deb-msgpack-python/msgpack/_unpacker.pyx

480 lines
17 KiB
Cython

# coding: utf-8
#cython: embedsignature=True
from cpython cimport *
cdef extern from "Python.h":
ctypedef struct PyObject
cdef int PyObject_AsReadBuffer(object o, const void** buff, Py_ssize_t* buf_len) except -1
from libc.stdlib cimport *
from libc.string cimport *
from libc.limits cimport *
from msgpack.exceptions import (
BufferFull,
OutOfData,
UnpackValueError,
ExtraData,
)
from msgpack import ExtType
cdef extern from "unpack.h":
ctypedef struct msgpack_user:
bint use_list
PyObject* object_hook
bint has_pairs_hook # call object_hook with k-v pairs
PyObject* list_hook
PyObject* ext_hook
char *encoding
char *unicode_errors
Py_ssize_t max_str_len
Py_ssize_t max_bin_len
Py_ssize_t max_array_len
Py_ssize_t max_map_len
Py_ssize_t max_ext_len
ctypedef struct unpack_context:
msgpack_user user
PyObject* obj
Py_ssize_t count
ctypedef int (*execute_fn)(unpack_context* ctx, const char* data,
Py_ssize_t len, Py_ssize_t* off) except? -1
execute_fn unpack_construct
execute_fn unpack_skip
execute_fn read_array_header
execute_fn read_map_header
void unpack_init(unpack_context* ctx)
object unpack_data(unpack_context* ctx)
void unpack_clear(unpack_context* ctx)
cdef inline init_ctx(unpack_context *ctx,
object object_hook, object object_pairs_hook,
object list_hook, object ext_hook,
bint use_list, char* encoding, char* unicode_errors,
Py_ssize_t max_str_len, Py_ssize_t max_bin_len,
Py_ssize_t max_array_len, Py_ssize_t max_map_len,
Py_ssize_t max_ext_len):
unpack_init(ctx)
ctx.user.use_list = use_list
ctx.user.object_hook = ctx.user.list_hook = <PyObject*>NULL
ctx.user.max_str_len = max_str_len
ctx.user.max_bin_len = max_bin_len
ctx.user.max_array_len = max_array_len
ctx.user.max_map_len = max_map_len
ctx.user.max_ext_len = max_ext_len
if object_hook is not None and object_pairs_hook is not None:
raise TypeError("object_pairs_hook and object_hook are mutually exclusive.")
if object_hook is not None:
if not PyCallable_Check(object_hook):
raise TypeError("object_hook must be a callable.")
ctx.user.object_hook = <PyObject*>object_hook
if object_pairs_hook is None:
ctx.user.has_pairs_hook = False
else:
if not PyCallable_Check(object_pairs_hook):
raise TypeError("object_pairs_hook must be a callable.")
ctx.user.object_hook = <PyObject*>object_pairs_hook
ctx.user.has_pairs_hook = True
if list_hook is not None:
if not PyCallable_Check(list_hook):
raise TypeError("list_hook must be a callable.")
ctx.user.list_hook = <PyObject*>list_hook
if ext_hook is not None:
if not PyCallable_Check(ext_hook):
raise TypeError("ext_hook must be a callable.")
ctx.user.ext_hook = <PyObject*>ext_hook
ctx.user.encoding = encoding
ctx.user.unicode_errors = unicode_errors
def default_read_extended_type(typecode, data):
raise NotImplementedError("Cannot decode extended type with typecode=%d" % typecode)
def unpackb(object packed, object object_hook=None, object list_hook=None,
bint use_list=1, encoding=None, unicode_errors="strict",
object_pairs_hook=None, ext_hook=ExtType,
Py_ssize_t max_str_len=2147483647, # 2**32-1
Py_ssize_t max_bin_len=2147483647,
Py_ssize_t max_array_len=2147483647,
Py_ssize_t max_map_len=2147483647,
Py_ssize_t max_ext_len=2147483647):
"""
Unpack packed_bytes to object. Returns an unpacked object.
