LowLevelKnitDataTests(TestCase):

    def create_gz_content(self, text):
        sio = BytesIO()
        with gzip.GzipFile(mode='wb', fileobj=sio) as gz_file:
            gz_file.write(text)
        return sio.getvalue()

    def make_multiple_records(self):
        """Create the content for multiple records."""
        sha1sum = osutils.sha_string(b'foo\nbar\n')
        total_txt = []
        gz_txt = self.create_gz_content(b'version rev-id-1 2 %s\n'
                                        b'foo\n'
                                        b'bar\n'
                                        b'end rev-id-1\n'
                                        % (sha1sum,))
        record_1 = (0, len(gz_txt), sha1sum)
        total_txt.append(gz_txt)
        sha1sum = osutils.sha_string(b'baz\n')
        gz_txt = self.create_gz_content(b'version rev-id-2 1 %s\n'
                                        b'baz\n'
                                        b'end rev-id-2\n'
                                        % (sha1sum,))
        record_2 = (record_1[1], len(gz_txt), sha1sum)
        total_txt.append(gz_txt)
        return total_txt, record_1, record_2

    def test_valid_knit_data(self):
        sha1sum = osutils.sha_string(b'foo\nbar\n')
        gz_txt = self.create_gz_content(b'version rev-id-1 2 %s\n'
                                        b'foo\n'
                                        b'bar\n'
                                        b'end rev-id-1\n'
                                        % (sha1sum,))
        transport = MockTransport([gz_txt])
        access = _KnitKeyAccess(transport, ConstantMapper('filename'))
        knit = KnitVersionedFiles(None, access)
        records = [((b'rev-id-1',), ((b'rev-id-1',), 0, len(gz_txt)))]

        contents = list(knit._read_records_iter(records))
        self.assertEqual([((b'rev-id-1',), [b'foo\n', b'bar\n'],
                           b'4e48e2c9a3d2ca8a708cb0cc545700544efb5021')], contents)

        raw_contents = list(knit._read_records_iter_raw(records))
        self.assertEqual([((b'rev-id-1',), gz_txt, sha1sum)], raw_contents)

    def test_multiple_records_valid(self):
        total_txt, record_1, record_2 = self.make_multiple_records()
        transport = MockTransport([b''.join(total_txt)])
        access = _KnitKeyAccess(transport, ConstantMapper('filename'))
        knit = KnitVersionedFiles(None, access)
        records = [((b'rev-id-1',), ((b'rev-id-1',), record_1[0], record_1[1])),
                   ((b'rev-id-2',), ((b'rev-id-2',), record_2[0], record_2[1]))]

        contents = list(knit._read_records_iter(records))
        self.assertEqual([((b'rev-id-1',), [b'foo\n', b'bar\n'], record_1[2]),
                          ((b'rev-id-2',), [b'baz\n'], record_2[2])],
                         contents)

        raw_contents = list(knit._read_records_iter_raw(records))
        self.assertEqual([((b'rev-id-1',), total_txt[0], record_1[2]),
                          ((b'rev-id-2',), total_txt[1], record_2[2])],
                         raw_contents)

    def test_not_enough_lines(self):
        sha1sum = osutils.sha_string(b'foo\n')
        # record says 2 lines data says 1
        gz_txt = self.create_gz_content(b'version rev-id-1 2 %s\n'
                                        b'foo\n'
                                        b'end rev-id-1\n'
                                        % (sha1sum,))
        transport = MockTransport([gz_txt])
        access = _KnitKeyAccess(transport, ConstantMapper('filename'))
        knit = KnitVersionedFiles(None, access)
        records = [((b'rev-id-1',), ((b'rev-id-1',), 0, len(gz_txt)))]
        self.assertRaises(KnitCorrupt, list,
                          knit._read_records_iter(records))

        # read_records_iter_raw won't detect that sort of mismatch/corruption
        raw_contents = list(knit._read_records_iter_raw(records))
        self.assertEqual([((b'rev-id-1',), gz_txt, sha1sum)], raw_contents)

    def test_too_many_lines(self):
        sha1sum = osutils.sha_string(b'foo\nbar\n')
        # record says 1 lines data says 2
        gz_txt = self.create_gz_content(b'version rev-id-1 1 %s\n'
                                        b'foo\n'
                                        b'bar\n'
                                        b'end rev-id-1\n'
                                        % (sha1sum,))
        transport = MockTransport([gz_txt])
        access = _KnitKeyAccess(transport, ConstantMapper('filename'))
        knit = KnitVersionedFiles(None, access)
        records = [((b'rev-id-1',), ((b'rev-id-1',), 0, len(gz_txt)))]
        self.assertRaises(KnitCorrupt, list,
                          knit._read_records_iter(records))

        # read_records_iter_raw won't detect that sort of mismatch/corruption
        raw_contents = list(knit._read_records_iter_raw(records))
        self.assertEqual([((b'rev-id-1',), gz_txt, sha1sum)], raw_contents)

    def test_mismatched_version_id(self):
        sha1sum = osutils.sha_string(b'foo\nbar\n')
        gz_txt = self.create_gz_content(b'version rev-id-1 2 %s\n'
                                        b'foo\n'
                                        b'bar\n'
                                        b'end rev-id-1\n'
                                        % (sha1sum,))
        transport = MockTransport([gz_txt])
        access = _KnitKeyAccess(transport, ConstantMapper('filename'))
        knit = KnitVersionedFiles(None, access)
        # We are asking for rev-id-2, but the data is rev-id-1
        records = [((b'rev-id-2',), ((b'rev-id-2',), 0, len(gz_txt)))]
        self.assertRaises(KnitCorrupt, list,
                          knit._read_records_iter(records))

        # read_records_iter_raw detects mismatches in the header
        self.assertRaises(KnitCorrupt, list,
                          knit._read_records_iter_raw(records))

    def test_uncompressed_data(self):
        sha1sum = osutils.sha_string(b'foo\nbar\n')
        txt = (b'version rev-id-1 2 %s\n'
               b'foo\n'
               b'bar\n'
               b'end rev-id-1\n'
               % (sha1sum,))
        transport = MockTransport([txt])
        access = _KnitKeyAccess(transport, ConstantMapper('filename'))
        knit = KnitVersionedFiles(None, access)
        records = [((b'rev-id-1',), ((b'rev-id-1',), 0, len(txt)))]

        # We don't have valid gzip data ==> corrupt
        self.assertRaises(KnitCorrupt, list,
                          knit._read_records_iter(records))

        # read_records_iter_raw will notice the bad data
        self.assertRaises(KnitCorrupt, list,
                          knit._read_records_iter_raw(records))

    def test_corrupted_data(self):
        sha1sum = osutils.sha_string(b'foo\nbar\n')
        gz_txt = self.create_gz_content(b'version rev-id-1 2 %s\n'
                                        b'foo\n'
                                        b'bar\n'
                                        b'end rev-id-1\n'
                                        % (sha1sum,))
        # Change 2 bytes in the middle to \xff
        gz_txt = gz_txt[:10] + b'\xff\xff' + gz_txt[12:]
        transport = MockTransport([gz_txt])
        access = _KnitKeyAccess(transport, ConstantMapper('filename'))
        knit = KnitVersionedFiles(None, access)
        records = [((b'rev-id-1',), ((b'rev-id-1',), 0, len(gz_txt)))]
        self.assertRaises(KnitCorrupt, list,
                          knit._read_records_iter(records))
        # read_records_iter_raw will barf on bad gz data
        self.assertRaises(KnitCorrupt, list,
                          knit._read_records_iter_raw(records))


class LowLevelKnitIndexTests(TestCase):

    @property
    def _load_data(self):
        from .._knit_load_data_py import _load_data_py
        return _load_data_py

    def get_knit_index(self, transport, name, mode):
        mapper = ConstantMapper(name)
        self.overrideAttr(knit, '_load_data', self._load_data)

        def allow_writes():
            return 'w' in mode
        return _KndxIndex(transport, mapper, lambda: None, allow_writes, lambda: True)

    def test_create_file(self):
        transport = MockTransport()
        index = self.get_knit_index(transport, "filename", "w")
        index.keys()
        call = transport.calls.pop(0)
        # call[1][1] is a BytesIO - we can't test it by simple equality.
        self.assertEqual('put_file_non_atomic', call[0])
        self.assertEqual('filename.kndx', call[1][0])
        # With no history, _KndxIndex writes a new index:
        self.assertEqual(_KndxIndex.HEADER,
                         call[1][1].getvalue())
        self.assertEqual({'create_parent_dir': True}, call[2])

    def test_read_utf8_version_id(self):
        unicode_revision_id = u"version-\N{CYRILLIC CAPITAL LETTER A}"
        utf8_revision_id = unicode_revision_id.encode('utf-8')
        transport = MockTransport([
            _KndxIndex.HEADER,
            b'%s option 0 1 :' % (utf8_revision_id,)
            ])
        index = self.get_knit_index(transport, "filename", "r")
        # _KndxIndex is a private class, and deals in utf8 revision_ids, not
        # Unicode revision_ids.
        self.assertEqual({(utf8_revision_id,): ()},
                         index.get_parent_map(index.keys()))
        self.assertFalse((unicode_revision_id,) in index.keys())

    def test_read_utf8_parents(self):
        unicode_revision_id = u"version-\N{CYRILLIC CAPITAL LETTER A}"
        utf8_revision_id = unicode_revision_id.encode('utf-8')
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"version option 0 1 .%s :" % (utf8_revision_id,)
            ])
        index = self.get_knit_index(transport, "filename", "r")
        self.assertEqual({(b"version",): ((utf8_revision_id,),)},
                         index.get_parent_map(index.keys()))

    def test_read_ignore_corrupted_lines(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"corrupted",
            b"corrupted options 0 1 .b .c ",
            b"version options 0 1 :"
            ])
        index = self.get_knit_index(transport, "filename", "r")
        self.assertEqual(1, len(index.keys()))
        self.assertEqual({(b"version",)}, index.keys())

    def test_read_corrupted_header(self):
        transport = MockTransport([b'not a bzr knit index header\n'])
        index = self.get_knit_index(transport, "filename", "r")
        self.assertRaises(KnitHeaderError, index.keys)

