Source Code for Module pyraf.graphcap

  1  """Finds device attributes from the graphcap 
  2   
  3  $Id: graphcap.py 1276 2010-10-04 14:44:39Z sontag $ 
  4  """ 
  5  from __future__ import division # confidence high 
  6   
  7  import string, filecache 
  8   
  9 -def merge(inlines): 
 10      out = [] 
 11      outbuff = [] 
 12      for inline in inlines: 
 13          tline = inline.strip() 
 14          if len(tline) > 0 and tline[0] != '#': 
 15              if tline[-1] == '\\': 
 16                  # continuation 
 17                  outbuff.append(tline[:-1]) 
 18              else: 
 19                  outbuff.append(tline) 
 20                  out.append(''.join(outbuff)) 
 21                  outbuff = [] 
 22      return out 
 23   
 24 -def getAliases(entry): 
 25      # return list of aliases (and dump the comment) 
 26      aend = entry.find(':') 
 27      if aend<0: 
 28          raise ValueError("Graphcap entry does not have any colons\n%s" % entry) 
 29      return entry[:aend].split("|")[:-1] 
 30   
 31 -def getAttributes(entry): 
 32      abeg = entry.find(':') 
 33      if abeg<0: 
 34          raise ValueError("Graphcap entry does not have any colons\n%s" % entry) 
 35      astring = entry[abeg+1:] 
 36      attr = {} 
 37      attrlist = astring.split(':') 
 38      for attrstr in attrlist: 
 39          if attrstr.strip(): 
 40              attrname = attrstr[:2] 
 41              attrval = attrstr[2:] 
 42              if len(attrstr) <= 2: 
 43                  value = -1 
 44              elif attrval[0] == '=': 
 45                  value = attrval[1:] 
 46              elif attrval[0] == '#': 
 47                  try: 
 48                      value = int(attrval[1:]) 
 49                  except ValueError: 
 50                      try: 
 51                          value = float(attrval[1:]) 
 52                      except ValueError: 
 53                          print "problem reading graphcap" 
 54                          raise 
 55              elif attrval[0] == '@': 
 56                  # implies false 
 57                  value = None 
 58              else: 
 59                  # ignore silently, at least as long as IRAF has a bad 
 60                  # entry in its distribution (illegal colons) 
 61                  # print "problem reading graphcap attributes: ", attrstr 
 62                  # print entry 
 63                  pass 
 64              attr[attrname] = value 
 65      return attr 
 66   
 67 -def getDevices(devlist): 
 68      devices = {} 
 69      for devdef in devlist: 
 70          aliases = getAliases(devdef) 
 71          attributes = getAttributes(devdef) 
 72          for alias in aliases: 
 73              devices[alias] = attributes 
 74      return devices 
 75   
 76 -class GraphCap(filecache.FileCache): 
 77   
 78      """Graphcap class that automatically updates if file changes""" 
 79   
 80 -    def __init__(self, graphcapPath): 
 81          filecache.FileCache.__init__(self, graphcapPath) 
 82   
 83 -    def updateValue(self): 
 84          """Called on init and if file changes""" 
 85          lines = open(self.filename,'r').readlines() 
 86          mergedlines = merge(lines) 
 87          self.dict = getDevices(mergedlines) 
 88   
 89 -    def getValue(self): 
 90          return self.dict 
 91   
 92 -    def __getitem__(self, key): 
 93          """Get up-to-date version of dictionary""" 
 94          dict = self.get() 
 95          if not dict.has_key(key): 
 96              print "Error: device not found in graphcap" 
 97              raise KeyError 
 98          return Device(dict, key) 
 99   
100 -    def has_key(self, key): 
101          dict = self.get() 
102          if dict.has_key(key): 
103              return 1 
104          else: 
105              return 0 
106   
107 -class Device: 
108   
109 -    def __init__(self, devices, devname): 
110          self.dict = devices 
111          self.devname = devname 
112   
113 -    def getAttribute(self, attrName): 
114          dict = self.dict[self.devname] 
115          value = None 
116          while 1: 
117              if dict.has_key(attrName): 
118                  value = dict[attrName] 
119                  break 
120              else: 
121                  if dict.has_key('tc'): 
122                      nextdev = dict['tc'] 
123                      dict = self.dict[nextdev] 
124                  else: 
125                      break 
126          return value 
127   
128 -    def __cmp__(self, other): 
129          if isinstance(other, Device): 
130              return cmp(id(self.dict[self.devname]), 
131                              id(other.dict[other.devname])) 
132          else: 
133              return cmp(id(self), id(other)) 
134   
135 -    def __getitem__(self, key): 
136          return self.getAttribute(key) 
137