tests/test-parseindex2.py

hg: make cachedlocalrepo cache appropriate repoview object

Before this patch, 'cachedlocalrepo' always caches "visible" repoview
object, because 'cachedlocalrepo' uses "visible" repoview returned by
'hg.repository()' without any additional processing.

If the client of 'cachedlocalrepo' wants "served" repoview, some
objects to be cached are discarded unintentionally.

    1. 'cachedlocalrepo' newly caches "visible" repoview object
       (call it VIEW1)

    2. 'cachedlocalrepo' returns VIEW1 to the client of it at 'fetch()'

    3. the client gets "served" repoview object by 'filtered("served")'
       on VIEW1 (call this "served" repoview VIEW2)

    4. accessing to 'repo.changelog' implies:
       - instantiation of changelog via 'localrepository.changelog'
       - instantiation of "filtered changelog" via 'repoview.changelog'

    5. "filtered changelog" above is cached in VIEW2

    6. VIEW2 is discarded after processing, because there is no
       reference to it

    7. 'cachedlocalrepo' returns VIEW1 cached at (1) above to the
       client at next 'fetch()'

    8. 'filtered("served")' on VIEW1 at the client side creates new
       "served" repoview again, because VIEW1 is "visible"
       (call this new "served" repoview VIEW3)

    9. accessing to 'repo.changelog' implies instantiation of filtered
       changelog again, because "filtered changelog" is cached in
       VIEW2 at (5), but not in VIEW3 currently used

    10. (go to (7) above)

As described above, "served" repoview object and "filtered changelog"
cached in it are discarded always, even if the repository itself
hasn't been changed since last access.

For example, in the case of 'hgweb_mod.hgweb', "newly caching" occurs,
when:

  - all cached objects are already assigned to another threads
    (in this case, repoview is created in 'cachedlocalrepo.copy()')

  - or, stat of '00changelog.i' is changed from last access
    (in this case, repoview is created in 'cachedlocalrepo.fetch()')

    once changes are pushed via HTTP, this always occurs.

The root cause of this inefficiency is that 'cachedlocalrepo' always
caches "visible" repoview object, even if the client of it wants
another view.

To make 'cachedlocalrepo' cache appropriate repoview object, this
patch adds additional filtering on the repo object returned by
'hg.repository()'. It is assumed that initial repoview object should
be already filtered by expected view.

After this patch:

  - 'filtered("served")' on VIEW1 at (3)/(7) above returns VIEW1
    itself, because VIEW1 is now "served", and

  - VIEW2 and VIEW3 equal VIEW1

  - therefore, "filtered changelog" is cached in VIEW1, and reused
    intentionally

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

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

from mercurial import parsers
from mercurial.node import nullid, nullrev
import struct
import subprocess
import sys

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

def offset_type(offset, type):
    return long(long(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)

    # add the magic null revision at -1
    index.append((0, 0, 0, -1, -1, -1, -1, nullid))

    return index, cache

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

data_non_inlined = '\x00\x00\x00\x01\x00\x00\x00\x00\x00\x01D\x19' \
    '\x00\x07e\x12\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff' \
    '\xff\xff\xff\xff\xd1\xf4\xbb\xb0\xbe\xfc\x13\xbd\x8c\xd3\x9d' \
    '\x0f\xcd\xd9;\x8c\x07\x8cJ/\x00\x00\x00\x00\x00\x00\x00\x00\x00' \
    '\x00\x00\x00\x00\x00\x00\x01D\x19\x00\x00\x00\x00\x00\xdf\x00' \
    '\x00\x01q\x00\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x00\xff' \
    '\xff\xff\xff\xc1\x12\xb9\x04\x96\xa4Z1t\x91\xdfsJ\x90\xf0\x9bh' \
    '\x07l&\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' \
    '\x00\x01D\xf8\x00\x00\x00\x00\x01\x1b\x00\x00\x01\xb8\x00\x00' \
    '\x00\x01\x00\x00\x00\x02\x00\x00\x00\x01\xff\xff\xff\xff\x02\n' \
    '\x0e\xc6&\xa1\x92\xae6\x0b\x02i\xfe-\xe5\xbao\x05\xd1\xe7\x00' \
    '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01F' \
    '\x13\x00\x00\x00\x00\x01\xec\x00\x00\x03\x06\x00\x00\x00\x01' \
    '\x00\x00\x00\x03\x00\x00\x00\x02\xff\xff\xff\xff\x12\xcb\xeby1' \
    '\xb6\r\x98B\xcb\x07\xbd`\x8f\x92\xd9\xc4\x84\xbdK\x00\x00\x00' \
    '\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.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 printhexfail(testnumber, hexversion, stdout, expected):
    try:
        hexstring = hex(hexversion)
    except TypeError:
        hexstring = None
    print ("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 testversionokay(testnumber, hexversion):
    stdout, stderr = importparsers(hexversion)
    if stdout:
        printhexfail(testnumber, hexversion, stdout, expected="no stdout")

def testversionfail(testnumber, hexversion):
    stdout, stderr = importparsers(hexversion)
    # We include versionerrortext to distinguish from other ImportErrors.
    errtext = "ImportError: %s" % parsers.versionerrortext
    if errtext not in stdout:
        printhexfail(testnumber, hexversion, stdout,
                     expected="stdout to contain %r" % errtext)

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

def runversiontests():
    """Check the version-detection logic when importing parsers."""
    info = sys.version_info
    major, minor, micro = info[0], info[1], info[2]
    # Test same major-minor versions.
    testversionokay(1, makehex(major, minor, micro))
    testversionokay(2, makehex(major, minor, micro + 1))
    # Test different major-minor versions.
    testversionfail(3, makehex(major + 1, minor, micro))
    testversionfail(4, makehex(major, minor + 1, micro))
    testversionfail(5, "'foo'")

def runtest() :
    # Only test the version-detection logic if it is present.
    try:
        parsers.versionerrortext
    except AttributeError:
        pass
    else:
        runversiontests()

    # Check that parse_index2() raises TypeError on bad arguments.
    try:
        parse_index2(0, True)
    except TypeError:
        pass
    else:
        print "Expected to get TypeError."

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

    py_res_1 = py_parseindex(data_inlined, True)
    c_res_1 = parse_index2(data_inlined, True)

    py_res_2 = py_parseindex(data_non_inlined, False)
    c_res_2 = parse_index2(data_non_inlined, False)

    if py_res_1 != c_res_1:
        print "Parse index result (with inlined data) differs!"

    if py_res_2 != c_res_2:
        print "Parse index result (no inlined data) differs!"

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

    print "done"

runtest()