    def test_read_duplicate_entries(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"parent options 0 1 :",
            b"version options1 0 1 0 :",
            b"version options2 1 2 .other :",
            b"version options3 3 4 0 .other :"
            ])
        index = self.get_knit_index(transport, "filename", "r")
        self.assertEqual(2, len(index.keys()))
        # check that the index used is the first one written. (Specific
        # to KnitIndex style indices.
        self.assertEqual(b"1", index._dictionary_compress([(b"version",)]))
        self.assertEqual(((b"version",), 3, 4),
                         index.get_position((b"version",)))
        self.assertEqual([b"options3"], index.get_options((b"version",)))
        self.assertEqual({(b"version",): ((b"parent",), (b"other",))},
                         index.get_parent_map([(b"version",)]))

    def test_read_compressed_parents(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 1 :",
            b"b option 0 1 0 :",
            b"c option 0 1 1 0 :",
            ])
        index = self.get_knit_index(transport, "filename", "r")
        self.assertEqual({(b"b",): ((b"a",),), (b"c",): ((b"b",), (b"a",))},
                         index.get_parent_map([(b"b",), (b"c",)]))

    def test_write_utf8_version_id(self):
        unicode_revision_id = u"version-\N{CYRILLIC CAPITAL LETTER A}"
        utf8_revision_id = unicode_revision_id.encode('utf-8')
        transport = MockTransport([
            _KndxIndex.HEADER
            ])
        index = self.get_knit_index(transport, "filename", "r")
        index.add_records([
            ((utf8_revision_id,), [b"option"], ((utf8_revision_id,), 0, 1), [])])
        call = transport.calls.pop(0)
        # call[1][1] is a BytesIO - we can't test it by simple equality.
        self.assertEqual('put_file_non_atomic', call[0])
        self.assertEqual('filename.kndx', call[1][0])
        # With no history, _KndxIndex writes a new index:
        self.assertEqual(_KndxIndex.HEADER +
                         b"\n%s option 0 1  :" % (utf8_revision_id,),
                         call[1][1].getvalue())
        self.assertEqual({'create_parent_dir': True}, call[2])

    def test_write_utf8_parents(self):
        unicode_revision_id = u"version-\N{CYRILLIC CAPITAL LETTER A}"
        utf8_revision_id = unicode_revision_id.encode('utf-8')
        transport = MockTransport([
            _KndxIndex.HEADER
            ])
        index = self.get_knit_index(transport, "filename", "r")
        index.add_records([
            ((b"version",), [b"option"], ((b"version",), 0, 1), [(utf8_revision_id,)])])
        call = transport.calls.pop(0)
        # call[1][1] is a BytesIO - we can't test it by simple equality.
        self.assertEqual('put_file_non_atomic', call[0])
        self.assertEqual('filename.kndx', call[1][0])
        # With no history, _KndxIndex writes a new index:
        self.assertEqual(_KndxIndex.HEADER +
                         b"\nversion option 0 1 .%s :" % (utf8_revision_id,),
                         call[1][1].getvalue())
        self.assertEqual({'create_parent_dir': True}, call[2])

    def test_keys(self):
        transport = MockTransport([
            _KndxIndex.HEADER
            ])
        index = self.get_knit_index(transport, "filename", "r")

        self.assertEqual(set(), index.keys())

        index.add_records([((b"a",), [b"option"], ((b"a",), 0, 1), [])])
        self.assertEqual({(b"a",)}, index.keys())

        index.add_records([((b"a",), [b"option"], ((b"a",), 0, 1), [])])
        self.assertEqual({(b"a",)}, index.keys())

        index.add_records([((b"b",), [b"option"], ((b"b",), 0, 1), [])])
        self.assertEqual({(b"a",), (b"b",)}, index.keys())

    def add_a_b(self, index, random_id=None):
        kwargs = {}
        if random_id is not None:
            kwargs["random_id"] = random_id
        index.add_records([
            ((b"a",), [b"option"], ((b"a",), 0, 1), [(b"b",)]),
            ((b"a",), [b"opt"], ((b"a",), 1, 2), [(b"c",)]),
            ((b"b",), [b"option"], ((b"b",), 2, 3), [(b"a",)])
            ], **kwargs)

    def assertIndexIsAB(self, index):
        self.assertEqual({
            (b'a',): ((b'c',),),
            (b'b',): ((b'a',),),
            },
            index.get_parent_map(index.keys()))
        self.assertEqual(((b"a",), 1, 2), index.get_position((b"a",)))
        self.assertEqual(((b"b",), 2, 3), index.get_position((b"b",)))
        self.assertEqual([b"opt"], index.get_options((b"a",)))

    def test_add_versions(self):
        transport = MockTransport([
            _KndxIndex.HEADER
            ])
        index = self.get_knit_index(transport, "filename", "r")

        self.add_a_b(index)
        call = transport.calls.pop(0)
        # call[1][1] is a BytesIO - we can't test it by simple equality.
        self.assertEqual('put_file_non_atomic', call[0])
        self.assertEqual('filename.kndx', call[1][0])
        # With no history, _KndxIndex writes a new index:
        self.assertEqual(
            _KndxIndex.HEADER +
            b"\na option 0 1 .b :"
            b"\na opt 1 2 .c :"
            b"\nb option 2 3 0 :",
            call[1][1].getvalue())
        self.assertEqual({'create_parent_dir': True}, call[2])
        self.assertIndexIsAB(index)

    def test_add_versions_random_id_is_accepted(self):
        transport = MockTransport([
            _KndxIndex.HEADER
            ])
        index = self.get_knit_index(transport, "filename", "r")
        self.add_a_b(index, random_id=True)

    def test_delay_create_and_add_versions(self):
        transport = MockTransport()

        index = self.get_knit_index(transport, "filename", "w")
        # dir_mode=0777)
        self.assertEqual([], transport.calls)
        self.add_a_b(index)
        # self.assertEqual(
        # [    {"dir_mode": 0777, "create_parent_dir": True, "mode": "wb"},
        #    kwargs)
        # Two calls: one during which we load the existing index (and when its
        # missing create it), then a second where we write the contents out.
        self.assertEqual(2, len(transport.calls))
        call = transport.calls.pop(0)
        self.assertEqual('put_file_non_atomic', call[0])
        self.assertEqual('filename.kndx', call[1][0])
        # With no history, _KndxIndex writes a new index:
        self.assertEqual(_KndxIndex.HEADER, call[1][1].getvalue())
        self.assertEqual({'create_parent_dir': True}, call[2])
        call = transport.calls.pop(0)
        # call[1][1] is a BytesIO - we can't test it by simple equality.
        self.assertEqual('put_file_non_atomic', call[0])
        self.assertEqual('filename.kndx', call[1][0])
        # With no history, _KndxIndex writes a new index:
        self.assertEqual(
            _KndxIndex.HEADER +
            b"\na option 0 1 .b :"
            b"\na opt 1 2 .c :"
            b"\nb option 2 3 0 :",
            call[1][1].getvalue())
        self.assertEqual({'create_parent_dir': True}, call[2])

    def assertTotalBuildSize(self, size, keys, positions):
        self.assertEqual(size,
                         knit._get_total_build_size(None, keys, positions))

    def test__get_total_build_size(self):
        positions = {
            (b'a',): (('fulltext', False), ((b'a',), 0, 100), None),
            (b'b',): (('line-delta', False), ((b'b',), 100, 21), (b'a',)),
            (b'c',): (('line-delta', False), ((b'c',), 121, 35), (b'b',)),
            (b'd',): (('line-delta', False), ((b'd',), 156, 12), (b'b',)),
            }
        self.assertTotalBuildSize(100, [(b'a',)], positions)
        self.assertTotalBuildSize(121, [(b'b',)], positions)
        # c needs both a & b
        self.assertTotalBuildSize(156, [(b'c',)], positions)
        # we shouldn't count 'b' twice
        self.assertTotalBuildSize(156, [(b'b',), (b'c',)], positions)
        self.assertTotalBuildSize(133, [(b'd',)], positions)
        self.assertTotalBuildSize(168, [(b'c',), (b'd',)], positions)

    def test_get_position(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 1 :",
            b"b option 1 2 :"
            ])
        index = self.get_knit_index(transport, "filename", "r")

        self.assertEqual(((b"a",), 0, 1), index.get_position((b"a",)))
        self.assertEqual(((b"b",), 1, 2), index.get_position((b"b",)))

    def test_get_method(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a fulltext,unknown 0 1 :",
            b"b unknown,line-delta 1 2 :",
            b"c bad 3 4 :"
            ])
        index = self.get_knit_index(transport, "filename", "r")

        self.assertEqual("fulltext", index.get_method(b"a"))
        self.assertEqual("line-delta", index.get_method(b"b"))
        self.assertRaises(knit.KnitIndexUnknownMethod, index.get_method, b"c")

    def test_get_options(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a opt1 0 1 :",
            b"b opt2,opt3 1 2 :"
            ])
        index = self.get_knit_index(transport, "filename", "r")

        self.assertEqual([b"opt1"], index.get_options(b"a"))
        self.assertEqual([b"opt2", b"opt3"], index.get_options(b"b"))

    def test_get_parent_map(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 1 :",
            b"b option 1 2 0 .c :",
            b"c option 1 2 1 0 .e :"
            ])
        index = self.get_knit_index(transport, "filename", "r")

        self.assertEqual({
            (b"a",): (),
            (b"b",): ((b"a",), (b"c",)),
            (b"c",): ((b"b",), (b"a",), (b"e",)),
            }, index.get_parent_map(index.keys()))

    def test_impossible_parent(self):
        """Test we get KnitCorrupt if the parent couldn't possibly exist."""
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 1 :",
            b"b option 0 1 4 :"  # We don't have a 4th record
            ])
        index = self.get_knit_index(transport, 'filename', 'r')
        self.assertRaises(KnitCorrupt, index.keys)

    def test_corrupted_parent(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 1 :",
            b"b option 0 1 :",
            b"c option 0 1 1v :",  # Can't have a parent of '1v'
            ])
        index = self.get_knit_index(transport, 'filename', 'r')
        self.assertRaises(KnitCorrupt, index.keys)

