comparison mercurial/pure/parsers.py @ 29133:255274719dc1

pure: write a really lazy version of pure indexObject

On PyPy this version performs reasonably well compared to C version.
Example command is "hg id" which gets faster, depending on details
of your operating system and hard drive (it's bottlenecked on stat mostly)
There is potential for improvements by storing extra as a condensed struct too.

29132:12769703d4ba

# code outside this module should always use dirstatetuple.
def dirstatetuple(*x):
    # x is a tuple
    return x

def parse_index2(data, inline):
    def gettype(q):
        return int(q & 0xFFFF)

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

    indexformatng = ">Qiiiiii20s12x"

    s = struct.calcsize(indexformatng)
    index = []
    cache = None
    off = 0

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

    if off != len(data):
        raise ValueError('corrupt index file')

    if index:
        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

def parse_dirstate(dmap, copymap, st):
    parents = [st[:20], st[20: 40]]
    # dereference fields so they will be local in loop
    format = ">cllll"

29133:255274719dc1

# code outside this module should always use dirstatetuple.
def dirstatetuple(*x):
    # x is a tuple
    return x

indexformatng = ">Qiiiiii20s12x"
indexfirst = struct.calcsize('Q')
sizeint = struct.calcsize('i')
indexsize = struct.calcsize(indexformatng)

def gettype(q):
    return int(q & 0xFFFF)

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

class BaseIndexObject(object):
    def __len__(self):
        return self._lgt + len(self._extra) + 1

    def insert(self, i, tup):
        assert i == -1
        self._extra.append(tup)

    def _fix_index(self, i):
        if not isinstance(i, int):
            raise TypeError("expecting int indexes")
        if i < 0:
            i = len(self) + i
        if i < 0 or i >= len(self):
            raise IndexError
        return i

    def __getitem__(self, i):
        i = self._fix_index(i)
        if i == len(self) - 1:
            return (0, 0, 0, -1, -1, -1, -1, nullid)
        if i >= self._lgt:
            return self._extra[i - self._lgt]
        index = self._calculate_index(i)
        r = struct.unpack(indexformatng, self._data[index:index + indexsize])
        if i == 0:
            e = list(r)
            type = gettype(e[0])
            e[0] = offset_type(0, type)
            return tuple(e)
        return r

class IndexObject(BaseIndexObject):
    def __init__(self, data):
        assert len(data) % indexsize == 0
        self._data = data
        self._lgt = len(data) // indexsize
        self._extra = []

    def _calculate_index(self, i):
        return i * indexsize

    def __delitem__(self, i):
        if not isinstance(i, slice) or not i.stop == -1 or not i.step is None:
            raise ValueError("deleting slices only supports a:-1 with step 1")
        i = self._fix_index(i.start)
        if i < self._lgt:
            self._data = self._data[:i * indexsize]
            self._lgt = i
            self._extra = []
        else:
            self._extra = self._extra[:i - self._lgt]

class InlinedIndexObject(BaseIndexObject):
    def __init__(self, data, inline=0):
        self._data = data
        self._lgt = self._inline_scan(None)
        self._inline_scan(self._lgt)
        self._extra = []

    def _inline_scan(self, lgt):
        off = 0
        if lgt is not None:
            self._offsets = [0] * lgt
        count = 0
        while off <= len(self._data) - indexsize:
            s, = struct.unpack('>i',
                self._data[off + indexfirst:off + sizeint + indexfirst])
            if lgt is not None:
                self._offsets[count] = off
            count += 1
            off += indexsize + s
        if off != len(self._data):
            raise ValueError("corrupted data")
        return count

    def __delitem__(self, i):
        if not isinstance(i, slice) or not i.stop == -1 or not i.step is None:
            raise ValueError("deleting slices only supports a:-1 with step 1")
        i = self._fix_index(i.start)
        if i < self._lgt:
            self._offsets = self._offsets[:i]
            self._lgt = i
            self._extra = []
        else:
            self._extra = self._extra[:i - self._lgt]

    def _calculate_index(self, i):
        return self._offsets[i]

def parse_index2(data, inline):
    if not inline:
        return IndexObject(data), None
    return InlinedIndexObject(data, inline), (0, data)

def parse_dirstate(dmap, copymap, st):
    parents = [st[:20], st[20: 40]]
    # dereference fields so they will be local in loop
    format = ">cllll"