testing: add file storage tests for getstrippoint() and strip()

Differential Revision: https://phab.mercurial-scm.org/D4864

mercurial/testing/storage.py

@@ -1,1039 +1,1156 b''
 # storage.py - Testing of storage primitives.
 #
 # Copyright 2018 Gregory Szorc <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import unittest
 
 from ..node import (
     hex,
     nullid,
     nullrev,
 )
 from .. import (
     error,
     mdiff,
     repository,
 )
 from ..utils import (
     storageutil,
 )
 
 class basetestcase(unittest.TestCase):
     if not getattr(unittest.TestCase, r'assertRaisesRegex', False):
         assertRaisesRegex = (# camelcase-required
             unittest.TestCase.assertRaisesRegexp)
 
 class ifileindextests(basetestcase):
     """Generic tests for the ifileindex interface.
 
     All file storage backends for index data should conform to the tests in this
     class.
 
     Use ``makeifileindextests()`` to create an instance of this type.
     """
     def testempty(self):
         f = self._makefilefn()
         self.assertEqual(len(f), 0, 'new file store has 0 length by default')
         self.assertEqual(list(f), [], 'iter yields nothing by default')
 
         gen = iter(f)
         with self.assertRaises(StopIteration):
             next(gen)
 
         # revs() should evaluate to an empty list.
         self.assertEqual(list(f.revs()), [])
 
         revs = iter(f.revs())
         with self.assertRaises(StopIteration):
             next(revs)
 
         self.assertEqual(list(f.revs(start=20)), [])
 
         # parents() and parentrevs() work with nullid/nullrev.
         self.assertEqual(f.parents(nullid), (nullid, nullid))
         self.assertEqual(f.parentrevs(nullrev), (nullrev, nullrev))
 
         with self.assertRaises(error.LookupError):
             f.parents(b'\x01' * 20)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.parentrevs(i)
 
         # nullid/nullrev lookup always works.
         self.assertEqual(f.rev(nullid), nullrev)
         self.assertEqual(f.node(nullrev), nullid)
 
         with self.assertRaises(error.LookupError):
             f.rev(b'\x01' * 20)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.node(i)
 
         self.assertEqual(f.lookup(nullid), nullid)
         self.assertEqual(f.lookup(nullrev), nullid)
         self.assertEqual(f.lookup(hex(nullid)), nullid)
         self.assertEqual(f.lookup(b'%d' % nullrev), nullid)
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'badvalue')
 
         with self.assertRaises(error.LookupError):
             f.lookup(hex(nullid)[0:12])
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'-2')
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'0')
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'1')
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'11111111111111111111111111111111111111')
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(LookupError):
                 f.lookup(i)
 
         self.assertEqual(f.linkrev(nullrev), nullrev)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.linkrev(i)
 
         self.assertFalse(f.iscensored(nullrev))
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.iscensored(i)
 
         self.assertEqual(list(f.commonancestorsheads(nullid, nullid)), [])
 
         with self.assertRaises(ValueError):
             self.assertEqual(list(f.descendants([])), [])
 
         self.assertEqual(list(f.descendants([nullrev])), [])
 
         self.assertEqual(f.heads(), [nullid])
         self.assertEqual(f.heads(nullid), [nullid])
         self.assertEqual(f.heads(None, [nullid]), [nullid])
         self.assertEqual(f.heads(nullid, [nullid]), [nullid])
 
         self.assertEqual(f.children(nullid), [])
 
         with self.assertRaises(error.LookupError):
             f.children(b'\x01' * 20)
 
     def testsinglerevision(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node = f.add(b'initial', None, tr, 0, nullid, nullid)
 
         self.assertEqual(len(f), 1)
         self.assertEqual(list(f), [0])
 
         gen = iter(f)
         self.assertEqual(next(gen), 0)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         self.assertEqual(list(f.revs()), [0])
         self.assertEqual(list(f.revs(start=1)), [])
         self.assertEqual(list(f.revs(start=0)), [0])
         self.assertEqual(list(f.revs(stop=0)), [0])
         self.assertEqual(list(f.revs(stop=1)), [0])
         self.assertEqual(list(f.revs(1, 1)), [])
         # TODO buggy
         self.assertEqual(list(f.revs(1, 0)), [1, 0])
         self.assertEqual(list(f.revs(2, 0)), [2, 1, 0])
 
         self.assertEqual(f.parents(node), (nullid, nullid))
         self.assertEqual(f.parentrevs(0), (nullrev, nullrev))
 
         with self.assertRaises(error.LookupError):
             f.parents(b'\x01' * 20)
 
         with self.assertRaises(IndexError):
             f.parentrevs(1)
 
