Class: Groupy::EntityGrouper

Inherits:
Object
  • Object
show all
Defined in:
lib/rugroupy/group.rb

Constant Summary collapse

@@defaultScoreFunction = 
"function(tag) { return 1; }"
@@defaultIncludeFunction = 
"function(tag) { return true; }"
@@dynamicTagFunction = 
"function(doc) {}"

Instance Method Summary collapse

Constructor Details

#initialize(database, entity) ⇒ EntityGrouper

Returns a new instance of EntityGrouper.



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# File 'lib/rugroupy/group.rb', line 12

def initialize(database, entity)
  @database, @entity = database, entity
  @database["#{@entity}_count"].ensure_index([['_id.tag', Mongo::DESCENDING],
    ['value.count', Mongo::DESCENDING]], :background => false)
end

Instance Method Details

#count_entities(scoreFunction) ⇒ Object 



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# File 'lib/rugroupy/group.rb', line 34

def count_entities(scoreFunction)
  map = BSON::Code.new(<<eos)
    function() { 
      score = #{scoreFunction}; 
      tag = this._id.tag; 
      tagScore = score(tag); 
      entities = this.value.entities.slice(0).sort(); 
      for (x in entities) { 
        for (y in entities) { 
          if (x < y) { 
            emit({tag:tag, e:[entities[x], entities[y]]}, {count:tagScore}); 
            emit({e:[entities[x], entities[y]]}, {count:tagScore}); 
          } 
        } 
      } 
    } 
eos

  reduce = BSON::Code.new(<<eos)
    function(key, values) { 
      result = {count:0}; 
      values.forEach(function(value) { 
        result.count += value.count; 
      }); 
      return result; 
    } 
eos

  @database["#{@entity}_invert"].map_reduce(map, reduce, :out => "#{@entity}_count")
  nil
end

#group(options = {}) ⇒ Object 



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# File 'lib/rugroupy/group.rb', line 28

def group(options={})
  self.invert_entities(options[:includeFunction] || @@defaultIncludeFunction,
    options[:dynamicTagFunction] || @@dynamicTagFunction)
  self.count_entities(options[:scoreFunction] || @@defaultScoreFunction)
end

#invert_entities(includeFunction, dynamicTagFunction) ⇒ Object 



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# File 'lib/rugroupy/group.rb', line 66

def invert_entities(includeFunction, dynamicTagFunction)
  map = BSON::Code.new(<<eos)
    function() { 
      include = #{includeFunction};
      dynamicTagFunction = #{dynamicTagFunction};
      entity_id = this._id; 
      if (this.tags) { 
        for (tag in this.tags) { 
          if (!include(tag)) continue; 
          this.tags[tag].forEach(function(z) { 
            emit({tag:tag, value:z}, {entities: [entity_id]}); 
          });
        }
        dynamicTagFunction(this);
      } 
    }
eos

  reduce = BSON::Code.new(<<eos)
    function(key, values) { 
      result = {entities:[]}; 
      values.forEach(function(value) { 
        value['entities'].forEach(function(entity_id) { 
          result['entities'].push( entity_id ); 
        }); 
      }); 
      return result; 
    }
eos
 
  @database[@entity].map_reduce(map, reduce, :out => "#{@entity}_invert")
  nil
end

#similiar(tag = nil, skip = nil, limit = nil, reverse = false) ⇒ Object 



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# File 'lib/rugroupy/group.rb', line 18

def similiar(tag=nil, skip=nil, limit=nil, reverse=false)
  q = BSON::OrderedHash.new
  q["_id.tag"] = tag ? tag : {"$exists" => false}
  cursor = @database["#{@entity}_count"].find(q, :fields => {"_id.e" => 1})
  cursor.skip(skip) if skip
  cursor.limit(limit) if limit
  cursor.sort("value.count", reverse ? Mongo::ASCENDING : Mongo::DESCENDING)
  cursor.collect { |r| r["_id"]["e"] }
end