Source Code for Module glue.cis

  1  # Copyright (C) 2013 Duncan Macleod 
  2  # 
  3  # This program is free software; you can redistribute it and/or modify it 
  4  # under the terms of the GNU General Public License as published by the 
  5  # Free Software Foundation; either version 3 of the License, or (at your 
  6  # option) any later version. 
  7  # 
  8  # This program is distributed in the hope that it will be useful, but 
  9  # WITHOUT ANY WARRANTY; without even the implied warranty of 
 10  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General 
 11  # Public License for more details. 
 12  # 
 13  # You should have received a copy of the GNU General Public License along 
 14  # with this program; if not, write to the Free Software Foundation, Inc., 
 15  # 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA. 
 16   
 17  """Interface to the LIGO Channel Information System 
 18   
 19  Queries can be made using any part of a channel name, returning a list 
 20  of entries (key,value dicts) of found channels:: 
 21   
 22  >>> from glue import cis 
 23  >>> out = cis.query('PSL-ISS_PSB_OUT_DQ') 
 24  >>> print([channel['name'] for channel in out]) 
 25  [u'H1:PSL-ISS_PDB_OUT_DQ', u'H2:PSL-ISS_PDB_OUT_DQ', u'L1:PSL-ISS_PDB_OUT_DQ'] 
 26   
 27  (example accessed August 26 2013). 
 28  """ 
 29   
 30  import json 
 31  import numpy 
 32  from six.moves import urllib 
 33   
 34  from glue.auth.saml import HTTPNegotiateAuthHandler 
 35   
 36  from . import (git_version, auth) 
 37   
 38  __author__ = "Duncan Macleod <duncan.macleod@ligo.org>" 
 39  __version__ = git_version.id 
 40  __date__ = git_version.date 
 41   
 42  CIS_API_URL = 'https://cis.ligo.org/api/channel' 
 43  CIS_DATA_TYPE = {4: numpy.float32} 
 44   
 45   
 46 -def query(name, debug=False): 
 47      """Query the Channel Information System for details on the given 
 48      channel name 
 49   
 50      Example:: 
 51   
 52      >>> from glue import cis 
 53      >>> out = cis.query('PSL-ISS_PSB_OUT_DQ') 
 54      >>> print([channel['name'] for channel in out]) 
 55      [u'H1:PSL-ISS_PDB_OUT_DQ', u'H2:PSL-ISS_PDB_OUT_DQ', 
 56       u'L1:PSL-ISS_PDB_OUT_DQ'] 
 57   
 58      Parameters 
 59      ---------- 
 60      name : str 
 61          Name of the channel of interest, or part of channel to query 
 62   
 63      Returns 
 64      ------- 
 65      list 
 66          list of (key, value) dicts recovered from the CIS 
 67   
 68      Raises 
 69      ------ 
 70      ValueError 
 71          if no channels are found matching the given name 
 72      """ 
 73      url = '%s/?q=%s' % (CIS_API_URL, name) 
 74      more = True 
 75      out = [] 
 76      while more: 
 77          reply = _get(url, debug=debug) 
 78          if reply['count'] == 0: 
 79              raise ValueError("No channels found with name '%s'" % name) 
 80          try: 
 81             out.extend(reply[u'results']) 
 82          except KeyError: 
 83             pass 
 84          more = 'next' in reply and reply['next'] is not None 
 85          if more: 
 86              url = reply['next'] 
 87          else: 
 88              break 
 89      out.sort(key=lambda c: c['name']) 
 90      return out 
 91   
 92   
 93 -def _get(url, debug=False): 
 94      """Perform a GET query against the CIS 
 95      """ 
 96      try: 
 97          response = auth.request_ligodotorg(url, debug=debug) 
 98      except urllib.error.HTTPError: 
 99          raise ValueError("Channel named '%s' not found in Channel " 
100                           "Information System. Please double check the " 
101                           "name and try again." % url.strip('=')[-1]) 
102      return json.loads(response.read()) 
103