         self.assertEqual(f.rev(node), 0)
 
         with self.assertRaises(error.LookupError):
             f.rev(b'\x01' * 20)
 
         self.assertEqual(f.node(0), node)
 
         with self.assertRaises(IndexError):
             f.node(1)
 
         self.assertEqual(f.lookup(node), node)
         self.assertEqual(f.lookup(0), node)
         self.assertEqual(f.lookup(-1), nullid)
         self.assertEqual(f.lookup(b'0'), node)
         self.assertEqual(f.lookup(hex(node)), node)
 
         with self.assertRaises(error.LookupError):
             f.lookup(hex(node)[0:12])
 
         with self.assertRaises(error.LookupError):
             f.lookup(-2)
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'-2')
 
         with self.assertRaises(error.LookupError):
             f.lookup(1)
 
         with self.assertRaises(error.LookupError):
             f.lookup(b'1')
 
         self.assertEqual(f.linkrev(0), 0)
 
         with self.assertRaises(IndexError):
             f.linkrev(1)
 
         self.assertFalse(f.iscensored(0))
 
         with self.assertRaises(IndexError):
             f.iscensored(1)
 
         self.assertEqual(list(f.descendants([0])), [])
 
         self.assertEqual(f.heads(), [node])
         self.assertEqual(f.heads(node), [node])
         self.assertEqual(f.heads(stop=[node]), [node])
 
         with self.assertRaises(error.LookupError):
             f.heads(stop=[b'\x01' * 20])
 
         self.assertEqual(f.children(node), [])
 
     def testmultiplerevisions(self):
         fulltext0 = b'x' * 1024
         fulltext1 = fulltext0 + b'y'
         fulltext2 = b'y' + fulltext0 + b'z'
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
             node1 = f.add(fulltext1, None, tr, 1, node0, nullid)
             node2 = f.add(fulltext2, None, tr, 3, node1, nullid)
 
         self.assertEqual(len(f), 3)
         self.assertEqual(list(f), [0, 1, 2])
 
         gen = iter(f)
         self.assertEqual(next(gen), 0)
         self.assertEqual(next(gen), 1)
         self.assertEqual(next(gen), 2)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         self.assertEqual(list(f.revs()), [0, 1, 2])
         self.assertEqual(list(f.revs(0)), [0, 1, 2])
         self.assertEqual(list(f.revs(1)), [1, 2])
         self.assertEqual(list(f.revs(2)), [2])
         self.assertEqual(list(f.revs(3)), [])
         self.assertEqual(list(f.revs(stop=1)), [0, 1])
         self.assertEqual(list(f.revs(stop=2)), [0, 1, 2])
         self.assertEqual(list(f.revs(stop=3)), [0, 1, 2])
         self.assertEqual(list(f.revs(2, 0)), [2, 1, 0])
         self.assertEqual(list(f.revs(2, 1)), [2, 1])
         # TODO this is wrong
         self.assertEqual(list(f.revs(3, 2)), [3, 2])
 
         self.assertEqual(f.parents(node0), (nullid, nullid))
         self.assertEqual(f.parents(node1), (node0, nullid))
         self.assertEqual(f.parents(node2), (node1, nullid))
 
         self.assertEqual(f.parentrevs(0), (nullrev, nullrev))
         self.assertEqual(f.parentrevs(1), (0, nullrev))
         self.assertEqual(f.parentrevs(2), (1, nullrev))
 
         self.assertEqual(f.rev(node0), 0)
         self.assertEqual(f.rev(node1), 1)
         self.assertEqual(f.rev(node2), 2)
 
         with self.assertRaises(error.LookupError):
             f.rev(b'\x01' * 20)
 
         self.assertEqual(f.node(0), node0)
         self.assertEqual(f.node(1), node1)
         self.assertEqual(f.node(2), node2)
 
         with self.assertRaises(IndexError):
             f.node(3)
 
         self.assertEqual(f.lookup(node0), node0)
         self.assertEqual(f.lookup(0), node0)
         self.assertEqual(f.lookup(b'0'), node0)
         self.assertEqual(f.lookup(hex(node0)), node0)
 
         self.assertEqual(f.lookup(node1), node1)
         self.assertEqual(f.lookup(1), node1)
         self.assertEqual(f.lookup(b'1'), node1)
         self.assertEqual(f.lookup(hex(node1)), node1)
 
         self.assertEqual(f.linkrev(0), 0)
         self.assertEqual(f.linkrev(1), 1)
         self.assertEqual(f.linkrev(2), 3)
 
         with self.assertRaises(IndexError):
             f.linkrev(3)
 
