view tests/test-cbor.py @ 40326:fed697fa1734

sqlitestore: file storage backend using SQLite

This commit provides an extension which uses SQLite to store file
data (as opposed to revlogs).

As the inline documentation describes, there are still several
aspects to the extension that are incomplete. But it's a start.
The extension does support basic clone, checkout, and commit
workflows, which makes it suitable for simple use cases.

One notable missing feature is support for "bundlerepos." This is
probably responsible for the most test failures when the extension
is activated as part of the test suite.

All revision data is stored in SQLite. Data is stored as zstd
compressed chunks (default if zstd is available), zlib compressed
chunks (default if zstd is not available), or raw chunks (if
configured or if a compressed delta is not smaller than the raw
delta). This makes things very similar to revlogs.

Unlike revlogs, the extension doesn't yet enforce a limit on delta
chain length. This is an obvious limitation and should be addressed.
This is somewhat mitigated by the use of zstd, which is much faster
than zlib to decompress.

There is a dedicated table for storing deltas. Deltas are stored
by the SHA-1 hash of their uncompressed content. The "fileindex" table
has columns that reference the delta for each revision and the base
delta that delta should be applied against. A recursive SQL query
is used to resolve the delta chain along with the delta data.

By storing deltas by hash, we are able to de-duplicate delta storage!
With revlogs, the same deltas in different revlogs would result in
duplicate storage of that delta. In this scheme, inserting the
duplicate delta is a no-op and delta chains simply reference the
existing delta.

When initially implementing this extension, I did not have
content-indexed deltas and deltas could be duplicated across files
(just like revlogs). When I implemented content-indexed deltas, the
size of the SQLite database for a full clone of mozilla-unified
dropped:

before: 2,554,261,504 bytes
after:  2,488,754,176 bytes

Surprisingly, this is still larger than the bytes size of revlog
files:

revlog files: 2,104,861,230 bytes
du -b:        2,254,381,614

I would have expected storage to be smaller since we're not limiting
delta chain length and since we're using zstd instead of zlib. I
suspect the SQLite indexes and per-column overhead account for the
bulk of the differences. (Keep in mind that revlog uses a 64-byte
packed struct for revision index data and deltas are stored without
padding. Aside from the 12 unused bytes in the 32 byte node field,
revlogs are pretty efficient.) Another source of overhead is file
name storage. With revlogs, file names are stored in the filesystem.
But with SQLite, we need to store file names in the database. This is
roughly equivalent to the size of the fncache file, which for the
mozilla-unified repository is ~34MB.

Since the SQLite database isn't append-only and since delta chains
can reference any delta, this opens some interesting possibilities.
For example, we could store deltas in reverse, such that fulltexts
are stored for newer revisions and deltas are applied to reconstruct
older revisions. This is likely a more optimal storage strategy for
version control, as new data tends to be more frequently accessed
than old data. We would obviously need wire protocol support for
transferring revision data from newest to oldest. And we would
probably need some kind of mechanism for "re-encoding" stores. But
it should be doable.

This extension is very much experimental quality. There are a handful
of features that don't work. It probably isn't suitable for day-to-day
use. But it could be used in limited cases (e.g. read-only checkouts
like in CI). And it is also a good proving ground for alternate
storage backends. As we continue to define interfaces for all things
storage, it will be useful to have a viable alternate storage backend
to see how things shake out in practice.

test-storage.py passes on Python 2 and introduces no new test failures on
Python 3. Having the storage-level unit tests has proved to be insanely
useful when developing this extension. Those tests caught numerous bugs
during development and I'm convinced this style of testing is the way
forward for ensuring alternate storage backends work as intended. Of
course, test coverage isn't close to what it needs to be. But it is
a start. And what coverage we have gives me confidence that basic store
functionality is implemented properly.