Raises `ValueError` when `packed` contains extra bytes.
See :class:`Unpacker` for options.
"""
cdef unpack_context ctx
cdef Py_ssize_t off = 0
cdef int ret
cdef char* buf
cdef Py_ssize_t buf_len
cdef char* cenc = NULL
cdef char* cerr = NULL
PyObject_AsReadBuffer(packed, <const void**>&buf, &buf_len)
if encoding is not None:
if isinstance(encoding, unicode):
encoding = encoding.encode('ascii')
cenc = PyBytes_AsString(encoding)
if unicode_errors is not None:
if isinstance(unicode_errors, unicode):
unicode_errors = unicode_errors.encode('ascii')
cerr = PyBytes_AsString(unicode_errors)
init_ctx(&ctx, object_hook, object_pairs_hook, list_hook, ext_hook,
use_list, cenc, cerr,
max_str_len, max_bin_len, max_array_len, max_map_len, max_ext_len)
ret = unpack_construct(&ctx, buf, buf_len, &off)
if ret == 1:
obj = unpack_data(&ctx)
if off < buf_len:
raise ExtraData(obj, PyBytes_FromStringAndSize(buf+off, buf_len-off))
return obj
unpack_clear(&ctx)
raise UnpackValueError("Unpack failed: error = %d" % (ret,))
def unpack(object stream, object object_hook=None, object list_hook=None,
bint use_list=1, encoding=None, unicode_errors="strict",
object_pairs_hook=None, ext_hook=ExtType,
Py_ssize_t max_str_len=2147483647, # 2**32-1
Py_ssize_t max_bin_len=2147483647,
Py_ssize_t max_array_len=2147483647,
Py_ssize_t max_map_len=2147483647,
Py_ssize_t max_ext_len=2147483647):
"""
Unpack an object from `stream`.
Raises `ValueError` when `stream` has extra bytes.
See :class:`Unpacker` for options.
"""
return unpackb(stream.read(), use_list=use_list,
object_hook=object_hook, object_pairs_hook=object_pairs_hook, list_hook=list_hook,
encoding=encoding, unicode_errors=unicode_errors, ext_hook=ext_hook,
max_str_len=max_str_len,
max_bin_len=max_bin_len,
max_array_len=max_array_len,
max_map_len=max_map_len,
max_ext_len=max_ext_len,
)
cdef class Unpacker(object):
"""Streaming unpacker.
arguments:
:param file_like:
File-like object having `.read(n)` method.
If specified, unpacker reads serialized data from it and :meth:`feed()` is not usable.
:param int read_size:
Used as `file_like.read(read_size)`. (default: `min(1024**2, max_buffer_size)`)
:param bool use_list:
If true, unpack msgpack array to Python list.
Otherwise, unpack to Python tuple. (default: True)
:param callable object_hook:
When specified, it should be callable.
Unpacker calls it with a dict argument after unpacking msgpack map.
(See also simplejson)
:param callable object_pairs_hook:
When specified, it should be callable.
Unpacker calls it with a list of key-value pairs after unpacking msgpack map.
(See also simplejson)
:param str encoding:
Encoding used for decoding msgpack raw.
If it is None (default), msgpack raw is deserialized to Python bytes.
:param str unicode_errors:
Used for decoding msgpack raw with *encoding*.
(default: `'strict'`)
:param int max_buffer_size:
Limits size of data waiting unpacked. 0 means system's INT_MAX (default).
Raises `BufferFull` exception when it is insufficient.
You shoud set this parameter when unpacking data from untrusted source.