         self.assertFalse(f.iscensored(0))
         self.assertFalse(f.iscensored(1))
         self.assertFalse(f.iscensored(2))
 
         with self.assertRaises(IndexError):
             f.iscensored(3)
 
         self.assertEqual(f.commonancestorsheads(node1, nullid), [])
         self.assertEqual(f.commonancestorsheads(node1, node0), [node0])
         self.assertEqual(f.commonancestorsheads(node1, node1), [node1])
         self.assertEqual(f.commonancestorsheads(node0, node1), [node0])
         self.assertEqual(f.commonancestorsheads(node1, node2), [node1])
         self.assertEqual(f.commonancestorsheads(node2, node1), [node1])
 
         self.assertEqual(list(f.descendants([0])), [1, 2])
         self.assertEqual(list(f.descendants([1])), [2])
         self.assertEqual(list(f.descendants([0, 1])), [1, 2])
 
         self.assertEqual(f.heads(), [node2])
         self.assertEqual(f.heads(node0), [node2])
         self.assertEqual(f.heads(node1), [node2])
         self.assertEqual(f.heads(node2), [node2])
 
         # TODO this behavior seems wonky. Is it correct? If so, the
         # docstring for heads() should be updated to reflect desired
         # behavior.
         self.assertEqual(f.heads(stop=[node1]), [node1, node2])
         self.assertEqual(f.heads(stop=[node0]), [node0, node2])
         self.assertEqual(f.heads(stop=[node1, node2]), [node1, node2])
 
         with self.assertRaises(error.LookupError):
             f.heads(stop=[b'\x01' * 20])
 
         self.assertEqual(f.children(node0), [node1])
         self.assertEqual(f.children(node1), [node2])
         self.assertEqual(f.children(node2), [])
 
     def testmultipleheads(self):
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
             node0 = f.add(b'0', None, tr, 0, nullid, nullid)
             node1 = f.add(b'1', None, tr, 1, node0, nullid)
             node2 = f.add(b'2', None, tr, 2, node1, nullid)
             node3 = f.add(b'3', None, tr, 3, node0, nullid)
             node4 = f.add(b'4', None, tr, 4, node3, nullid)
             node5 = f.add(b'5', None, tr, 5, node0, nullid)
 
         self.assertEqual(len(f), 6)
 
         self.assertEqual(list(f.descendants([0])), [1, 2, 3, 4, 5])
         self.assertEqual(list(f.descendants([1])), [2])
         self.assertEqual(list(f.descendants([2])), [])
         self.assertEqual(list(f.descendants([3])), [4])
         self.assertEqual(list(f.descendants([0, 1])), [1, 2, 3, 4, 5])
         self.assertEqual(list(f.descendants([1, 3])), [2, 4])
 
         self.assertEqual(f.heads(), [node2, node4, node5])
         self.assertEqual(f.heads(node0), [node2, node4, node5])
         self.assertEqual(f.heads(node1), [node2])
         self.assertEqual(f.heads(node2), [node2])
         self.assertEqual(f.heads(node3), [node4])
         self.assertEqual(f.heads(node4), [node4])
         self.assertEqual(f.heads(node5), [node5])
 
         # TODO this seems wrong.
         self.assertEqual(f.heads(stop=[node0]), [node0, node2, node4, node5])
         self.assertEqual(f.heads(stop=[node1]), [node1, node2, node4, node5])
 
         self.assertEqual(f.children(node0), [node1, node3, node5])
         self.assertEqual(f.children(node1), [node2])
         self.assertEqual(f.children(node2), [])
         self.assertEqual(f.children(node3), [node4])
         self.assertEqual(f.children(node4), [])
         self.assertEqual(f.children(node5), [])
 
 class ifiledatatests(basetestcase):
     """Generic tests for the ifiledata interface.
 
     All file storage backends for data should conform to the tests in this
     class.
 
     Use ``makeifiledatatests()`` to create an instance of this type.
     """
     def testempty(self):
         f = self._makefilefn()
 
         self.assertEqual(f.storageinfo(), {})
         self.assertEqual(f.storageinfo(revisionscount=True, trackedsize=True),
                          {'revisionscount': 0, 'trackedsize': 0})
 
         self.assertEqual(f.size(nullrev), 0)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.size(i)
 
         self.assertEqual(f.revision(nullid), b'')
         self.assertEqual(f.revision(nullid, raw=True), b'')
 
         with self.assertRaises(error.LookupError):
             f.revision(b'\x01' * 20)
 
         self.assertEqual(f.read(nullid), b'')
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
         self.assertFalse(f.renamed(nullid))
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
         self.assertTrue(f.cmp(nullid, b''))
         self.assertTrue(f.cmp(nullid, b'foo'))
 
         with self.assertRaises(error.LookupError):
             f.cmp(b'\x01' * 20, b'irrelevant')
 