Differential Revision: https://phab.mercurial-scm.org/D4928

from __future__ import absolute_import

import unittest

from mercurial.thirdparty import (
    cbor,
)
from mercurial.utils import (
    cborutil,
)

class TestCase(unittest.TestCase):
    if not getattr(unittest.TestCase, 'assertRaisesRegex', False):
        # Python 3.7 deprecates the regex*p* version, but 2.7 lacks
        # the regex version.
        assertRaisesRegex = (# camelcase-required
            unittest.TestCase.assertRaisesRegexp)

def loadit(it):
    return cbor.loads(b''.join(it))

class BytestringTests(TestCase):
    def testsimple(self):
        self.assertEqual(
            list(cborutil.streamencode(b'foobar')),
            [b'\x46', b'foobar'])

        self.assertEqual(
            loadit(cborutil.streamencode(b'foobar')),
            b'foobar')

        self.assertEqual(cborutil.decodeall(b'\x46foobar'),
                         [b'foobar'])

        self.assertEqual(cborutil.decodeall(b'\x46foobar\x45fizbi'),
                         [b'foobar', b'fizbi'])

    def testlong(self):
        source = b'x' * 1048576

        self.assertEqual(loadit(cborutil.streamencode(source)), source)

        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeall(encoded), [source])

    def testfromiter(self):
        # This is the example from RFC 7049 Section 2.2.2.
        source = [b'\xaa\xbb\xcc\xdd', b'\xee\xff\x99']

        self.assertEqual(
            list(cborutil.streamencodebytestringfromiter(source)),
            [
                b'\x5f',
                b'\x44',
                b'\xaa\xbb\xcc\xdd',
                b'\x43',
                b'\xee\xff\x99',
                b'\xff',
            ])

        self.assertEqual(
            loadit(cborutil.streamencodebytestringfromiter(source)),
            b''.join(source))

        self.assertEqual(cborutil.decodeall(b'\x5f\x44\xaa\xbb\xcc\xdd'
                                            b'\x43\xee\xff\x99\xff'),
                         [b'\xaa\xbb\xcc\xdd', b'\xee\xff\x99', b''])

        for i, chunk in enumerate(
            cborutil.decodeall(b'\x5f\x44\xaa\xbb\xcc\xdd'
                               b'\x43\xee\xff\x99\xff')):
            self.assertIsInstance(chunk, cborutil.bytestringchunk)

            if i == 0:
                self.assertTrue(chunk.isfirst)
            else:
                self.assertFalse(chunk.isfirst)

            if i == 2:
                self.assertTrue(chunk.islast)
            else:
                self.assertFalse(chunk.islast)

    def testfromiterlarge(self):
        source = [b'a' * 16, b'b' * 128, b'c' * 1024, b'd' * 1048576]

        self.assertEqual(
            loadit(cborutil.streamencodebytestringfromiter(source)),
            b''.join(source))

    def testindefinite(self):
        source = b'\x00\x01\x02\x03' + b'\xff' * 16384

        it = cborutil.streamencodeindefinitebytestring(source, chunksize=2)

        self.assertEqual(next(it), b'\x5f')
        self.assertEqual(next(it), b'\x42')
        self.assertEqual(next(it), b'\x00\x01')
        self.assertEqual(next(it), b'\x42')
        self.assertEqual(next(it), b'\x02\x03')
        self.assertEqual(next(it), b'\x42')
        self.assertEqual(next(it), b'\xff\xff')

        dest = b''.join(cborutil.streamencodeindefinitebytestring(
            source, chunksize=42))
        self.assertEqual(cbor.loads(dest), source)

        self.assertEqual(b''.join(cborutil.decodeall(dest)), source)

        for chunk in cborutil.decodeall(dest):
            self.assertIsInstance(chunk, cborutil.bytestringchunk)
            self.assertIn(len(chunk), (0, 8, 42))

        encoded = b'\x5f\xff'
        b = cborutil.decodeall(encoded)
        self.assertEqual(b, [b''])
        self.assertTrue(b[0].isfirst)
        self.assertTrue(b[0].islast)

    def testdecodevariouslengths(self):
        for i in (0, 1, 22, 23, 24, 25, 254, 255, 256, 65534, 65535, 65536):
            source = b'x' * i
            encoded = b''.join(cborutil.streamencode(source))

