initial work and specs to properly support lazy-loading results from Finder objects

lib/redistat/finder.rb

@@ -2,97 +2,7 @@ module Redistat
   class Finder
     include Database
     
-    attr_reader :options
-    
-    def initialize(options = {})
-      @options = options
-    end
-    
-    def db
-      super(@options[:connection_ref])
-    end
-    
-    def valid_options?
-      return true if !@options[:scope].blank? && !@options[:label].blank? && !@options[:from].blank? && !@options[:till].blank?
-      false
-    end
-    
-    def find(options = {})
-      @options.merge!(options)
-      raise InvalidOptions.new if !valid_options?
-      if @options[:interval].nil? || !@options[:interval]
-        find_by_magic
-      else
-        find_by_interval
-      end
-    end
-    
-    def find_by_interval(options = {})
-      @options.merge!(options)
-      raise InvalidOptions.new if !valid_options?
-      key = build_key
-      col = Collection.new(@options)
-      col.total = Result.new(@options)
-      build_date_sets.each do |set|
-        set[:add].each do |date|
-          result = Result.new
-          result.date = Date.new(date).to_time
-          db.hgetall("#{key.prefix}#{date}").each do |k, v|
-            result[k] = v
-            col.total.set_or_incr(k, v.to_i)
-          end
-          col << result
-        end
-      end
-      col
-    end
-    
-    def find_by_magic(options = {})
-      @options.merge!(options)
-      raise InvalidOptions.new if !valid_options?
-      key = Key.new(@options[:scope], @options[:label])
-      col = Collection.new(@options)
-      col.total = Result.new(@options)
-      col << col.total
-      build_date_sets.each do |set|
-        sum = Result.new
-        sum = summarize_add_keys(set[:add], key, sum)
-        sum = summarize_rem_keys(set[:rem], key, sum)
-        sum.each do |k, v|
-          col.total.set_or_incr(k, v.to_i)
-        end
-      end
-      col
-    end
-    
-    def build_date_sets
-      Finder::DateSet.new(@options[:from], @options[:till], @options[:depth], @options[:interval])
-    end
-    
-    def build_key
-      Key.new(@options[:scope], @options[:label])
-    end
-    
-    def summarize_add_keys(sets, key, sum)
-      sets.each do |date|
-        db.hgetall("#{key.prefix}#{date}").each do |k, v|
-          sum.set_or_incr(k, v.to_i)
-        end
-      end
-      sum
-    end
-    
-    def summarize_rem_keys(sets, key, sum)
-      sets.each do |date|
-        db.hgetall("#{key.prefix}#{date}").each do |k, v|
-          sum.set_or_incr(k, -v.to_i)
-        end
-      end
-      sum
-    end
-    
     class << self
-    
       def find(*args)
         new.find(*args)
       end
@@ -126,15 +36,49 @@ module Redistat
       def interval(unit)
         new.interval(unit)
       end
-      
+    end
+    
+    attr_reader :options
+    
+    def initialize(options = {})
+      @options = options
+    end
+    
+    def all(reload = false)
+      @result = nil if reload
+      @result ||= find
+    end
+    
+    def each(&block)
+      all.each(&block)
+    end
+    
+    def map(&block)
+      all.map(&block)
+    end
+    
+    def each_with_index(&block)
+      all.each_with_index(&block)
+    end
+    
+    def reset!
+      @result = nil
+    end
+    
+    def connection_ref(ref)
+      reset! if @options[:connection_ref] != ref
+      @options[:connection_ref] = ref
+      self
     end
     
     def scope(scope)
+      reset! if @options[:scope] != scope
       @options[:scope] = scope
       self
     end
     
     def label(label)
+      reset! if @options[:label] != label
       @options[:label] = label
       self
     end
@@ -145,25 +89,120 @@ module Redistat
     alias :date :dates
     
     def from(date)
+      reset! if @options[:from] != date
       @options[:from] = date
       self
     end
     
     def till(date)
+      reset! if @options[:till] != date
       @options[:till] = date
       self
     end
     alias :until :till
     
     def depth(unit)
+      reset! if @options[:depth] != unit
       @options[:depth] = unit
       self
     end
     
     def interval(unit)
+      reset! if @options[:interval] != unit
       @options[:interval] = unit
       self
     end
     