         # Emitting empty list is an empty generator.
         gen = f.emitrevisions([])
         with self.assertRaises(StopIteration):
             next(gen)
 
         # Emitting null node yields nothing.
         gen = f.emitrevisions([nullid])
         with self.assertRaises(StopIteration):
             next(gen)
 
         # Requesting unknown node fails.
         with self.assertRaises(error.LookupError):
             list(f.emitrevisions([b'\x01' * 20]))
 
     def testsinglerevision(self):
         fulltext = b'initial'
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node = f.add(fulltext, None, tr, 0, nullid, nullid)
 
         self.assertEqual(f.storageinfo(), {})
         self.assertEqual(f.storageinfo(revisionscount=True, trackedsize=True),
                          {'revisionscount': 1, 'trackedsize': len(fulltext)})
 
         self.assertEqual(f.size(0), len(fulltext))
 
         with self.assertRaises(IndexError):
             f.size(1)
 
         self.assertEqual(f.revision(node), fulltext)
         self.assertEqual(f.revision(node, raw=True), fulltext)
 
         self.assertEqual(f.read(node), fulltext)
 
         self.assertFalse(f.renamed(node))
 
         self.assertFalse(f.cmp(node, fulltext))
         self.assertTrue(f.cmp(node, fulltext + b'extra'))
 
         # Emitting a single revision works.
         gen = f.emitrevisions([node])
         rev = next(gen)
 
         self.assertEqual(rev.node, node)
         self.assertEqual(rev.p1node, nullid)
         self.assertEqual(rev.p2node, nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertIsNone(rev.delta)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         # Requesting revision data works.
         gen = f.emitrevisions([node], revisiondata=True)
         rev = next(gen)
 
         self.assertEqual(rev.node, node)
         self.assertEqual(rev.p1node, nullid)
         self.assertEqual(rev.p2node, nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext)
         self.assertIsNone(rev.delta)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         # Emitting an unknown node after a known revision results in error.
         with self.assertRaises(error.LookupError):
             list(f.emitrevisions([node, b'\x01' * 20]))
 
     def testmultiplerevisions(self):
         fulltext0 = b'x' * 1024
         fulltext1 = fulltext0 + b'y'
         fulltext2 = b'y' + fulltext0 + b'z'
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
             node1 = f.add(fulltext1, None, tr, 1, node0, nullid)
             node2 = f.add(fulltext2, None, tr, 3, node1, nullid)
 
         self.assertEqual(f.storageinfo(), {})
         self.assertEqual(
             f.storageinfo(revisionscount=True, trackedsize=True),
             {
                 'revisionscount': 3,
                 'trackedsize': len(fulltext0) + len(fulltext1) + len(fulltext2),
             })
 
         self.assertEqual(f.size(0), len(fulltext0))
         self.assertEqual(f.size(1), len(fulltext1))
         self.assertEqual(f.size(2), len(fulltext2))
 
         with self.assertRaises(IndexError):
             f.size(3)
 
         self.assertEqual(f.revision(node0), fulltext0)
         self.assertEqual(f.revision(node0, raw=True), fulltext0)
         self.assertEqual(f.revision(node1), fulltext1)
         self.assertEqual(f.revision(node1, raw=True), fulltext1)
         self.assertEqual(f.revision(node2), fulltext2)
         self.assertEqual(f.revision(node2, raw=True), fulltext2)
 
         with self.assertRaises(error.LookupError):
             f.revision(b'\x01' * 20)
 
         self.assertEqual(f.read(node0), fulltext0)
         self.assertEqual(f.read(node1), fulltext1)
         self.assertEqual(f.read(node2), fulltext2)
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
         self.assertFalse(f.renamed(node0))
         self.assertFalse(f.renamed(node1))
         self.assertFalse(f.renamed(node2))
 
         with self.assertRaises(error.LookupError):
             f.renamed(b'\x01' * 20)
 
         self.assertFalse(f.cmp(node0, fulltext0))
         self.assertFalse(f.cmp(node1, fulltext1))
         self.assertFalse(f.cmp(node2, fulltext2))
 
         self.assertTrue(f.cmp(node1, fulltext0))
         self.assertTrue(f.cmp(node2, fulltext1))
 
         with self.assertRaises(error.LookupError):
             f.cmp(b'\x01' * 20, b'irrelevant')
 
