mapped_struct.py 文件源码

def unpack_from(cls, buf, offs, idmap = None):
        if cython.compiled:
            buf = _likebuffer(buf)
            PyObject_GetBuffer(buf, cython.address(pybuf), PyBUF_SIMPLE)  # lint:ok
            pbuf = cython.cast(cython.p_uchar, pybuf.buf)  # lint:ok
            if offs >= pybuf.len:
                PyBuffer_Release(cython.address(pybuf))  # lint
                raise IndexError("Offset out of range")
        else:
            pbuf = buf
        try:
            if pbuf[offs] == 'm':
                # inline bitmap
                if cython.compiled and offs+7 >= pybuf.len:
                    raise IndexError("Object spans beyond buffer end")
                rv = []
                for i in xrange(7):
                    b = ord(pbuf[offs+1+i])
                    if b:
                        for j in xrange(8):
                            if b & (1<<j):
                                rv.append(i*8+j)
                return frozenset(rv)
            else:
                # unpack a list, build a set from it
                return frozenset(mapped_list.unpack_from(buf, offs, idmap))
        finally:
            if cython.compiled:
                if type(buf) is buffer:
                    PyBuffer_Release(cython.address(pybuf))  # lint:ok