streamclone: define first iteration of version 2 of stream format
(This patch is based on a first draft from Gregory Szorc, with deeper rework)
Version 1 of the stream clone format was invented many years ago and suffers
from a few deficiencies:
1) Filenames are stored in store-encoded (on filesystem) form rather than in
their internal form. This makes future compatibility with new store
filename encodings more difficult.
2) File entry "headers" consist of a newline of the file name followed by the
string file size. Converting strings to integers is avoidable overhead. We
can't store filenames with newlines (manifests have this limitation as
well, so it isn't a major concern). But the big concern here is the
necessity for readline(). Scanning for newlines means reading ahead and
that means extra buffer allocations and slicing (in Python) and this makes
performance suffer.
3) Filenames aren't compressed optimally. Filenames should be compressed well
since there is a lot of repeated data. However, since they are scattered
all over the stream (with revlog data in between), they typically fall
outside the window size of the compressor and don't compress.
4) It can only exchange stored based content, being able to exchange caches
too would be nice.
5) It is limited to a stream-based protocol and isn't suitable for an on-disk
format for general repository reading because the offset of individual file
entries requires scanning the entire file to find file records.
As part of enabling streaming clones to work in bundle2, #2 proved to have a
significant negative impact on performance. Since bundle2 provides the
opportunity to start fresh, Gregory Szorc figured he would take the
opportunity to invent a new streaming clone data format.
The new format devised in this series addresses #1, #2, and #4. It punts on #3
because it was complex without yielding a significant gain and on #5 because
devising a new store format that "packs" multiple revlogs into a single
"packed revlog" is massive scope bloat. However, this v2 format might be
suitable for streaming into a "packed revlog" with minimal processing. If it
works, great. If not, we can always invent stream format when it is needed.
This patch only introduces the bases of the format. We'll get it usable through
bundle2 first, then we'll extend the format in future patches to bring it to its
full potential (especially #4).
from __future__ import absolute_import
import binascii
import itertools
import silenttestrunner
import unittest
from mercurial import (
manifest as manifestmod,
match as matchmod,
)
EMTPY_MANIFEST = b''
EMTPY_MANIFEST_V2 = b'\0\n'
HASH_1 = b'1' * 40
BIN_HASH_1 = binascii.unhexlify(HASH_1)
HASH_2 = b'f' * 40
BIN_HASH_2 = binascii.unhexlify(HASH_2)
HASH_3 = b'1234567890abcdef0987654321deadbeef0fcafe'
BIN_HASH_3 = binascii.unhexlify(HASH_3)
A_SHORT_MANIFEST = (
b'bar/baz/qux.py\0%(hash2)s%(flag2)s\n'
b'foo\0%(hash1)s%(flag1)s\n'
) % {b'hash1': HASH_1,
b'flag1': b'',
b'hash2': HASH_2,
b'flag2': b'l',
}
# Same data as A_SHORT_MANIFEST
A_SHORT_MANIFEST_V2 = (
b'\0\n'
b'\x00bar/baz/qux.py\0%(flag2)s\n%(hash2)s\n'
b'\x00foo\0%(flag1)s\n%(hash1)s\n'
) % {b'hash1': BIN_HASH_1,
b'flag1': b'',
b'hash2': BIN_HASH_2,
b'flag2': b'l',
}
