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| 1 | +#!/usr/bin/env python |
| 2 | + |
| 3 | +# Copyright 2017 Google Inc. |
| 4 | +# |
| 5 | +# Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | +# you may not use this file except in compliance with the License. |
| 7 | +# You may obtain a copy of the License at |
| 8 | +# |
| 9 | +# http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | +# |
| 11 | +# Unless required by applicable law or agreed to in writing, software |
| 12 | +# distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | +# See the License for the specific language governing permissions and |
| 15 | +# limitations under the License. |
| 16 | + |
| 17 | +# [START sample] |
| 18 | +"""A sample app that uses GCS client to operate on bucket and file.""" |
| 19 | + |
| 20 | +# [START imports] |
| 21 | +import os |
| 22 | + |
| 23 | +import cloudstorage |
| 24 | +from google.appengine.api import app_identity |
| 25 | + |
| 26 | +import webapp2 |
| 27 | + |
| 28 | +# [END imports] |
| 29 | + |
| 30 | +# [START retries] |
| 31 | +cloudstorage.set_default_retry_params( |
| 32 | + cloudstorage.RetryParams( |
| 33 | + initial_delay=0.2, max_delay=5.0, backoff_factor=2, max_retry_period=15 |
| 34 | + )) |
| 35 | +# [END retries] |
| 36 | + |
| 37 | + |
| 38 | +class MainPage(webapp2.RequestHandler): |
| 39 | + """Main page for GCS demo application.""" |
| 40 | + |
| 41 | +# [START get_default_bucket] |
| 42 | + def get(self): |
| 43 | + bucket_name = os.environ.get( |
| 44 | + 'BUCKET_NAME', app_identity.get_default_gcs_bucket_name()) |
| 45 | + |
| 46 | + self.response.headers['Content-Type'] = 'text/plain' |
| 47 | + self.response.write( |
| 48 | + 'Demo GCS Application running from Version: {}\n'.format( |
| 49 | + os.environ['CURRENT_VERSION_ID'])) |
| 50 | + self.response.write('Using bucket name: \n\n'.format(bucket_name)) |
| 51 | +# [END get_default_bucket] |
| 52 | + |
| 53 | + bucket = '/' + bucket_name |
| 54 | + filename = bucket + '/demo-testfile' |
| 55 | + self.tmp_filenames_to_clean_up = [] |
| 56 | + |
| 57 | + self.create_file(filename) |
| 58 | + self.response.write('\n\n') |
| 59 | + |
| 60 | + self.read_file(filename) |
| 61 | + self.response.write('\n\n') |
| 62 | + |
| 63 | + self.stat_file(filename) |
| 64 | + self.response.write('\n\n') |
| 65 | + |
| 66 | + self.create_files_for_list_bucket(bucket) |
| 67 | + self.response.write('\n\n') |
| 68 | + |
| 69 | + self.list_bucket(bucket) |
| 70 | + self.response.write('\n\n') |
| 71 | + |
| 72 | + self.list_bucket_directory_mode(bucket) |
| 73 | + self.response.write('\n\n') |
| 74 | + |
| 75 | + self.delete_files() |
| 76 | + self.response.write('\n\nThe demo ran successfully!\n') |
| 77 | + |
| 78 | +# [START write] |
| 79 | + def create_file(self, filename): |
| 80 | + """Create a file.""" |
| 81 | + |
| 82 | + self.response.write('Creating file {}\n'.format(filename)) |
| 83 | + |
| 84 | + # The retry_params specified in the open call will override the default |
| 85 | + # retry params for this particular file handle. |
| 86 | + write_retry_params = cloudstorage.RetryParams(backoff_factor=1.1) |
| 87 | + with cloudstorage.open( |
| 88 | + filename, 'w', content_type='text/plain', options={ |