         # Nodes should be emitted in order.
         gen = f.emitrevisions([node0, node1, node2], revisiondata=True)
 
         rev = next(gen)
 
         self.assertEqual(rev.node, node0)
         self.assertEqual(rev.p1node, nullid)
         self.assertEqual(rev.p2node, nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext0)
         self.assertIsNone(rev.delta)
 
         rev = next(gen)
 
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
         self.assertEqual(rev.p2node, nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(rev.delta,
                          b'\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x04\x01' +
                          fulltext1)
 
         rev = next(gen)
 
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
         self.assertEqual(rev.p2node, nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(rev.delta,
                          b'\x00\x00\x00\x00\x00\x00\x04\x01\x00\x00\x04\x02' +
                          fulltext2)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         # Request not in DAG order is reordered to be in DAG order.
         gen = f.emitrevisions([node2, node1, node0], revisiondata=True)
 
         rev = next(gen)
 
         self.assertEqual(rev.node, node0)
         self.assertEqual(rev.p1node, nullid)
         self.assertEqual(rev.p2node, nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext0)
         self.assertIsNone(rev.delta)
 
         rev = next(gen)
 
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
         self.assertEqual(rev.p2node, nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(rev.delta,
                          b'\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x04\x01' +
                          fulltext1)
 
         rev = next(gen)
 
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
         self.assertEqual(rev.p2node, nullid)
         self.assertIsNone(rev.linknode)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(rev.delta,
                          b'\x00\x00\x00\x00\x00\x00\x04\x01\x00\x00\x04\x02' +
                          fulltext2)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         # Unrecognized nodesorder value raises ProgrammingError.
         with self.assertRaises(error.ProgrammingError):
             list(f.emitrevisions([], nodesorder='bad'))
 
         # nodesorder=storage is recognized. But we can't test it thoroughly
         # because behavior is storage-dependent.
         res = list(f.emitrevisions([node2, node1, node0],
                                          nodesorder='storage'))
         self.assertEqual(len(res), 3)
         self.assertEqual({o.node for o in res}, {node0, node1, node2})
 
         # nodesorder=nodes forces the order.
         gen = f.emitrevisions([node2, node0], nodesorder='nodes',
                               revisiondata=True)
 
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
         self.assertEqual(rev.p2node, nullid)
         self.assertEqual(rev.basenode, nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext2)
         self.assertIsNone(rev.delta)
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
         self.assertEqual(rev.p1node, nullid)
         self.assertEqual(rev.p2node, nullid)
         # Delta behavior is storage dependent, so we can't easily test it.
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         # assumehaveparentrevisions=False (the default) won't send a delta for
         # the first revision.
         gen = f.emitrevisions({node2, node1}, revisiondata=True)
 
         rev = next(gen)
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
         self.assertEqual(rev.p2node, nullid)
         self.assertEqual(rev.basenode, nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertEqual(rev.revision, fulltext1)
         self.assertIsNone(rev.delta)
 
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
         self.assertEqual(rev.p2node, nullid)
         self.assertEqual(rev.basenode, node1)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(rev.delta,
                          b'\x00\x00\x00\x00\x00\x00\x04\x01\x00\x00\x04\x02' +
                          fulltext2)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         # assumehaveparentrevisions=True allows delta against initial revision.
         gen = f.emitrevisions([node2, node1],
                               revisiondata=True, assumehaveparentrevisions=True)
 
         rev = next(gen)
         self.assertEqual(rev.node, node1)
         self.assertEqual(rev.p1node, node0)
         self.assertEqual(rev.p2node, nullid)
         self.assertEqual(rev.basenode, node0)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(rev.delta,
                          b'\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x04\x01' +
                          fulltext1)
 
         # forceprevious=True forces a delta against the previous revision.
         # Special case for initial revision.
         gen = f.emitrevisions([node0], revisiondata=True, deltaprevious=True)
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
         self.assertEqual(rev.p1node, nullid)
         self.assertEqual(rev.p2node, nullid)
         self.assertEqual(rev.basenode, nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(rev.delta,
                          b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00' +
                          fulltext0)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         gen = f.emitrevisions([node0, node2], revisiondata=True,
                               deltaprevious=True)
 
         rev = next(gen)
         self.assertEqual(rev.node, node0)
         self.assertEqual(rev.p1node, nullid)
         self.assertEqual(rev.p2node, nullid)
         self.assertEqual(rev.basenode, nullid)
         self.assertIsNone(rev.baserevisionsize)
         self.assertIsNone(rev.revision)
         self.assertEqual(rev.delta,
                          b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x04\x00' +
                          fulltext0)
 
