Added support for views that emit 1 rather than the doc as a val.

This is now the default behaviour. It's required to keep view index size manageable.

lib/relaxdb.rb

@@ -38,6 +38,7 @@
 require 'relaxdb/relaxdb'
 require 'relaxdb/server'
 require 'relaxdb/uuid_generator'
+require 'relaxdb/view_by_delegator'
 require 'relaxdb/view_object'
 require 'relaxdb/view_result'
 require 'relaxdb/view_uploader'

lib/relaxdb/document.rb

@@ -24,6 +24,9 @@ class Document
     class_inheritable_accessor :__view_docs_by_list__
     self.__view_docs_by_list__ = []
 
+    class_inheritable_accessor :__view_by_list__
+    self.__view_by_list__ = []    
+
     class_inheritable_accessor :belongs_to_rels, :reader => true
     self.belongs_to_rels = {}
 
@@ -523,7 +526,7 @@ def after_save
     end
 
     #
-    # Creates the corresponding view and stores it in CouchDB
+    # Creates the corresponding view, emitting the doc as the val
     # Adds by_ and paginate_by_ methods to the class
     #
     def self.view_docs_by *atts
@@ -539,11 +542,11 @@ def self.view_docs_by *atts
         define_method by_name do |*params|
           view_name = "#{self.name}_#{by_name}"
           if params.empty?
-            res = RelaxDB.rf_view view_name, opts
+            RelaxDB.rf_view view_name, opts
           elsif params[0].is_a? Hash
-            res = RelaxDB.rf_view view_name, opts.merge(params[0])
+            RelaxDB.rf_view view_name, opts.merge(params[0])
           else
-            res = RelaxDB.rf_view(view_name, :key => params[0]).first
+            RelaxDB.rf_view(view_name, :key => params[0]).first
           end            
         end
       end
@@ -559,6 +562,37 @@ def self.view_docs_by *atts
       end
     end
 
+
+    #
+    # Creates the corresponding view, emitting 1 as the val
+    # Adds a by_ method to this class, but does not add a 
+    # paginate method.
+    #
+    def self.view_by *atts
+      opts = atts.last.is_a?(Hash) ? atts.pop : {}
+      opts = opts.merge :raw => true, :reduce => false 
+      __view_by_list__ << atts
+
+      if RelaxDB.create_views?
+        ViewCreator.by_att_list([self.name], *atts).add_to_design_doc
+      end
+
+      by_name = "by_#{atts.join "_and_"}"
+      meta_class.instance_eval do
+        define_method by_name do |*params|
+          view_name = "#{self.name}_#{by_name}"
+          if params.empty?
+            ViewByDelegator.new(RelaxDB.doc_ids(view_name, opts))
+          elsif params[0].is_a? Hash
+            ViewByDelegator.new(RelaxDB.doc_ids(view_name, opts.merge(params[0])))
+          else
+            ViewByDelegator.new(
+              RelaxDB.doc_ids(view_name, opts.merge(:key => params[0]))).load!.first
+          end            
+        end
+      end      
+    end
+
     # Create a view allowing all instances of a particular class to be retreived    
     def self.create_all_by_class_view
       ViewCreator.all.add_to_design_doc if RelaxDB.create_views?        
@@ -589,6 +623,10 @@ def self.create_views chain
         __view_docs_by_list__.each do |atts|
           ViewCreator.docs_by_att_list(@hierarchy, *atts).add_to_design_doc
         end
+
+        __view_by_list__.each do |atts|
+          ViewCreator.by_att_list(@hierarchy, *atts).add_to_design_doc
+        end        
       end
     end
 

lib/relaxdb/view_by_delegator.rb

@@ -0,0 +1,11 @@
+module RelaxDB
+
+  class ViewByDelegator < DelegateClass(Array)
+
+    def load!
+      RelaxDB.load! self.to_a
+    end
+
+  end
+
+end

lib/relaxdb/views.rb

@@ -17,6 +17,14 @@ def self.all(kls)
     end
 
     def self.docs_by_att_list(kls, *atts)
+      create_by_att_list "doc", "_count", kls, *atts
+    end
+
+    def self.by_att_list(kls, *atts)
+      create_by_att_list 1, "_sum", kls, *atts
+    end
+
+    def self.create_by_att_list emit_val, reduce_func, kls, *atts
       class_name = kls[0]
       key = atts.map { |a| "doc.#{a}" }.join(", ")
       key = atts.size > 1 ? key.sub(/^/, "[").sub(/$/, "]") : key
@@ -26,15 +34,14 @@ def self.docs_by_att_list(kls, *atts)
       function(doc) {
         var class_match = #{kls_check kls}
         if (class_match && #{prop_check}) {
-          emit(#{key}, doc);
+          emit(#{key}, #{emit_val});
         }
       }
       QUERY
 
       view_name = "#{class_name}_by_" << atts.join("_and_")
-      View.new view_name, map, "_count"
+      View.new view_name, map, reduce_func      
     end
-
 
     def self.has_n(client_class, relationship, target_class, relationship_to_client)
       map = <<-QUERY