# Same data as A_SHORT_MANIFEST
A_METADATA_MANIFEST = (
b'\0foo\0bar\n'
b'\x00bar/baz/qux.py\0%(flag2)s\0foo\0bar\n%(hash2)s\n' # flag and metadata
b'\x00foo\0%(flag1)s\0foo\n%(hash1)s\n' # no flag, but metadata
) % {b'hash1': BIN_HASH_1,
b'flag1': b'',
b'hash2': BIN_HASH_2,
b'flag2': b'l',
}
A_STEM_COMPRESSED_MANIFEST = (
b'\0\n'
b'\x00bar/baz/qux.py\0%(flag2)s\n%(hash2)s\n'
b'\x04qux/foo.py\0%(flag1)s\n%(hash1)s\n' # simple case of 4 stem chars
b'\x0az.py\0%(flag1)s\n%(hash1)s\n' # tricky newline = 10 stem characters
b'\x00%(verylongdir)sx/x\0\n%(hash1)s\n'
b'\xffx/y\0\n%(hash2)s\n' # more than 255 stem chars
) % {b'hash1': BIN_HASH_1,
b'flag1': b'',
b'hash2': BIN_HASH_2,
b'flag2': b'l',
b'verylongdir': 255 * b'x',
}
A_DEEPER_MANIFEST = (
b'a/b/c/bar.py\0%(hash3)s%(flag1)s\n'
b'a/b/c/bar.txt\0%(hash1)s%(flag1)s\n'
b'a/b/c/foo.py\0%(hash3)s%(flag1)s\n'
b'a/b/c/foo.txt\0%(hash2)s%(flag2)s\n'
b'a/b/d/baz.py\0%(hash3)s%(flag1)s\n'
b'a/b/d/qux.py\0%(hash1)s%(flag2)s\n'
b'a/b/d/ten.txt\0%(hash3)s%(flag2)s\n'
b'a/b/dog.py\0%(hash3)s%(flag1)s\n'
b'a/b/fish.py\0%(hash2)s%(flag1)s\n'
b'a/c/london.py\0%(hash3)s%(flag2)s\n'
b'a/c/paper.txt\0%(hash2)s%(flag2)s\n'
b'a/c/paris.py\0%(hash2)s%(flag1)s\n'
b'a/d/apple.py\0%(hash3)s%(flag1)s\n'
b'a/d/pizza.py\0%(hash3)s%(flag2)s\n'
b'a/green.py\0%(hash1)s%(flag2)s\n'
b'a/purple.py\0%(hash2)s%(flag1)s\n'
b'app.py\0%(hash3)s%(flag1)s\n'
b'readme.txt\0%(hash2)s%(flag1)s\n'
) % {b'hash1': HASH_1,
b'flag1': b'',
b'hash2': HASH_2,
b'flag2': b'l',
b'hash3': HASH_3,
}
HUGE_MANIFEST_ENTRIES = 200001
izip = getattr(itertools, 'izip', zip)
if 'xrange' not in globals():
xrange = range
A_HUGE_MANIFEST = b''.join(sorted(
b'file%d\0%s%s\n' % (i, h, f) for i, h, f in
izip(xrange(200001),
itertools.cycle((HASH_1, HASH_2)),
itertools.cycle((b'', b'x', b'l')))))
class basemanifesttests(object):
def parsemanifest(self, text):
raise NotImplementedError('parsemanifest not implemented by test case')
def testEmptyManifest(self):
m = self.parsemanifest(EMTPY_MANIFEST)
self.assertEqual(0, len(m))
self.assertEqual([], list(m))
def testEmptyManifestv2(self):
m = self.parsemanifest(EMTPY_MANIFEST_V2)
self.assertEqual(0, len(m))
self.assertEqual([], list(m))
def testManifest(self):
m = self.parsemanifest(A_SHORT_MANIFEST)
self.assertEqual([b'bar/baz/qux.py', b'foo'], list(m))
self.assertEqual(BIN_HASH_2, m[b'bar/baz/qux.py'])
self.assertEqual(b'l', m.flags(b'bar/baz/qux.py'))
self.assertEqual(BIN_HASH_1, m[b'foo'])
self.assertEqual(b'', m.flags(b'foo'))
with self.assertRaises(KeyError):
m[b'wat']
def testParseManifestV2(self):
m1 = self.parsemanifest(A_SHORT_MANIFEST)
m2 = self.parsemanifest(A_SHORT_MANIFEST_V2)
# Should have same content as A_SHORT_MANIFEST
self.assertEqual(m1.text(), m2.text())
def testParseManifestMetadata(self):
# Metadata is for future-proofing and should be accepted but ignored
m = self.parsemanifest(A_METADATA_MANIFEST)
self.assertEqual(A_SHORT_MANIFEST, m.text())
def testParseManifestStemCompression(self):
m = self.parsemanifest(A_STEM_COMPRESSED_MANIFEST)
self.assertIn(b'bar/baz/qux.py', m)
self.assertIn(b'bar/qux/foo.py', m)
self.assertIn(b'bar/qux/foz.py', m)
self.assertIn(256 * b'x' + b'/x', m)
self.assertIn(256 * b'x' + b'/y', m)
