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# -*- coding: utf-8 -*-
# Licensed under the MIT license
# http://opensource.org/licenses/mit-license.php
# Copyright 2007, Frank Scholz <coherence@beebits.net>
"""
Covers by Amazon
methods to retrieve covers/album art via the
Amazon E-Commerce WebService v4
http://docs.amazonwebservices.com/AWSECommerceService/2007-04-04/DG/
The licence agreement says something about only
one request per second, so we need to serialize
and delay the calls a bit.
The AWSAccessKeyId supplied is _ONLY_ for the use
in conjunction with Coherence, http://coherence.beebits.net
If you use this library in your own software please
apply for your own key @ http://www.amazon.com/webservices
and follow the rules of their license.
Especially you must add the following disclaimer in a place
that is reasonably viewable by the user of your application:
PLEASE KEEP IN MIND THAT SOME OF THE CONTENT THAT WE
MAKE AVAILABLE TO YOU THROUGH THIS APPLICATION COMES
FROM AMAZON WEB SERVICES. ALL SUCH CONTENT IS PROVIDED
TO YOU "AS IS." THIS CONTENT AND YOUR USE OF IT
ARE SUBJECT TO CHANGE AND/OR REMOVAL AT ANY TIME.
Furthermore if you save any of the cover images you
have to take care that they are stored no longer than
a maximum of one month and requested then from Amazon
again.
"""
import os
import urllib
import StringIO
from twisted.internet import reactor
from twisted.internet import defer
from twisted.web import client
from et import parse_xml
aws_server = { 'de': 'de',
'jp': 'jp',
'ca': 'ca',
'uk': 'co.uk',
'fr': 'fr'}
aws_artist_query = '&Operation=ItemSearch' \
'&SearchIndex=Music'
aws_asin_query = '&Operation=ItemLookup'
aws_response_group = '&ResponseGroup=Images'
aws_ns = 'http://webservices.amazon.com/AWSECommerceService/2005-10-05'
aws_image_size = { 'large': 'LargeImage',
'medium': 'MediumImage',
'small': 'SmallImage'}
class WorkQueue(object):
_instance_ = None # Singleton
def __new__(cls, *args, **kwargs):
obj = getattr(cls,'_instance_',None)
if obj is not None:
return obj
else:
obj = super(WorkQueue, cls).__new__(cls, *args, **kwargs)
cls._instance_ = obj
obj.max_workers = kwargs.get('max_workers', 1)
obj.queue = []
obj.workers = []
return obj
def __init__(self, method, *args, **kwargs):
self.queue.append((method,args,kwargs))
self.queue_run()
def queue_run(self):
if len(self.queue) == 0:
return
if len(self.workers) >= self.max_workers:
#print "WorkQueue - all workers busy"
return
work = self.queue.pop()
d = defer.maybeDeferred(work[0], *work[1],**work[2])
self.workers.append(d)
d.addCallback(self.remove_from_workers, d)
d.addErrback(self.remove_from_workers, d)
def remove_from_workers(self, result, d):
self.workers.remove(d)
reactor.callLater(1,self.queue_run) # a very,very weak attempt
class CoverGetter(object):
"""
retrieve a cover image for a given ASIN,
a TITLE or
an ARTIST/TITLE combo
parameters are:
filename: where to save a received image
if NONE the image will be passed to the callback
callback: a method to call with the filename
or the image as a parameter
after the image request and save was successful
can be:
- only a callable
- a tuple with a callable,
- optional an argument or a tuple of arguments
- optional a dict with keyword arguments
not_found_callback: a method to call when the search at Amazon failed
can be:
- only a callable
- a tuple with a callable,
- optional an argument or a tuple of arguments
- optional a dict with keyword arguments
locale: which Amazon Webservice Server to use, defaults to .com
image_size: request the cover as large|medium|small image
resolution seems to be in pixels for
large: 500x500, medium: 160x160 and small: 75x75
asin: the Amazon Store Identification Number
artist: the artists name
title: the album title
if the filename extension and the received image extension differ,
the image is converted with PIL to the desired format
http://www.pythonware.com/products/pil/index.htm
"""
def __init__(self, filename, aws_key, callback=None, not_found_callback=None,
locale=None,
image_size='large',
title=None, artist=None, asin=None):
self.aws_base_query = '/onca/xml?Service=AWSECommerceService' \
'&AWSAccessKeyId=%s' % aws_key
self.filename = filename
self.callback = callback
self._errcall = not_found_callback
self.server = 'http://ecs.amazonaws.%s' % aws_server.get(locale,'com')
self.image_size = image_size
def sanitize(s):