| 89 | + 'x-goog-meta-foo': 'foo', 'x-goog-meta-bar': 'bar'}, |
| 90 | + retry_params=write_retry_params) as cloudstorage_file: |
| 91 | + cloudstorage_file.write('abcde\n') |
| 92 | + cloudstorage_file.write('f'*1024*4 + '\n') |
| 93 | + self.tmp_filenames_to_clean_up.append(filename) |
| 94 | +# [END write] |
| 95 | + |
| 96 | +# [START read] |
| 97 | + def read_file(self, filename): |
| 98 | + self.response.write( |
| 99 | + 'Abbreviated file content (first line and last 1K):\n') |
| 100 | + |
| 101 | + with cloudstorage.open(filename) as cloudstorage_file: |
| 102 | + self.response.write(cloudstorage_file.readline()) |
| 103 | + cloudstorage_file.seek(-1024, os.SEEK_END) |
| 104 | + self.response.write(cloudstorage_file.read()) |
| 105 | +# [END read] |
| 106 | + |
| 107 | + def stat_file(self, filename): |
| 108 | + self.response.write('File stat:\n') |
| 109 | + |
| 110 | + stat = cloudstorage.stat(filename) |
| 111 | + self.response.write(repr(stat)) |
| 112 | + |
| 113 | + def create_files_for_list_bucket(self, bucket): |
| 114 | + self.response.write('Creating more files for listbucket...\n') |
| 115 | + filenames = [bucket + n for n in [ |
| 116 | + '/foo1', '/foo2', '/bar', '/bar/1', '/bar/2', '/boo/']] |
| 117 | + for f in filenames: |
| 118 | + self.create_file(f) |
| 119 | + |
| 120 | +# [START list_bucket] |
| 121 | + def list_bucket(self, bucket): |
| 122 | + """Create several files and paginate through them.""" |
| 123 | + |
| 124 | + self.response.write('Listbucket result:\n') |
| 125 | + |
| 126 | + # Production apps should set page_size to a practical value. |
| 127 | + page_size = 1 |
| 128 | + stats = cloudstorage.listbucket(bucket + '/foo', max_keys=page_size) |
| 129 | + while True: |
| 130 | + count = 0 |
| 131 | + for stat in stats: |
| 132 | + count += 1 |
| 133 | + self.response.write(repr(stat)) |
| 134 | + self.response.write('\n') |
| 135 | + |
| 136 | + if count != page_size or count == 0: |
| 137 | + break |
| 138 | + stats = cloudstorage.listbucket( |
| 139 | + bucket + '/foo', max_keys=page_size, marker=stat.filename) |
| 140 | +# [END list_bucket] |
| 141 | + |
| 142 | + def list_bucket_directory_mode(self, bucket): |
| 143 | + self.response.write('Listbucket directory mode result:\n') |
| 144 | + for stat in cloudstorage.listbucket(bucket + '/b', delimiter='/'): |
| 145 | + self.response.write(stat) |
| 146 | + self.response.write('\n') |
| 147 | + if stat.is_dir: |
| 148 | + for subdir_file in cloudstorage.listbucket( |
| 149 | + stat.filename, delimiter='/'): |
| 150 | + self.response.write(' {}'.format(subdir_file)) |
| 151 | + self.response.write('\n') |
| 152 | + |
| 153 | +# [START delete_files] |
| 154 | + def delete_files(self): |
| 155 | + self.response.write('Deleting files...\n') |
| 156 | + for filename in self.tmp_filenames_to_clean_up: |
| 157 | + self.response.write('Deleting file {}\n'.format(filename)) |
| 158 | + try: |
| 159 | + cloudstorage.delete(filename) |
| 160 | + except cloudstorage.NotFoundError: |
| 161 | + pass |
| 162 | +# [END delete_files] |
| 163 | + |
| 164 | + |
| 165 | +app = webapp2.WSGIApplication( |
| 166 | + [('/', MainPage)], debug=True) |
| 167 | +# [END sample] |
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