         rev = next(gen)
         self.assertEqual(rev.node, node2)
         self.assertEqual(rev.p1node, node1)
         self.assertEqual(rev.p2node, nullid)
         self.assertEqual(rev.basenode, node0)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
     def testrenamed(self):
         fulltext0 = b'foo'
         fulltext1 = b'bar'
         fulltext2 = b'baz'
 
         meta1 = {
             b'copy': b'source0',
             b'copyrev': b'a' * 40,
         }
 
         meta2 = {
             b'copy': b'source1',
             b'copyrev': b'b' * 40,
         }
 
         stored1 = b''.join([
             b'\x01\ncopy: source0\n',
             b'copyrev: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n\x01\n',
             fulltext1,
         ])
 
         stored2 = b''.join([
             b'\x01\ncopy: source1\n',
             b'copyrev: bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\n\x01\n',
             fulltext2,
         ])
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
             node1 = f.add(fulltext1, meta1, tr, 1, node0, nullid)
             node2 = f.add(fulltext2, meta2, tr, 2, nullid, nullid)
 
         # Metadata header isn't recognized when parent isn't nullid.
         self.assertEqual(f.size(1), len(stored1))
         self.assertEqual(f.size(2), len(fulltext2))
 
         self.assertEqual(f.revision(node1), stored1)
         self.assertEqual(f.revision(node1, raw=True), stored1)
         self.assertEqual(f.revision(node2), stored2)
         self.assertEqual(f.revision(node2, raw=True), stored2)
 
         self.assertEqual(f.read(node1), fulltext1)
         self.assertEqual(f.read(node2), fulltext2)
 
         # Returns False when first parent is set.
         self.assertFalse(f.renamed(node1))
         self.assertEqual(f.renamed(node2), (b'source1', b'\xbb' * 20))
 
         self.assertTrue(f.cmp(node1, fulltext1))
         self.assertTrue(f.cmp(node1, stored1))
         self.assertFalse(f.cmp(node2, fulltext2))
         self.assertTrue(f.cmp(node2, stored2))
 
     def testmetadataprefix(self):
         # Content with metadata prefix has extra prefix inserted in storage.
         fulltext0 = b'\x01\nfoo'
         stored0 = b'\x01\n\x01\n\x01\nfoo'
 
         fulltext1 = b'\x01\nbar'
         meta1 = {
             b'copy': b'source0',
             b'copyrev': b'b' * 40,
         }
         stored1 = b''.join([
             b'\x01\ncopy: source0\n',
             b'copyrev: %s\n' % (b'b' * 40),
             b'\x01\n\x01\nbar',
         ])
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(fulltext0, {}, tr, 0, nullid, nullid)
             node1 = f.add(fulltext1, meta1, tr, 1, nullid, nullid)
 
         # TODO this is buggy.
         self.assertEqual(f.size(0), len(fulltext0) + 4)
 
         self.assertEqual(f.size(1), len(fulltext1))
 
         self.assertEqual(f.revision(node0), stored0)
         self.assertEqual(f.revision(node0, raw=True), stored0)
 
         self.assertEqual(f.revision(node1), stored1)
         self.assertEqual(f.revision(node1, raw=True), stored1)
 
         self.assertEqual(f.read(node0), fulltext0)
         self.assertEqual(f.read(node1), fulltext1)
 
         self.assertFalse(f.cmp(node0, fulltext0))
         self.assertTrue(f.cmp(node0, stored0))
 
         self.assertFalse(f.cmp(node1, fulltext1))
         self.assertTrue(f.cmp(node1, stored0))
 
     def testcensored(self):
         f = self._makefilefn()
 
         stored1 = storageutil.packmeta({
             b'censored': b'tombstone',
         }, b'')
 
         # TODO tests are incomplete because we need the node to be
         # different due to presence of censor metadata. But we can't
         # do this with addrevision().
         with self._maketransactionfn() as tr:
             node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
             f.addrevision(stored1, tr, 1, node0, nullid,
                           flags=repository.REVISION_FLAG_CENSORED)
 
         self.assertTrue(f.iscensored(1))
 
         self.assertEqual(f.revision(1), stored1)
         self.assertEqual(f.revision(1, raw=True), stored1)
 
         self.assertEqual(f.read(1), b'')
 
 class ifilemutationtests(basetestcase):
     """Generic tests for the ifilemutation interface.
 
     All file storage backends that support writing should conform to this
     interface.
 
