Fixes #20167 - speed up errata api

app/controllers/katello/api/v2/errata_controller.rb

@@ -14,6 +14,7 @@ class Api::V2::ErrataController < Api::V2::ApiController
     param :errata_restrict_installable, :bool, :desc => N_("show only errata with one or more installable hosts")
     param_group :search, Api::V2::ApiController
     def index
+      params[:errata_restrict_applicable] = false if ::Foreman::Cast.to_bool(params[:errata_restrict_installable])
       super
     end
 
@@ -39,11 +40,11 @@ def custom_index_relation(collection)
       hosts = ::Host::Managed.authorized("view_hosts")
       hosts = hosts.where(:organization_id => params[:organization_id]) if params[:organization_id]
       if ::Foreman::Cast.to_bool(params[:errata_restrict_applicable])
-        collection = collection.applicable_to_hosts(hosts)
+        collection = collection.where(:id => Erratum.applicable_to_hosts(hosts))
       end
 
       if ::Foreman::Cast.to_bool(params[:errata_restrict_installable])
-        collection = collection.installable_for_hosts(hosts)
+        collection = collection.where(:id => Erratum.ids_installable_for_hosts(hosts))
       end
       collection
     end

app/models/katello/erratum.rb

@@ -52,7 +52,7 @@ def self.applicable_to_hosts(hosts)
       # which is calculated elsewhere.
 
       self.joins(:content_facets).
-        where("#{Katello::Host::ContentFacet.table_name}.host_id" => hosts).uniq
+        where("#{Katello::Host::ContentFacet.table_name}.host_id" => hosts)
     end
 
     def self.applicable_to_hosts_dashboard(hosts)
@@ -89,21 +89,31 @@ def hosts_available(org_id = nil)
     end
 
     def self.installable_for_hosts(hosts = nil)
+      self.where(:id => ids_installable_for_hosts(hosts))
+    end
+
+    def self.ids_installable_for_hosts(hosts = nil)
+      hosts = ::Host.where(:id => hosts) if hosts && hosts.is_a?(Array)
+
       # Main goal of this query
       # 1) Get me the applicable errata for these set of hosts
       # 2) Now further prune this list. Only include errata from repos that have been "enabled" on those hosts.
       #    In other words, prune the list to only include the errate in the "bound" repositories signified by
       #    the inner join between ContentFacetRepository and RepositoryErratum
-      query = self.
+      query = self.joins(:content_facet_errata).
         joins("INNER JOIN #{Katello::ContentFacetRepository.table_name} on \
         #{Katello::ContentFacetRepository.table_name}.content_facet_id = #{Katello::ContentFacetErratum.table_name}.content_facet_id").
         joins("INNER JOIN #{Katello::RepositoryErratum.table_name} AS host_repo_errata ON \
           host_repo_errata.erratum_id = #{Katello::Erratum.table_name}.id AND \
           #{Katello::ContentFacetRepository.table_name}.repository_id = host_repo_errata.repository_id")
-      query = query.joins(:content_facet_errata) unless hosts
 
-      query = query.joins(:content_facets).where("#{Katello::Host::ContentFacet.table_name}.host_id" => hosts.map(&:id)) if hosts
-      query.uniq
+      if hosts
+        query = query.where("#{Katello::ContentFacetRepository.table_name}.content_facet_id" => hosts.joins(:content_facet))
+      else
+        query = query.joins(:content_facet_errata)
+      end
+
+      query
     end
 
     def update_from_json(json)

app/models/katello/host/content_facet.rb

@@ -125,7 +125,7 @@ def self.in_content_view_version_environments(version_environments)
       end
 
       def self.with_non_installable_errata(errata)
-        subquery = Katello::Erratum.select("#{Katello::Erratum.table_name}.id").installable_for_hosts
+        subquery = Katello::Erratum.select("#{Katello::Erratum.table_name}.id").ids_installable_for_hosts
         .where("#{Katello::ContentFacetRepository.table_name}.content_facet_id = #{Katello::Host::ContentFacet.table_name}.id").to_sql
         self.joins(:applicable_errata).where("#{Katello::Erratum.table_name}.id" => errata).where("#{Katello::Erratum.table_name}.id NOT IN (#{subquery})").uniq
       end