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R3600/modules/websubmit/lib/websubmit_file_metadata.py
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websubmit_file_metadata.py
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# -*- coding: utf-8 -*-
##
## This file is part of CDS Invenio.
## Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 CERN.
##
## CDS 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.
##
## CDS 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 CDS Invenio; if not, write to the Free Software Foundation, Inc.,
## 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
"""
This is the metadata reader and writer module. Contains the proper
plugin containers in order to read/write metadata from images or other
files.
Public APIs:
- read_metadata()
- write_metadata()
"""
__required_plugin_API_version__ = "WebSubmit File Metadata Plugin API 1.0"
import os, sys
import traceback
from optparse import OptionParser
from invenio.pluginutils import PluginContainer
from invenio.config import CFG_PYLIBDIR
from invenio.bibdocfile import decompose_file
from invenio.websubmit_config import InvenioWebSubmitFileMetadataRuntimeError
def read_metadata(inputfile, force=None, remote=False,
loginpw=None, verbose=0):
"""
Returns metadata extracted from given file as dictionary.
Availability depends on input file format and installed plugins
(return C{TypeError} if unsupported file format).
@param inputfile: path to a file
@type inputfile: string
@param verbose: verbosity
@type verbose: int
@param force: name of plugin to use, to skip plugin auto-discovery
@type force: string
@param remote: if the file is accessed remotely or not
@type remote: boolean
@param loginpw: credentials to access secure servers (username:password)
@type loginpw: string
@return: dictionary of metadata tags as keys, and (interpreted)
value as value
@rtype: dict
@raise TypeError: if file format is not supported.
@raise RuntimeError: if required library to process file is missing.
@raise InvenioWebSubmitFileMetadataRuntimeError: when metadata cannot be read.
"""
metadata = None
# Check file type (0 base, 1 name, 2 ext)
ext = decompose_file(inputfile)[2]
if verbose > 5:
print ext.lower(), 'extension to extract from'
# Load plugins
metadata_extractor_plugins = PluginContainer(
os.path.join(CFG_PYLIBDIR,
'invenio', 'websubmit_file_metadata_plugins', 'wsm_*.py'),
plugin_builder=plugin_builder_function,
api_version=__required_plugin_API_version__)
# Loop through the plugins to find a good one for given file
for plugin_name, plugin in metadata_extractor_plugins.iteritems():
# Local file
if plugin.has_key('can_read_local') and \
plugin['can_read_local'](inputfile) and not remote and \
(not force or plugin_name == force):
if verbose > 5:
print 'Using ' + plugin_name
fetched_metadata = plugin['read_metadata_local'](inputfile,
verbose)
if not metadata:
metadata = fetched_metadata
else:
metadata.update(fetched_metadata)
# Remote file
elif remote and plugin.has_key('can_read_remote') and \
plugin['can_read_remote'](inputfile) and \
(not force or plugin_name == force):
if verbose > 5:
print 'Using ' + plugin_name
fetched_metadata = plugin['read_metadata_remote'](inputfile,
loginpw,
verbose)
if not metadata:
metadata = fetched_metadata
else:
metadata.update(fetched_metadata)
# Return in case we have something
if metadata is not None:
return metadata
# Case of no plugin found, raise
raise TypeError, 'Unsupported file type'
def write_metadata(inputfile, outputfile, metadata_dictionary,
force=None, verbose=0):
"""
Writes metadata to given file.
Availability depends on input file format and installed plugins
(return C{TypeError} if unsupported file format).
@param inputfile: path to a file
@type inputfile: string
@param outputfile: path to the resulting file.
@type outputfile: string
@param verbose: verbosity
@type verbose: int
@param metadata_dictionary: keys and values of metadata to update.
@type metadata_dictionary: dict
@param force: name of plugin to use, to skip plugin auto-discovery
@type force: string
@return: output of the plugin
@rtype: string
@raise TypeError: if file format is not supported.
@raise RuntimeError: if required library to process file is missing.
@raise InvenioWebSubmitFileMetadataRuntimeError: when metadata cannot be updated.
"""
# Check file type (0 base, 1 name, 2 ext)
ext = decompose_file(inputfile)[2]
if verbose > 5:
print ext.lower(), 'extension to write to'
# Plugins
metadata_extractor_plugins = PluginContainer(
os.path.join(CFG_PYLIBDIR,
'invenio', 'websubmit_file_metadata_plugins', 'wsm_*.py'),
plugin_builder=plugin_builder_function,
api_version=__required_plugin_API_version__
)
# Loop through the plugins to find a good one to ext
for plugin_name, plugin in metadata_extractor_plugins.iteritems():
if plugin.has_key('can_write_local') and \
plugin['can_write_local'](inputfile) and \
(not force or plugin_name == force):
if verbose > 5:
print 'Using ' + plugin_name
return plugin['write_metadata_local'](inputfile,
outputfile,
metadata_dictionary,
verbose)
# Case of no plugin found, raise
raise TypeError, 'Unsupported file type'
def metadata_info(verbose=0):
"""Shows information about the available plugins"""
print 'Plugin APIs version: %s' % str(__required_plugin_API_version__)
# Plugins
print 'Available plugins:'
metadata_extractor_plugins = PluginContainer(
os.path.join(CFG_PYLIBDIR,
'invenio', 'websubmit_file_metadata_plugins', 'wsm_*.py'),
plugin_builder=plugin_builder_function,
api_version=__required_plugin_API_version__
)
# Print each operation on each plugin
for plugin_name, plugin_funcs in metadata_extractor_plugins.iteritems():
if len(plugin_funcs) > 0:
print '-- Name: ' + plugin_name
print ' Supported operation%s: ' % \
(len(plugin_funcs) > 1 and 's' or '') + \
', '.join(plugin_funcs)