     Use ``makeifilemutationtests()`` to create an instance of this type.
     """
     def testaddnoop(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
             node1 = f.add(b'foo', None, tr, 0, nullid, nullid)
             # Varying by linkrev shouldn't impact hash.
             node2 = f.add(b'foo', None, tr, 1, nullid, nullid)
 
         self.assertEqual(node1, node0)
         self.assertEqual(node2, node0)
         self.assertEqual(len(f), 1)
 
     def testaddrevisionbadnode(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             # Adding a revision with bad node value fails.
             with self.assertRaises(error.StorageError):
                 f.addrevision(b'foo', tr, 0, nullid, nullid, node=b'\x01' * 20)
 
     def testaddrevisionunknownflag(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             for i in range(15, 0, -1):
                 if (1 << i) & ~repository.REVISION_FLAGS_KNOWN:
                     flags = 1 << i
                     break
 
             with self.assertRaises(error.StorageError):
                 f.addrevision(b'foo', tr, 0, nullid, nullid, flags=flags)
 
     def testaddgroupsimple(self):
         f = self._makefilefn()
 
         callbackargs = []
         def cb(*args, **kwargs):
             callbackargs.append((args, kwargs))
 
         def linkmapper(node):
             return 0
 
         with self._maketransactionfn() as tr:
             nodes = f.addgroup([], None, tr, addrevisioncb=cb)
 
         self.assertEqual(nodes, [])
         self.assertEqual(callbackargs, [])
         self.assertEqual(len(f), 0)
 
         fulltext0 = b'foo'
         delta0 = mdiff.trivialdiffheader(len(fulltext0)) + fulltext0
 
         deltas = [
             (b'\x01' * 20, nullid, nullid, nullid, nullid, delta0, 0),
         ]
 
         with self._maketransactionfn() as tr:
             with self.assertRaises(error.StorageError):
                 f.addgroup(deltas, linkmapper, tr, addrevisioncb=cb)
 
             node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
 
         f = self._makefilefn()
 
         deltas = [
             (node0, nullid, nullid, nullid, nullid, delta0, 0),
         ]
 
         with self._maketransactionfn() as tr:
             nodes = f.addgroup(deltas, linkmapper, tr, addrevisioncb=cb)
 
         self.assertEqual(nodes, [
             b'\x49\xd8\xcb\xb1\x5c\xe2\x57\x92\x04\x47'
             b'\x00\x6b\x46\x97\x8b\x7a\xf9\x80\xa9\x79'])
 
         self.assertEqual(len(callbackargs), 1)
         self.assertEqual(callbackargs[0][0][1], nodes[0])
 
         self.assertEqual(list(f.revs()), [0])
         self.assertEqual(f.rev(nodes[0]), 0)
         self.assertEqual(f.node(0), nodes[0])
 
     def testaddgroupmultiple(self):
         f = self._makefilefn()
 
         fulltexts = [
             b'foo',
             b'bar',
             b'x' * 1024,
         ]
 
         nodes = []
         with self._maketransactionfn() as tr:
             for fulltext in fulltexts:
                 nodes.append(f.add(fulltext, None, tr, 0, nullid, nullid))
 
         f = self._makefilefn()
         deltas = []
         for i, fulltext in enumerate(fulltexts):
             delta = mdiff.trivialdiffheader(len(fulltext)) + fulltext
 
             deltas.append((nodes[i], nullid, nullid, nullid, nullid, delta, 0))
 
         with self._maketransactionfn() as tr:
             self.assertEqual(f.addgroup(deltas, lambda x: 0, tr), nodes)
 
         self.assertEqual(len(f), len(deltas))
         self.assertEqual(list(f.revs()), [0, 1, 2])
         self.assertEqual(f.rev(nodes[0]), 0)
         self.assertEqual(f.rev(nodes[1]), 1)
         self.assertEqual(f.rev(nodes[2]), 2)
         self.assertEqual(f.node(0), nodes[0])
         self.assertEqual(f.node(1), nodes[1])
         self.assertEqual(f.node(2), nodes[2])
 