self.assertEqual(A_STEM_COMPRESSED_MANIFEST, m.text(usemanifestv2=True))
def testTextV2(self):
m1 = self.parsemanifest(A_SHORT_MANIFEST)
v2text = m1.text(usemanifestv2=True)
self.assertEqual(A_SHORT_MANIFEST_V2, v2text)
def testSetItem(self):
want = BIN_HASH_1
m = self.parsemanifest(EMTPY_MANIFEST)
m[b'a'] = want
self.assertIn(b'a', m)
self.assertEqual(want, m[b'a'])
self.assertEqual(b'a\0' + HASH_1 + b'\n', m.text())
m = self.parsemanifest(A_SHORT_MANIFEST)
m[b'a'] = want
self.assertEqual(want, m[b'a'])
self.assertEqual(b'a\0' + HASH_1 + b'\n' + A_SHORT_MANIFEST,
m.text())
def testSetFlag(self):
want = b'x'
m = self.parsemanifest(EMTPY_MANIFEST)
# first add a file; a file-less flag makes no sense
m[b'a'] = BIN_HASH_1
m.setflag(b'a', want)
self.assertEqual(want, m.flags(b'a'))
self.assertEqual(b'a\0' + HASH_1 + want + b'\n', m.text())
m = self.parsemanifest(A_SHORT_MANIFEST)
# first add a file; a file-less flag makes no sense
m[b'a'] = BIN_HASH_1
m.setflag(b'a', want)
self.assertEqual(want, m.flags(b'a'))
self.assertEqual(b'a\0' + HASH_1 + want + b'\n' + A_SHORT_MANIFEST,
m.text())
def testCopy(self):
m = self.parsemanifest(A_SHORT_MANIFEST)
m[b'a'] = BIN_HASH_1
m2 = m.copy()
del m
del m2 # make sure we don't double free() anything
def testCompaction(self):
unhex = binascii.unhexlify
h1, h2 = unhex(HASH_1), unhex(HASH_2)
m = self.parsemanifest(A_SHORT_MANIFEST)
m[b'alpha'] = h1
m[b'beta'] = h2
del m[b'foo']
want = b'alpha\0%s\nbar/baz/qux.py\0%sl\nbeta\0%s\n' % (
HASH_1, HASH_2, HASH_2)
self.assertEqual(want, m.text())
self.assertEqual(3, len(m))
self.assertEqual([b'alpha', b'bar/baz/qux.py', b'beta'], list(m))
self.assertEqual(h1, m[b'alpha'])
self.assertEqual(h2, m[b'bar/baz/qux.py'])
self.assertEqual(h2, m[b'beta'])
self.assertEqual(b'', m.flags(b'alpha'))
self.assertEqual(b'l', m.flags(b'bar/baz/qux.py'))
self.assertEqual(b'', m.flags(b'beta'))
with self.assertRaises(KeyError):
m[b'foo']
def testSetGetNodeSuffix(self):
clean = self.parsemanifest(A_SHORT_MANIFEST)
m = self.parsemanifest(A_SHORT_MANIFEST)
h = m[b'foo']
f = m.flags(b'foo')
want = h + b'a'
# Merge code wants to set 21-byte fake hashes at times
m[b'foo'] = want
self.assertEqual(want, m[b'foo'])
self.assertEqual([(b'bar/baz/qux.py', BIN_HASH_2),
(b'foo', BIN_HASH_1 + b'a')],
list(m.iteritems()))
# Sometimes it even tries a 22-byte fake hash, but we can
# return 21 and it'll work out
m[b'foo'] = want + b'+'
self.assertEqual(want, m[b'foo'])
# make sure the suffix survives a copy
match = matchmod.match(b'', b'', [b're:foo'])
m2 = m.matches(match)
self.assertEqual(want, m2[b'foo'])
self.assertEqual(1, len(m2))
m2 = m.copy()
self.assertEqual(want, m2[b'foo'])
# suffix with iteration
self.assertEqual([(b'bar/baz/qux.py', BIN_HASH_2),
(b'foo', want)],
list(m.iteritems()))
# shows up in diff
self.assertEqual({b'foo': ((want, f), (h, b''))}, m.diff(clean))
self.assertEqual({b'foo': ((h, b''), (want, f))}, clean.diff(m))
def testMatchException(self):
m = self.parsemanifest(A_SHORT_MANIFEST)
match = matchmod.match(b'', b'', [b're:.*'])
def filt(path):
if path == b'foo':
assert False
return True
match.matchfn = filt
with self.assertRaises(AssertionError):
m.matches(match)
def testRemoveItem(self):
m = self.parsemanifest(A_SHORT_MANIFEST)