if s is not None:
s = unicode(s.lower())
s = s.replace(unicode(u'ä'),unicode('ae'))
s = s.replace(unicode(u'ö'),unicode('oe'))
s = s.replace(unicode(u'ü'),unicode('ue'))
s = s.replace(unicode(u'ß'),unicode('ss'))
if isinstance(s,unicode):
s = s.encode('ascii','ignore')
else:
s = s.decode('utf-8').encode('ascii','ignore')
return s
if asin != None:
query = aws_asin_query + '&ItemId=%s' % urllib.quote(asin)
elif (artist is not None or title is not None):
query = aws_artist_query
if artist is not None:
artist = sanitize(artist)
query = '&'.join((query, 'Artist=%s' % urllib.quote(artist)))
if title is not None:
title = sanitize(title)
query = '&'.join((query, 'Title=%s' % urllib.quote(title)))
else:
raise KeyError, "Please supply either asin, title or artist and title arguments"
url = self.server+self.aws_base_query+aws_response_group+query
WorkQueue(self.send_request, url)
def send_request(self,url,*args,**kwargs):
#print "send_request", url
d= client.getPage(url)
d.addCallback(self.got_response)
d.addErrback(self.got_error, url)
return d
def got_image(self, result, convert_from='', convert_to=''):
#print "got_image"
if(len(convert_from) and len(convert_to)):
#print "got_image %d, convert to %s" % (len(result), convert_to)
try:
import Image
im = Image.open(StringIO.StringIO(result))
name,file_ext = os.path.splitext(self.filename)
self.filename = name + convert_to
im.save(self.filename)
except ImportError:
print "we need the Python Imaging Library to do image conversion"
if self.filename == None:
data = result
else:
data = self.filename
if self.callback is not None:
#print "got_image", self.callback
if isinstance(self.callback,tuple):
if len(self.callback) == 3:
c,a,kw = self.callback
if not isinstance(a,tuple):
a = (a,)
a=(data,) + a
c(*a,**kw)
if len(self.callback) == 2:
c,a = self.callback
if isinstance(a,dict):
c(data,**a)
else:
if not isinstance(a,tuple):
a = (a,)
a=(data,) + a
c(*a)
if len(self.callback) == 1:
c = self.callback
c(data)
else:
self.callback(data)
def got_response(self, result):
convert_from = convert_to = ''
result = parse_xml(result, encoding='utf-8')
image_tag = result.find('.//{%s}%s' % (aws_ns,aws_image_size.get(self.image_size,'large')))
if image_tag != None:
image_url = image_tag.findtext('{%s}URL' % aws_ns)
if self.filename == None:
d = client.getPage(image_url)
else:
_,file_ext = os.path.splitext(self.filename)
if file_ext == '':
_,image_ext = os.path.splitext(image_url)
if image_ext != '':
self.filename = ''.join((self.filename, image_ext))
else:
_,image_ext = os.path.splitext(image_url)
if image_ext != '' and file_ext != image_ext:
#print "hmm, we need a conversion..."
convert_from = image_ext
convert_to = file_ext
if len(convert_to):
d = client.getPage(image_url)
else:
d = client.downloadPage(image_url, self.filename)
d.addCallback(self.got_image, convert_from=convert_from, convert_to=convert_to)
d.addErrback(self.got_error, image_url)
else:
if self._errcall is not None:
if isinstance(self._errcall,tuple):
if len(self._errcall) == 3:
c,a,kw = self._errcall
if not isinstance(a,tuple):
a = (a,)
c(*a,**kw)
if len(self._errcall) == 2:
c,a = self._errcall
if isinstance(a,dict):
c(**a)
else:
if not isinstance(a,tuple):
a = (a,)
c(*a)
if len(self._errcall) == 1:
c = self._errcall
c()
else:
self._errcall()
def got_error(self, failure, url):
print "got_error", failure, url
if __name__ == '__main__':
from twisted.python import usage
class Options(usage.Options):
optParameters = [['artist', 'a', '', 'artist name'],
['title', 't', '', 'title'],
['asin', 's', '', 'ASIN'],
['filename', 'f', 'cover.jpg', 'filename'],
]
options = Options()
try:
options.parseOptions()
except usage.UsageError, errortext:
import sys
print '%s: %s' % (sys.argv[0], errortext)
print '%s: Try --help for usage details.' % (sys.argv[0])
sys.exit(1)
def got_it(filename, *args, **kwargs):
print "Mylady, it is an image and its name is", filename, args, kwargs
aws_key = '1XHSE4FQJ0RK0X3S9WR2'
print options['asin'],options['artist'],options['title']
if len(options['asin']):
reactor.callWhenRunning(CoverGetter,options['filename'],aws_key, callback=got_it,asin=options['asin'])
elif len(options['artist']) and len(options['title']):
reactor.callWhenRunning(CoverGetter,options['filename'],aws_key, callback=got_it,artist=options['artist'],title=options['title'])
reactor.run()
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