            if len(source) < 24:
                hlen = 1
            elif len(source) < 256:
                hlen = 2
            elif len(source) < 65536:
                hlen = 3
            elif len(source) < 1048576:
                hlen = 5

            self.assertEqual(cborutil.decodeitem(encoded),
                             (True, source, hlen + len(source),
                              cborutil.SPECIAL_NONE))

    def testpartialdecode(self):
        encoded = b''.join(cborutil.streamencode(b'foobar'))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -6, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -5, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -4, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (False, None, -3, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:6]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:7]),
                         (True, b'foobar', 7, cborutil.SPECIAL_NONE))

    def testpartialdecodevariouslengths(self):
        lens = [
            2,
            3,
            10,
            23,
            24,
            25,
            31,
            100,
            254,
            255,
            256,
            257,
            16384,
            65534,
            65535,
            65536,
            65537,
            131071,
            131072,
            131073,
            1048575,
            1048576,
            1048577,
        ]

        for size in lens:
            if size < 24:
                hlen = 1
            elif size < 2**8:
                hlen = 2
            elif size < 2**16:
                hlen = 3
            elif size < 2**32:
                hlen = 5
            else:
                assert False

            source = b'x' * size
            encoded = b''.join(cborutil.streamencode(source))

            res = cborutil.decodeitem(encoded[0:1])

            if hlen > 1:
                self.assertEqual(res, (False, None, -(hlen - 1),
                                       cborutil.SPECIAL_NONE))
            else:
                self.assertEqual(res, (False, None, -(size + hlen - 1),
                                       cborutil.SPECIAL_NONE))

            # Decoding partial header reports remaining header size.
            for i in range(hlen - 1):
                self.assertEqual(cborutil.decodeitem(encoded[0:i + 1]),
                                 (False, None, -(hlen - i - 1),
                                  cborutil.SPECIAL_NONE))

            # Decoding complete header reports item size.
            self.assertEqual(cborutil.decodeitem(encoded[0:hlen]),
                             (False, None, -size, cborutil.SPECIAL_NONE))

            # Decoding single byte after header reports item size - 1
            self.assertEqual(cborutil.decodeitem(encoded[0:hlen + 1]),
                             (False, None, -(size - 1), cborutil.SPECIAL_NONE))

            # Decoding all but the last byte reports -1 needed.
            self.assertEqual(cborutil.decodeitem(encoded[0:hlen + size - 1]),
                             (False, None, -1, cborutil.SPECIAL_NONE))

            # Decoding last byte retrieves value.
            self.assertEqual(cborutil.decodeitem(encoded[0:hlen + size]),
                             (True, source, hlen + size, cborutil.SPECIAL_NONE))

    def testindefinitepartialdecode(self):
        encoded = b''.join(cborutil.streamencodebytestringfromiter(
            [b'foobar', b'biz']))

        # First item should be begin of bytestring special.
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (True, None, 1,
                          cborutil.SPECIAL_START_INDEFINITE_BYTESTRING))

        # Second item should be the first chunk. But only available when
        # we give it 7 bytes (1 byte header + 6 byte chunk).
        self.assertEqual(cborutil.decodeitem(encoded[1:2]),
                         (False, None, -6, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[1:3]),
                         (False, None, -5, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[1:4]),
                         (False, None, -4, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[1:5]),
                         (False, None, -3, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[1:6]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[1:7]),
                         (False, None, -1, cborutil.SPECIAL_NONE))

        self.assertEqual(cborutil.decodeitem(encoded[1:8]),
                         (True, b'foobar', 7, cborutil.SPECIAL_NONE))

        # Third item should be second chunk. But only available when
        # we give it 4 bytes (1 byte header + 3 byte chunk).
        self.assertEqual(cborutil.decodeitem(encoded[8:9]),
                         (False, None, -3, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[8:10]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[8:11]),
                         (False, None, -1, cborutil.SPECIAL_NONE))

        self.assertEqual(cborutil.decodeitem(encoded[8:12]),
                         (True, b'biz', 4, cborutil.SPECIAL_NONE))

