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R3600/modules/oairepository/lib/oai_repository_webinterface.py
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oai_repository_webinterface.py
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## This file is part of Invenio.
## Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 CERN.
##
## Invenio is free software; you can redistribute it and/or
## modify it under the terms of the GNU General Public License as
## published by the Free Software Foundation; either version 2 of the
## License, or (at your option) any later version.
##
## Invenio is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Invenio; if not, write to the Free Software Foundation, Inc.,
## 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
"""Invenio OAI provider interface, compliant with OAI-PMH/2.0"""
__revision__ = "$Id$"
import os
import time
import cStringIO
from invenio import webinterface_handler_config as apache
from invenio import oai_repository_server
from invenio.errorlib import register_exception
from invenio.config import CFG_CACHEDIR, CFG_OAI_SLEEP, CFG_DEVEL_SITE, \
CFG_ETCDIR
from invenio.webinterface_handler import wash_urlargd, WebInterfaceDirectory
CFG_VALIDATE_RESPONSES = False
OAI_PMH_VALIDATOR = None
if CFG_DEVEL_SITE:
try:
from lxml import etree
OAI_PMH_VALIDATOR = etree.XMLSchema(etree.parse(open(os.path.join(CFG_ETCDIR, 'oairepository', 'OAI-PMH.xsd'))))
CFG_VALIDATE_RESPONSES = True
except ImportError:
pass
class WebInterfaceOAIProviderPages(WebInterfaceDirectory):
"""Defines the set of /oai2d OAI provider pages."""
_exports = ['']
def __call__(self, req, form):
"""OAI repository interface"""
# Clean input arguments. The protocol specifies that an error
# has to be returned if the same argument is specified several
# times. Eg:
# oai2d?verb=ListIdentifiers&metadataPrefix=marcxml&metadataPrefix=marcxml
# So keep the arguments as list for now so that check_argd can
# return an error if needed (check_argd also transforms these
# lists into strings)
argd = wash_urlargd(form, {'verb': (list, []),
'metadataPrefix': (list, []),
'from': (list, []),
'until': (list, []),
'set': (list, []),
'identifier': (list, []),
'resumptionToken': (list, []),
})
if CFG_VALIDATE_RESPONSES:
req.track_writings = True
## wash_urlargd(..) function cleaned everything, but also added
## unwanted parameters. Remove them now
for param in argd.keys():
if not param in form and param != 'verb':
del argd[param]
## wash_urlargd(..) function also removed unknown parameters
## that we would like to keep in order to send back an error
## as required by the protocol. But we do not need that value,
## so set it to empty string.
for param in form.keys():
if param not in argd.keys():
argd[param] = ''
## But still remove 'ln' parameter that was automatically added.
if argd.has_key('ln'):
del argd['ln']
## check request for OAI compliancy
## also transform all the list arguments into string
oai_errors = oai_repository_server.check_argd(argd)
## check availability (OAI requests for Identify, ListSets and
## ListMetadataFormats are served immediately, otherwise we
## shall wait for CFG_OAI_SLEEP seconds between requests):
if os.path.exists("%s/RTdata/RTdata" % CFG_CACHEDIR) and (argd['verb'] not in ["Identify", "ListMetadataFormats", "ListSets"] and not argd.get('resumptionToken')):
time_gap = int(time.time() - os.path.getmtime("%s/RTdata/RTdata" % CFG_CACHEDIR))
if(time_gap < CFG_OAI_SLEEP):
req.headers_out["Status-Code"] = "503"
req.headers_out["Retry-After"] = "%d" % (CFG_OAI_SLEEP - time_gap)
req.status = apache.HTTP_SERVICE_UNAVAILABLE
return "Retry after %d seconds" % (CFG_OAI_SLEEP - time_gap)
command = "touch %s/RTdata/RTdata" % CFG_CACHEDIR
os.system(command)
## create OAI response
req.content_type = "text/xml"
req.send_http_header()
if not oai_errors:
## OAI Identify
if argd['verb'] == "Identify":
req.write(oai_repository_server.oai_identify(argd))
## OAI ListSets
elif argd['verb'] == "ListSets":
req.write(oai_repository_server.oai_list_sets(argd))
## OAI ListIdentifiers or OAI ListRecords
elif argd['verb'] in ("ListIdentifiers", "ListRecords"):
oai_repository_server.oai_list_records_or_identifiers(req, argd)
## OAI GetRecord
elif argd['verb'] == "GetRecord":
req.write(oai_repository_server.oai_get_record(argd))
## OAI ListMetadataFormats
elif argd['verb'] == "ListMetadataFormats":
req.write(oai_repository_server.oai_list_metadata_formats(argd))
## Unknown verb
## OAI error
else:
req.write(oai_repository_server.oai_error(argd, oai_errors))
if CFG_VALIDATE_RESPONSES:
req.track_writings = False
try:
OAI_PMH_VALIDATOR.assertValid(etree.parse(cStringIO.StringIO(req.what_was_written)))
except etree.DocumentInvalid:
register_exception(req=req, alert_admin=True)
raise
return "\n"
## Return the same page wether we ask for /oai2d?verb or /oai2d/?verb
index = __call__
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