initial global snapshot solution with store in memory

lib/sandthorn.rb

@@ -2,6 +2,7 @@
 require "sandthorn/errors"
 require "sandthorn/aggregate_root"
 require "sandthorn/event_stores"
+require "sandthorn/snapshot_store"
 require 'yaml'
 require 'securerandom'
 
@@ -10,7 +11,8 @@ class << self
     extend Forwardable
 
     def_delegators :configuration, :event_stores
-    def_delegators :configuration, :snapshot
+    def_delegators :configuration, :snapshot?
+    def_delegators :configuration, :snapshot_store
 
     def default_event_store
       event_stores.default_store
@@ -40,12 +42,16 @@ def all aggregate_type
       event_store_for(aggregate_type).all(aggregate_type)
     end
 
-    def find aggregate_id, aggregate_type
-      event_store_for(aggregate_type).find(aggregate_id, aggregate_type)
+    def find aggregate_id, aggregate_type, after_aggregate_version = 0
+      event_store_for(aggregate_type).find(aggregate_id, aggregate_type, after_aggregate_version)
     end
 
-    def save_snapshot(aggregate)
-      raise "Not Implemented"
+    def save_snapshot aggregate
+      snapshot_store.save aggregate.aggregate_id, aggregate
+    end
+
+    def find_snapshot aggregate_id
+      return snapshot_store.find aggregate_id
     end
 
     def find_event_store(name)
@@ -85,14 +91,18 @@ def map_types= data
         @event_stores.map_types data
       end
 
-      def snapshot
+      def snapshot?
         @snapshot ||= false
       end
 
       def snapshot=(value)
         @snapshot = value
       end
 
+      def snapshot_store
+        @snapshot_store ||= SnapshotStore.new
+      end
+
       alias_method :event_stores=, :event_store=
     end
   end

lib/sandthorn/aggregate_root_base.rb

@@ -29,6 +29,8 @@ def save
           @aggregate_originating_version = @aggregate_current_event_version
         end
 
+        Sandthorn.save_snapshot self if Sandthorn.snapshot?
+
         self
       end
 
@@ -70,9 +72,17 @@ def event_store(event_store = nil)
           end
         end
 
+        def snapshot(value = nil)
+          if value
+            @snapshot = value
+          else
+            @snapshot
+          end
+        end
+
         def all
           Sandthorn.all(self).map { |events|
-            aggregate_build events
+            aggregate_build events, nil
           }
         end
 
@@ -83,13 +93,15 @@ def find id
 
         def aggregate_find aggregate_id
           begin
-            events = Sandthorn.find(aggregate_id, self)
-            unless events && !events.empty?
+            aggregate_from_snapshot = Sandthorn.find_snapshot(aggregate_id) if Sandthorn.snapshot?
+            current_aggregate_version = aggregate_from_snapshot.nil? ? 0 : aggregate_from_snapshot.aggregate_current_event_version
+            events = Sandthorn.find(aggregate_id, self, current_aggregate_version)
+            if aggregate_from_snapshot.nil? && events.empty?
               raise Errors::AggregateNotFound
             end
 
-            return aggregate_build events
-          rescue Exception
+            return aggregate_build events, aggregate_from_snapshot
+          rescue Exception => error
             raise Errors::AggregateNotFound
           end
 
@@ -111,8 +123,8 @@ def new *args, &block
 
         end
 
-        def aggregate_build events
-          aggregate = create_new_empty_aggregate
+        def aggregate_build events, aggregate_from_snapshot = nil
+          aggregate = aggregate_from_snapshot || create_new_empty_aggregate
 
           if events.any?
             current_aggregate_version = events.last[:aggregate_version]

lib/sandthorn/snapshot_store.rb

@@ -0,0 +1,15 @@
+module Sandthorn
+  class SnapshotStore
+  	def initialize
+      @store = Hash.new
+    end
+
+    def save key, value
+      @store[key] = value
+    end
+
+    def find key
+      @store[key]
+    end
+  end
+end

sandthorn.gemspec

@@ -30,5 +30,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "autotest-standalone"
   spec.add_development_dependency "sqlite3"  
   spec.add_development_dependency "coveralls"
-  spec.add_development_dependency "sandthorn_driver_sequel", ">= 4.0"
+#  spec.add_development_dependency "sandthorn_driver_sequel", ">= 4.0"
 end

spec/aggregate_root_spec.rb

@@ -51,6 +51,17 @@ def no_state_change_only_empty_event
       end
     end
 
+    describe "::snapshot" do
+      let(:klass) { Class.new { include Sandthorn::AggregateRoot } }
+      it "is available as a class method" do
+        expect(klass).to respond_to(:snapshot)
+      end
+      it "sets the snapshot to true and returns it" do
+        klass.snapshot(true)
+        expect(klass.snapshot).to eq(true)
+      end
+    end
+
     describe "when get all aggregates from DirtyClass" do
 
       before(:each) do

spec/spec_helper.rb

@@ -45,17 +45,13 @@ def class_including(mod)
 def url
   "sqlite://spec/db/sequel_driver.sqlite3"
 end
+
 def sqlite_store_setup
 
   SandthornDriverSequel.migrate_db url: url
-
-  driver = SandthornDriverSequel.driver_from_url(url: url) do |conf|
-    conf.event_serializer       = Proc.new { |data| YAML::dump(data) }
-    conf.event_deserializer     = Proc.new { |data| YAML::load(data) }
-  end
 
   Sandthorn.configure do |c|
-    c.event_store = driver
+    c.event_store = SandthornDriverSequel.driver_from_url(url: url)
     c.snapshot = true
   end