        # Fourth item should be end of indefinite stream marker.
        self.assertEqual(cborutil.decodeitem(encoded[12:13]),
                         (True, None, 1, cborutil.SPECIAL_INDEFINITE_BREAK))

        # Now test the behavior when going through the decoder.

        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:1]),
                         (False, 1, 0))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:2]),
                         (False, 1, 6))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:3]),
                         (False, 1, 5))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:4]),
                         (False, 1, 4))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:5]),
                         (False, 1, 3))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:6]),
                         (False, 1, 2))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:7]),
                         (False, 1, 1))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:8]),
                         (True, 8, 0))

        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:9]),
                         (True, 8, 3))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:10]),
                         (True, 8, 2))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:11]),
                         (True, 8, 1))
        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:12]),
                         (True, 12, 0))

        self.assertEqual(cborutil.sansiodecoder().decode(encoded[0:13]),
                         (True, 13, 0))

        decoder = cborutil.sansiodecoder()
        decoder.decode(encoded[0:8])
        values = decoder.getavailable()
        self.assertEqual(values, [b'foobar'])
        self.assertTrue(values[0].isfirst)
        self.assertFalse(values[0].islast)

        self.assertEqual(decoder.decode(encoded[8:12]),
                         (True, 4, 0))
        values = decoder.getavailable()
        self.assertEqual(values, [b'biz'])
        self.assertFalse(values[0].isfirst)
        self.assertFalse(values[0].islast)

        self.assertEqual(decoder.decode(encoded[12:]),
                         (True, 1, 0))
        values = decoder.getavailable()
        self.assertEqual(values, [b''])
        self.assertFalse(values[0].isfirst)
        self.assertTrue(values[0].islast)

class StringTests(TestCase):
    def testdecodeforbidden(self):
        encoded = b'\x63foo'
        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'string major type not supported'):
            cborutil.decodeall(encoded)

class IntTests(TestCase):
    def testsmall(self):
        self.assertEqual(list(cborutil.streamencode(0)), [b'\x00'])
        self.assertEqual(cborutil.decodeall(b'\x00'), [0])

        self.assertEqual(list(cborutil.streamencode(1)), [b'\x01'])
        self.assertEqual(cborutil.decodeall(b'\x01'), [1])

        self.assertEqual(list(cborutil.streamencode(2)), [b'\x02'])
        self.assertEqual(cborutil.decodeall(b'\x02'), [2])

        self.assertEqual(list(cborutil.streamencode(3)), [b'\x03'])
        self.assertEqual(cborutil.decodeall(b'\x03'), [3])

        self.assertEqual(list(cborutil.streamencode(4)), [b'\x04'])
        self.assertEqual(cborutil.decodeall(b'\x04'), [4])

        # Multiple value decode works.
        self.assertEqual(cborutil.decodeall(b'\x00\x01\x02\x03\x04'),
                         [0, 1, 2, 3, 4])

    def testnegativesmall(self):
        self.assertEqual(list(cborutil.streamencode(-1)), [b'\x20'])
        self.assertEqual(cborutil.decodeall(b'\x20'), [-1])

        self.assertEqual(list(cborutil.streamencode(-2)), [b'\x21'])
        self.assertEqual(cborutil.decodeall(b'\x21'), [-2])

        self.assertEqual(list(cborutil.streamencode(-3)), [b'\x22'])
        self.assertEqual(cborutil.decodeall(b'\x22'), [-3])

        self.assertEqual(list(cborutil.streamencode(-4)), [b'\x23'])
        self.assertEqual(cborutil.decodeall(b'\x23'), [-4])

        self.assertEqual(list(cborutil.streamencode(-5)), [b'\x24'])
        self.assertEqual(cborutil.decodeall(b'\x24'), [-5])