    def test_corrupted_parent_in_list(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 1 :",
            b"b option 0 1 :",
            b"c option 0 1 1 v :",  # Can't have a parent of 'v'
            ])
        index = self.get_knit_index(transport, 'filename', 'r')
        self.assertRaises(KnitCorrupt, index.keys)

    def test_invalid_position(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 1v 1 :",
            ])
        index = self.get_knit_index(transport, 'filename', 'r')
        self.assertRaises(KnitCorrupt, index.keys)

    def test_invalid_size(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 1 1v :",
            ])
        index = self.get_knit_index(transport, 'filename', 'r')
        self.assertRaises(KnitCorrupt, index.keys)

    def test_scan_unvalidated_index_not_implemented(self):
        transport = MockTransport()
        index = self.get_knit_index(transport, 'filename', 'r')
        self.assertRaises(
            NotImplementedError, index.scan_unvalidated_index,
            'dummy graph_index')
        self.assertRaises(
            NotImplementedError, index.get_missing_compression_parents)

    def test_short_line(self):
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 10  :",
            b"b option 10 10 0",  # This line isn't terminated, ignored
            ])
        index = self.get_knit_index(transport, "filename", "r")
        self.assertEqual({(b'a',)}, index.keys())

    def test_skip_incomplete_record(self):
        # A line with bogus data should just be skipped
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 10  :",
            b"b option 10 10 0",  # This line isn't terminated, ignored
            b"c option 20 10 0 :",  # Properly terminated, and starts with '\n'
            ])
        index = self.get_knit_index(transport, "filename", "r")
        self.assertEqual({(b'a',), (b'c',)}, index.keys())

    def test_trailing_characters(self):
        # A line with bogus data should just be skipped
        transport = MockTransport([
            _KndxIndex.HEADER,
            b"a option 0 10  :",
            b"b option 10 10 0 :a",  # This line has extra trailing characters
            b"c option 20 10 0 :",  # Properly terminated, and starts with '\n'
            ])
        index = self.get_knit_index(transport, "filename", "r")
        self.assertEqual({(b'a',), (b'c',)}, index.keys())


class LowLevelKnitIndexTests_c(LowLevelKnitIndexTests):

    _test_needs_features = [compiled_knit_feature]

    @property
    def _load_data(self):
        from .._knit_load_data_pyx import _load_data_c
        return _load_data_c


class Test_KnitAnnotator(TestCaseWithMemoryTransport):

    def make_annotator(self):
        factory = knit.make_pack_factory(True, True, 1)
        vf = factory(self.get_transport())
        return knit._KnitAnnotator(vf)

    def test__expand_fulltext(self):
        ann = self.make_annotator()
        rev_key = (b'rev-id',)
        ann._num_compression_children[rev_key] = 1
        res = ann._expand_record(rev_key, ((b'parent-id',),), None,
                                 [b'line1\n', b'line2\n'], ('fulltext', True))
        # The content object and text lines should be cached appropriately
        self.assertEqual([b'line1\n', b'line2'], res)
        content_obj = ann._content_objects[rev_key]
        self.assertEqual([b'line1\n', b'line2\n'], content_obj._lines)
        self.assertEqual(res, content_obj.text())
        self.assertEqual(res, ann._text_cache[rev_key])

    def test__expand_delta_comp_parent_not_available(self):
        # Parent isn't available yet, so we return nothing, but queue up this
        # node for later processing
        ann = self.make_annotator()
        rev_key = (b'rev-id',)
        parent_key = (b'parent-id',)
        record = [b'0,1,1\n', b'new-line\n']
        details = ('line-delta', False)
        res = ann._expand_record(rev_key, (parent_key,), parent_key,
                                 record, details)
        self.assertEqual(None, res)
        self.assertTrue(parent_key in ann._pending_deltas)
        pending = ann._pending_deltas[parent_key]
        self.assertEqual(1, len(pending))
        self.assertEqual((rev_key, (parent_key,), record, details), pending[0])

    def test__expand_record_tracks_num_children(self):
        ann = self.make_annotator()
        rev_key = (b'rev-id',)
        rev2_key = (b'rev2-id',)
        parent_key = (b'parent-id',)
        record = [b'0,1,1\n', b'new-line\n']
        details = ('line-delta', False)
        ann._num_compression_children[parent_key] = 2
        ann._expand_record(parent_key, (), None, [b'line1\n', b'line2\n'],
                           ('fulltext', False))
        res = ann._expand_record(rev_key, (parent_key,), parent_key,
                                 record, details)
        self.assertEqual({parent_key: 1}, ann._num_compression_children)
        # Expanding the second child should remove the content object, and the
        # num_compression_children entry
        res = ann._expand_record(rev2_key, (parent_key,), parent_key,
                                 record, details)
        self.assertFalse(parent_key in ann._content_objects)
        self.assertEqual({}, ann._num_compression_children)
        # We should not cache the content_objects for rev2 and rev, because
        # they do not have compression children of their own.
        self.assertEqual({}, ann._content_objects)

    def test__expand_delta_records_blocks(self):
        ann = self.make_annotator()
        rev_key = (b'rev-id',)
        parent_key = (b'parent-id',)
        record = [b'0,1,1\n', b'new-line\n']
        details = ('line-delta', True)
        ann._num_compression_children[parent_key] = 2
        ann._expand_record(parent_key, (), None,
                           [b'line1\n', b'line2\n', b'line3\n'],
                           ('fulltext', False))
        ann._expand_record(rev_key, (parent_key,), parent_key, record, details)
        self.assertEqual({(rev_key, parent_key): [(1, 1, 1), (3, 3, 0)]},
                         ann._matching_blocks)
        rev2_key = (b'rev2-id',)
        record = [b'0,1,1\n', b'new-line\n']
        details = ('line-delta', False)
        ann._expand_record(rev2_key, (parent_key,),
                           parent_key, record, details)
        self.assertEqual([(1, 1, 2), (3, 3, 0)],
                         ann._matching_blocks[(rev2_key, parent_key)])

    def test__get_parent_ann_uses_matching_blocks(self):
        ann = self.make_annotator()
        rev_key = (b'rev-id',)
        parent_key = (b'parent-id',)
        parent_ann = [(parent_key,)] * 3
        block_key = (rev_key, parent_key)
        ann._annotations_cache[parent_key] = parent_ann
        ann._matching_blocks[block_key] = [(0, 1, 1), (3, 3, 0)]
        # We should not try to access any parent_lines content, because we know
        # we already have the matching blocks
        par_ann, blocks = ann._get_parent_annotations_and_matches(rev_key,
                                                                  [b'1\n', b'2\n', b'3\n'], parent_key)
        self.assertEqual(parent_ann, par_ann)
        self.assertEqual([(0, 1, 1), (3, 3, 0)], blocks)
        self.assertEqual({}, ann._matching_blocks)

    def test__process_pending(self):
        ann = self.make_annotator()
        rev_key = (b'rev-id',)
        p1_key = (b'p1-id',)
        p2_key = (b'p2-id',)
        record = [b'0,1,1\n', b'new-line\n']
        details = ('line-delta', False)
        p1_record = [b'line1\n', b'line2\n']
        ann._num_compression_children[p1_key] = 1
        res = ann._expand_record(rev_key, (p1_key, p2_key), p1_key,
                                 record, details)
        self.assertEqual(None, res)
        # self.assertTrue(p1_key in ann._pending_deltas)
        self.assertEqual({}, ann._pending_annotation)
        # Now insert p1, and we should be able to expand the delta
        res = ann._expand_record(p1_key, (), None, p1_record,
                                 ('fulltext', False))
        self.assertEqual(p1_record, res)
        ann._annotations_cache[p1_key] = [(p1_key,)] * 2
        res = ann._process_pending(p1_key)
        self.assertEqual([], res)
        self.assertFalse(p1_key in ann._pending_deltas)
        self.assertTrue(p2_key in ann._pending_annotation)
        self.assertEqual({p2_key: [(rev_key, (p1_key, p2_key))]},
                         ann._pending_annotation)
        # Now fill in parent 2, and pending annotation should be satisfied
        res = ann._expand_record(p2_key, (), None, [], ('fulltext', False))
        ann._annotations_cache[p2_key] = []
        res = ann._process_pending(p2_key)
        self.assertEqual([rev_key], res)
        self.assertEqual({}, ann._pending_annotation)
        self.assertEqual({}, ann._pending_deltas)

    def test_record_delta_removes_basis(self):
        ann = self.make_annotator()
        ann._expand_record((b'parent-id',), (), None,
                           [b'line1\n', b'line2\n'], ('fulltext', False))
        ann._num_compression_children[b'parent-id'] = 2

    def test_annotate_special_text(self):
        ann = self.make_annotator()
        vf = ann._vf
        rev1_key = (b'rev-1',)
        rev2_key = (b'rev-2',)
        rev3_key = (b'rev-3',)
        spec_key = (b'special:',)
        vf.add_lines(rev1_key, [], [b'initial content\n'])
        vf.add_lines(rev2_key, [rev1_key], [b'initial content\n',
                                            b'common content\n',
                                            b'content in 2\n'])
        vf.add_lines(rev3_key, [rev1_key], [b'initial content\n',
                                            b'common content\n',
                                            b'content in 3\n'])
        spec_text = (b'initial content\n'
                     b'common content\n'
                     b'content in 2\n'
                     b'content in 3\n')
        ann.add_special_text(spec_key, [rev2_key, rev3_key], spec_text)
        anns, lines = ann.annotate(spec_key)
        self.assertEqual([(rev1_key,),
                          (rev2_key, rev3_key),
                          (rev2_key,),
                          (rev3_key,),
                          ], anns)
        self.assertEqualDiff(spec_text, b''.join(lines))


class KnitTests(TestCaseWithTransport):
    """Class containing knit test helper routines."""

    def make_test_knit(self, annotate=False, name='test'):
        mapper = ConstantMapper(name)
        return make_file_factory(annotate, mapper)(self.get_transport())


class TestBadShaError(KnitTests):
    """Tests for handling of sha errors."""

