view tests/test-parseindex2.py @ 40009:842ffcf1d42f

storageutil: extract most of emitrevisions() to standalone function

As part of implementing a storage backend, I found myself copying
most of revlog.emitrevisions(). This code is highly nuanced and it
bothered me greatly to be copying such low-level code.

This commit extracts the bulk of revlog.emitrevisions() into a
new standalone function. In order to make the function generally
usable, all "self" function calls that aren't exposed on the
ifilestorage interface are passed in via callable arguments.

No meaningful behavior should have changed as part of the port.

Upcoming commits will tweak behavior to make the code more
generically usable.

Differential Revision: https://phab.mercurial-scm.org/D4803

"""This unit test primarily tests parsers.parse_index2().

It also checks certain aspects of the parsers module as a whole.
"""

from __future__ import absolute_import, print_function

import struct
import subprocess
import sys
import unittest

from mercurial.node import (
    nullid,
    nullrev,
)
from mercurial import (
    node as nodemod,
    policy,
    pycompat,
)

parsers = policy.importmod(r'parsers')

# original python implementation
def gettype(q):
    return int(q & 0xFFFF)

def offset_type(offset, type):
    return int(int(offset) << 16 | type)

indexformatng = ">Qiiiiii20s12x"

def py_parseindex(data, inline) :
    s = 64
    cache = None
    index = []
    nodemap = {nullid: nullrev}
    n = off = 0

    l = len(data) - s
    append = index.append
    if inline:
        cache = (0, data)
        while off <= l:
            e = struct.unpack(indexformatng, data[off:off + s])
            nodemap[e[7]] = n
            append(e)
            n += 1
            if e[1] < 0:
                break
            off += e[1] + s
    else:
        while off <= l:
            e = struct.unpack(indexformatng, data[off:off + s])
            nodemap[e[7]] = n
            append(e)
            n += 1
            off += s

    e = list(index[0])
    type = gettype(e[0])
    e[0] = offset_type(0, type)
    index[0] = tuple(e)

    return index, cache

data_inlined = (
    b'\x00\x01\x00\x01\x00\x00\x00\x00\x00\x00\x01\x8c'
    b'\x00\x00\x04\x07\x00\x00\x00\x00\x00\x00\x15\x15\xff\xff\xff'
    b'\xff\xff\xff\xff\xff\xebG\x97\xb7\x1fB\x04\xcf\x13V\x81\tw\x1b'
    b'w\xdduR\xda\xc6\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
    b'x\x9c\x9d\x93?O\xc30\x10\xc5\xf7|\x8a\xdb\x9a\xa8m\x06\xd8*\x95'
    b'\x81B\xa1\xa2\xa2R\xcb\x86Pd\x9a\x0b5$vd_\x04\xfd\xf6\x9c\xff@'
    b'\x11!\x0b\xd9\xec\xf7\xbbw\xe7gG6\xad6\x04\xdaN\xc0\x92\xa0$)'
    b'\xb1\x82\xa2\xd1%\x16\xa4\x8b7\xa9\xca\xd4-\xb2Y\x02\xfc\xc9'
    b'\xcaS\xf9\xaeX\xed\xb6\xd77Q\x02\x83\xd4\x19\xf5--Y\xea\xe1W'
    b'\xab\xed\x10\xceR\x0f_\xdf\xdf\r\xe1,\xf5\xf0\xcb\xf5 \xceR\x0f'
    b'_\xdc\x0e\x0e\xc3R\x0f_\xae\x96\x9b!\x9e\xa5\x1e\xbf\xdb,\x06'
    b'\xc7q\x9a/\x88\x82\xc3B\xea\xb5\xb4TJ\x93\xb6\x82\x0e\xe16\xe6'
    b'KQ\xdb\xaf\xecG\xa3\xd1 \x01\xd3\x0b_^\xe8\xaa\xa0\xae\xad\xd1'
    b'&\xbef\x1bz\x08\xb0|\xc9Xz\x06\xf6Z\x91\x90J\xaa\x17\x90\xaa'
    b'\xd2\xa6\x11$5C\xcf\xba#\xa0\x03\x02*2\x92-\xfc\xb1\x94\xdf\xe2'
    b'\xae\xb8\'m\x8ey0^\x85\xd3\x82\xb4\xf0`:\x9c\x00\x8a\xfd\x01'
    b'\xb0\xc6\x86\x8b\xdd\xae\x80\xf3\xa9\x9fd\x16\n\x00R%\x1a\x06'
    b'\xe9\xd8b\x98\x1d\xf4\xf3+\x9bf\x01\xd8p\x1b\xf3.\xed\x9f^g\xc3'
    b'^\xd9W81T\xdb\xd5\x04sx|\xf2\xeb\xd6`%?x\xed"\x831\xbf\xf3\xdc'
    b'b\xeb%gaY\xe1\xad\x9f\xb9f\'1w\xa9\xa5a\x83s\x82J\xb98\xbc4\x8b'
    b'\x83\x00\x9f$z\xb8#\xa5\xb1\xdf\x98\xd9\xec\x1b\x89O\xe3Ts\x9a4'
    b'\x17m\x8b\xfc\x8f\xa5\x95\x9a\xfc\xfa\xed,\xe5|\xa1\xfe\x15\xb9'
    b'\xbc\xb2\x93\x1f\xf2\x95\xff\xdf,\x1a\xc5\xe7\x17*\x93Oz:>\x0e'
    )