        # Multiple value decode works.
        self.assertEqual(cborutil.decodeall(b'\x20\x21\x22\x23\x24'),
                         [-1, -2, -3, -4, -5])

    def testrange(self):
        for i in range(-70000, 70000, 10):
            encoded = b''.join(cborutil.streamencode(i))

            self.assertEqual(encoded, cbor.dumps(i))
            self.assertEqual(cborutil.decodeall(encoded), [i])

    def testdecodepartialubyte(self):
        encoded = b''.join(cborutil.streamencode(250))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (True, 250, 2, cborutil.SPECIAL_NONE))

    def testdecodepartialbyte(self):
        encoded = b''.join(cborutil.streamencode(-42))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (True, -42, 2, cborutil.SPECIAL_NONE))

    def testdecodepartialushort(self):
        encoded = b''.join(cborutil.streamencode(2**15))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (True, 2**15, 3, cborutil.SPECIAL_NONE))

    def testdecodepartialshort(self):
        encoded = b''.join(cborutil.streamencode(-1024))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (True, -1024, 3, cborutil.SPECIAL_NONE))

    def testdecodepartialulong(self):
        encoded = b''.join(cborutil.streamencode(2**28))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -4, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -3, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (True, 2**28, 5, cborutil.SPECIAL_NONE))

    def testdecodepartiallong(self):
        encoded = b''.join(cborutil.streamencode(-1048580))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -4, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -3, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (True, -1048580, 5, cborutil.SPECIAL_NONE))

    def testdecodepartialulonglong(self):
        encoded = b''.join(cborutil.streamencode(2**32))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -8, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -7, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -6, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (False, None, -5, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (False, None, -4, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:6]),
                         (False, None, -3, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:7]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:8]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:9]),
                         (True, 2**32, 9, cborutil.SPECIAL_NONE))

        with self.assertRaisesRegex(
            cborutil.CBORDecodeError, 'input data not fully consumed'):
            cborutil.decodeall(encoded[0:1])

        with self.assertRaisesRegex(
            cborutil.CBORDecodeError, 'input data not fully consumed'):
            cborutil.decodeall(encoded[0:2])

    def testdecodepartiallonglong(self):
        encoded = b''.join(cborutil.streamencode(-7000000000))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -8, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -7, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -6, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (False, None, -5, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (False, None, -4, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:6]),
                         (False, None, -3, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:7]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:8]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:9]),
                         (True, -7000000000, 9, cborutil.SPECIAL_NONE))

class ArrayTests(TestCase):
    def testempty(self):
        self.assertEqual(list(cborutil.streamencode([])), [b'\x80'])
        self.assertEqual(loadit(cborutil.streamencode([])), [])

        self.assertEqual(cborutil.decodeall(b'\x80'), [[]])

    def testbasic(self):
        source = [b'foo', b'bar', 1, -10]

        chunks = [
            b'\x84', b'\x43', b'foo', b'\x43', b'bar', b'\x01', b'\x29']

        self.assertEqual(list(cborutil.streamencode(source)), chunks)

        self.assertEqual(cborutil.decodeall(b''.join(chunks)), [source])

    def testemptyfromiter(self):
        self.assertEqual(b''.join(cborutil.streamencodearrayfromiter([])),
                         b'\x9f\xff')

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'indefinite length uint not allowed'):
            cborutil.decodeall(b'\x9f\xff')

    def testfromiter1(self):
        source = [b'foo']

        self.assertEqual(list(cborutil.streamencodearrayfromiter(source)), [
            b'\x9f',
            b'\x43', b'foo',
            b'\xff',
        ])

        dest = b''.join(cborutil.streamencodearrayfromiter(source))
        self.assertEqual(cbor.loads(dest), source)

