Source Code for Module hdf4MapReader

  1  """\
 
  2  Created on 03/01/2011
 
  3  
 
  4  @author: Luis Lopez
 
  5  @contact:  Luis dot Lopez at nsidc dot org
 
  6  
 
  7  HDF map reader
 
  8  V. 0.1.14
 
  9  
 
 10  This program is licensed under the GPL v3 GNU GENERAL PUBLIC LICENSE Version 3, 29 June 2007
 
 11  
 
 12  About the project:
 
 13  
 
 14  The main goal of the HDF mapping project is data preservation to ensure that scientific data stored as HDF4 files
 
 15  will be accessible in the future without relaying on a specific API or platform.  This is being addressed 
 
 16  using XML to represent all the necessary information of an HDF4 file and its content in a structured way.
 
 17  
 
 18  The HDF map reader is being developed using this approach.
 
 19      
 
 20  
 
 21  hdf4MapReader  is the main module, it parses command line argument as follows:
 
 22  
 
 23  ./hdf4MapReader  -f [filename] -l|-e [HDF_object]
 
 24  
 
 25  [filename]: a Valid XML map file
 
 26  
 
 27  -e: extract the object(s)
 
 28  
 
 29  -l: list the object(s)
 
 30  
 
 31  [HDF_object]: VData, SDS, RIS, MDATA, ALL     
 
 32     
 
 33    
 
 34  """ 
 35  from Utils import utils 
 36  from XMLparser import XMLparser 
 37  from optparse import OptionParser 
 38  import os 
 39  import sys 
 40  #from optparse import OptionParser
 
 41  #from time import gmtime, strftime
 
 42  
 
 43  
 
 44  
 
 45 -def usage(args): 
 46      '''
 
 47      Print the usage of the command line, the paths are relative to the script location. 
 
 48        
 
 49      ./hdf4MapReader -f [filename] -l|-e [HDF_object] [-b]
 
 50       
 
 51      [filename]: a Valid XML map file
 
 52      -e: extract the object(s)
 
 53      -l: list the object(s)
 
 54      [HDF_object]: VData, SDS, RIS, MDATA, ALL
 
 55      -b: dumps the object(s) in binary .dat files.
 
 56      ''' 
 57      print "Usage: ", args[len(args)-1] ," -f [filename] -l|-e [HDF_object]" 
 58      print " " 
 59      print " [filename]: a Valid XML map file" 
 60      print " -e: extract the object(s)" 
 61      print " -l: list the object(s)" 
 62      print " [HDF_object]: VData, SDS, RIS, MDATA, ALL" 
 63      
 
 64 -def main(): 
 65      '''
 
 66      This function validate the command line arguments and creates a sub directory in the same path as the XML file and
 
 67      with the same name. This directory will be used to store the output files.
 
 68      
 
 69      If the parameters are correct and the reader has the necessary permissions to create the output directory, an instance of
 
 70      'XMLparser' will be created. 
 
 71      
 
 72      ''' 
 73      util=utils() 
 74      parser = OptionParser() 
 75  
 
 76      parser.add_option("-f", "--file", dest="filename",type="string", 
 
 77                    help="Loads the XML FILE", metavar="FILE") 
 78      
 
 79      parser.add_option("-l", "--list", dest="list",
 
 80                    help="List all the mapped objects in the XML FILE", metavar="LIST") 
 81      
 
 82      parser.add_option("-e", "--extract", dest="extract",
 
 83                    help="Extracts all the mapped objects in the XML FILE", metavar="OBJECTS") 
 84      
 
 85      parser.add_option("-b", "--binary", dest="binary",default=False,nargs=0,
 
 86                    help="Extracts each selected object in a binary .dat file", metavar="DUMP") 
 87      
 
 88      
 
 89    
 
 90      (options, args) = parser.parse_args() 
 91      
 
 92      
 
 93      #Getting the program name
 
 94      args=sys.argv[0].split("/") 
 95      if len(args)==1: 
 96          args=sys.argv[0].split("\\") 
 97  
 
 98      #Relative paths for Windows:
 
 99      if options.filename!=None:         
100          if not os.path.isabs(options.filename): 
101              if sys.platform.find("WIN") and (sys.argv[0].find(".exe")!=-1): 
102                  options.filename= os.path.normpath(os.path.join(sys.path[0],"..\\" +options.filename)) 
103      else: 
104          usage(args) 
105          return 
106  
 
107  
 
108      if options.filename==None:  
109          print "Required argument [-f|--file] missing" 
110          print "" 
111          usage(args) 
112          exit(-1) 
113      elif not os.path.exists( options.filename): 
114          print "The file does not exist or it is an incorrect filename: " + options.filename 
115          print "" 
116          usage(args) 
117          exit(-1) 
118      else: 
119          if options.list==None and options.extract==None: 
120              print " -l or -e required" 
121              print "" 
122              usage() 
123              exit(-1) 
124          elif options.list and options.extract: 
125              print "Options -l and -e are mutually exclusive" 
126              print "" 
127              print options 
128              print "" 
129              usage(args) 
130              exit(-1) 
131          elif options.list not in ["VData","SDS","RIS","MDATA","ALL"] and options.extract not in ["VData","SDS","RIS","MDATA","ALL"]: 
132              print " A valid HDF object name is required" 
133              print "" 
134              print options 
135              print "" 
136              usage(args) 
137              exit(-1) 
138          else: 
139              #print options
 
140              #We have correct arguments
 
141              relative_path=util.getRelativePath(options.filename) 
142              print relative_path, len(relative_path)  
143              if not os.path.exists(options.filename + "_dump"):# Be careful with relative paths in Linux 
144                  try: 
145                      os.makedirs(options.filename+ "_dump") 
146                      print "Directory created :" + options.filename 
147                  except: 
148                      print "Failed to create a sub directory to store the output files: " + options.filename 
149                      exit(-1)                         
150              else: 
151                  print "The output directory already exist: " + options.filename 
152              
 
153              if options.list:# We call the parser just to list the objects mapped in the XML file                 
154                  parser= XMLparser(relative_path,options.filename,"l",options.list,options.binary) 
155                  parser.parseXML() 
156              else:# We call the parser to extract a given object(s) described in the XML map.  
157                  #  At the moment just Gruops and VData are supported                
 
158                  #print strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime())  # benchmarking    
 
159                  parser= XMLparser(relative_path,options.filename,"e",options.extract,options.binary) 
160                  parser.parseXML() 
161                  print "Dumping complete" 
162                  #print strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime())
 
163      
 
164  
 
165  if __name__ == '__main__':     
166      main()# Call the main function to parse the command line arguments and create an instance of XMLparser. 
167