view tests/test-cbor.py @ 40021:c537144fdbef

wireprotov2: support response caching

One of the things I've learned from managing VCS servers over the
years is that they are hard to scale. It is well known that some
companies have very beefy (read: very expensive) servers to power
their VCS needs. It is also known that specialized servers for
various VCS exist in order to facilitate scaling servers. (Mercurial
is in this boat.)

One of the aspects that make a VCS server hard to scale is the
high CPU load incurred by constant client clone/pull operations.

To alleviate the scaling pain associated with data retrieval
operations, I want to integrate caching into the Mercurial wire
protocol server as robustly as possible such that servers can
aggressively cache responses and defer as much server load as
possible.

This commit represents the initial implementation of a general
caching layer in wire protocol version 2.

We define a new interface and behavior for a wire protocol cacher
in repository.py. (This is probably where a reviewer should look
first to understand what is going on.)

The bulk of the added code is in wireprotov2server.py, where we
define how a command can opt in to being cached and integrate
caching into command dispatching.

From a very high-level:

* A command can declare itself as cacheable by providing a callable
  that can be used to derive a cache key.
* At dispatch time, if a command is cacheable, we attempt to
  construct a cacher and use it for serving the request and/or
  caching the request.
* The dispatch layer handles the bulk of the business logic for
  caching, making cachers mostly "dumb content stores."
* The mechanism for invalidating cached entries (one of the harder
  parts about caching in general) is by varying the cache key when
  state changes. As such, cachers don't need to be concerned with
  cache invalidation.

Initially, we've hooked up support for caching "manifestdata" and
"filedata" commands. These are the simplest to cache, as they should
be immutable over time. Caching of commands related to changeset
data is a bit harder (because cache validation is impacted by
changes to bookmarks, phases, etc). This will be implemented later.
(Strictly speaking, censoring a file should invalidate caches. I've
added an inline TODO to track this edge case.)

To prove it works, this commit implements a test-only extension
providing in-memory caching backed by an lrucachedict. A new test
showing this extension behaving properly is added. FWIW, the
cacher is ~50 lines of code, demonstrating the relative ease with
which a cache can be added to a server.

While the test cacher is not suitable for production workloads, just
for kicks I performed a clone of just the changeset and manifest data
for the mozilla-unified repository. With a fully warmed cache (of just
the manifest data since changeset data is not cached), server-side
CPU usage dropped from ~73s to ~28s. That's pretty significant and
demonstrates the potential that response caching has on server
scalability!

Differential Revision: https://phab.mercurial-scm.org/D4773

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])

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__)