from cpython.bytes cimport PyBytes_AS_STRING

# char* PyBytes_AS_STRING(object string)

# Macro form of PyBytes_AsString() but without error

# checking. Only string objects are supported; no Unicode objects

# should be passed.

cdef struct Buffer:

char *ptr

Py_ssize_t size

cdef inline bytes to_bytes(Buffer *buf):

return buf.ptr[:buf.size]

cdef inline char *buf_ptr(Buffer *buf):

return buf.ptr

cdef inline char *buf_read(Buffer *buf, Py_ssize_t size) except NULL:

if size > buf.size:

raise IndexError("Requested more than length of buffer")

return buf.ptr

cdef inline int slice_buffer(Buffer *buf, Buffer *out,

Py_ssize_t start, Py_ssize_t size) except -1:

if size < 0:

raise ValueError("Length must be positive")

if start + size > buf.size:

raise IndexError("Buffer slice out of bounds")

out.ptr = buf.ptr + start

out.size = size

return 0

cdef inline void from_ptr_and_size(char *ptr, Py_ssize_t size, Buffer *out):

out.ptr = ptr

out.size = size