+    def find(options = {})
+      set_options(options)
+      raise InvalidOptions.new if !valid_options?
+      if @options[:interval].nil? || !@options[:interval]
+        find_by_magic
+      else
+        find_by_interval
+      end
+    end
+    
+    private
+    
+    def set_options(opts = {})
+      opts = opts.clone
+      opts.each do |key, value|
+        self.send(key, opts.delete(key)) if self.respond_to?(key)
+      end
+      @options.merge!(opts)
+    end
+    
+    def find_by_interval(options = {})
+      raise InvalidOptions.new if !valid_options?
+      key = build_key
+      col = Collection.new(@options)
+      col.total = Result.new(@options)
+      build_date_sets.each do |set|
+        set[:add].each do |date|
+          result = Result.new
+          result.date = Date.new(date).to_time
+          db.hgetall("#{key.prefix}#{date}").each do |k, v|
+            result[k] = v
+            col.total.set_or_incr(k, v.to_i)
+          end
+          col << result
+        end
+      end
+      col
+    end
+    
+    def find_by_magic(options = {})
+      raise InvalidOptions.new if !valid_options?
+      key = Key.new(@options[:scope], @options[:label])
+      col = Collection.new(@options)
+      col.total = Result.new(@options)
+      col << col.total
+      build_date_sets.each do |set|
+        sum = Result.new
+        sum = summarize_add_keys(set[:add], key, sum)
+        sum = summarize_rem_keys(set[:rem], key, sum)
+        sum.each do |k, v|
+          col.total.set_or_incr(k, v.to_i)
+        end
+      end
+      col
+    end
+    
+    def db
+      super(@options[:connection_ref])
+    end
+    
+    def valid_options?
+      return true if !@options[:scope].blank? && !@options[:label].blank? && !@options[:from].blank? && !@options[:till].blank?
+      false
+    end
+    
+    def build_date_sets
+      Finder::DateSet.new(@options[:from], @options[:till], @options[:depth], @options[:interval])
+    end
+    
+    def build_key
+      Key.new(@options[:scope], @options[:label])
+    end
+    
+    def summarize_add_keys(sets, key, sum)
+      sets.each do |date|
+        db.hgetall("#{key.prefix}#{date}").each do |k, v|
+          sum.set_or_incr(k, v.to_i)
+        end
+      end
+      sum
+    end
+    
+    def summarize_rem_keys(sets, key, sum)
+      sets.each do |date|
+        db.hgetall("#{key.prefix}#{date}").each do |k, v|
+          sum.set_or_incr(k, -v.to_i)
+        end
+      end
+      sum
+    end
+    
   end
 end

spec/finder_spec.rb

@@ -19,6 +19,10 @@ describe Redistat::Finder do
     
     finder = Redistat::Finder.new(options)
     finder.options.should == options
+    
+    finder = Redistat::Finder.new
+    finder.send(:set_options, options)
+    finder.options.should == options
 
     finder = Redistat::Finder.dates(two_hours_ago, one_hour_ago).scope("PageViews").label("Label").depth(:hour).interval(:hour)
     finder.options.should == options
@@ -57,6 +61,29 @@ describe Redistat::Finder do
     stats.first.should == stats.total
   end
   
+  it "should be lazy-loaded" do
+    first_stat, last_stat = create_example_stats
+    
+    finder = Redistat::Finder.new
+    finder.from(first_stat).till(last_stat)
+    finder.scope(@scope).label(@label)
+    finder.depth(:hour)
+    
+    finder.instance_variable_get("@result").should be_nil
+    stats = finder.all
+    finder.instance_variable_get("@result").should_not be_nil
+    
+    stats.total.should == { "views" => 12, "visitors" => 8 }
+    stats.total.from.should == first_stat
+    stats.total.till.should == last_stat
+    stats.first.should == stats.total
+    
+    finder.all.object_id.should == stats.object_id
+    finder.from(first_stat + 1.hour)
+    finder.instance_variable_get("@result").should be_nil
+    finder.all.object_id.should_not == stats.object_id
+  end
+  
   it "should fetch data per unit when interval option is specified" do
     first_stat, last_stat = create_example_stats