    def test_sha_exception_has_text(self):
        # having the failed text included in the error allows for recovery.
        source = self.make_test_knit()
        target = self.make_test_knit(name="target")
        if not source._max_delta_chain:
            raise TestNotApplicable(
                "cannot get delta-caused sha failures without deltas.")
        # create a basis
        basis = (b'basis',)
        broken = (b'broken',)
        source.add_lines(basis, (), [b'foo\n'])
        source.add_lines(broken, (basis,), [b'foo\n', b'bar\n'])
        # Seed target with a bad basis text
        target.add_lines(basis, (), [b'gam\n'])
        target.insert_record_stream(
            source.get_record_stream([broken], 'unordered', False))
        err = self.assertRaises(KnitCorrupt,
                                next(target.get_record_stream([broken], 'unordered', True
                                                              )).get_bytes_as, 'chunked')
        self.assertEqual([b'gam\n', b'bar\n'], err.content)
        # Test for formatting with live data
        self.assertStartsWith(str(err), "Knit ")


class TestKnitIndex(KnitTests):

    def test_add_versions_dictionary_compresses(self):
        """Adding versions to the index should update the lookup dict"""
        knit = self.make_test_knit()
        idx = knit._index
        idx.add_records([((b'a-1',), [b'fulltext'], ((b'a-1',), 0, 0), [])])
        self.check_file_contents('test.kndx',
                                 b'# bzr knit index 8\n'
                                 b'\n'
                                 b'a-1 fulltext 0 0  :'
                                 )
        idx.add_records([
            ((b'a-2',), [b'fulltext'], ((b'a-2',), 0, 0), [(b'a-1',)]),
            ((b'a-3',), [b'fulltext'], ((b'a-3',), 0, 0), [(b'a-2',)]),
            ])
        self.check_file_contents('test.kndx',
                                 b'# bzr knit index 8\n'
                                 b'\n'
                                 b'a-1 fulltext 0 0  :\n'
                                 b'a-2 fulltext 0 0 0 :\n'
                                 b'a-3 fulltext 0 0 1 :'
                                 )
        self.assertEqual({(b'a-3',), (b'a-1',), (b'a-2',)}, idx.keys())
        self.assertEqual({
            (b'a-1',): (((b'a-1',), 0, 0), None, (), ('fulltext', False)),
            (b'a-2',): (((b'a-2',), 0, 0), None, ((b'a-1',),), ('fulltext', False)),
            (b'a-3',): (((b'a-3',), 0, 0), None, ((b'a-2',),), ('fulltext', False)),
            }, idx.get_build_details(idx.keys()))
        self.assertEqual({(b'a-1',): (),
                          (b'a-2',): ((b'a-1',),),
                          (b'a-3',): ((b'a-2',),), },
                         idx.get_parent_map(idx.keys()))

    def test_add_versions_fails_clean(self):
        """If add_versions fails in the middle, it restores a pristine state.

        Any modifications that are made to the index are reset if all versions
        cannot be added.
        """
        # This cheats a little bit by passing in a generator which will
        # raise an exception before the processing finishes
        # Other possibilities would be to have an version with the wrong number
        # of entries, or to make the backing transport unable to write any
        # files.

        knit = self.make_test_knit()
        idx = knit._index
        idx.add_records([((b'a-1',), [b'fulltext'], ((b'a-1',), 0, 0), [])])

        class StopEarly(Exception):
            pass

        def generate_failure():
            """Add some entries and then raise an exception"""
            yield ((b'a-2',), [b'fulltext'], (None, 0, 0), (b'a-1',))
            yield ((b'a-3',), [b'fulltext'], (None, 0, 0), (b'a-2',))
            raise StopEarly()

        # Assert the pre-condition
        def assertA1Only():
            self.assertEqual({(b'a-1',)}, set(idx.keys()))
            self.assertEqual(
                {(b'a-1',): (((b'a-1',), 0, 0), None, (), ('fulltext', False))},
                idx.get_build_details([(b'a-1',)]))
            self.assertEqual({(b'a-1',): ()}, idx.get_parent_map(idx.keys()))

        assertA1Only()
        self.assertRaises(StopEarly, idx.add_records, generate_failure())
        # And it shouldn't be modified
        assertA1Only()

    def test_knit_index_ignores_empty_files(self):
        # There was a race condition in older bzr, where a ^C at the right time
        # could leave an empty .kndx file, which bzr would later claim was a
        # corrupted file since the header was not present. In reality, the file
        # just wasn't created, so it should be ignored.
        t = transport.get_transport_from_path('.')
        t.put_bytes('test.kndx', b'')

        knit = self.make_test_knit()

    def test_knit_index_checks_header(self):
        t = transport.get_transport_from_path('.')
        t.put_bytes('test.kndx', b'# not really a knit header\n\n')
        k = self.make_test_knit()
        self.assertRaises(KnitHeaderError, k.keys)


class TestGraphIndexKnit(KnitTests):
    """Tests for knits using a GraphIndex rather than a KnitIndex."""

    def make_g_index(self, name, ref_lists=0, nodes=[]):
        builder = GraphIndexBuilder(ref_lists)
        for node, references, value in nodes:
            builder.add_node(node, references, value)
        stream = builder.finish()
        trans = self.get_transport()
        size = trans.put_file(name, stream)
        return GraphIndex(trans, name, size)

    def two_graph_index(self, deltas=False, catch_adds=False):
        """Build a two-graph index.

        :param deltas: If true, use underlying indices with two node-ref
            lists and 'parent' set to a delta-compressed against tail.
        """
        # build a complex graph across several indices.
        if deltas:
            # delta compression inn the index
            index1 = self.make_g_index('1', 2, [
                ((b'tip', ), b'N0 100', ([(b'parent', )], [], )),
                ((b'tail', ), b'', ([], []))])
            index2 = self.make_g_index('2', 2, [
                ((b'parent', ), b' 100 78',
                 ([(b'tail', ), (b'ghost', )], [(b'tail', )])),
                ((b'separate', ), b'', ([], []))])
        else:
            # just blob location and graph in the index.
            index1 = self.make_g_index('1', 1, [
                ((b'tip', ), b'N0 100', ([(b'parent', )], )),
                ((b'tail', ), b'', ([], ))])
            index2 = self.make_g_index('2', 1, [
                ((b'parent', ), b' 100 78', ([(b'tail', ), (b'ghost', )], )),
                ((b'separate', ), b'', ([], ))])
        combined_index = CombinedGraphIndex([index1, index2])
        if catch_adds:
            self.combined_index = combined_index
            self.caught_entries = []
            add_callback = self.catch_add
        else:
            add_callback = None
        return _KnitGraphIndex(combined_index, lambda: True, deltas=deltas,
                               add_callback=add_callback)

    def test_keys(self):
        index = self.two_graph_index()
        self.assertEqual({(b'tail',), (b'tip',), (b'parent',), (b'separate',)},
                         set(index.keys()))

    def test_get_position(self):
        index = self.two_graph_index()
        self.assertEqual(
            (index._graph_index._indices[0], 0, 100), index.get_position((b'tip',)))
        self.assertEqual(
            (index._graph_index._indices[1], 100, 78), index.get_position((b'parent',)))

    def test_get_method_deltas(self):
        index = self.two_graph_index(deltas=True)
        self.assertEqual('fulltext', index.get_method((b'tip',)))
        self.assertEqual('line-delta', index.get_method((b'parent',)))

    def test_get_method_no_deltas(self):
        # check that the parent-history lookup is ignored with deltas=False.
        index = self.two_graph_index(deltas=False)
        self.assertEqual('fulltext', index.get_method((b'tip',)))
        self.assertEqual('fulltext', index.get_method((b'parent',)))

    def test_get_options_deltas(self):
        index = self.two_graph_index(deltas=True)
        self.assertEqual([b'fulltext', b'no-eol'],
                         index.get_options((b'tip',)))
        self.assertEqual([b'line-delta'], index.get_options((b'parent',)))

    def test_get_options_no_deltas(self):
        # check that the parent-history lookup is ignored with deltas=False.
        index = self.two_graph_index(deltas=False)
        self.assertEqual([b'fulltext', b'no-eol'],
                         index.get_options((b'tip',)))
        self.assertEqual([b'fulltext'], index.get_options((b'parent',)))

    def test_get_parent_map(self):
        index = self.two_graph_index()
        self.assertEqual({(b'parent',): ((b'tail',), (b'ghost',))},
                         index.get_parent_map([(b'parent',), (b'ghost',)]))

    def catch_add(self, entries):
        self.caught_entries.append(entries)

    def test_add_no_callback_errors(self):
        index = self.two_graph_index()
        self.assertRaises(errors.ReadOnlyError, index.add_records,
                          [((b'new',), b'fulltext,no-eol', (None, 50, 60), [b'separate'])])

    def test_add_version_smoke(self):
        index = self.two_graph_index(catch_adds=True)
        index.add_records([((b'new',), b'fulltext,no-eol', (None, 50, 60),
                            [(b'separate',)])])
        self.assertEqual([[((b'new', ), b'N50 60', (((b'separate',),),))]],
                         self.caught_entries)

    def test_add_version_delta_not_delta_index(self):
        index = self.two_graph_index(catch_adds=True)
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'new',), b'no-eol,line-delta', (None, 0, 100), [(b'parent',)])])
        self.assertEqual([], self.caught_entries)

    def test_add_version_same_dup(self):
        index = self.two_graph_index(catch_adds=True)
        # options can be spelt two different ways
        index.add_records(
            [((b'tip',), b'fulltext,no-eol', (None, 0, 100), [(b'parent',)])])
        index.add_records(
            [((b'tip',), b'no-eol,fulltext', (None, 0, 100), [(b'parent',)])])
        # position/length are ignored (because each pack could have fulltext or
        # delta, and be at a different position.
        index.add_records([((b'tip',), b'fulltext,no-eol', (None, 50, 100),
                            [(b'parent',)])])
        index.add_records([((b'tip',), b'fulltext,no-eol', (None, 0, 1000),
                            [(b'parent',)])])
        # but neither should have added data:
        self.assertEqual([[], [], [], []], self.caught_entries)