:param int max_str_len:
Limits max length of str. (default: 2**31-1)
:param int max_bin_len:
Limits max length of bin. (default: 2**31-1)
:param int max_array_len:
Limits max length of array. (default: 2**31-1)
:param int max_map_len:
Limits max length of map. (default: 2**31-1)
example of streaming deserialize from file-like object::
unpacker = Unpacker(file_like)
for o in unpacker:
process(o)
example of streaming deserialize from socket::
unpacker = Unpacker()
while True:
buf = sock.recv(1024**2)
if not buf:
break
unpacker.feed(buf)
for o in unpacker:
process(o)
"""
cdef unpack_context ctx
cdef char* buf
cdef Py_ssize_t buf_size, buf_head, buf_tail
cdef object file_like
cdef object file_like_read
cdef Py_ssize_t read_size
# To maintain refcnt.
cdef object object_hook, object_pairs_hook, list_hook, ext_hook
cdef object encoding, unicode_errors
cdef Py_ssize_t max_buffer_size
def __cinit__(self):
self.buf = NULL
def __dealloc__(self):
free(self.buf)
self.buf = NULL
def __init__(self, file_like=None, Py_ssize_t read_size=0, bint use_list=1,
object object_hook=None, object object_pairs_hook=None, object list_hook=None,
encoding=None, unicode_errors='strict', int max_buffer_size=0,
object ext_hook=ExtType,
Py_ssize_t max_str_len=2147483647, # 2**32-1
Py_ssize_t max_bin_len=2147483647,
Py_ssize_t max_array_len=2147483647,
Py_ssize_t max_map_len=2147483647,
Py_ssize_t max_ext_len=2147483647):
cdef char *cenc=NULL,
cdef char *cerr=NULL
self.object_hook = object_hook
self.object_pairs_hook = object_pairs_hook
self.list_hook = list_hook
self.ext_hook = ext_hook
self.file_like = file_like
if file_like:
self.file_like_read = file_like.read
if not PyCallable_Check(self.file_like_read):
raise TypeError("`file_like.read` must be a callable.")
if not max_buffer_size:
max_buffer_size = INT_MAX
if read_size > max_buffer_size:
raise ValueError("read_size should be less or equal to max_buffer_size")
if not read_size:
read_size = min(max_buffer_size, 1024**2)
self.max_buffer_size = max_buffer_size
self.read_size = read_size
self.buf = <char*>malloc(read_size)
if self.buf == NULL:
raise MemoryError("Unable to allocate internal buffer.")
self.buf_size = read_size
self.buf_head = 0
self.buf_tail = 0
if encoding is not None:
if isinstance(encoding, unicode):
self.encoding = encoding.encode('ascii')
elif isinstance(encoding, bytes):
self.encoding = encoding
else:
raise TypeError("encoding should be bytes or unicode")
cenc = PyBytes_AsString(self.encoding)
if unicode_errors is not None:
if isinstance(unicode_errors, unicode):
self.unicode_errors = unicode_errors.encode('ascii')
elif isinstance(unicode_errors, bytes):
self.unicode_errors = unicode_errors
else:
raise TypeError("unicode_errors should be bytes or unicode")
cerr = PyBytes_AsString(self.unicode_errors)
init_ctx(&self.ctx, object_hook, object_pairs_hook, list_hook,
ext_hook, use_list, cenc, cerr,
max_str_len, max_bin_len, max_array_len,
max_map_len, max_ext_len)
def feed(self, object next_bytes):
"""Append `next_bytes` to internal buffer."""
cdef Py_buffer pybuff
if self.file_like is not None:
raise AssertionError(
"unpacker.feed() is not be able to use with `file_like`.")
PyObject_GetBuffer(next_bytes, &pybuff, PyBUF_SIMPLE)
try:
self.append_buffer(<char*>pybuff.buf, pybuff.len)
finally:
PyBuffer_Release(&pybuff)
cdef append_buffer(self, void* _buf, Py_ssize_t _buf_len):
cdef:
char* buf = self.buf
char* new_buf
Py_ssize_t head = self.buf_head
Py_ssize_t tail = self.buf_tail
Py_ssize_t buf_size = self.buf_size
Py_ssize_t new_size
if tail + _buf_len > buf_size:
if ((tail - head) + _buf_len) <= buf_size:
# move to front.
memmove(buf, buf + head, tail - head)
tail -= head
head = 0
else:
# expand buffer.
new_size = (tail-head) + _buf_len
if new_size > self.max_buffer_size:
raise BufferFull
new_size = min(new_size*2, self.max_buffer_size)
new_buf = <char*>malloc(new_size)
if new_buf == NULL:
# self.buf still holds old buffer and will be freed during
# obj destruction
raise MemoryError("Unable to enlarge internal buffer.")