+    def testgetstrippointnoparents(self):
+        # N revisions where none have parents.
+        f = self._makefilefn()
+
+        with self._maketransactionfn() as tr:
+            for rev in range(10):
+                f.add(b'%d' % rev, None, tr, rev, nullid, nullid)
+
+        for rev in range(10):
+            self.assertEqual(f.getstrippoint(rev), (rev, set()))
+
+    def testgetstrippointlinear(self):
+        # N revisions in a linear chain.
+        f = self._makefilefn()
+
+        with self._maketransactionfn() as tr:
+            p1 = nullid
+
+            for rev in range(10):
+                f.add(b'%d' % rev, None, tr, rev, p1, nullid)
+
+        for rev in range(10):
+            self.assertEqual(f.getstrippoint(rev), (rev, set()))
+
+    def testgetstrippointmultipleheads(self):
+        f = self._makefilefn()
+
+        with self._maketransactionfn() as tr:
+            node0 = f.add(b'0', None, tr, 0, nullid, nullid)
+            node1 = f.add(b'1', None, tr, 1, node0, nullid)
+            f.add(b'2', None, tr, 2, node1, nullid)
+            f.add(b'3', None, tr, 3, node0, nullid)
+            f.add(b'4', None, tr, 4, node0, nullid)
+
+        for rev in range(5):
+            self.assertEqual(f.getstrippoint(rev), (rev, set()))
+
+    def testgetstrippointearlierlinkrevs(self):
+        f = self._makefilefn()
+
+        with self._maketransactionfn() as tr:
+            node0 = f.add(b'0', None, tr, 0, nullid, nullid)
+            f.add(b'1', None, tr, 10, node0, nullid)
+            f.add(b'2', None, tr, 5, node0, nullid)
+
+        self.assertEqual(f.getstrippoint(0), (0, set()))
+        self.assertEqual(f.getstrippoint(1), (1, set()))
+        self.assertEqual(f.getstrippoint(2), (1, set()))
+        self.assertEqual(f.getstrippoint(3), (1, set()))
+        self.assertEqual(f.getstrippoint(4), (1, set()))
+        self.assertEqual(f.getstrippoint(5), (1, set()))
+        self.assertEqual(f.getstrippoint(6), (1, {2}))
+        self.assertEqual(f.getstrippoint(7), (1, {2}))
+        self.assertEqual(f.getstrippoint(8), (1, {2}))
+        self.assertEqual(f.getstrippoint(9), (1, {2}))
+        self.assertEqual(f.getstrippoint(10), (1, {2}))
+        self.assertEqual(f.getstrippoint(11), (3, set()))
+
+    def teststripempty(self):
+        f = self._makefilefn()
+
+        with self._maketransactionfn() as tr:
+            f.strip(0, tr)
+
+        self.assertEqual(len(f), 0)
+
+    def teststripall(self):
+        f = self._makefilefn()
+
+        with self._maketransactionfn() as tr:
+            p1 = nullid
+            for rev in range(10):
+                p1 = f.add(b'%d' % rev, None, tr, rev, p1, nullid)
+
+        self.assertEqual(len(f), 10)
+
+        with self._maketransactionfn() as tr:
+            f.strip(0, tr)
+
+        self.assertEqual(len(f), 0)
+
+    def teststrippartial(self):
+        f = self._makefilefn()
+
+        with self._maketransactionfn() as tr:
+            f.add(b'0', None, tr, 0, nullid, nullid)
+            node1 = f.add(b'1', None, tr, 5, nullid, nullid)
+            node2 = f.add(b'2', None, tr, 10, nullid, nullid)
+
+        self.assertEqual(len(f), 3)
+
+        with self._maketransactionfn() as tr:
+            f.strip(11, tr)
+
+        self.assertEqual(len(f), 3)
+
+        with self._maketransactionfn() as tr:
+            f.strip(10, tr)
+
+        self.assertEqual(len(f), 2)
+
+        with self.assertRaises(error.LookupError):
+            f.rev(node2)
+
+        with self._maketransactionfn() as tr:
+            f.strip(6, tr)
+
+        self.assertEqual(len(f), 2)
+
+        with self._maketransactionfn() as tr:
+            f.strip(3, tr)
+
+        self.assertEqual(len(f), 1)
+
+        with self.assertRaises(error.LookupError):
+            f.rev(node1)
+
 def makeifileindextests(makefilefn, maketransactionfn):
     """Create a unittest.TestCase class suitable for testing file storage.
 
     ``makefilefn`` is a callable which receives the test case as an
     argument and returns an object implementing the ``ifilestorage`` interface.
 
     ``maketransactionfn`` is a callable which receives the test case as an
     argument and returns a transaction object.
 
     Returns a type that is a ``unittest.TestCase`` that can be used for
     testing the object implementing the file storage interface. Simply
     assign the returned value to a module-level attribute and a test loader
     should find and run it automatically.
     """
     d = {
         r'_makefilefn': makefilefn,
         r'_maketransactionfn': maketransactionfn,
     }
     return type(r'ifileindextests', (ifileindextests,), d)
 
 def makeifiledatatests(makefilefn, maketransactionfn):
     d = {
         r'_makefilefn': makefilefn,
         r'_maketransactionfn': maketransactionfn,
     }
     return type(r'ifiledatatests', (ifiledatatests,), d)
 
 def makeifilemutationtests(makefilefn, maketransactionfn):
     d = {
         r'_makefilefn': makefilefn,
         r'_maketransactionfn': maketransactionfn,
     }
     return type(r'ifilemutationtests', (ifilemutationtests,), d)