Source code for google.appengine.api.files.blobstore

#!/usr/bin/env python
# Copyright 2007 Google Inc.
# 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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

"""Files API.

.. deprecated:: 1.8.1
   Use Google Cloud Storage Client library instead.

Blobstore-specific Files API calls."""

from __future__ import with_statement

__all__ = ['create', 'get_blob_key', 'get_file_name']

import hashlib
import urllib

from google.appengine.api import datastore
from google.appengine.api import namespace_manager
from google.appengine.api.files import file as files
from google.appengine.ext import blobstore

_MIME_TYPE_PARAMETER = 'content_type'

[docs]def create(mime_type='application/octet-stream', _blobinfo_uploaded_filename=None): """Create a writable blobstore file. Args: mime_type: Resulting blob content MIME type as string. _blobinfo_uploaded_filename: Resulting blob's BlobInfo file name as string. Returns: A file name for blobstore file. This file can be opened for write by File API open function. To read the file or obtain its blob key, finalize it and call get_blob_key function. """ if not mime_type: raise files.InvalidArgumentError('Empty mime_type') if not isinstance(mime_type, basestring): raise files.InvalidArgumentError('Expected string for mime_type') params = {_MIME_TYPE_PARAMETER: mime_type} if _blobinfo_uploaded_filename: if not isinstance(_blobinfo_uploaded_filename, basestring): raise files.InvalidArgumentError( 'Expected string for _blobinfo_uploaded_filename') params[_BLOBINFO_UPLOADED_FILENAME_PARAMETER] = _blobinfo_uploaded_filename return files._create(_BLOBSTORE_FILESYSTEM, params=params)
_BLOB_FILE_INDEX_KIND = '__BlobFileIndex__' _BLOB_KEY_PROPERTY_NAME = 'blob_key' def _get_blob_file_index_key_name(creation_handle): """Get key name for a __BlobFileIndex__ entity. Returns creation_handle if it is < _DATASTORE_MAX_PROPERTY_SIZE symbols and its sha512 otherwise. """ if len(creation_handle) < _DATASTORE_MAX_PROPERTY_SIZE: return creation_handle return hashlib.sha512(creation_handle).hexdigest()
[docs]def get_blob_key(create_file_name): """Get a blob key for finalized blobstore file. Args: create_file_name: Writable blobstore filename as obtained from create() function. The file should be finalized. Returns: An instance of apphosting.ext.blobstore.BlobKey for corresponding blob or None if the blob referred to by the file name is not finalized. Raises: google.appengine.api.files.InvalidFileNameError if the file name is not a valid nonfinalized blob file name. """ if not create_file_name: raise files.InvalidArgumentError('Empty file name') if not isinstance(create_file_name, basestring): raise files.InvalidArgumentError('Expected string for file name') if not create_file_name.startswith(_BLOBSTORE_DIRECTORY): raise files.InvalidFileNameError( 'Filename %s passed to get_blob_key doesn\'t have prefix %s' % (create_file_name, _BLOBSTORE_DIRECTORY)) ticket = create_file_name[len(_BLOBSTORE_DIRECTORY):] if not ticket.startswith(files._CREATION_HANDLE_PREFIX): return blobstore.BlobKey(ticket) blob_file_index = datastore.Get([datastore.Key.from_path( _BLOB_FILE_INDEX_KIND, _get_blob_file_index_key_name(ticket), namespace='')])[0] if blob_file_index: blob_key_str = blob_file_index[_BLOB_KEY_PROPERTY_NAME] results = datastore.Get([datastore.Key.from_path( blobstore.BLOB_INFO_KIND, blob_key_str, namespace='')]) if results[0] is None: return None elif len(ticket) >= _DATASTORE_MAX_PROPERTY_SIZE: return None else: query = datastore.Query(blobstore.BLOB_INFO_KIND, {'creation_handle =': ticket}, keys_only=True, namespace='') results = query.Get(1) if not results: return None blob_key_str = results[0].name() return blobstore.BlobKey(blob_key_str)
[docs]def get_file_name(blob_key): """Get a filename to read from the blob. Args: blob_key: An instance of BlobKey. Returns: File name as string which can be used with File API to read the file. """ if not blob_key: raise files.InvalidArgumentError('Empty blob key') if not isinstance(blob_key, (blobstore.BlobKey, basestring)): raise files.InvalidArgumentError('Expected string or blobstore.BlobKey') return '%s%s' % (_BLOBSTORE_DIRECTORY, blob_key)
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