del m[b'foo']
with self.assertRaises(KeyError):
m[b'foo']
self.assertEqual(1, len(m))
self.assertEqual(1, len(list(m)))
# now restore and make sure everything works right
m[b'foo'] = b'a' * 20
self.assertEqual(2, len(m))
self.assertEqual(2, len(list(m)))
def testManifestDiff(self):
MISSING = (None, b'')
addl = b'z-only-in-left\0' + HASH_1 + b'\n'
addr = b'z-only-in-right\0' + HASH_2 + b'x\n'
left = self.parsemanifest(
A_SHORT_MANIFEST.replace(HASH_1, HASH_3 + b'x') + addl)
right = self.parsemanifest(A_SHORT_MANIFEST + addr)
want = {
b'foo': ((BIN_HASH_3, b'x'),
(BIN_HASH_1, b'')),
b'z-only-in-left': ((BIN_HASH_1, b''), MISSING),
b'z-only-in-right': (MISSING, (BIN_HASH_2, b'x')),
}
self.assertEqual(want, left.diff(right))
want = {
b'bar/baz/qux.py': (MISSING, (BIN_HASH_2, b'l')),
b'foo': (MISSING, (BIN_HASH_3, b'x')),
b'z-only-in-left': (MISSING, (BIN_HASH_1, b'')),
}
self.assertEqual(want, self.parsemanifest(EMTPY_MANIFEST).diff(left))
want = {
b'bar/baz/qux.py': ((BIN_HASH_2, b'l'), MISSING),
b'foo': ((BIN_HASH_3, b'x'), MISSING),
b'z-only-in-left': ((BIN_HASH_1, b''), MISSING),
}
self.assertEqual(want, left.diff(self.parsemanifest(EMTPY_MANIFEST)))
copy = right.copy()
del copy[b'z-only-in-right']
del right[b'foo']
want = {
b'foo': (MISSING, (BIN_HASH_1, b'')),
b'z-only-in-right': ((BIN_HASH_2, b'x'), MISSING),
}
self.assertEqual(want, right.diff(copy))
short = self.parsemanifest(A_SHORT_MANIFEST)
pruned = short.copy()
del pruned[b'foo']
want = {
b'foo': ((BIN_HASH_1, b''), MISSING),
}
self.assertEqual(want, short.diff(pruned))
want = {
b'foo': (MISSING, (BIN_HASH_1, b'')),
}
self.assertEqual(want, pruned.diff(short))
want = {
b'bar/baz/qux.py': None,
b'foo': (MISSING, (BIN_HASH_1, b'')),
}
self.assertEqual(want, pruned.diff(short, clean=True))
def testReversedLines(self):
backwards = b''.join(
l + b'\n' for l in reversed(A_SHORT_MANIFEST.split(b'\n')) if l)
try:
self.parsemanifest(backwards)
self.fail('Should have raised ValueError')
except ValueError as v:
self.assertIn('Manifest lines not in sorted order.', str(v))
def testNoTerminalNewline(self):
try:
self.parsemanifest(A_SHORT_MANIFEST + b'wat')
self.fail('Should have raised ValueError')
except ValueError as v:
self.assertIn('Manifest did not end in a newline.', str(v))
def testNoNewLineAtAll(self):
try:
self.parsemanifest(b'wat')
self.fail('Should have raised ValueError')
except ValueError as v:
self.assertIn('Manifest did not end in a newline.', str(v))
def testHugeManifest(self):
m = self.parsemanifest(A_HUGE_MANIFEST)
self.assertEqual(HUGE_MANIFEST_ENTRIES, len(m))
self.assertEqual(len(m), len(list(m)))
def testMatchesMetadata(self):
'''Tests matches() for a few specific files to make sure that both
the set of files as well as their flags and nodeids are correct in
the resulting manifest.'''
m = self.parsemanifest(A_HUGE_MANIFEST)
match = matchmod.match(b'/', b'',
[b'file1', b'file200', b'file300'], exact=True)
m2 = m.matches(match)
w = (b'file1\0%sx\n'
b'file200\0%sl\n'
b'file300\0%s\n') % (HASH_2, HASH_1, HASH_1)
self.assertEqual(w, m2.text())
def testMatchesNonexistentFile(self):
'''Tests matches() for a small set of specific files, including one
nonexistent file to make sure in only matches against existing files.