# Are there any unloaded plugins?
broken_plugins = metadata_extractor_plugins.get_broken_plugins()
if len(broken_plugins.keys()) > 0:
print 'Could not load the following plugin%s:' % \
(len(broken_plugins.keys()) > 1 and 's' or '')
for broken_plugin_name, broken_plugin_trace_info in broken_plugins.iteritems():
print '-- Name: ' + broken_plugin_name
if verbose > 5:
formatted_traceback = \
traceback.format_exception(broken_plugin_trace_info[0],
broken_plugin_trace_info[1],
broken_plugin_trace_info[2])
print ' ' + ''.join(formatted_traceback).replace('\n', '\n ')
elif verbose > 0:
print ' ' + str(broken_plugin_trace_info[1])
def print_metadata(metadata):
"""
Pretty-prints metadata returned by the plugins to standard output.
@param metadata: object returned by the plugins when reading metadata
@type metadata: dict
"""
if metadata:
max_key_length = max([len(key) for key in metadata.keys()])
for key, value in metadata.iteritems():
print key, "." * (max_key_length - len(key)), str(value)
else:
print '(No metadata)'
def plugin_builder_function(plugin_name, plugin_code):
"""
Internal function used to build the plugin container, so it behaves as a
dictionary.
@param plugin_name: plugin_name
@param plugin_code: plugin_code
@return: the plugin container
@rtype: dict
"""
ret = {}
for funct_name in ('can_read_local',
'can_read_remote',
'can_write_local',
'read_metadata_local',
'write_metadata_local',
'read_metadata_remote'):
funct = getattr(plugin_code, funct_name, None)
if funct is not None:
ret[funct_name] = funct
return ret
def main():
"""
Manages the arguments, in order to call the proper metadata
handling function
"""
def dictionary_callback(option, opt, value, parser, *args, **kwargs):
"""callback function used to get strings from command line
of the type tag=value and push it into a dictionary
@param parameters: optparse parameters"""
if '=' in value:
key, val = value.split('=', 1)
if getattr(parser.values, 'metadata', None) is None:
parser.values.metadata = {}
parser.values.metadata[key] = val
return
else:
raise ValueError("%s is not in the form key=value" % value)
# Parse arguments
parser = OptionParser(usage="websubmit_file_metadata {-e | -u | -i} " + \
"[-f arg2] [-v] [-d tag=value] [-r] [-l arg3] " + \
"/path/to/file")
parser.add_option("-e", "--extract", dest="extract", action='store_true',
help="extract metadata from file", default=False)
parser.add_option("-u", "--update", dest="update", action='store_true',
help="update file metadata", default=False)
parser.add_option("-o", "--output-file", dest="output_file",
help="Place to save updated file (when --update). Default is same as input file",
type="string", default=None)
parser.add_option("-f", "--force", dest="force_plugin",
help="Plugin we want to be used", type="string",
default=None)
parser.add_option('-v', '--verbose', type="int",
dest='verbose', help='shows detailed information',
default=1)
parser.add_option('-r', '--remote', action='store_true',
dest='remote', help='working with remote file',
default=False)
parser.add_option('-d', '--dictionary-entry',
action="callback",
callback=dictionary_callback, type="string",
help='metadata to update [-d tag=value]')
parser.add_option('-i', '--info', action='store_true',
dest='info', help='shows plugin information',
default=False)
parser.add_option("-l", "--loginpw", dest="loginpw",
help="Login and password to access remote server [login:pw]",
type="string", default=None)
(options, args) = parser.parse_args()
## Get the input file from the arguments list (it should be the
## first argument):
input_file = None
if len(args) > 0:
input_file = args[0]
# If there is no option -d, we avoid metadata option being undefined
if getattr(parser.values, 'metadata', None) is None:
parser.values.metadata = {}
# Is output file specified?
if options.update and not options.output_file:
if options.verbose > 5:
print "Option --output-file not specified. Updating input file."
options.output_file = input_file
elif options.extract and options.output_file:
print "Option --output-file cannot be used with --extract."
print parser.get_usage()
sys.exit(1)
# Make sure there is not extract / write / info at the same time
if (options.extract and options.update) or \
(options.extract and options.info) or \
(options.info and options.update):
print "Choose either --extract, --update or --info"
print parser.get_usage()
sys.exit(1)
elif (options.extract and not input_file) or \
(options.update and not input_file):
print "Input file is missing"
print parser.get_usage()
sys.exit(1)
# Function call based on args
if options.extract:
try:
metadata = read_metadata(input_file,
options.force_plugin,
options.remote,
options.loginpw,
options.verbose)
print_metadata(metadata)
except TypeError, err:
print err
return 1
except RuntimeError, err:
print err
return 1
except InvenioWebSubmitFileMetadataRuntimeError, err:
print err
return 1
elif options.update:
try:
write_metadata(input_file,
options.output_file,
options.metadata,
options.force_plugin,
options.verbose)
except TypeError, err:
print err
return 1
except RuntimeError, err:
print err
return 1
except InvenioWebSubmitFileMetadataRuntimeError, err:
print err
return 1
elif options.info:
try:
metadata_info(options.verbose)
except TypeError:
print 'Problem retrieving plugin information\n'
return 1
else:
parser.error("Incorrect number of arguments\n")
if __name__ == "__main__":
main()
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