feat: keep track of the latest verification for a pact version for ea…

…ch provider version, rather than calculating it

db/migrations/20180517_create_latest_pact_publication_ids.rb

@@ -10,7 +10,7 @@
     create_table(:latest_pact_publication_ids_by_consumer_versions, charset: 'utf8') do
       foreign_key :consumer_version_id, :versions, nil: false, on_delete: :cascade
       foreign_key :provider_id, :pacticipants, nil: false, on_delete: :cascade
-      foreign_key :pact_publication_id, :pact_publications, nil: false, on_delete: :cascade
+      foreign_key :pact_publication_id, :pact_publications, nil: false, on_delete: :cascade, unique: true
       index [:provider_id, :consumer_version_id], unique: true, name: "unq_latest_ppid_prov_conver"
     end
   end

db/migrations/20180521_create_latest_verification_ids.rb

@@ -0,0 +1,18 @@
+Sequel.migration do
+  up do
+    # Latest verification_id for each pact version/provider version.
+    # Keeping track of this in a table rather than having to calculate the
+    # latest revision speeds queries up.
+    create_table(:latest_verification_id_for_pact_version_and_provider_version, charset: 'utf8') do
+      foreign_key :pact_version_id, :pact_versions, nil: false, on_delete: :cascade
+      foreign_key :provider_version_id, :versions, nil: false, on_delete: :cascade
+      foreign_key :provider_id, :pacticipants, nil: false, on_delete: :cascade
+      foreign_key :verification_id, :verifications, nil: false, on_delete: :cascade, unique: true
+      index [:pact_version_id, :provider_version_id], unique: true, name: "unq_latest_verifid_pvid_provid"
+    end
+  end
+
+  down do
+    drop_table(:latest_verification_id_for_pact_version_and_provider_version)
+  end
+end

db/migrations/20180522_migrate_latest_verification_ids.rb

@@ -0,0 +1,18 @@
+Sequel.migration do
+  up do
+    # Not sure if we need the provider_id, but it might come in handy
+    rows = from(:verifications).select_group(
+          Sequel[:verifications][:pact_version_id],
+          Sequel[:verifications][:provider_version_id],
+          Sequel[:versions][:pacticipant_id].as(:provider_id))
+        .select_append{ max(verifications[id]).as(verification_id) }
+        .join(:versions, { Sequel[:verifications][:provider_version_id] => Sequel[:versions][:id] })
+
+    # The danger with this migration is that a verification created by an old node will be lost
+    from(:latest_verification_id_for_pact_version_and_provider_version).insert(rows)
+  end
+
+  down do
+
+  end
+end

db/migrations/20180523_recreate_views.rb

@@ -0,0 +1,30 @@
+Sequel.migration do
+  up do
+    # joining with latest_pact_publication_revision_numbers gets rid of the overwritten
+    # pact revisions, and the max(verification_id) gets rid of the overwritten
+    # verifications
+    create_or_replace_view(:latest_verification_id_for_consumer_version_and_provider_version,
+      "select pp.consumer_version_id, lv.provider_version_id, lv.verification_id as latest_verification_id
+      from latest_pact_publication_ids_by_consumer_versions lpp
+      inner join pact_publications pp
+        on pp.id = lpp.pact_publication_id
+      left outer join latest_verification_id_for_pact_version_and_provider_version lv
+          on lv.pact_version_id = pp.pact_version_id"
+    )
+
+  end
+
+  down do
+    create_or_replace_view(:latest_verification_id_for_consumer_version_and_provider_version,
+          "select consumer_version_id, provider_version_id, max(verification_id) as latest_verification_id
+          from matrix
+          inner join latest_pact_publication_revision_numbers lr
+            on matrix.consumer_id = lr.consumer_id
+            and matrix.provider_id = lr.provider_id
+            and matrix.consumer_version_order = lr.consumer_version_order
+            and matrix.pact_revision_number = lr.latest_revision_number
+            group by consumer_version_id, provider_version_id"
+        )
+
+  end
+end

lib/pact_broker/api/resources/verification.rb

@@ -14,6 +14,8 @@ def content_types_provided
           [["application/hal+json", :to_json], ["application/json", :to_json]]
         end
 
+        # Remember to update latest_verification_id_for_pact_version_and_provider_version
+        # if/when DELETE is implemented
         def allowed_methods
           ["GET"]
         end

lib/pact_broker/verifications/repository.rb

@@ -25,6 +25,19 @@ def create verification, provider_version_number, pact
         verification.pact_version_id = pact_version_id_for(pact)
         verification.provider_version = version
         verification.save
+        update_latest_verification_id(verification)
+        verification
+      end
+
+      def update_latest_verification_id verification
+        if PactBroker::Domain::Verification.db.table_exists?(:latest_verification_id_for_pact_version_and_provider_version)
+          table = PactBroker::Domain::Verification.db[:latest_verification_id_for_pact_version_and_provider_version]
+          if table.where(pact_version_id: verification.pact_version_id, provider_version_id: verification.provider_version_id).count == 0
+            table.insert(pact_version_id: verification.pact_version_id, provider_version_id: verification.provider_version_id, provider_id: verification.provider_version.pacticipant_id, verification_id: verification.id)
+          else
+            table.where(pact_version_id: verification.pact_version_id, provider_version_id: verification.provider_version_id).update(verification_id: verification.id)
+          end
+        end
       end
 
       def find consumer_name, provider_name, pact_version_sha, verification_number