'''
m = self.parsemanifest(A_DEEPER_MANIFEST)
match = matchmod.match(b'/', b'',
[b'a/b/c/bar.txt', b'a/b/d/qux.py',
b'readme.txt', b'nonexistent'],
exact=True)
m2 = m.matches(match)
self.assertEqual(
[b'a/b/c/bar.txt', b'a/b/d/qux.py', b'readme.txt'],
m2.keys())
def testMatchesNonexistentDirectory(self):
'''Tests matches() for a relpath match on a directory that doesn't
actually exist.'''
m = self.parsemanifest(A_DEEPER_MANIFEST)
match = matchmod.match(b'/', b'', [b'a/f'], default=b'relpath')
m2 = m.matches(match)
self.assertEqual([], m2.keys())
def testMatchesExactLarge(self):
'''Tests matches() for files matching a large list of exact files.
'''
m = self.parsemanifest(A_HUGE_MANIFEST)
flist = m.keys()[80:300]
match = matchmod.match(b'/', b'', flist, exact=True)
m2 = m.matches(match)
self.assertEqual(flist, m2.keys())
def testMatchesFull(self):
'''Tests matches() for what should be a full match.'''
m = self.parsemanifest(A_DEEPER_MANIFEST)
match = matchmod.match(b'/', b'', [b''])
m2 = m.matches(match)
self.assertEqual(m.keys(), m2.keys())
def testMatchesDirectory(self):
'''Tests matches() on a relpath match on a directory, which should
match against all files within said directory.'''
m = self.parsemanifest(A_DEEPER_MANIFEST)
match = matchmod.match(b'/', b'', [b'a/b'], default=b'relpath')
m2 = m.matches(match)
self.assertEqual([
b'a/b/c/bar.py', b'a/b/c/bar.txt', b'a/b/c/foo.py',
b'a/b/c/foo.txt',
b'a/b/d/baz.py', b'a/b/d/qux.py', b'a/b/d/ten.txt', b'a/b/dog.py',
b'a/b/fish.py'], m2.keys())
def testMatchesExactPath(self):
'''Tests matches() on an exact match on a directory, which should
result in an empty manifest because you can't perform an exact match
against a directory.'''
m = self.parsemanifest(A_DEEPER_MANIFEST)
match = matchmod.match(b'/', b'', [b'a/b'], exact=True)
m2 = m.matches(match)
self.assertEqual([], m2.keys())
def testMatchesCwd(self):
'''Tests matches() on a relpath match with the current directory ('.')
when not in the root directory.'''
m = self.parsemanifest(A_DEEPER_MANIFEST)
match = matchmod.match(b'/', b'a/b', [b'.'], default=b'relpath')
m2 = m.matches(match)
self.assertEqual([
b'a/b/c/bar.py', b'a/b/c/bar.txt', b'a/b/c/foo.py',
b'a/b/c/foo.txt', b'a/b/d/baz.py', b'a/b/d/qux.py',
b'a/b/d/ten.txt', b'a/b/dog.py', b'a/b/fish.py'], m2.keys())
def testMatchesWithPattern(self):
'''Tests matches() for files matching a pattern that reside
deeper than the specified directory.'''
m = self.parsemanifest(A_DEEPER_MANIFEST)
match = matchmod.match(b'/', b'', [b'a/b/*/*.txt'])
m2 = m.matches(match)
self.assertEqual(
[b'a/b/c/bar.txt', b'a/b/c/foo.txt', b'a/b/d/ten.txt'],
m2.keys())
class testmanifestdict(unittest.TestCase, basemanifesttests):
def parsemanifest(self, text):
return manifestmod.manifestdict(text)
class testtreemanifest(unittest.TestCase, basemanifesttests):
def parsemanifest(self, text):
return manifestmod.treemanifest(b'', text)
def testWalkSubtrees(self):
m = self.parsemanifest(A_DEEPER_MANIFEST)
dirs = [s._dir for s in m.walksubtrees()]
self.assertEqual(
sorted([
b'', b'a/', b'a/c/', b'a/d/', b'a/b/', b'a/b/c/', b'a/b/d/']),
sorted(dirs)
)
match = matchmod.match(b'/', b'', [b'path:a/b/'])
dirs = [s._dir for s in m.walksubtrees(matcher=match)]
self.assertEqual(
sorted([b'a/b/', b'a/b/c/', b'a/b/d/']),
sorted(dirs)
)
if __name__ == '__main__':
silenttestrunner.main(__name__)