manifold/manifoldquery.py

   1 import json
   2 import uuid
   3
   4 def uniqid ():
   5     return uuid.uuid4().hex
   6
   7 class ManifoldQuery:
   8
   9     def __init__ (self, action=None, method=None, timestamp='now',
  10                   filters=[], params=[], fields=[],
  11                   sort=None, limit=None, offset=None,
  12                   ):
  13         self.uuid=uniqid()
  14         # settable
  15         self.action=action
  16         self.method=method
  17         self.timestamp=timestamp
  18         self.filters=filters
  19         self.params=params
  20         self.fields=fields
  21         self.sort=sort
  22         self.limit=limit
  23         self.offset=offset
  24         # internal data
  25         self.analyzed_query=None
  26         self.subqueries = {}
  27
  28     def to_json (self):
  29         uuid=self.uuid
  30         a=self.action
  31         m=self.method
  32         t=self.timestamp
  33         f=json.dumps (self.filters)
  34         p=json.dumps (self.params)
  35         c=json.dumps (self.fields)
  36         # xxx unique can be removed, but for now we pad the js structure
  37         unique=0
  38
  39         aq = self.analyzed_query.to_json() if self.analyzed_query else 'null'
  40         # subqueries is a dictionary method:query
  41         if not self.subqueries:
  42             sq="{}"
  43         else:
  44             sq=", ".join ( [ "'%s':%s" % (method, subquery.to_json())
  45                       for (method, subquery) in self.subqueries.iteritems()])
  46             sq="{%s}"%sq
  47
  48         return """ new ManifoldQuery('%(a)s', '%(m)s', '%(t)s', %(f)s, %(p)s, %(c)s, %(unique)s, '%(uuid)s', %(aq)s, %(sq)s)"""%locals()
  49
  50     # this builds a ManifoldQuery object from a dict as received from javascript through its ajax request
  51     # e.g. here's what I captured from the server's output
  52     # incoming POST <QueryDict: {u'query[method]': [u'slice'], u'query[fields][]': [u'slice_hrn'], u'query[timestamp]': [u'latest'], u'query[action]': [u'get']}>
  53     def fill_from_dict (self, d):
  54         for key in d.keys():
  55             for arg in ['action', 'method', 'filters', 'fields', 'timestamp', 'params']:
  56                 if arg in key:
  57                     # dirty hack around fields; fields must be a list
  58                     if arg == 'fields':
  59                         setattr(self, arg, [d[key]])
  60                     else:
  61                         setattr(self, arg, d[key])
  62                     break
  63
  64
  65
  66     def analyze_subqueries(self):
  67         analyzed_query = ManifoldQuery()
  68         analyzed_query.uuid = self.uuid
  69         analyzed_query.action = self.action
  70         analyzed_query.method = self.method
  71         analyzed_query.timestamp = self.timestamp
  72
  73         # analyse query filters
  74         # filter syntax : ['key', 'oparation', 'value']
  75         for filter in self.filters:
  76             key = filter[0]
  77             operation = filter[1]
  78             value = filter[2]
  79             if '.' in key:
  80                 method = key.split('.')[0]
  81                 field = key.split('.')[1]
  82                 if not analyzed_query.subqueries[method]:
  83                     subquery = ManifoldQuery()
  84                     subquery.action = self.action
  85                     subquery.method = method
  86                     subquery.timestamp = self.timestamp
  87                     analyzed_query.subqueries[method] = subquery
  88
  89                 analyzed_query.subqueries[method].filters.append([field, operation, value])
  90             else:
  91                 analyzed_query.filters.append(filter)
  92
  93         # analyse query params
  94         # params syntax : params = {'param1': value1, 'param2': value2, ...}
  95         for param in self.params.keys():
  96             if '.' in param:
  97                 method = param.split('.')[0]
  98                 field = param.split('.')[1]
  99                 if not analyzed_query.subqueries[method]:
 100                     subquery = ManifoldQuery()
 101                     subquery.action = self.action
 102                     subquery.method = method
 103                     subquery.timestamp = self.timestamp
 104                     analyzed_query.subqueries[method] = subquery
 105
 106                 analyzed_query.subqueries[method].params[field] = self.params[param]
 107             else:
 108                 analyzed_query.params[param] = self.params[param]
 109
 110         # analyse query fields
 111         # fields syntax: fields = [element1, element2, ....]
 112         for element in self.fields:
 113             if '.' in element:
 114                 method = element.split('.')[0]
 115                 field = element.split('.')[1]
 116                 if not analyzed_query.subqueries[method]:
 117                     subquery = ManifoldQuery()
 118                     subquery.action = self.action
 119                     subquery.method = method
 120                     subquery.timestamp = self.timestamp
 121                     analyzed_query.subqueries[method] = subquery
 122
 123                 analyzed_query.subqueries[method].fields.append(field)
 124             else:
 125                 analyzed_query.fields.append(element)
 126
 127
 128         # default subqueries
 129         if analyzed_query.method == 'slice':
 130             if not analyzed_query.subqueries['resource']:
 131                 subquery = ManifoldQuery()
 132                 subquery.action = self.action
 133                 subquery.method = method
 134                 subquery.timestamp = self.timestamp
 135                 analyzed_query.subqueries['resource'] = subquery
 136
 137             if not analyzed_query.subqueries['lease']:
 138                 subquery = ManifoldQuery()
 139                 subquery.action = self.action
 140                 subquery.method = method
 141                 subquery.timestamp = self.timestamp
 142                 analyzed_query.subqueries['lease'] = subquery
 143
 144
 145         self.analyzed_query = analyzed_query