    def test_add_version_different_dup(self):
        index = self.two_graph_index(deltas=True, catch_adds=True)
        # change options
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'line-delta', (None, 0, 100), [(b'parent',)])])
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext', (None, 0, 100), [(b'parent',)])])
        # parents
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext,no-eol', (None, 0, 100), [])])
        self.assertEqual([], self.caught_entries)

    def test_add_versions_nodeltas(self):
        index = self.two_graph_index(catch_adds=True)
        index.add_records([
            ((b'new',), b'fulltext,no-eol', (None, 50, 60), [(b'separate',)]),
            ((b'new2',), b'fulltext', (None, 0, 6), [(b'new',)]),
            ])
        self.assertEqual([((b'new', ), b'N50 60', (((b'separate',),),)),
                          ((b'new2', ), b' 0 6', (((b'new',),),))],
                         sorted(self.caught_entries[0]))
        self.assertEqual(1, len(self.caught_entries))

    def test_add_versions_deltas(self):
        index = self.two_graph_index(deltas=True, catch_adds=True)
        index.add_records([
            ((b'new',), b'fulltext,no-eol', (None, 50, 60), [(b'separate',)]),
            ((b'new2',), b'line-delta', (None, 0, 6), [(b'new',)]),
            ])
        self.assertEqual([((b'new', ), b'N50 60', (((b'separate',),), ())),
                          ((b'new2', ), b' 0 6', (((b'new',),), ((b'new',),), ))],
                         sorted(self.caught_entries[0]))
        self.assertEqual(1, len(self.caught_entries))

    def test_add_versions_delta_not_delta_index(self):
        index = self.two_graph_index(catch_adds=True)
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'new',), b'no-eol,line-delta', (None, 0, 100), [(b'parent',)])])
        self.assertEqual([], self.caught_entries)

    def test_add_versions_random_id_accepted(self):
        index = self.two_graph_index(catch_adds=True)
        index.add_records([], random_id=True)

    def test_add_versions_same_dup(self):
        index = self.two_graph_index(catch_adds=True)
        # options can be spelt two different ways
        index.add_records([((b'tip',), b'fulltext,no-eol', (None, 0, 100),
                            [(b'parent',)])])
        index.add_records([((b'tip',), b'no-eol,fulltext', (None, 0, 100),
                            [(b'parent',)])])
        # position/length are ignored (because each pack could have fulltext or
        # delta, and be at a different position.
        index.add_records([((b'tip',), b'fulltext,no-eol', (None, 50, 100),
                            [(b'parent',)])])
        index.add_records([((b'tip',), b'fulltext,no-eol', (None, 0, 1000),
                            [(b'parent',)])])
        # but neither should have added data.
        self.assertEqual([[], [], [], []], self.caught_entries)

    def test_add_versions_different_dup(self):
        index = self.two_graph_index(deltas=True, catch_adds=True)
        # change options
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'line-delta', (None, 0, 100), [(b'parent',)])])
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext', (None, 0, 100), [(b'parent',)])])
        # parents
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext,no-eol', (None, 0, 100), [])])
        # change options in the second record
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext,no-eol', (None, 0, 100), [(b'parent',)]),
                           ((b'tip',), b'line-delta', (None, 0, 100), [(b'parent',)])])
        self.assertEqual([], self.caught_entries)

    def make_g_index_missing_compression_parent(self):
        graph_index = self.make_g_index('missing_comp', 2,
                                        [((b'tip', ), b' 100 78',
                                          ([(b'missing-parent', ), (b'ghost', )], [(b'missing-parent', )]))])
        return graph_index

    def make_g_index_missing_parent(self):
        graph_index = self.make_g_index('missing_parent', 2,
                                        [((b'parent', ), b' 100 78', ([], [])),
                                         ((b'tip', ), b' 100 78',
                                            ([(b'parent', ), (b'missing-parent', )], [(b'parent', )])),
                                         ])
        return graph_index

    def make_g_index_no_external_refs(self):
        graph_index = self.make_g_index('no_external_refs', 2,
                                        [((b'rev', ), b' 100 78',
                                          ([(b'parent', ), (b'ghost', )], []))])
        return graph_index

    def test_add_good_unvalidated_index(self):
        unvalidated = self.make_g_index_no_external_refs()
        combined = CombinedGraphIndex([unvalidated])
        index = _KnitGraphIndex(combined, lambda: True, deltas=True)
        index.scan_unvalidated_index(unvalidated)
        self.assertEqual(frozenset(), index.get_missing_compression_parents())

    def test_add_missing_compression_parent_unvalidated_index(self):
        unvalidated = self.make_g_index_missing_compression_parent()
        combined = CombinedGraphIndex([unvalidated])
        index = _KnitGraphIndex(combined, lambda: True, deltas=True)
        index.scan_unvalidated_index(unvalidated)
        # This also checks that its only the compression parent that is
        # examined, otherwise 'ghost' would also be reported as a missing
        # parent.
        self.assertEqual(
            frozenset([(b'missing-parent',)]),
            index.get_missing_compression_parents())

    def test_add_missing_noncompression_parent_unvalidated_index(self):
        unvalidated = self.make_g_index_missing_parent()
        combined = CombinedGraphIndex([unvalidated])
        index = _KnitGraphIndex(combined, lambda: True, deltas=True,
                                track_external_parent_refs=True)
        index.scan_unvalidated_index(unvalidated)
        self.assertEqual(
            frozenset([(b'missing-parent',)]), index.get_missing_parents())

    def test_track_external_parent_refs(self):
        g_index = self.make_g_index('empty', 2, [])
        combined = CombinedGraphIndex([g_index])
        index = _KnitGraphIndex(combined, lambda: True, deltas=True,
                                add_callback=self.catch_add, track_external_parent_refs=True)
        self.caught_entries = []
        index.add_records([
            ((b'new-key',), b'fulltext,no-eol', (None, 50, 60),
             [(b'parent-1',), (b'parent-2',)])])
        self.assertEqual(
            frozenset([(b'parent-1',), (b'parent-2',)]),
            index.get_missing_parents())

    def test_add_unvalidated_index_with_present_external_references(self):
        index = self.two_graph_index(deltas=True)
        # Ugly hack to get at one of the underlying GraphIndex objects that
        # two_graph_index built.
        unvalidated = index._graph_index._indices[1]
        # 'parent' is an external ref of _indices[1] (unvalidated), but is
        # present in _indices[0].
        index.scan_unvalidated_index(unvalidated)
        self.assertEqual(frozenset(), index.get_missing_compression_parents())

    def make_new_missing_parent_g_index(self, name):
        missing_parent = name.encode('ascii') + b'-missing-parent'
        graph_index = self.make_g_index(name, 2,
                                        [((name.encode('ascii') + b'tip', ), b' 100 78',
                                          ([(missing_parent, ), (b'ghost', )], [(missing_parent, )]))])
        return graph_index

    def test_add_mulitiple_unvalidated_indices_with_missing_parents(self):
        g_index_1 = self.make_new_missing_parent_g_index('one')
        g_index_2 = self.make_new_missing_parent_g_index('two')
        combined = CombinedGraphIndex([g_index_1, g_index_2])
        index = _KnitGraphIndex(combined, lambda: True, deltas=True)
        index.scan_unvalidated_index(g_index_1)
        index.scan_unvalidated_index(g_index_2)
        self.assertEqual(
            frozenset([(b'one-missing-parent',), (b'two-missing-parent',)]),
            index.get_missing_compression_parents())

    def test_add_mulitiple_unvalidated_indices_with_mutual_dependencies(self):
        graph_index_a = self.make_g_index('one', 2,
                                          [((b'parent-one', ), b' 100 78', ([(b'non-compression-parent',)], [])),
                                           ((b'child-of-two', ), b' 100 78',
                                              ([(b'parent-two',)], [(b'parent-two',)]))])
        graph_index_b = self.make_g_index('two', 2,
                                          [((b'parent-two', ), b' 100 78', ([(b'non-compression-parent',)], [])),
                                           ((b'child-of-one', ), b' 100 78',
                                              ([(b'parent-one',)], [(b'parent-one',)]))])
        combined = CombinedGraphIndex([graph_index_a, graph_index_b])
        index = _KnitGraphIndex(combined, lambda: True, deltas=True)
        index.scan_unvalidated_index(graph_index_a)
        index.scan_unvalidated_index(graph_index_b)
        self.assertEqual(
            frozenset([]), index.get_missing_compression_parents())


class TestNoParentsGraphIndexKnit(KnitTests):
    """Tests for knits using _KnitGraphIndex with no parents."""

    def make_g_index(self, name, ref_lists=0, nodes=[]):
        builder = GraphIndexBuilder(ref_lists)
        for node, references in nodes:
            builder.add_node(node, references)
        stream = builder.finish()
        trans = self.get_transport()
        size = trans.put_file(name, stream)
        return GraphIndex(trans, name, size)

    def test_add_good_unvalidated_index(self):
        unvalidated = self.make_g_index('unvalidated')
        combined = CombinedGraphIndex([unvalidated])
        index = _KnitGraphIndex(combined, lambda: True, parents=False)
        index.scan_unvalidated_index(unvalidated)
        self.assertEqual(frozenset(),
                         index.get_missing_compression_parents())

    def test_parents_deltas_incompatible(self):
        index = CombinedGraphIndex([])
        self.assertRaises(knit.KnitError, _KnitGraphIndex, lambda: True,
                          index, deltas=True, parents=False)

    def two_graph_index(self, catch_adds=False):
        """Build a two-graph index.

