78 lines
2.3 KiB
Python
78 lines
2.3 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright 2010 United States Government as represented by the
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# Administrator of the National Aeronautics and Space Administration.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""
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System-level utilities and helper functions.
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"""
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import sys
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import uuid
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from heat.common import exception
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def chunkreadable(iter, chunk_size=65536):
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"""
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Wrap a readable iterator with a reader yielding chunks of
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a preferred size, otherwise leave iterator unchanged.
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:param iter: an iter which may also be readable
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:param chunk_size: maximum size of chunk
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"""
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return chunkiter(iter, chunk_size) if hasattr(iter, 'read') else iter
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def chunkiter(fp, chunk_size=65536):
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"""
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Return an iterator to a file-like obj which yields fixed size chunks
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:param fp: a file-like object
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:param chunk_size: maximum size of chunk
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"""
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while True:
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chunk = fp.read(chunk_size)
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if chunk:
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yield chunk
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else:
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break
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def import_class(import_str):
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"""Returns a class from a string including module and class"""
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mod_str, _sep, class_str = import_str.rpartition('.')
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try:
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__import__(mod_str)
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return getattr(sys.modules[mod_str], class_str)
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except (ImportError, ValueError, AttributeError), e:
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raise exception.ImportFailure(import_str=import_str,
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reason=e)
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def import_object(import_str):
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"""Returns an object including a module or module and class"""
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try:
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__import__(import_str)
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return sys.modules[import_str]
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except ImportError:
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cls = import_class(import_str)
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return cls()
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def generate_uuid():
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return str(uuid.uuid4())
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