data_non_inlined = (
    b'\x00\x00\x00\x01\x00\x00\x00\x00\x00\x01D\x19'
    b'\x00\x07e\x12\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff'
    b'\xff\xff\xff\xff\xd1\xf4\xbb\xb0\xbe\xfc\x13\xbd\x8c\xd3\x9d'
    b'\x0f\xcd\xd9;\x8c\x07\x8cJ/\x00\x00\x00\x00\x00\x00\x00\x00\x00'
    b'\x00\x00\x00\x00\x00\x00\x01D\x19\x00\x00\x00\x00\x00\xdf\x00'
    b'\x00\x01q\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x00\xff'
    b'\xff\xff\xff\xc1\x12\xb9\x04\x96\xa4Z1t\x91\xdfsJ\x90\xf0\x9bh'
    b'\x07l&\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
    b'\x00\x01D\xf8\x00\x00\x00\x00\x01\x1b\x00\x00\x01\xb8\x00\x00'
    b'\x00\x01\x00\x00\x00\x02\x00\x00\x00\x01\xff\xff\xff\xff\x02\n'
    b'\x0e\xc6&\xa1\x92\xae6\x0b\x02i\xfe-\xe5\xbao\x05\xd1\xe7\x00'
    b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01F'
    b'\x13\x00\x00\x00\x00\x01\xec\x00\x00\x03\x06\x00\x00\x00\x01'
    b'\x00\x00\x00\x03\x00\x00\x00\x02\xff\xff\xff\xff\x12\xcb\xeby1'
    b'\xb6\r\x98B\xcb\x07\xbd`\x8f\x92\xd9\xc4\x84\xbdK\x00\x00\x00'
    b'\x00\x00\x00\x00\x00\x00\x00\x00\x00'
    )

def parse_index2(data, inline):
    index, chunkcache = parsers.parse_index2(data, inline)
    return list(index), chunkcache

def importparsers(hexversion):
    """Import mercurial.parsers with the given sys.hexversion."""
    # The file parsers.c inspects sys.hexversion to determine the version
    # of the currently-running Python interpreter, so we monkey-patch
    # sys.hexversion to simulate using different versions.
    code = ("import sys; sys.hexversion=%s; "
            "import mercurial.cext.parsers" % hexversion)
    cmd = "python -c \"%s\"" % code
    # We need to do these tests inside a subprocess because parser.c's
    # version-checking code happens inside the module init function, and
    # when using reload() to reimport an extension module, "The init function
    # of extension modules is not called a second time"
    # (from http://docs.python.org/2/library/functions.html?#reload).
    p = subprocess.Popen(cmd, shell=True,
                         stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    return p.communicate()  # returns stdout, stderr

def hexfailmsg(testnumber, hexversion, stdout, expected):
    try:
        hexstring = hex(hexversion)
    except TypeError:
        hexstring = None
    return ("FAILED: version test #%s with Python %s and patched "
            "sys.hexversion %r (%r):\n Expected %s but got:\n-->'%s'\n" %
            (testnumber, sys.version_info, hexversion, hexstring, expected,
             stdout))

def makehex(major, minor, micro):
    return int("%x%02x%02x00" % (major, minor, micro), 16)

class parseindex2tests(unittest.TestCase):

    def assertversionokay(self, testnumber, hexversion):
        stdout, stderr = importparsers(hexversion)
        self.assertFalse(
            stdout, hexfailmsg(testnumber, hexversion, stdout, 'no stdout'))

    def assertversionfail(self, testnumber, hexversion):
        stdout, stderr = importparsers(hexversion)
        # We include versionerrortext to distinguish from other ImportErrors.
        errtext = b"ImportError: %s" % pycompat.sysbytes(
            parsers.versionerrortext)
        self.assertIn(errtext, stdout,
                      hexfailmsg(testnumber, hexversion, stdout,
                                 expected="stdout to contain %r" % errtext))

    def testversiondetection(self):
        """Check the version-detection logic when importing parsers."""
        # Only test the version-detection logic if it is present.
        try:
            parsers.versionerrortext
        except AttributeError:
            return
        info = sys.version_info
        major, minor, micro = info[0], info[1], info[2]
        # Test same major-minor versions.
        self.assertversionokay(1, makehex(major, minor, micro))
        self.assertversionokay(2, makehex(major, minor, micro + 1))
        # Test different major-minor versions.
        self.assertversionfail(3, makehex(major + 1, minor, micro))
        self.assertversionfail(4, makehex(major, minor + 1, micro))
        self.assertversionfail(5, "'foo'")

    def testbadargs(self):
        # Check that parse_index2() raises TypeError on bad arguments.
        with self.assertRaises(TypeError):
            parse_index2(0, True)

    def testparseindexfile(self):
        # Check parsers.parse_index2() on an index file against the
        # original Python implementation of parseindex, both with and
        # without inlined data.

        want = py_parseindex(data_inlined, True)
        got = parse_index2(data_inlined, True)
        self.assertEqual(want, got) # inline data

        want = py_parseindex(data_non_inlined, False)
        got = parse_index2(data_non_inlined, False)
        self.assertEqual(want, got) # no inline data

        ix = parsers.parse_index2(data_inlined, True)[0]
        for i, r in enumerate(ix):
            if r[7] == nullid:
                i = -1
            try:
                self.assertEqual(
                    ix[r[7]], i,
                    'Reverse lookup inconsistent for %r' % nodemod.hex(r[7]))
            except TypeError:
                # pure version doesn't support this
                break

    def testminusone(self):
        want = (0, 0, 0, -1, -1, -1, -1, nullid)
        index, junk = parsers.parse_index2(data_inlined, True)
        got = index[-1]
        self.assertEqual(want, got) # inline data

        index, junk = parsers.parse_index2(data_non_inlined, False)
        got = index[-1]
        self.assertEqual(want, got) # no inline data

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