Files
galaxy/tools/data_source/data_source.py
T

80 lines
3.0 KiB
Python

#!/usr/bin/env python
# Retrieves data from external data source applications and stores in a dataset file.
# Data source application parameters are temporarily stored in the dataset file.
import socket, urllib, sys, os, gzip, tempfile, shutil
from galaxy import eggs
from galaxy.util import gzip_magic
assert sys.version_info[:2] >= ( 2, 4 )
def stop_err( msg ):
sys.stderr.write( msg )
sys.exit()
def check_gzip( filename ):
temp = open( filename, "U" )
magic_check = temp.read( 2 )
temp.close()
if magic_check != gzip_magic:
return False
return True
def __main__():
filename = sys.argv[1]
params = {}
for line in open( filename, 'r' ):
try:
line = line.strip()
fields = line.split( '\t' )
params[ fields[0] ] = fields[1]
except:
continue
URL = params.get( 'URL', None )
if not URL:
open( filename, 'w' ).write( "" )
stop_err( 'The remote data source application has not sent back a URL parameter in the request.' )
URL_method = params.get( 'URL_method', None )
CHUNK_SIZE = 2**20 # 1Mb
# The Python support for fetching resources from the web is layered. urllib uses the httplib
# library, which in turn uses the socket library. As of Python 2.3 you can specify how long
# a socket should wait for a response before timing out. By default the socket module has no
# timeout and can hang. Currently, the socket timeout is not exposed at the httplib or urllib2
# levels. However, you can set the default timeout ( in seconds ) globally for all sockets by
# doing the following.
socket.setdefaulttimeout( 600 )
# The following calls to urllib2.urlopen() will use the above default timeout
try:
if not URL_method or URL_method == 'get':
page = urllib.urlopen( URL )
elif URL_method == 'post':
page = urllib.urlopen( URL, urllib.urlencode( params ) )
except Exception, e:
stop_err( 'The remote data source application may be off line, please try again later. Error: %s' % str( e ) )
out = open( filename, 'w' )
while 1:
chunk = page.read( CHUNK_SIZE )
if not chunk:
break
out.write( chunk )
out.close()
if check_gzip( filename ):
fd, uncompressed = tempfile.mkstemp()
gzipped_file = gzip.GzipFile( filename )
while 1:
try:
chunk = gzipped_file.read( CHUNK_SIZE )
except IOError:
os.close( fd )
os.remove( uncompressed )
gzipped_file.close()
stop_err( 'Problem uncompressing gzipped data, please try retrieving the data uncompressed.' )
if not chunk:
break
os.write( fd, chunk )
os.close( fd )
gzipped_file.close()
# Replace the gzipped file with the uncompressed file
shutil.move( uncompressed, filename )
if __name__ == "__main__": __main__()