relaxdb.gemspec

@@ -35,6 +35,7 @@ Gem::Specification.new do |s|
    "lib/relaxdb/uuid_generator.rb",
    "lib/relaxdb/taf2_curb_server.rb",
    "lib/relaxdb/validators.rb",
+   "lib/relaxdb/view_by_delegator",
    "lib/relaxdb/view_object.rb",
    "lib/relaxdb/view_result.rb",
    "lib/relaxdb/view_uploader.rb",
@@ -61,8 +62,7 @@ Gem::Specification.new do |s|
    "spec/spec_helper.rb",
    "spec/spec_models.rb",
    "spec/view_docs_by_spec.rb",
-   "spec/view_object_spec.rb",
-   "spec/view_spec.rb"]
+   "spec/view_object_spec.rb"]
   s.bindir = "bin"
   s.autorequire = "relaxdb"
   s.add_dependency "extlib", ">= 0.9.4" # removed ", runtime" as was failing locally

scratch/view_by_bench.rb

@@ -0,0 +1,71 @@
+require 'benchmark'
+
+$:.unshift(File.dirname(__FILE__) + "/../lib")
+require 'relaxdb'
+require File.dirname(__FILE__) + "/../spec/spec_models"
+
+RelaxDB.configure :host => "localhost", :port => 5984, :design_doc => "spec_doc"
+
+RelaxDB.delete_db "relaxdb_spec" rescue :ok
+RelaxDB.use_db "relaxdb_spec"
+RelaxDB.replicate_db "relaxdb_spec_base", "relaxdb_spec"
+
+
+docs = (1..100).map { |i| Primitives.new :_id => "id#{i}", :str => i.to_s }
+RelaxDB.bulk_save! *docs
+
+count = 100
+
+Benchmark.bm do |x|
+
+  # Before a delegator existed
+  # x.report("simple") do
+  #   count.times do
+  #     doc_ids = Primitives.by_str
+  #     RelaxDB.load! doc_ids
+  #   end
+  # end 
+
+  x.report("delegator") do
+    count.times do
+      docs = Primitives.by_str.load!
+    end
+  end 
+
+end
+
+# for 1000 docs and count = 100
+#      user     system      total        real
+# simple 131.520000   2.930000 134.450000 (174.333752)
+
+# for 100 docs and count = 1000
+#      user     system      total        real
+# simple 121.880000   3.470000 125.350000 (161.864292)
+
+#
+# Take Ruby out of the equation and we get...
+#
+# time for i in {1..100}
+# do
+#   curl -s 'localhost:5984/relaxdb_spec/_design/spec_doc/_view/Primitives_by_str?reduce=false' > /dev/null
+#   curl -s -X POST 'localhost:5984/relaxdb_spec/_all_docs?include_docs=true' -d '{"keys":["id1","id2","id3","id4","id5","id6","id7","id8","id9","id10","id11","id12","id13","id14","id15","id16","id17","id18","id19","id20","id21","id22","id23","id24","id25","id26","id27","id28","id29","id30","id31","id32","id33","id34","id35","id36","id37","id38","id39","id40","id41","id42","id43","id44","id45","id46","id47","id48","id49","id50","id51","id52","id53","id54","id55","id56","id57","id58","id59","id60","id61","id62","id63","id64","id65","id66","id67","id68","id69","id70","id71","id72","id73","id74","id75","id76","id77","id78","id79","id80","id81","id82","id83","id84","id85","id86","id87","id88","id89","id90","id91","id92","id93","id94","id95","id96","id97","id98","id99","id100"]}' > /dev/null
+# done
+# 
+# for 100 docs and count = 1000 via curl and bash
+#
+# real  0m6.177s
+# user  0m0.618s
+# sys 0m1.066s
+
+
+# for 100 docs and count = 100 
+#
+#       user     system      total        real
+# simple 12.240000   0.350000  12.590000 ( 16.987776)
+#
+#       user     system      total        real
+# delegator 12.300000   0.350000  12.650000 ( 16.810736)
+
+# Conclusion - if a penalty exists for using a delegator, it's minimal
+# The simplification offered by a delegator to client code is well worth it
+#

spec/spec_models.rb

@@ -22,6 +22,8 @@ class Primitives < RelaxDB::Document
   property :empty
 
   view_docs_by :num
+
+  view_by :str
 
 end
 

spec/view_by_spec.rb

@@ -0,0 +1,47 @@
+require File.dirname(__FILE__) + '/spec_helper.rb'
+require File.dirname(__FILE__) + '/spec_models.rb'
+
+describe "view_by" do
+
+  before(:each) do
+    setup_test_db
+
+    docs = (1..10).map { |i| Primitives.new :_id => "id#{i}", :str => i.to_s }
+    RelaxDB.bulk_save! *docs
+  end
+
+  it "should return an array of doc ids for a key" do
+    docs = Primitives.by_str :key => "5"
+    docs.first.should == "id5"
+  end
+
+  it "should obey startkey and endkey directives" do
+    docs = Primitives.by_str :startkey => "3", :endkey => "6"
+    docs.should == %w(id3 id4 id5 id6)
+  end
+
+  it "should return all when none specified" do
+    docs = Primitives.by_str 
+    docs.size.should == 10
+  end
+
+  describe "delegator" do
+
+    it "should load the returned doc ids" do
+      docs = Primitives.by_str :key => "5"
+      docs.load!.first.str.should == "5"
+    end
+
+    it "should load the doc for a single param" do
+      res = Primitives.by_str "8"
+      res.str.should == "8"
+    end
+
+    it "should return the delegator when no params given" do
+      docs = Primitives.by_str.load!
+      docs.map { |d| d.str }.join.length.should == 11
+    end
+
+  end
+
+end