Adds version cache field to composer metadata

Refactor composer json classes and adds
SHA cache metadata field for future
storage of cached values.

app/presenters/packages/composer/packages_presenter.rb

@@ -20,33 +20,17 @@ module Packages
       end
 
       def package_versions(packages = @packages)
-        { 'packages' => { packages.first.name => package_versions_map(packages) } }
+        package_versions_index(packages).as_json
       end
 
       private
 
-      def package_versions_map(packages)
-        packages.each_with_object({}) do |package, map|
-          map[package.version] = package_metadata(package)
-        end
+      def package_versions_sha(packages = @packages)
+        package_versions_index(packages).sha
       end
 
-      def package_metadata(package)
-        json = package.composer_metadatum.composer_json
-
-        json.merge('dist' => package_dist(package), 'uid' => package.id, 'version' => package.version)
-      end
-
-      def package_dist(package)
-        sha = package.composer_metadatum.target_sha
-        archive_api_path = api_v4_projects_packages_composer_archives_package_name_path({ id: package.project_id, package_name: package.name, format: '.zip' }, true)
-
-        {
-          'type' => 'zip',
-          'url' => expose_url(archive_api_path) + "?sha=#{sha}",
-          'reference' => sha,
-          'shasum' => ''
-        }
+      def package_versions_index(packages)
+        ::Gitlab::Composer::VersionIndex.new(packages)
       end
 
       def providers_map
@@ -59,10 +43,6 @@ module Packages
         map
       end
 
-      def package_versions_sha(packages)
-        Digest::SHA256.hexdigest(package_versions(packages).to_json)
-      end
-
       def provider_sha
         Digest::SHA256.hexdigest(provider.to_json)
       end

changelogs/unreleased/290288-composer-cache-prep.yml

+---
+title: Add version cache field to composer metadata
+merge_request: 50906
+author:
+type: other

db/migrate/20201209193551_add_version_sha_cache_to_composer_metadata.rb

+# frozen_string_literal: true
+
+class AddVersionShaCacheToComposerMetadata < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    with_lock_retries do
+      add_column :packages_composer_metadata, :version_cache_sha, :binary, null: true
+    end
+  end
+
+  def down
+    with_lock_retries do
+      remove_column :packages_composer_metadata, :version_cache_sha, :binary
+    end
+  end
+end

db/schema_migrations/20201209193551

+2278b1e4e19b5306e4b616eb87b622427ef2dcf73dae761739cb3106d5e64718
\ No newline at end of file

db/structure.sql

@@ -14668,7 +14668,8 @@ ALTER SEQUENCE packages_build_infos_id_seq OWNED BY packages_build_infos.id;
 CREATE TABLE packages_composer_metadata (
     package_id bigint NOT NULL,
     target_sha bytea NOT NULL,
-    composer_json jsonb DEFAULT '{}'::jsonb NOT NULL
+    composer_json jsonb DEFAULT '{}'::jsonb NOT NULL,
+    version_cache_sha bytea
 );
 
 CREATE TABLE packages_conan_file_metadata (

lib/gitlab/composer/version_index.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Composer
+    class VersionIndex
+      include API::Helpers::RelatedResourcesHelpers
+
+      def initialize(packages)
+        @packages = packages
+      end
+
+      def as_json(_options = nil)
+        { 'packages' => { @packages.first.name => package_versions_map } }
+      end
+
+      def sha
+        Digest::SHA256.hexdigest(to_json)
+      end
+
+      private
+
+      def package_versions_map
+        @packages.each_with_object({}) do |package, map|
+          map[package.version] = package_metadata(package)
+        end
+      end
+
+      def package_metadata(package)
+        json = package.composer_metadatum.composer_json
+
+        json.merge('dist' => package_dist(package), 'uid' => package.id, 'version' => package.version)
+      end
+
+      def package_dist(package)
+        sha = package.composer_metadatum.target_sha
+        archive_api_path = api_v4_projects_packages_composer_archives_package_name_path({ id: package.project_id, package_name: package.name, format: '.zip' }, true)
+
+        {
+          'type' => 'zip',
+          'url' => expose_url(archive_api_path) + "?sha=#{sha}",
+          'reference' => sha,
+          'shasum' => ''
+        }
+      end
+    end
+  end
+end

spec/lib/gitlab/composer/version_index_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Composer::VersionIndex do
+  let_it_be(:package_name) { 'sample-project' }
+  let_it_be(:json) { { 'name' => package_name } }
+  let_it_be(:group) { create(:group) }
+  let_it_be(:project) { create(:project, :custom_repo, files: { 'composer.json' => json.to_json }, group: group) }
+  let_it_be(:package1) { create(:composer_package, :with_metadatum, project: project, name: package_name, version: '1.0.0', json: json) }
+  let_it_be(:package2) { create(:composer_package, :with_metadatum, project: project, name: package_name, version: '2.0.0', json: json) }
+
+  let(:branch) { project.repository.find_branch('master') }
+
+  let(:packages) { [package1, package2] }
+
+  describe '#as_json' do
+    subject(:index) { described_class.new(packages).as_json }
+
+    def expected_json(package)
+      {
+        'dist' => {
+          'reference' => branch.target,
+          'shasum' => '',
+          'type' => 'zip',
+          'url' => "http://localhost/api/v4/projects/#{project.id}/packages/composer/archives/#{package.name}.zip?sha=#{branch.target}"
+        },
+        'name' => package.name,
+        'uid' => package.id,
+        'version' => package.version
+      }
+    end
+
+    it 'returns the packages json' do
+      packages = index['packages'][package_name]
+
+      expect(packages['1.0.0']).to eq(expected_json(package1))
+      expect(packages['2.0.0']).to eq(expected_json(package2))
+    end
+  end
+
+  describe '#sha' do
+    subject(:sha) { described_class.new(packages).sha }
+
+    it 'returns the json SHA' do
+      expect(sha).to match /^[A-Fa-f0-9]{64}$/
+    end
+  end
+end