memcpy(new_buf, buf + head, tail - head)
free(buf)
buf = new_buf
buf_size = new_size
tail -= head
head = 0
memcpy(buf + tail, <char*>(_buf), _buf_len)
self.buf = buf
self.buf_head = head
self.buf_size = buf_size
self.buf_tail = tail + _buf_len
cdef read_from_file(self):
next_bytes = self.file_like_read(
min(self.read_size,
self.max_buffer_size - (self.buf_tail - self.buf_head)
))
if next_bytes:
self.append_buffer(PyBytes_AsString(next_bytes), PyBytes_Size(next_bytes))
else:
self.file_like = None
cdef object _unpack(self, execute_fn execute, object write_bytes, bint iter=0):
cdef int ret
cdef object obj
cdef Py_ssize_t prev_head
if self.buf_head >= self.buf_tail and self.file_like is not None:
self.read_from_file()
while 1:
prev_head = self.buf_head
if prev_head >= self.buf_tail:
if iter:
raise StopIteration("No more data to unpack.")
else:
raise OutOfData("No more data to unpack.")
try:
ret = execute(&self.ctx, self.buf, self.buf_tail, &self.buf_head)
if write_bytes is not None:
write_bytes(PyBytes_FromStringAndSize(self.buf + prev_head, self.buf_head - prev_head))
if ret == 1:
obj = unpack_data(&self.ctx)
unpack_init(&self.ctx)
return obj
elif ret == 0:
if self.file_like is not None:
self.read_from_file()
continue
if iter:
raise StopIteration("No more data to unpack.")
else:
raise OutOfData("No more data to unpack.")
else:
raise UnpackValueError("Unpack failed: error = %d" % (ret,))
except ValueError as e:
raise UnpackValueError(e)
def read_bytes(self, Py_ssize_t nbytes):
"""Read a specified number of raw bytes from the stream"""
cdef Py_ssize_t nread
nread = min(self.buf_tail - self.buf_head, nbytes)
ret = PyBytes_FromStringAndSize(self.buf + self.buf_head, nread)
self.buf_head += nread
if len(ret) < nbytes and self.file_like is not None:
ret += self.file_like.read(nbytes - len(ret))
return ret
def unpack(self, object write_bytes=None):
"""Unpack one object
If write_bytes is not None, it will be called with parts of the raw
message as it is unpacked.
Raises `OutOfData` when there are no more bytes to unpack.
"""
return self._unpack(unpack_construct, write_bytes)
def skip(self, object write_bytes=None):
"""Read and ignore one object, returning None
If write_bytes is not None, it will be called with parts of the raw
message as it is unpacked.
Raises `OutOfData` when there are no more bytes to unpack.
"""
return self._unpack(unpack_skip, write_bytes)
def read_array_header(self, object write_bytes=None):
"""assuming the next object is an array, return its size n, such that
the next n unpack() calls will iterate over its contents.
Raises `OutOfData` when there are no more bytes to unpack.
"""
return self._unpack(read_array_header, write_bytes)
def read_map_header(self, object write_bytes=None):
"""assuming the next object is a map, return its size n, such that the
next n * 2 unpack() calls will iterate over its key-value pairs.
Raises `OutOfData` when there are no more bytes to unpack.
"""
return self._unpack(read_map_header, write_bytes)
def __iter__(self):
return self
def __next__(self):
return self._unpack(unpack_construct, None, 1)
# for debug.
#def _buf(self):
# return PyString_FromStringAndSize(self.buf, self.buf_tail)
#def _off(self):
# return self.buf_head