| # 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() | |
| FILE_IDENTIFIER_LENGTH=4 | |
| 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) | |