From 123f86298c517d0b69a17e88606f67e38bb475e5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bartek=20Bu=C5=82at?= <barthez@users.noreply.github.com>
Date: Mon, 21 Feb 2022 21:38:25 +0100
Subject: [PATCH] fix: Improve Matrix request performance (#537)

Fix some N+1 query issues by using sequel eager loading and similar
preloading techniques.
---
 lib/pact_broker/domain/version.rb    |  7 +++++++
 lib/pact_broker/matrix/quick_row.rb  | 20 +++++++++++---------
 lib/pact_broker/matrix/repository.rb | 11 ++++++-----
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/lib/pact_broker/domain/version.rb b/lib/pact_broker/domain/version.rb
index d0cd51801..25c3ea338 100644
--- a/lib/pact_broker/domain/version.rb
+++ b/lib/pact_broker/domain/version.rb
@@ -241,6 +241,13 @@ def for_selector(selector)
         end
         # rubocop: enable Metrics/CyclomaticComplexity
 
+        def pacticipants_set
+          from_self(alias: :v)
+            .select_group(Sequel[:v][:pacticipant_id])
+            .collect(&:pacticipant_id)
+            .to_set
+        end
+
         # private
 
         def calculate_max_version_order_and_join_back_to_versions(query, selector)
diff --git a/lib/pact_broker/matrix/quick_row.rb b/lib/pact_broker/matrix/quick_row.rb
index 027808bb6..04f5b5f74 100644
--- a/lib/pact_broker/matrix/quick_row.rb
+++ b/lib/pact_broker/matrix/quick_row.rb
@@ -124,15 +124,17 @@ def order_by_pact_publication_created_at
         end
 
         def eager_all_the_things
-          eager(:consumer)
-          .eager(:provider)
-          .eager(consumer_version: [{ current_deployed_versions: :environment }, { current_supported_released_versions: :environment }, { branch_versions: :branch_head }])
-          .eager(provider_version: [{ current_deployed_versions: :environment }, { current_supported_released_versions: :environment }, { branch_versions: :branch_head }])
-          .eager(:verification)
-          .eager(:pact_publication)
-          .eager(:pact_version)
-          .eager(:consumer_version_tags)
-          .eager(:provider_version_tags)
+          eager(
+            :consumer,
+            :provider,
+            :verification,
+            :pact_publication,
+            :pact_version,
+            consumer_version: { current_deployed_versions: :environment, current_supported_released_versions: :environment, branch_versions: [:branch_head, :version, branch: :pacticipant] },
+            provider_version: { current_deployed_versions: :environment, current_supported_released_versions: :environment, branch_versions: [:branch_head, :version, branch: :pacticipant] },
+            consumer_version_tags: { version: :pacticipant },
+            provider_version_tags: { version: :pacticipant }
+          )
         end
 
         def default_scope
diff --git a/lib/pact_broker/matrix/repository.rb b/lib/pact_broker/matrix/repository.rb
index b35dcd81a..8348ed3b7 100644
--- a/lib/pact_broker/matrix/repository.rb
+++ b/lib/pact_broker/matrix/repository.rb
@@ -127,20 +127,19 @@ def integrations_where_specified_selector_is_consumer(resolved_specified_selecto
       def integrations_where_specified_selector_is_provider(resolved_specified_selectors, options)
         integrations_involving_specified_providers = PactBroker::Integrations::Integration
                                                       .where(provider_id: resolved_specified_selectors.collect(&:pacticipant_id))
-                                                      .eager(:consumer)
+                                                      .eager(:consumer, :provider)
                                                       .all
 
         destination_selector = PactBroker::Matrix::UnresolvedSelector.new(options.slice(:latest, :tag, :branch, :environment_name).compact)
+        required = PactBroker::Domain::Version.for_selector(destination_selector).pacticipants_set
 
         integrations_involving_specified_providers.collect do | integration |
-          required = PactBroker::Domain::Version.where(pacticipant: integration.consumer).for_selector(destination_selector).any?
-
           Integration.from_hash(
             consumer_id: integration.consumer.id,
             consumer_name: integration.consumer.name,
             provider_id: integration.provider.id,
             provider_name: integration.provider.name,
-            required: required
+            required: required.member?(integration.consumer.id)
           )
         end
       end
@@ -221,8 +220,10 @@ def base_model_for_integrations
 
       # Find the version number for selectors with the latest and/or tag specified
       def resolve_versions_and_add_ids(unresolved_selectors, selector_type, resolved_ignore_selectors = [])
+        names = unresolved_selectors.collect(&:pacticipant_name)
+        pacticipants = PactBroker::Domain::Pacticipant.where(name: names).to_a.group_by(&:name).transform_values(&:first)
         unresolved_selectors.collect do | unresolved_selector |
-          pacticipant = PactBroker::Domain::Pacticipant.find(name: unresolved_selector.pacticipant_name)
+          pacticipant = pacticipants[unresolved_selector.pacticipant_name]
           if pacticipant
             versions = find_versions_for_selector(unresolved_selector)
             build_resolved_selectors(pacticipant, versions, unresolved_selector, selector_type, resolved_ignore_selectors)