gridspec_api/host/nccf_access_hostfile.py

#!/usr/bin/env python
"""
CDAT cdms2 gridspec extension. Allow a gridspec hostfile to opened as a single
point of access to a mosaic.

$Id: nccf_access_hostfile.py 336 2011-01-07 00:02:25Z dkindig $
"""
from ctypes import * 
import os.path
import sys
import cdms2

class gridspecLibrary():
  def __init__(self):
    """
    Constructor - Create the gridspec cf library object
    """

    self.home = "/home/kindig/software/"
    self.libcf_dir = "libcf_uuid/lib/"
    self.libcf_so  = "libcf_gridspec.so"

    self.cf = CDLL(self.home + self.libcf_dir + self.libcf_so)

    return

class hostFile:
  def __init__(self, hostfile, origHostFile):
    """
    Constructor
    @param filename - open the file and create an entire mosaic object
    @param gsLib - The GRIDSPEC API library
    """

    cf = gridspecLibrary()
    self.cf = cf.cf

    self.CF_MAX_STRING_SIZE = 256

    self.hId = c_int()
    self.mId = c_int()
    self.mosaic_filename = create_string_buffer(self.CF_MAX_STRING_SIZE)

    # Query the hostfile
    self.openHost(hostfile)
    self.getMosaicFilename()

#    self.getGridFilenames()

  def openHost(self, hostfile):
    """
    Open and create the host file object with hId
    @param hostfile - The name of the host file
    """

    self.cf.nccf_def_host_from_file(hostfile, byref(self.hId))

  def getGridIds(self):
    """
    Read the grid filenames from host object
    """
    pass

  def getMosaicFilename(self):
    """
    Read the mosaic filename from host object
    """

    self.cf.nccf_get_host_mosaic_filename(self.hId, self.mosaic_filename)
    self.cf.nccf_get_host_mosaicid(self.hId, byref(self.mId))

    crdnm = (c_char_p*2)
    aa = crdnm()
    aa[0] = " " * self.CF_MAX_STRING_SIZE
    aa[1] = " " * self.CF_MAX_STRING_SIZE

    self.cf.nccf_get_mosaic_coord_names(self.mId, aa)
    self.coordinates = [aa[0], aa[1]]

    return

  # These functions get various items within the mosaic

  def getGrid(self, gridId):
    """
    Return a specific grid from the mosaic
    """
    pass

  def getVariable(self):
    """
    Return a specific variable from the mosaic
    """
    pass

  def getVariables(self):
    """
    Return all variables from the mosaic
    """
    pass

  def getAttribute(self, attid):
    """
    Return an attribute from the mosaic
    """
    pass

  def getDimensionUnits(self, dimid):
    """
    Return the units for a dimension from the mosaic
    """
    pass

  def getGlobal(self, attid):
    """
    Return a global attribute from the mosaic
    """
    pass

  def getSlab(self, varid, slabinfo ):
    """
    Return a slab of data for a variable from the mosaic
    """
    pass

  # These functions return information regarding the details of the mosaic 
  # described by the host file.
  def listall(self):
    """
    List all global attributes, attributes, dimensions and variables 
    associated with the hostfile
    """
    pass

  def listattributes(self):
    """
    List attributes associated with the hostfile
    """
    pass

  def listdimensions(self):
    """
    List dimensions associated with the hostfile
    """
    pass

  def listglobals(self):
    """
    List global attributes associated with the hostfile
    """
    pass

  def listvariable(self, varid):
    """
    List a specific variable attributes and dimensions associated with the
    hostfile
    """
    pass

  def listvariables(self):
    """
    List all variables attributes and dimensions associated with the
    hostfile
    """
    pass

def main():

  # Define a file
  home = "/home/kindig/projects/libcf/libcf/build/gridspec_api/"
  host = "host/"
  hfil = "tst_three_tile_cubed_sphere_host.nc"
  hostfile = home + host + hfil

  # Exit if file doesn't exist
  if not os.path.isfile(hostfile): 
    sys.exit(1)

  origHostFile = cdms2.open(hostfile)

  if 'file_type' in origHostFile.listglobal():
    newHostFile = hostFile(hostfile, origHostFile)

if __name__ == '__main__':
  main()