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'indefinite length uint not allowed'):
            cborutil.decodeall(dest)

    def testtuple(self):
        source = (b'foo', None, 42)
        encoded = b''.join(cborutil.streamencode(source))

        self.assertEqual(cbor.loads(encoded), list(source))

        self.assertEqual(cborutil.decodeall(encoded), [list(source)])

    def testpartialdecode(self):
        source = list(range(4))
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (True, 4, 1, cborutil.SPECIAL_START_ARRAY))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (True, 4, 1, cborutil.SPECIAL_START_ARRAY))

        source = list(range(23))
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (True, 23, 1, cborutil.SPECIAL_START_ARRAY))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (True, 23, 1, cborutil.SPECIAL_START_ARRAY))

        source = list(range(24))
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (True, 24, 2, cborutil.SPECIAL_START_ARRAY))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (True, 24, 2, cborutil.SPECIAL_START_ARRAY))

        source = list(range(256))
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (True, 256, 3, cborutil.SPECIAL_START_ARRAY))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (True, 256, 3, cborutil.SPECIAL_START_ARRAY))

    def testnested(self):
        source = [[], [], [[], [], []]]
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeall(encoded), [source])

        source = [True, None, [True, 0, 2], [None], [], [[[]], -87]]
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeall(encoded), [source])

        # A set within an array.
        source = [None, {b'foo', b'bar', None, False}, set()]
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeall(encoded), [source])

        # A map within an array.
        source = [None, {}, {b'foo': b'bar', True: False}, [{}]]
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeall(encoded), [source])

    def testindefinitebytestringvalues(self):
        # Single value array whose value is an empty indefinite bytestring.
        encoded = b'\x81\x5f\x40\xff'

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'indefinite length bytestrings not '
                                    'allowed as array values'):
            cborutil.decodeall(encoded)

class SetTests(TestCase):
    def testempty(self):
        self.assertEqual(list(cborutil.streamencode(set())), [
            b'\xd9\x01\x02',
            b'\x80',
        ])

        self.assertEqual(cborutil.decodeall(b'\xd9\x01\x02\x80'), [set()])

    def testset(self):
        source = {b'foo', None, 42}
        encoded = b''.join(cborutil.streamencode(source))

        self.assertEqual(cbor.loads(encoded), source)

        self.assertEqual(cborutil.decodeall(encoded), [source])

    def testinvalidtag(self):
        # Must use array to encode sets.
        encoded = b'\xd9\x01\x02\xa0'

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'expected array after finite set '
                                    'semantic tag'):
            cborutil.decodeall(encoded)

    def testpartialdecode(self):
        # Semantic tag item will be 3 bytes. Set header will be variable
        # depending on length.
        encoded = b''.join(cborutil.streamencode({i for i in range(23)}))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (True, 23, 4, cborutil.SPECIAL_START_SET))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (True, 23, 4, cborutil.SPECIAL_START_SET))

        encoded = b''.join(cborutil.streamencode({i for i in range(24)}))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (True, 24, 5, cborutil.SPECIAL_START_SET))
        self.assertEqual(cborutil.decodeitem(encoded[0:6]),
                         (True, 24, 5, cborutil.SPECIAL_START_SET))

        encoded = b''.join(cborutil.streamencode({i for i in range(256)}))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:6]),
                         (True, 256, 6, cborutil.SPECIAL_START_SET))

    def testinvalidvalue(self):
        encoded = b''.join([
            b'\xd9\x01\x02', # semantic tag
            b'\x81', # array of size 1
            b'\x5f\x43foo\xff', # indefinite length bytestring "foo"
        ])

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'indefinite length bytestrings not '
                                    'allowed as set values'):
            cborutil.decodeall(encoded)

        encoded = b''.join([
            b'\xd9\x01\x02',
            b'\x81',
            b'\x80', # empty array
        ])

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'collections not allowed as set values'):
            cborutil.decodeall(encoded)

        encoded = b''.join([
            b'\xd9\x01\x02',
            b'\x81',
            b'\xa0', # empty map
        ])

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'collections not allowed as set values'):
            cborutil.decodeall(encoded)

        encoded = b''.join([
            b'\xd9\x01\x02',
            b'\x81',
            b'\xd9\x01\x02\x81\x01', # set with integer 1
        ])