        :param deltas: If true, use underlying indices with two node-ref
            lists and 'parent' set to a delta-compressed against tail.
        """
        # put several versions in the index.
        index1 = self.make_g_index('1', 0, [
            ((b'tip', ), b'N0 100'),
            ((b'tail', ), b'')])
        index2 = self.make_g_index('2', 0, [
            ((b'parent', ), b' 100 78'),
            ((b'separate', ), b'')])
        combined_index = CombinedGraphIndex([index1, index2])
        if catch_adds:
            self.combined_index = combined_index
            self.caught_entries = []
            add_callback = self.catch_add
        else:
            add_callback = None
        return _KnitGraphIndex(combined_index, lambda: True, parents=False,
                               add_callback=add_callback)

    def test_keys(self):
        index = self.two_graph_index()
        self.assertEqual({(b'tail',), (b'tip',), (b'parent',), (b'separate',)},
                         set(index.keys()))

    def test_get_position(self):
        index = self.two_graph_index()
        self.assertEqual((index._graph_index._indices[0], 0, 100),
                         index.get_position((b'tip',)))
        self.assertEqual((index._graph_index._indices[1], 100, 78),
                         index.get_position((b'parent',)))

    def test_get_method(self):
        index = self.two_graph_index()
        self.assertEqual('fulltext', index.get_method((b'tip',)))
        self.assertEqual([b'fulltext'], index.get_options((b'parent',)))

    def test_get_options(self):
        index = self.two_graph_index()
        self.assertEqual([b'fulltext', b'no-eol'],
                         index.get_options((b'tip',)))
        self.assertEqual([b'fulltext'], index.get_options((b'parent',)))

    def test_get_parent_map(self):
        index = self.two_graph_index()
        self.assertEqual({(b'parent',): None},
                         index.get_parent_map([(b'parent',), (b'ghost',)]))

    def catch_add(self, entries):
        self.caught_entries.append(entries)

    def test_add_no_callback_errors(self):
        index = self.two_graph_index()
        self.assertRaises(errors.ReadOnlyError, index.add_records,
                          [((b'new',), b'fulltext,no-eol', (None, 50, 60), [(b'separate',)])])

    def test_add_version_smoke(self):
        index = self.two_graph_index(catch_adds=True)
        index.add_records(
            [((b'new',), b'fulltext,no-eol', (None, 50, 60), [])])
        self.assertEqual([[((b'new', ), b'N50 60')]],
                         self.caught_entries)

    def test_add_version_delta_not_delta_index(self):
        index = self.two_graph_index(catch_adds=True)
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'new',), b'no-eol,line-delta', (None, 0, 100), [])])
        self.assertEqual([], self.caught_entries)

    def test_add_version_same_dup(self):
        index = self.two_graph_index(catch_adds=True)
        # options can be spelt two different ways
        index.add_records(
            [((b'tip',), b'fulltext,no-eol', (None, 0, 100), [])])
        index.add_records(
            [((b'tip',), b'no-eol,fulltext', (None, 0, 100), [])])
        # position/length are ignored (because each pack could have fulltext or
        # delta, and be at a different position.
        index.add_records(
            [((b'tip',), b'fulltext,no-eol', (None, 50, 100), [])])
        index.add_records(
            [((b'tip',), b'fulltext,no-eol', (None, 0, 1000), [])])
        # but neither should have added data.
        self.assertEqual([[], [], [], []], self.caught_entries)

    def test_add_version_different_dup(self):
        index = self.two_graph_index(catch_adds=True)
        # change options
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'no-eol,line-delta', (None, 0, 100), [])])
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'line-delta,no-eol', (None, 0, 100), [])])
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext', (None, 0, 100), [])])
        # parents
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext,no-eol', (None, 0, 100), [(b'parent',)])])
        self.assertEqual([], self.caught_entries)

    def test_add_versions(self):
        index = self.two_graph_index(catch_adds=True)
        index.add_records([
            ((b'new',), b'fulltext,no-eol', (None, 50, 60), []),
            ((b'new2',), b'fulltext', (None, 0, 6), []),
            ])
        self.assertEqual([((b'new', ), b'N50 60'), ((b'new2', ), b' 0 6')],
                         sorted(self.caught_entries[0]))
        self.assertEqual(1, len(self.caught_entries))

    def test_add_versions_delta_not_delta_index(self):
        index = self.two_graph_index(catch_adds=True)
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'new',), b'no-eol,line-delta', (None, 0, 100), [(b'parent',)])])
        self.assertEqual([], self.caught_entries)

    def test_add_versions_parents_not_parents_index(self):
        index = self.two_graph_index(catch_adds=True)
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'new',), b'no-eol,fulltext', (None, 0, 100), [(b'parent',)])])
        self.assertEqual([], self.caught_entries)

    def test_add_versions_random_id_accepted(self):
        index = self.two_graph_index(catch_adds=True)
        index.add_records([], random_id=True)

    def test_add_versions_same_dup(self):
        index = self.two_graph_index(catch_adds=True)
        # options can be spelt two different ways
        index.add_records(
            [((b'tip',), b'fulltext,no-eol', (None, 0, 100), [])])
        index.add_records(
            [((b'tip',), b'no-eol,fulltext', (None, 0, 100), [])])
        # position/length are ignored (because each pack could have fulltext or
        # delta, and be at a different position.
        index.add_records(
            [((b'tip',), b'fulltext,no-eol', (None, 50, 100), [])])
        index.add_records(
            [((b'tip',), b'fulltext,no-eol', (None, 0, 1000), [])])
        # but neither should have added data.
        self.assertEqual([[], [], [], []], self.caught_entries)

    def test_add_versions_different_dup(self):
        index = self.two_graph_index(catch_adds=True)
        # change options
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'no-eol,line-delta', (None, 0, 100), [])])
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'line-delta,no-eol', (None, 0, 100), [])])
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext', (None, 0, 100), [])])
        # parents
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext,no-eol', (None, 0, 100), [(b'parent',)])])
        # change options in the second record
        self.assertRaises(KnitCorrupt, index.add_records,
                          [((b'tip',), b'fulltext,no-eol', (None, 0, 100), []),
                           ((b'tip',), b'no-eol,line-delta', (None, 0, 100), [])])
        self.assertEqual([], self.caught_entries)


class TestKnitVersionedFiles(KnitTests):

    def assertGroupKeysForIo(self, exp_groups, keys, non_local_keys,
                             positions, _min_buffer_size=None):
        kvf = self.make_test_knit()
        if _min_buffer_size is None:
            _min_buffer_size = knit._STREAM_MIN_BUFFER_SIZE
        self.assertEqual(exp_groups, kvf._group_keys_for_io(keys,
                                                            non_local_keys, positions,
                                                            _min_buffer_size=_min_buffer_size))

    def assertSplitByPrefix(self, expected_map, expected_prefix_order,
                            keys):
        split, prefix_order = KnitVersionedFiles._split_by_prefix(keys)
        self.assertEqual(expected_map, split)
        self.assertEqual(expected_prefix_order, prefix_order)

    def test__group_keys_for_io(self):
        ft_detail = ('fulltext', False)
        ld_detail = ('line-delta', False)
        f_a = (b'f', b'a')
        f_b = (b'f', b'b')
        f_c = (b'f', b'c')
        g_a = (b'g', b'a')
        g_b = (b'g', b'b')
        g_c = (b'g', b'c')
        positions = {
            f_a: (ft_detail, (f_a, 0, 100), None),
            f_b: (ld_detail, (f_b, 100, 21), f_a),
            f_c: (ld_detail, (f_c, 180, 15), f_b),
            g_a: (ft_detail, (g_a, 121, 35), None),
            g_b: (ld_detail, (g_b, 156, 12), g_a),
            g_c: (ld_detail, (g_c, 195, 13), g_a),
            }
        self.assertGroupKeysForIo([([f_a], set())],
                                  [f_a], [], positions)
        self.assertGroupKeysForIo([([f_a], {f_a})],
                                  [f_a], [f_a], positions)
        self.assertGroupKeysForIo([([f_a, f_b], set([]))],
                                  [f_a, f_b], [], positions)
        self.assertGroupKeysForIo([([f_a, f_b], {f_b})],
                                  [f_a, f_b], [f_b], positions)
        self.assertGroupKeysForIo([([f_a, f_b, g_a, g_b], set())],
                                  [f_a, g_a, f_b, g_b], [], positions)
        self.assertGroupKeysForIo([([f_a, f_b, g_a, g_b], set())],
                                  [f_a, g_a, f_b, g_b], [], positions,
                                  _min_buffer_size=150)
        self.assertGroupKeysForIo([([f_a, f_b], set()), ([g_a, g_b], set())],
                                  [f_a, g_a, f_b, g_b], [], positions,
                                  _min_buffer_size=100)
        self.assertGroupKeysForIo([([f_c], set()), ([g_b], set())],
                                  [f_c, g_b], [], positions,
                                  _min_buffer_size=125)
        self.assertGroupKeysForIo([([g_b, f_c], set())],
                                  [g_b, f_c], [], positions,
                                  _min_buffer_size=125)

    def test__split_by_prefix(self):
        self.assertSplitByPrefix({b'f': [(b'f', b'a'), (b'f', b'b')],
                                  b'g': [(b'g', b'b'), (b'g', b'a')],
                                  }, [b'f', b'g'],
                                 [(b'f', b'a'), (b'g', b'b'),
                                  (b'g', b'a'), (b'f', b'b')])

        self.assertSplitByPrefix({b'f': [(b'f', b'a'), (b'f', b'b')],
                                  b'g': [(b'g', b'b'), (b'g', b'a')],
                                  }, [b'f', b'g'],
                                 [(b'f', b'a'), (b'f', b'b'),
                                  (b'g', b'b'), (b'g', b'a')])

        self.assertSplitByPrefix({b'f': [(b'f', b'a'), (b'f', b'b')],
                                  b'g': [(b'g', b'b'), (b'g', b'a')],
                                  }, [b'f', b'g'],
                                 [(b'f', b'a'), (b'f', b'b'),
                                  (b'g', b'b'), (b'g', b'a')])

        self.assertSplitByPrefix({b'f': [(b'f', b'a'), (b'f', b'b')],
                                  b'g': [(b'g', b'b'), (b'g', b'a')],
                                  b'': [(b'a',), (b'b',)]
                                  }, [b'f', b'g', b''],
                                 [(b'f', b'a'), (b'g', b'b'),
                                  (b'a',), (b'b',),
                                  (b'g', b'a'), (b'f', b'b')])


class TestStacking(KnitTests):

    def get_basis_and_test_knit(self):
        basis = self.make_test_knit(name='basis')
        basis = RecordingVersionedFilesDecorator(basis)
        test = self.make_test_knit(name='test')
        test.add_fallback_versioned_files(basis)
        return basis, test

    def test_add_fallback_versioned_files(self):
        basis = self.make_test_knit(name='basis')
        test = self.make_test_knit(name='test')
        # It must not error; other tests test that the fallback is referred to
        # when accessing data.
        test.add_fallback_versioned_files(basis)

