1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
# -*- coding: utf-8 -*-
#
# jQuery File Upload Plugin GAE Python Example
# https://github.com/blueimp/jQuery-File-Upload
#
# Copyright 2011, Sebastian Tschan
# https://blueimp.net
#
# Licensed under the MIT license:
# https://opensource.org/licenses/MIT
#
from google.appengine.api import memcache, images
import json
import os
import re
import urllib
import webapp2
DEBUG=os.environ.get('SERVER_SOFTWARE', '').startswith('Dev')
WEBSITE = 'https://blueimp.github.io/jQuery-File-Upload/'
MIN_FILE_SIZE = 1 # bytes
# Max file size is memcache limit (1MB) minus key size minus overhead:
MAX_FILE_SIZE = 999000 # bytes
IMAGE_TYPES = re.compile('image/(gif|p?jpeg|(x-)?png)')
ACCEPT_FILE_TYPES = IMAGE_TYPES
THUMB_MAX_WIDTH = 80
THUMB_MAX_HEIGHT = 80
THUMB_SUFFIX = '.'+str(THUMB_MAX_WIDTH)+'x'+str(THUMB_MAX_HEIGHT)+'.png'
EXPIRATION_TIME = 300 # seconds
# If set to None, only allow redirects to the referer protocol+host.
# Set to a regexp for custom pattern matching against the redirect value:
REDIRECT_ALLOW_TARGET = None
class CORSHandler(webapp2.RequestHandler):
def cors(self):
headers = self.response.headers
headers['Access-Control-Allow-Origin'] = '*'
headers['Access-Control-Allow-Methods'] =\
'OPTIONS, HEAD, GET, POST, DELETE'
headers['Access-Control-Allow-Headers'] =\
'Content-Type, Content-Range, Content-Disposition'
def initialize(self, request, response):
super(CORSHandler, self).initialize(request, response)
self.cors()
def json_stringify(self, obj):
return json.dumps(obj, separators=(',', ':'))
def options(self, *args, **kwargs):
pass
class UploadHandler(CORSHandler):
def validate(self, file):
if file['size'] < MIN_FILE_SIZE:
file['error'] = 'File is too small'
elif file['size'] > MAX_FILE_SIZE:
file['error'] = 'File is too big'
elif not ACCEPT_FILE_TYPES.match(file['type']):
file['error'] = 'Filetype not allowed'
else:
return True
return False
def validate_redirect(self, redirect):
if redirect:
if REDIRECT_ALLOW_TARGET:
return REDIRECT_ALLOW_TARGET.match(redirect)
referer = self.request.headers['referer']
if referer:
from urlparse import urlparse
parts = urlparse(referer)
redirect_allow_target = '^' + re.escape(
parts.scheme + '://' + parts.netloc + '/'
)
return re.match(redirect_allow_target, redirect)
return False
def get_file_size(self, file):
file.seek(0, 2) # Seek to the end of the file
size = file.tell() # Get the position of EOF
file.seek(0) # Reset the file position to the beginning
return size
def write_blob(self, data, info):
key = urllib.quote(info['type'].encode('utf-8'), '') +\
'/' + str(hash(data)) +\
'/' + urllib.quote(info['name'].encode('utf-8'), '')
try:
memcache.set(key, data, time=EXPIRATION_TIME)
except: #Failed to add to memcache
return (None, None)
thumbnail_key = None
if IMAGE_TYPES.match(info['type']):
try:
img = images.Image(image_data=data)
img.resize(
width=THUMB_MAX_WIDTH,
height=THUMB_MAX_HEIGHT
)
thumbnail_data = img.execute_transforms()
thumbnail_key = key + THUMB_SUFFIX
memcache.set(
thumbnail_key,
thumbnail_data,
time=EXPIRATION_TIME
)
except: #Failed to resize Image or add to memcache
thumbnail_key = None
return (key, thumbnail_key)
def handle_upload(self):
results = []
for name, fieldStorage in self.request.POST.items():
if type(fieldStorage) is unicode:
continue
result = {}
result['name'] = urllib.unquote(fieldStorage.filename)
result['type'] = fieldStorage.type
result['size'] = self.get_file_size(fieldStorage.file)
if self.validate(result):
key, thumbnail_key = self.write_blob(
fieldStorage.value,
result
)
if key is not None:
result['url'] = self.request.host_url + '/' + key
result['deleteUrl'] = result['url']
result['deleteType'] = 'DELETE'
if thumbnail_key is not None:
result['thumbnailUrl'] = self.request.host_url +\
'/' + thumbnail_key
else:
result['error'] = 'Failed to store uploaded file.'
results.append(result)
return results
def head(self):
pass
def get(self):
self.redirect(WEBSITE)
def post(self):
if (self.request.get('_method') == 'DELETE'):
return self.delete()
result = {'files': self.handle_upload()}
s = self.json_stringify(result)
redirect = self.request.get('redirect')
if self.validate_redirect(redirect):
return self.redirect(str(
redirect.replace('%s', urllib.quote(s, ''), 1)
))
if 'application/json' in self.request.headers.get('Accept'):
self.response.headers['Content-Type'] = 'application/json'
self.response.write(s)
class FileHandler(CORSHandler):
def normalize(self, str):
return urllib.quote(urllib.unquote(str), '')
def get(self, content_type, data_hash, file_name):
content_type = self.normalize(content_type)
file_name = self.normalize(file_name)
key = content_type + '/' + data_hash + '/' + file_name
data = memcache.get(key)
if data is None:
return self.error(404)
# Prevent browsers from MIME-sniffing the content-type:
self.response.headers['X-Content-Type-Options'] = 'nosniff'
content_type = urllib.unquote(content_type)
if not IMAGE_TYPES.match(content_type):
# Force a download dialog for non-image types:
content_type = 'application/octet-stream'
elif file_name.endswith(THUMB_SUFFIX):
content_type = 'image/png'
self.response.headers['Content-Type'] = content_type
# Cache for the expiration time:
self.response.headers['Cache-Control'] = 'public,max-age=%d' \
% EXPIRATION_TIME
self.response.write(data)
def delete(self, content_type, data_hash, file_name):
content_type = self.normalize(content_type)
file_name = self.normalize(file_name)
key = content_type + '/' + data_hash + '/' + file_name
result = {key: memcache.delete(key)}
content_type = urllib.unquote(content_type)
if IMAGE_TYPES.match(content_type):
thumbnail_key = key + THUMB_SUFFIX
result[thumbnail_key] = memcache.delete(thumbnail_key)
if 'application/json' in self.request.headers.get('Accept'):
self.response.headers['Content-Type'] = 'application/json'
s = self.json_stringify(result)
self.response.write(s)
app = webapp2.WSGIApplication(
[
('/', UploadHandler),
('/(.+)/([^/]+)/([^/]+)', FileHandler)
],
debug=DEBUG
)
|
