comparison mercurial/revlog.py @ 4975:8b7e480a7603

revlog: simplify the v1 immediate parser

- read all the data at once (large files are handled by the lazy parser)
- cache the entire file for inline revlogs
- simplify looping

4974:a335345100ba

            return index, nodemap

        s = struct.calcsize(indexformatng)
        index = []
        nodemap =  {nullid: nullrev}
        n = 0
        leftover = None
        while True:
            if st:
                data = fp.read(65536)
            else:
                # hack for httprangereader, it doesn't do partial reads well
                data = fp.read()
            if not data:
                break
            if n == 0 and inline:
                # cache the first chunk
                self.chunkcache = (0, data)
            if leftover:
                data = leftover + data
                leftover = None
            off = 0
            l = len(data)
            while off < l:
                if l - off < s:
                    leftover = data[off:]
                    break
                cur = data[off:off + s]
                off += s
                e = struct.unpack(indexformatng, cur)
                index.append(e)
                nodemap[e[-1]] = n
                n += 1
                if inline:
                    if e[1] < 0:
                        break
                    off += e[1]
                    if off > l:
                        # some things don't seek well, just read it
                        fp.read(off - l)
                        break
            if not st:
                break

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

4975:8b7e480a7603

            return index, nodemap

        s = struct.calcsize(indexformatng)
        index = []
        nodemap =  {nullid: nullrev}
        n = off = 0
        # if we're not using lazymap, always read the whole index
        data = fp.read()
        l = len(data)
        if inline:
            self.chunkcache = (0, data)
        while off + s <= l:
            e = struct.unpack(indexformatng, data[off:off + s])
            index.append(e)
            nodemap[e[-1]] = n
            n += 1
            off += s
            if inline:
                if e[1] < 0:
                    break
                off += e[1]

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