    def test_add_lines(self):
        # lines added to the test are not added to the basis
        basis, test = self.get_basis_and_test_knit()
        key = (b'foo',)
        key_basis = (b'bar',)
        key_cross_border = (b'quux',)
        key_delta = (b'zaphod',)
        test.add_lines(key, (), [b'foo\n'])
        self.assertEqual({}, basis.get_parent_map([key]))
        # lines added to the test that reference across the stack do a
        # fulltext.
        basis.add_lines(key_basis, (), [b'foo\n'])
        basis.calls = []
        test.add_lines(key_cross_border, (key_basis,), [b'foo\n'])
        self.assertEqual('fulltext', test._index.get_method(key_cross_border))
        # we don't even need to look at the basis to see that this should be
        # stored as a fulltext
        self.assertEqual([], basis.calls)
        # Subsequent adds do delta.
        basis.calls = []
        test.add_lines(key_delta, (key_cross_border,), [b'foo\n'])
        self.assertEqual('line-delta', test._index.get_method(key_delta))
        self.assertEqual([], basis.calls)

    def test_annotate(self):
        # annotations from the test knit are answered without asking the basis
        basis, test = self.get_basis_and_test_knit()
        key = (b'foo',)
        key_basis = (b'bar',)
        test.add_lines(key, (), [b'foo\n'])
        details = test.annotate(key)
        self.assertEqual([(key, b'foo\n')], details)
        self.assertEqual([], basis.calls)
        # But texts that are not in the test knit are looked for in the basis
        # directly.
        basis.add_lines(key_basis, (), [b'foo\n', b'bar\n'])
        basis.calls = []
        details = test.annotate(key_basis)
        self.assertEqual(
            [(key_basis, b'foo\n'), (key_basis, b'bar\n')], details)
        # Not optimised to date:
        # self.assertEqual([("annotate", key_basis)], basis.calls)
        self.assertEqual([('get_parent_map', {key_basis}),
                          ('get_parent_map', {key_basis}),
                          ('get_record_stream', [key_basis], 'topological', True)],
                         basis.calls)

    def test_check(self):
        # At the moment checking a stacked knit does implicitly check the
        # fallback files.
        basis, test = self.get_basis_and_test_knit()
        test.check()

    def test_get_parent_map(self):
        # parents in the test knit are answered without asking the basis
        basis, test = self.get_basis_and_test_knit()
        key = (b'foo',)
        key_basis = (b'bar',)
        key_missing = (b'missing',)
        test.add_lines(key, (), [])
        parent_map = test.get_parent_map([key])
        self.assertEqual({key: ()}, parent_map)
        self.assertEqual([], basis.calls)
        # But parents that are not in the test knit are looked for in the basis
        basis.add_lines(key_basis, (), [])
        basis.calls = []
        parent_map = test.get_parent_map([key, key_basis, key_missing])
        self.assertEqual({key: (),
                          key_basis: ()}, parent_map)
        self.assertEqual([("get_parent_map", {key_basis, key_missing})],
                         basis.calls)

    def test_get_record_stream_unordered_fulltexts(self):
        # records from the test knit are answered without asking the basis:
        basis, test = self.get_basis_and_test_knit()
        key = (b'foo',)
        key_basis = (b'bar',)
        key_missing = (b'missing',)
        test.add_lines(key, (), [b'foo\n'])
        records = list(test.get_record_stream([key], 'unordered', True))
        self.assertEqual(1, len(records))
        self.assertEqual([], basis.calls)
        # Missing (from test knit) objects are retrieved from the basis:
        basis.add_lines(key_basis, (), [b'foo\n', b'bar\n'])
        basis.calls = []
        records = list(test.get_record_stream([key_basis, key_missing],
                                              'unordered', True))
        self.assertEqual(2, len(records))
        calls = list(basis.calls)
        for record in records:
            self.assertSubset([record.key], (key_basis, key_missing))
            if record.key == key_missing:
                self.assertIsInstance(record, AbsentContentFactory)
            else:
                reference = list(basis.get_record_stream([key_basis],
                                                         'unordered', True))[0]
                self.assertEqual(reference.key, record.key)
                self.assertEqual(reference.sha1, record.sha1)
                self.assertEqual(reference.storage_kind, record.storage_kind)
                self.assertEqual(reference.get_bytes_as(reference.storage_kind),
                                 record.get_bytes_as(record.storage_kind))
                self.assertEqual(reference.get_bytes_as('fulltext'),
                                 record.get_bytes_as('fulltext'))
        # It's not strictly minimal, but it seems reasonable for now for it to
        # ask which fallbacks have which parents.
        self.assertEqual([
            ("get_parent_map", {key_basis, key_missing}),
            ("get_record_stream", [key_basis], 'unordered', True)],
            calls)

    def test_get_record_stream_ordered_fulltexts(self):
        # ordering is preserved down into the fallback store.
        basis, test = self.get_basis_and_test_knit()
        key = (b'foo',)
        key_basis = (b'bar',)
        key_basis_2 = (b'quux',)
        key_missing = (b'missing',)
        test.add_lines(key, (key_basis,), [b'foo\n'])
        # Missing (from test knit) objects are retrieved from the basis:
        basis.add_lines(key_basis, (key_basis_2,), [b'foo\n', b'bar\n'])
        basis.add_lines(key_basis_2, (), [b'quux\n'])
        basis.calls = []
        # ask for in non-topological order
        records = list(test.get_record_stream(
            [key, key_basis, key_missing, key_basis_2], 'topological', True))
        self.assertEqual(4, len(records))
        results = []
        for record in records:
            self.assertSubset([record.key],
                              (key_basis, key_missing, key_basis_2, key))
            if record.key == key_missing:
                self.assertIsInstance(record, AbsentContentFactory)
            else:
                results.append((record.key, record.sha1, record.storage_kind,
                                record.get_bytes_as('fulltext')))
        calls = list(basis.calls)
        order = [record[0] for record in results]
        self.assertEqual([key_basis_2, key_basis, key], order)
        for result in results:
            if result[0] == key:
                source = test
            else:
                source = basis
            record = next(source.get_record_stream([result[0]], 'unordered',
                                                   True))
            self.assertEqual(record.key, result[0])
            self.assertEqual(record.sha1, result[1])
            # We used to check that the storage kind matched, but actually it
            # depends on whether it was sourced from the basis, or in a single
            # group, because asking for full texts returns proxy objects to a
            # _ContentMapGenerator object; so checking the kind is unneeded.
            self.assertEqual(record.get_bytes_as('fulltext'), result[3])
        # It's not strictly minimal, but it seems reasonable for now for it to
        # ask which fallbacks have which parents.
        self.assertEqual(2, len(calls))
        self.assertEqual(
            ("get_parent_map", {key_basis, key_basis_2, key_missing}),
            calls[0])
        # topological is requested from the fallback, because that is what
        # was requested at the top level.
        self.assertIn(
            calls[1], [
                ("get_record_stream", [key_basis_2,
                                       key_basis], 'topological', True),
                ("get_record_stream", [key_basis, key_basis_2], 'topological', True)])

    def test_get_record_stream_unordered_deltas(self):
        # records from the test knit are answered without asking the basis:
        basis, test = self.get_basis_and_test_knit()
        key = (b'foo',)
        key_basis = (b'bar',)
        key_missing = (b'missing',)
        test.add_lines(key, (), [b'foo\n'])
        records = list(test.get_record_stream([key], 'unordered', False))
        self.assertEqual(1, len(records))
        self.assertEqual([], basis.calls)
        # Missing (from test knit) objects are retrieved from the basis:
        basis.add_lines(key_basis, (), [b'foo\n', b'bar\n'])
        basis.calls = []
        records = list(test.get_record_stream([key_basis, key_missing],
                                              'unordered', False))
        self.assertEqual(2, len(records))
        calls = list(basis.calls)
        for record in records:
            self.assertSubset([record.key], (key_basis, key_missing))
            if record.key == key_missing:
                self.assertIsInstance(record, AbsentContentFactory)
            else:
                reference = list(basis.get_record_stream([key_basis],
                                                         'unordered', False))[0]
                self.assertEqual(reference.key, record.key)
                self.assertEqual(reference.sha1, record.sha1)
                self.assertEqual(reference.storage_kind, record.storage_kind)
                self.assertEqual(reference.get_bytes_as(reference.storage_kind),
                                 record.get_bytes_as(record.storage_kind))
        # It's not strictly minimal, but it seems reasonable for now for it to
        # ask which fallbacks have which parents.
        self.assertEqual([
            ("get_parent_map", {key_basis, key_missing}),
            ("get_record_stream", [key_basis], 'unordered', False)],
            calls)

    def test_get_record_stream_ordered_deltas(self):
        # ordering is preserved down into the fallback store.
        basis, test = self.get_basis_and_test_knit()
        key = (b'foo',)
        key_basis = (b'bar',)
        key_basis_2 = (b'quux',)
        key_missing = (b'missing',)
        test.add_lines(key, (key_basis,), [b'foo\n'])
        # Missing (from test knit) objects are retrieved from the basis:
        basis.add_lines(key_basis, (key_basis_2,), [b'foo\n', b'bar\n'])
        basis.add_lines(key_basis_2, (), [b'quux\n'])
        basis.calls = []
        # ask for in non-topological order
        records = list(test.get_record_stream(
            [key, key_basis, key_missing, key_basis_2], 'topological', False))
        self.assertEqual(4, len(records))
        results = []
        for record in records:
            self.assertSubset([record.key],
                              (key_basis, key_missing, key_basis_2, key))
            if record.key == key_missing:
                self.assertIsInstance(record, AbsentContentFactory)
            else:
                results.append((record.key, record.sha1, record.storage_kind,
                                record.get_bytes_as(record.storage_kind)))
        calls = list(basis.calls)
        order = [record[0] for record in results]
        self.assertEqual([key_basis_2, key_basis, key], order)
        for result in results:
            if result[0] == key:
                source = test
            else:
                source = basis
            record = next(source.get_record_stream([result[0]], 'unordered',
                                                   False))
            self.assertEqual(record.key, result[0])
            self.assertEqual(record.sha1, result[1])
            self.assertEqual(record.storage_kind, result[2])
            self.assertEqual(record.get_bytes_as(
                record.storage_kind), result[3])
        # It's not strictly minimal, but it seems reasonable for now for it to
        # ask which fallbacks have which parents.
        self.assertEqual([
            ("get_parent_map", {key_basis, key_basis_2, key_missing}),
            ("get_record_stream", [key_basis_2, key_basis], 'topological', False)],
            calls)

