# Copyright 2014 Google Inc. All rights reserved.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

from . import number_types as N

from . import packer

from .compat import memoryview_type

from .compat import import_numpy, NumpyRequiredForThisFeature

np = import_numpy()

def Get(packer_type, buf, head):

""" Get decodes a value at buf[head] using `packer_type`. """

return packer_type.unpack_from(memoryview_type(buf), head)[0]

def GetVectorAsNumpy(numpy_type, buf, count, offset):

""" GetVecAsNumpy decodes values starting at buf[head] as

`numpy_type`, where `numpy_type` is a numpy dtype. """

if np is not None:

# TODO: could set .flags.writeable = False to make users jump through

# hoops before modifying...

return np.frombuffer(buf, dtype=numpy_type, count=count, offset=offset)

else:

raise NumpyRequiredForThisFeature('Numpy was not found.')

def Write(packer_type, buf, head, n):

""" Write encodes `n` at buf[head] using `packer_type`. """

packer_type.pack_into(buf, head, n)