Add graph#temp_index, available regardless of native index support.

Implemented in simple Ruby hashes. Use them in graph cloning when the index is temporary anyway.

lib/pacer/graph.rb

@@ -6,7 +6,8 @@ module Pacer
 end
 
 require 'pacer/graph/graph_transactions_mixin'
-require 'pacer/graph/pacer_graph.rb'
-require 'pacer/graph/simple_encoder.rb'
-require 'pacer/graph/yaml_encoder.rb'
+require 'pacer/graph/pacer_graph'
+require 'pacer/graph/simple_encoder'
+require 'pacer/graph/yaml_encoder'
 require 'pacer/graph/graph_ml'
+require 'pacer/graph/hash_index'

lib/pacer/graph/hash_index.rb

@@ -0,0 +1,29 @@
+module Pacer::Graph
+  class HashIndex
+    attr_reader :name, :type
+
+    def initialize(element_type, name)
+      @type = type
+      @name = name
+      @data = Hash.new do |h, k|
+        h[k] = Hash.new { |h, k| h[k] = Set[] }
+      end
+    end
+
+    def get(key, value)
+      Pacer::Pipes::EnumerablePipe.new data[key][value]
+    end
+
+    def put(key, value, element)
+      data[key][value] << element
+    end
+
+    def count(key, value)
+      data[key][value].count
+    end
+
+    private
+
+    attr_reader :data
+  end
+end

lib/pacer/graph/pacer_graph.rb

@@ -266,7 +266,7 @@ module Indices
       # @option opts [true] :create create the index if it doesn't exist
       # @return [Pacer::IndexMixin]
       def index(name, type = nil, opts = {})
-        return unless features.supportsIndices
+        return temp_index(name, type, opts) unless features.supportsIndices
         name = name.to_s
         if type
           type = index_class element_type type
@@ -281,14 +281,31 @@ def index(name, type = nil, opts = {})
       end
 
       def drop_index(idx)
-        return unless features.supportsIndices
+        return drop_temp_index(idx) unless features.supportsIndices
         if idx.is_a? String or idx.is_a? Symbol
           blueprints_graph.dropIndex idx
         else
           blueprints_graph.dropIndex idx.indexName
         end
       end
 
+      def temp_index(name, type = nil, opts = {})
+        @temp_indices ||= {}
+        idx = @temp_indices[name]
+        unless idx
+          if name and type and opts[:create]
+            idx = @temp_indices[name] = Pacer::Graph::HashIndex.new type, name
+          elsif opts[:create]
+            idx = Pacer::Graph::HashIndex.new type, nil
+          end
+        end
+        Pacer::Wrappers::IndexWrapper.new self, idx, idx.type if idx
+      end
+
+      def drop_temp_index(idx)
+        @temp_indices.delete idx.name
+      end
+
       # Return an object that can be compared to the return value of
       # Index#index_class.
       def index_class(et)

lib/pacer/wrappers/edge_wrapper.rb

@@ -130,7 +130,7 @@ def delete!
     #
     # @raise [StandardError] If this the associated vertices don't exist and :create_vertices is not set
     def clone_into(target_graph, opts = {})
-      e_idx = target_graph.index("tmp-e-#{graph.graph_id}", :edge, :create => true)
+      e_idx = target_graph.temp_index("tmp-e-#{graph.graph_id}", :edge, :create => true)
       e = target_graph.edge(element_id)
       unless e
         e = e_idx.first('id', element_id)
@@ -139,7 +139,7 @@ def clone_into(target_graph, opts = {})
         end
       end
       unless e
-        v_idx = target_graph.index("tmp-v-#{graph.graph_id}", :vertex, :create => true)
+        v_idx = target_graph.temp_index("tmp-v-#{graph.graph_id}", :vertex, :create => true)
         iv = target_graph.vertex(in_vertex.element_id) || v_idx.first('id', in_vertex.element_id)
         ov = target_graph.vertex(out_vertex.element_id) || v_idx.first('id', out_vertex.element_id)
         if opts[:create_vertices]
@@ -168,7 +168,7 @@ def clone_into(target_graph, opts = {})
     #
     # @raise [StandardError] If this the associated vertices don't exist
     def copy_into(target_graph)
-      v_idx = target_graph.index("tmp-v-#{graph.graph_id}", :vertex, :create => true)
+      v_idx = target_graph.temp_index("tmp-v-#{graph.graph_id}", :vertex, :create => true)
       iv = v_idx.first('id', in_vertex.element_id) || target_graph.vertex(in_vertex.element_id)
       ov = v_idx.first('id', out_vertex.element_id) || target_graph.vertex(out_vertex.element_id)
 

lib/pacer/wrappers/vertex_wrapper.rb

@@ -131,7 +131,7 @@ def delete!
     # @yield [v] Optional block yields the vertex after it has been created.
     # @return [Pacer::Wrappers::VertexWrapper] the new vertex
     def clone_into(target_graph, opts = nil)
-      v_idx = target_graph.index("tmp-v-#{graph.graph_id}", :vertex, :create => true)
+      v_idx = target_graph.temp_index("tmp-v-#{graph.graph_id}", :vertex, :create => true)
       v = target_graph.vertex(element_id) || v_idx.first('id', element_id)
       unless v
         v = target_graph.create_vertex element_id, properties