    def test_get_sha1s(self):
        # sha1's in the test knit are answered without asking the basis
        basis, test = self.get_basis_and_test_knit()
        key = (b'foo',)
        key_basis = (b'bar',)
        key_missing = (b'missing',)
        test.add_lines(key, (), [b'foo\n'])
        key_sha1sum = osutils.sha_string(b'foo\n')
        sha1s = test.get_sha1s([key])
        self.assertEqual({key: key_sha1sum}, sha1s)
        self.assertEqual([], basis.calls)
        # But texts that are not in the test knit are looked for in the basis
        # directly (rather than via text reconstruction) so that remote servers
        # etc don't have to answer with full content.
        basis.add_lines(key_basis, (), [b'foo\n', b'bar\n'])
        basis_sha1sum = osutils.sha_string(b'foo\nbar\n')
        basis.calls = []
        sha1s = test.get_sha1s([key, key_missing, key_basis])
        self.assertEqual({key: key_sha1sum,
                          key_basis: basis_sha1sum}, sha1s)
        self.assertEqual([("get_sha1s", {key_basis, key_missing})],
                         basis.calls)

    def test_insert_record_stream(self):
        # records are inserted as normal; insert_record_stream builds on
        # add_lines, so a smoke test should be all that's needed:
        key_basis = (b'bar',)
        key_delta = (b'zaphod',)
        basis, test = self.get_basis_and_test_knit()
        source = self.make_test_knit(name='source')
        basis.add_lines(key_basis, (), [b'foo\n'])
        basis.calls = []
        source.add_lines(key_basis, (), [b'foo\n'])
        source.add_lines(key_delta, (key_basis,), [b'bar\n'])
        stream = source.get_record_stream([key_delta], 'unordered', False)
        test.insert_record_stream(stream)
        # XXX: this does somewhat too many calls in making sure of whether it
        # has to recreate the full text.
        self.assertEqual([("get_parent_map", {key_basis}),
                          ('get_parent_map', {key_basis}),
                          ('get_record_stream', [key_basis], 'unordered', True)],
                         basis.calls)
        self.assertEqual({key_delta: (key_basis,)},
                         test.get_parent_map([key_delta]))
        self.assertEqual(b'bar\n', next(test.get_record_stream([key_delta],
                                                               'unordered', True)).get_bytes_as('fulltext'))

    def test_iter_lines_added_or_present_in_keys(self):
        # Lines from the basis are returned, and lines for a given key are only
        # returned once.
        key1 = (b'foo1',)
        key2 = (b'foo2',)
        # all sources are asked for keys:
        basis, test = self.get_basis_and_test_knit()
        basis.add_lines(key1, (), [b"foo"])
        basis.calls = []
        lines = list(test.iter_lines_added_or_present_in_keys([key1]))
        self.assertEqual([(b"foo\n", key1)], lines)
        self.assertEqual([("iter_lines_added_or_present_in_keys", {key1})],
                         basis.calls)
        # keys in both are not duplicated:
        test.add_lines(key2, (), [b"bar\n"])
        basis.add_lines(key2, (), [b"bar\n"])
        basis.calls = []
        lines = list(test.iter_lines_added_or_present_in_keys([key2]))
        self.assertEqual([(b"bar\n", key2)], lines)
        self.assertEqual([], basis.calls)

    def test_keys(self):
        key1 = (b'foo1',)
        key2 = (b'foo2',)
        # all sources are asked for keys:
        basis, test = self.get_basis_and_test_knit()
        keys = test.keys()
        self.assertEqual(set(), set(keys))
        self.assertEqual([("keys",)], basis.calls)
        # keys from a basis are returned:
        basis.add_lines(key1, (), [])
        basis.calls = []
        keys = test.keys()
        self.assertEqual({key1}, set(keys))
        self.assertEqual([("keys",)], basis.calls)
        # keys in both are not duplicated:
        test.add_lines(key2, (), [])
        basis.add_lines(key2, (), [])
        basis.calls = []
        keys = test.keys()
        self.assertEqual(2, len(keys))
        self.assertEqual({key1, key2}, set(keys))
        self.assertEqual([("keys",)], basis.calls)

    def test_add_mpdiffs(self):
        # records are inserted as normal; add_mpdiff builds on
        # add_lines, so a smoke test should be all that's needed:
        key_basis = (b'bar',)
        key_delta = (b'zaphod',)
        basis, test = self.get_basis_and_test_knit()
        source = self.make_test_knit(name='source')
        basis.add_lines(key_basis, (), [b'foo\n'])
        basis.calls = []
        source.add_lines(key_basis, (), [b'foo\n'])
        source.add_lines(key_delta, (key_basis,), [b'bar\n'])
        diffs = source.make_mpdiffs([key_delta])
        test.add_mpdiffs([(key_delta, (key_basis,),
                           source.get_sha1s([key_delta])[key_delta], diffs[0])])
        self.assertEqual([("get_parent_map", {key_basis}),
                          ('get_record_stream', [key_basis], 'unordered', True), ],
                         basis.calls)
        self.assertEqual({key_delta: (key_basis,)},
                         test.get_parent_map([key_delta]))
        self.assertEqual(b'bar\n', next(test.get_record_stream([key_delta],
                                                               'unordered', True)).get_bytes_as('fulltext'))

    def test_make_mpdiffs(self):
        # Generating an mpdiff across a stacking boundary should detect parent
        # texts regions.
        key = (b'foo',)
        key_left = (b'bar',)
        key_right = (b'zaphod',)
        basis, test = self.get_basis_and_test_knit()
        basis.add_lines(key_left, (), [b'bar\n'])
        basis.add_lines(key_right, (), [b'zaphod\n'])
        basis.calls = []
        test.add_lines(key, (key_left, key_right),
                       [b'bar\n', b'foo\n', b'zaphod\n'])
        diffs = test.make_mpdiffs([key])
        self.assertEqual([
            multiparent.MultiParent([multiparent.ParentText(0, 0, 0, 1),
                                     multiparent.NewText([b'foo\n']),
                                     multiparent.ParentText(1, 0, 2, 1)])],
                         diffs)
        self.assertEqual(3, len(basis.calls))
        self.assertEqual([
            ("get_parent_map", {key_left, key_right}),
            ("get_parent_map", {key_left, key_right}),
            ],
            basis.calls[:-1])
        last_call = basis.calls[-1]
        self.assertEqual('get_record_stream', last_call[0])
        self.assertEqual({key_left, key_right}, set(last_call[1]))
        self.assertEqual('topological', last_call[2])
        self.assertEqual(True, last_call[3])


class TestNetworkBehaviour(KnitTests):
    """Tests for getting data out of/into knits over the network."""

    def test_include_delta_closure_generates_a_knit_delta_closure(self):
        vf = self.make_test_knit(name='test')
        # put in three texts, giving ft, delta, delta
        vf.add_lines((b'base',), (), [b'base\n', b'content\n'])
        vf.add_lines((b'd1',), ((b'base',),), [b'd1\n'])
        vf.add_lines((b'd2',), ((b'd1',),), [b'd2\n'])
        # But heuristics could interfere, so check what happened:
        self.assertEqual(['knit-ft-gz', 'knit-delta-gz', 'knit-delta-gz'],
                         [record.storage_kind for record in
                          vf.get_record_stream([(b'base',), (b'd1',), (b'd2',)],
                                               'topological', False)])
        # generate a stream of just the deltas include_delta_closure=True,
        # serialise to the network, and check that we get a delta closure on the wire.
        stream = vf.get_record_stream(
            [(b'd1',), (b'd2',)], 'topological', True)
        netb = [record.get_bytes_as(record.storage_kind) for record in stream]
        # The first bytes should be a memo from _ContentMapGenerator, and the
        # second bytes should be empty (because its a API proxy not something
        # for wire serialisation.
        self.assertEqual(b'', netb[1])
        bytes = netb[0]
        kind, line_end = network_bytes_to_kind_and_offset(bytes)
        self.assertEqual('knit-delta-closure', kind)


class TestContentMapGenerator(KnitTests):
    """Tests for ContentMapGenerator"""

    def test_get_record_stream_gives_records(self):
        vf = self.make_test_knit(name='test')
        # put in three texts, giving ft, delta, delta
        vf.add_lines((b'base',), (), [b'base\n', b'content\n'])
        vf.add_lines((b'd1',), ((b'base',),), [b'd1\n'])
        vf.add_lines((b'd2',), ((b'd1',),), [b'd2\n'])
        keys = [(b'd1',), (b'd2',)]
        generator = _VFContentMapGenerator(vf, keys,
                                           global_map=vf.get_parent_map(keys))
        for record in generator.get_record_stream():
            if record.key == (b'd1',):
                self.assertEqual(b'd1\n', record.get_bytes_as('fulltext'))
            else:
                self.assertEqual(b'd2\n', record.get_bytes_as('fulltext'))

    def test_get_record_stream_kinds_are_raw(self):
        vf = self.make_test_knit(name='test')
        # put in three texts, giving ft, delta, delta
        vf.add_lines((b'base',), (), [b'base\n', b'content\n'])
        vf.add_lines((b'd1',), ((b'base',),), [b'd1\n'])
        vf.add_lines((b'd2',), ((b'd1',),), [b'd2\n'])
        keys = [(b'base',), (b'd1',), (b'd2',)]
        generator = _VFContentMapGenerator(vf, keys,
                                           global_map=vf.get_parent_map(keys))
        kinds = {(b'base',): 'knit-delta-closure',
                 (b'd1',): 'knit-delta-closure-ref',
                 (b'd2',): 'knit-delta-closure-ref',
                 }
        for record in generator.get_record_stream():
            self.assertEqual(kinds[record.key], record.storage_kind)