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'collections not allowed as set values'):
            cborutil.decodeall(encoded)

class BoolTests(TestCase):
    def testbasic(self):
        self.assertEqual(list(cborutil.streamencode(True)),  [b'\xf5'])
        self.assertEqual(list(cborutil.streamencode(False)), [b'\xf4'])

        self.assertIs(loadit(cborutil.streamencode(True)), True)
        self.assertIs(loadit(cborutil.streamencode(False)), False)

        self.assertEqual(cborutil.decodeall(b'\xf4'), [False])
        self.assertEqual(cborutil.decodeall(b'\xf5'), [True])

        self.assertEqual(cborutil.decodeall(b'\xf4\xf5\xf5\xf4'),
                         [False, True, True, False])

class NoneTests(TestCase):
    def testbasic(self):
        self.assertEqual(list(cborutil.streamencode(None)), [b'\xf6'])

        self.assertIs(loadit(cborutil.streamencode(None)), None)

        self.assertEqual(cborutil.decodeall(b'\xf6'), [None])
        self.assertEqual(cborutil.decodeall(b'\xf6\xf6'), [None, None])

class MapTests(TestCase):
    def testempty(self):
        self.assertEqual(list(cborutil.streamencode({})), [b'\xa0'])
        self.assertEqual(loadit(cborutil.streamencode({})), {})

        self.assertEqual(cborutil.decodeall(b'\xa0'), [{}])

    def testemptyindefinite(self):
        self.assertEqual(list(cborutil.streamencodemapfromiter([])), [
            b'\xbf', b'\xff'])

        self.assertEqual(loadit(cborutil.streamencodemapfromiter([])), {})

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'indefinite length uint not allowed'):
            cborutil.decodeall(b'\xbf\xff')

    def testone(self):
        source = {b'foo': b'bar'}
        self.assertEqual(list(cborutil.streamencode(source)), [
            b'\xa1', b'\x43', b'foo', b'\x43', b'bar'])

        self.assertEqual(loadit(cborutil.streamencode(source)), source)

        self.assertEqual(cborutil.decodeall(b'\xa1\x43foo\x43bar'), [source])

    def testmultiple(self):
        source = {
            b'foo': b'bar',
            b'baz': b'value1',
        }

        self.assertEqual(loadit(cborutil.streamencode(source)), source)

        self.assertEqual(
            loadit(cborutil.streamencodemapfromiter(source.items())),
            source)

        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeall(encoded), [source])

    def testcomplex(self):
        source = {
            b'key': 1,
            2: -10,
        }

        self.assertEqual(loadit(cborutil.streamencode(source)),
                         source)

        self.assertEqual(
            loadit(cborutil.streamencodemapfromiter(source.items())),
            source)

        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeall(encoded), [source])

    def testnested(self):
        source = {b'key1': None, b'key2': {b'sub1': b'sub2'}, b'sub2': {}}
        encoded = b''.join(cborutil.streamencode(source))

        self.assertEqual(cborutil.decodeall(encoded), [source])

        source = {
            b'key1': [],
            b'key2': [None, False],
            b'key3': {b'foo', b'bar'},
            b'key4': {},
        }
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeall(encoded), [source])

    def testillegalkey(self):
        encoded = b''.join([
            # map header + len 1
            b'\xa1',
            # indefinite length bytestring "foo" in key position
            b'\x5f\x03foo\xff'
        ])

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'indefinite length bytestrings not '
                                    'allowed as map keys'):
            cborutil.decodeall(encoded)

        encoded = b''.join([
            b'\xa1',
            b'\x80', # empty array
            b'\x43foo',
        ])

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'collections not supported as map keys'):
            cborutil.decodeall(encoded)

    def testillegalvalue(self):
        encoded = b''.join([
            b'\xa1', # map headers
            b'\x43foo', # key
            b'\x5f\x03bar\xff', # indefinite length value
        ])

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'indefinite length bytestrings not '
                                    'allowed as map values'):
            cborutil.decodeall(encoded)

    def testpartialdecode(self):
        source = {b'key1': b'value1'}
        encoded = b''.join(cborutil.streamencode(source))

