comparison mercurial/revlog.py @ 8314:57a41c08feab

revlog: preread revlog .i file

Smaller revlogs can be read with a single read, do it on open.

8313:b695392491e7

REVLOGNG = 1
REVLOGNGINLINEDATA = (1 << 16)
REVLOG_DEFAULT_FLAGS = REVLOGNGINLINEDATA
REVLOG_DEFAULT_FORMAT = REVLOGNG
REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_FORMAT | REVLOG_DEFAULT_FLAGS

RevlogError = error.RevlogError
LookupError = error.LookupError

def getoffset(q):

class revlogoldio(object):
    def __init__(self):
        self.size = struct.calcsize(indexformatv0)

    def parseindex(self, fp, inline):
        s = self.size
        index = []
        nodemap =  {nullid: nullrev}
        n = off = 0
        data = fp.read()
        l = len(data)
        while off + s <= l:
            cur = data[off:off + s]
            off += s
            e = _unpack(indexformatv0, cur)

class revlogio(object):
    def __init__(self):
        self.size = struct.calcsize(indexformatng)

    def parseindex(self, fp, inline):
        try:
            size = util.fstat(fp).st_size
        except AttributeError:
            size = 0

        if util.openhardlinks() and not inline and size > 1000000:
            # big index, let's parse it on demand
            parser = lazyparser(fp, size)
            index = lazyindex(parser)
            nodemap = lazymap(parser)
            e = list(index[0])
            type = gettype(e[0])
            e[0] = offset_type(0, type)
            index[0] = e
            return index, nodemap, None

        data = fp.read()
        # call the C implementation to parse the index data
        index, nodemap, cache = parsers.parse_index(data, inline)
        return index, nodemap, cache

    def packentry(self, entry, node, version, rev):

        if hasattr(opener, "defversion"):
            v = opener.defversion
            if v & REVLOGNG:
                v |= REVLOGNGINLINEDATA

        i = ""
        try:
            f = self.opener(self.indexfile)
            i = f.read(4)
            f.seek(0)
            if len(i) > 0:
                v = struct.unpack(versionformat, i)[0]
        except IOError, inst:
            if inst.errno != errno.ENOENT:
                raise

        self.version = v

        self._io = revlogio()
        if self.version == REVLOGV0:
            self._io = revlogoldio()
        if i:
            try:
                d = self._io.parseindex(f, self._inline)
            except (ValueError, IndexError), e:
                raise RevlogError(_("index %s is corrupted") % (self.indexfile))
            self.index, self.nodemap, self._chunkcache = d

        # add the magic null revision at -1 (if it hasn't been done already)

8314:57a41c08feab

REVLOGNG = 1
REVLOGNGINLINEDATA = (1 << 16)
REVLOG_DEFAULT_FLAGS = REVLOGNGINLINEDATA
REVLOG_DEFAULT_FORMAT = REVLOGNG
REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_FORMAT | REVLOG_DEFAULT_FLAGS

_prereadsize = 1048576

RevlogError = error.RevlogError
LookupError = error.LookupError

def getoffset(q):

class revlogoldio(object):
    def __init__(self):
        self.size = struct.calcsize(indexformatv0)

    def parseindex(self, fp, data, inline):
        s = self.size
        index = []
        nodemap =  {nullid: nullrev}
        n = off = 0
        if len(data) < _prereadsize:
            data += fp.read() # read the rest
        l = len(data)
        while off + s <= l:
            cur = data[off:off + s]
            off += s
            e = _unpack(indexformatv0, cur)

class revlogio(object):
    def __init__(self):
        self.size = struct.calcsize(indexformatng)

    def parseindex(self, fp, data, inline):
        try:
            size = len(data)
            if size == _prereadsize:
                size = util.fstat(fp).st_size
        except AttributeError:
            size = 0

        if util.openhardlinks() and not inline and size > _prereadsize:
            # big index, let's parse it on demand
            parser = lazyparser(fp, size)
            index = lazyindex(parser)
            nodemap = lazymap(parser)
            e = list(index[0])
            type = gettype(e[0])
            e[0] = offset_type(0, type)
            index[0] = e
            return index, nodemap, None

        # call the C implementation to parse the index data
        index, nodemap, cache = parsers.parse_index(data, inline)
        return index, nodemap, cache

    def packentry(self, entry, node, version, rev):

        if hasattr(opener, "defversion"):
            v = opener.defversion
            if v & REVLOGNG:
                v |= REVLOGNGINLINEDATA

        i = ''
        try:
            f = self.opener(self.indexfile)
            i = f.read(_prereadsize)
            if len(i) > 0:
                v = struct.unpack(versionformat, i[:4])[0]
        except IOError, inst:
            if inst.errno != errno.ENOENT:
                raise

        self.version = v

        self._io = revlogio()
        if self.version == REVLOGV0:
            self._io = revlogoldio()
        if i:
            try:
                d = self._io.parseindex(f, i, self._inline)
            except (ValueError, IndexError), e:
                raise RevlogError(_("index %s is corrupted") % (self.indexfile))
            self.index, self.nodemap, self._chunkcache = d

        # add the magic null revision at -1 (if it hasn't been done already)