engine/manifoldquery.py

   1 import json
   2
   3 # xxx php has uniqid, need to find a module for that
   4 counter=1
   5 def uniqid (): global counter; counter += 1; return counter
   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 Query('%(a)s', '%(m)s', '%(t)s', %(f)s, %(p)s, %(c)s, %(unique)s, '%(uuid)s', %(aq)s, %(sq)s)"""%locals()
  49
  50     # 4amine
  51     # xxx
  52     # this should build an object from a dict as received from javascript
  53     # to see an example just look at the server's output
  54     # incoming POST <QueryDict: {u'query[method]': [u'slice'], u'query[fields][]': [u'slice_hrn'], u'query[timestamp]': [u'latest'], u'query[action]': [u'get']}>
  55     def fill_from_dict (self, d):
  56         for key in d.keys():
  57            for arg in ['action', 'method', 'filters', 'fields', 'timestamp', 'params']:
  58                 if arg in key:
  59                     # dirty hack around fields; fields must be a list
  60                     if arg == 'fields':
  61                         setattr(self, arg, [d[key]])
  62                     else:
  63                         setattr(self, arg, d[key])
  64                     break
  65
  66
  67
  68     def analyze_subqueries(self):
  69         analyzed_query = ManifoldQuery()
  70         analyzed_query.uuid = self.uuid
  71         analyzed_query.action = self.action
  72         analyzed_query.method = self.method
  73         analyzed_query.timestamp = self.timestamp
  74
  75         # analyse query filters
  76         # filter syntax : ['key', 'oparation', 'value']
  77         for filter in self.filters:
  78             key = filter[0]
  79             operation = filter[1]
  80             value = filter[2]
  81             if '.' in key:
  82                 method = key.split('.')[0]
  83                 field = key.split('.')[1]
  84                 if not analyzed_query.subqueries[method]:
  85                     subquery = ManifoldQuery()
  86                     subquery.action = self.action
  87                     subquery.method = method
  88                     subquery.timestamp = self.timestamp
  89                     analyzed_query.subqueries[method] = subquery
  90
  91                 analyzed_query.subqueries[method].filters.append([field, operation, value])
  92             else:
  93                 analyzed_query.filters.append(filter)
  94
  95         # analyse query params
  96         # params syntax : params = {'param1': value1, 'param2': value2, ...}
  97         for param in self.params.keys():
  98             if '.' in param:
  99                 method = param.split('.')[0]
 100                 field = param.split('.')[1]
 101                 if not analyzed_query.subqueries[method]:
 102                     subquery = ManifoldQuery()
 103                     subquery.action = self.action
 104                     subquery.method = method
 105                     subquery.timestamp = self.timestamp
 106                     analyzed_query.subqueries[method] = subquery
 107
 108                 analyzed_query.subqueries[method].params[field] = self.params[param]
 109             else:
 110                 analyzed_query.params[param] = self.params[param]
 111
 112         # analyse query fields
 113         # fields syntax: fields = [element1, element2, ....]
 114         for element in self.fields:
 115             if '.' in element:
 116                 method = element.split('.')[0]
 117                 field = element.split('.')[1]
 118                 if not analyzed_query.subqueries[method]:
 119                     subquery = ManifoldQuery()
 120                     subquery.action = self.action
 121                     subquery.method = method
 122                     subquery.timestamp = self.timestamp
 123                     analyzed_query.subqueries[method] = subquery
 124
 125                 analyzed_query.subqueries[method].fields.append(field)
 126             else:
 127                 analyzed_query.fields.append(element)
 128
 129
 130         # default subqueries
 131         if analyzed_query.method == 'slice':
 132             if not analyzed_query.subqueries['resource']:
 133                 subquery = ManifoldQuery()
 134                 subquery.action = self.action
 135                 subquery.method = method
 136                 subquery.timestamp = self.timestamp
 137                 analyzed_query.subqueries['resource'] = subquery
 138
 139             if not analyzed_query.subqueries['lease']:
 140                 subquery = ManifoldQuery()
 141                 subquery.action = self.action
 142                 subquery.method = method
 143                 subquery.timestamp = self.timestamp
 144                 analyzed_query.subqueries['lease'] = subquery
 145
 146
 147         self.analyzed_query = analyzed_query