        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (True, 1, 1, cborutil.SPECIAL_START_MAP))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (True, 1, 1, cborutil.SPECIAL_START_MAP))

        source = {b'key%d' % i: None for i in range(23)}
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (True, 23, 1, cborutil.SPECIAL_START_MAP))

        source = {b'key%d' % i: None for i in range(24)}
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (True, 24, 2, cborutil.SPECIAL_START_MAP))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (True, 24, 2, cborutil.SPECIAL_START_MAP))

        source = {b'key%d' % i: None for i in range(256)}
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (True, 256, 3, cborutil.SPECIAL_START_MAP))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (True, 256, 3, cborutil.SPECIAL_START_MAP))

        source = {b'key%d' % i: None for i in range(65536)}
        encoded = b''.join(cborutil.streamencode(source))
        self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                         (False, None, -4, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                         (False, None, -3, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:3]),
                         (False, None, -2, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:4]),
                         (False, None, -1, cborutil.SPECIAL_NONE))
        self.assertEqual(cborutil.decodeitem(encoded[0:5]),
                         (True, 65536, 5, cborutil.SPECIAL_START_MAP))
        self.assertEqual(cborutil.decodeitem(encoded[0:6]),
                         (True, 65536, 5, cborutil.SPECIAL_START_MAP))

class SemanticTagTests(TestCase):
    def testdecodeforbidden(self):
        for i in range(500):
            if i == cborutil.SEMANTIC_TAG_FINITE_SET:
                continue

            tag = cborutil.encodelength(cborutil.MAJOR_TYPE_SEMANTIC,
                                        i)

            encoded = tag + cborutil.encodelength(cborutil.MAJOR_TYPE_UINT, 42)

            # Partial decode is incomplete.
            if i < 24:
                pass
            elif i < 256:
                self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                                 (False, None, -1, cborutil.SPECIAL_NONE))
            elif i < 65536:
                self.assertEqual(cborutil.decodeitem(encoded[0:1]),
                                 (False, None, -2, cborutil.SPECIAL_NONE))
                self.assertEqual(cborutil.decodeitem(encoded[0:2]),
                                 (False, None, -1, cborutil.SPECIAL_NONE))

            with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                        'semantic tag \d+ not allowed'):
                cborutil.decodeitem(encoded)

class SpecialTypesTests(TestCase):
    def testforbiddentypes(self):
        for i in range(256):
            if i == cborutil.SUBTYPE_FALSE:
                continue
            elif i == cborutil.SUBTYPE_TRUE:
                continue
            elif i == cborutil.SUBTYPE_NULL:
                continue

            encoded = cborutil.encodelength(cborutil.MAJOR_TYPE_SPECIAL, i)

            with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                        'special type \d+ not allowed'):
                cborutil.decodeitem(encoded)

class SansIODecoderTests(TestCase):
    def testemptyinput(self):
        decoder = cborutil.sansiodecoder()
        self.assertEqual(decoder.decode(b''), (False, 0, 0))

class BufferingDecoderTests(TestCase):
    def testsimple(self):
        source = [
            b'foobar',
            b'x' * 128,
            {b'foo': b'bar'},
            True,
            False,
            None,
            [None for i in range(128)],
        ]

        encoded = b''.join(cborutil.streamencode(source))

        for step in range(1, 32):
            decoder = cborutil.bufferingdecoder()
            start = 0

            while start < len(encoded):
                decoder.decode(encoded[start:start + step])
                start += step

            self.assertEqual(decoder.getavailable(), [source])

    def testbytearray(self):
        source = b''.join(cborutil.streamencode(b'foobar'))

        decoder = cborutil.bufferingdecoder()
        decoder.decode(bytearray(source))

        self.assertEqual(decoder.getavailable(), [b'foobar'])

class DecodeallTests(TestCase):
    def testemptyinput(self):
        self.assertEqual(cborutil.decodeall(b''), [])

    def testpartialinput(self):
        encoded = b''.join([
            b'\x82', # array of 2 elements
            b'\x01', # integer 1
        ])

        with self.assertRaisesRegex(cborutil.CBORDecodeError,
                                    'input data not complete'):
            cborutil.decodeall(encoded)

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