Merge branch 'rz-memory-report-pb-poc' into 'master'

Move the MemoryProfiler to the Performance Bar

See merge request gitlab-org/gitlab!78670

app/assets/javascripts/performance_bar/components/performance_bar_app.vue

@@ -124,6 +124,9 @@ export default {
       const fileName = this.requests[0].truncatedUrl;
       return `${fileName}_perf_bar_${Date.now()}.json`;
     },
+    memoryReportPath() {
+      return mergeUrlParams({ performance_bar: 'memory' }, window.location.href);
+    },
   },
   mounted() {
     this.currentRequest = this.requestId;
@@ -182,6 +185,15 @@ export default {
           s__('PerformanceBar|Download')
         }}</a>
       </div>
+      <div
+        v-if="currentRequest.details && env === 'development'"
+        id="peek-memory-report"
+        class="view"
+      >
+        <a class="gl-text-blue-200" :href="memoryReportPath">{{
+          s__('PerformanceBar|Memory report')
+        }}</a>
+      </div>
       <div v-if="currentRequest.details" id="peek-flamegraph" class="view">
         <span class="gl-text-white-200">{{ s__('PerformanceBar|Flamegraph with mode:') }}</span>
         <a class="gl-text-blue-200" :href="flamegraphPath('wall')">{{

config/initializers/request_profiler.rb

@@ -3,4 +3,5 @@
 Rails.application.configure do |config|
   config.middleware.use(Gitlab::RequestProfiler::Middleware)
   config.middleware.use(Gitlab::Middleware::Speedscope)
+  config.middleware.use(Gitlab::Middleware::MemoryReport)
 end

lib/gitlab/middleware/memory_report.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Middleware
+    class MemoryReport
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        request = ActionDispatch::Request.new(env)
+
+        return @app.call(env) unless rendering_memory_profiler?(request)
+
+        begin
+          require 'memory_profiler'
+
+          report = MemoryProfiler.report do
+            @app.call(env)
+          end
+
+          report = report_to_string(report)
+          headers = { 'Content-Type' => 'text/plain' }
+
+          [200, headers, [report]]
+        rescue StandardError => e
+          ::Gitlab::ErrorTracking.track_exception(e)
+          [500, { 'Content-Type' => 'text/plain' }, ["Could not generate memory report: #{e}"]]
+        end
+      end
+
+      private
+
+      def rendering_memory_profiler?(request)
+        Rails.env.development? && request.params['performance_bar'] == 'memory'
+      end
+
+      def report_to_string(report)
+        io = StringIO.new
+        report.pretty_print(io, detailed_report: true, scale_bytes: true, normalize_paths: true)
+        io.string
+      end
+    end
+  end
+end

locale/gitlab.pot

@@ -26199,6 +26199,9 @@ msgstr ""
 msgid "PerformanceBar|Memory"
 msgstr ""
 
+msgid "PerformanceBar|Memory report"
+msgstr ""
+
 msgid "PerformanceBar|Redis calls"
 msgstr ""
 

spec/lib/gitlab/middleware/memory_report_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'memory_profiler'
+
+RSpec.describe Gitlab::Middleware::MemoryReport do
+  let(:app) { proc { |env| [200, { 'Content-Type' => 'text/plain' }, ['Hello world!']] } }
+  let(:middleware) { described_class.new(app) }
+
+  describe '#call' do
+    shared_examples 'returns original response' do
+      it 'returns original response' do
+        expect(MemoryProfiler).not_to receive(:report)
+
+        status, headers, body = middleware.call(env)
+
+        expect(status).to eq(200)
+        expect(headers).to eq({ 'Content-Type' => 'text/plain' })
+        expect(body.first).to eq('Hello world!')
+      end
+
+      it 'does not call the MemoryProfiler' do
+        expect(MemoryProfiler).not_to receive(:report)
+
+        middleware.call(env)
+      end
+    end
+
+    context 'when the Rails environment is not development' do
+      let(:env) { Rack::MockRequest.env_for('/') }
+
+      it_behaves_like 'returns original response'
+    end
+
+    context 'when the Rails environment is development' do
+      before do
+        allow(Rails.env).to receive(:development?).and_return(true)
+      end
+
+      context 'when memory report is not requested' do
+        let(:env) { Rack::MockRequest.env_for('/') }
+
+        it_behaves_like 'returns original response'
+      end
+
+      context 'when memory report is requested' do
+        let(:env) { Rack::MockRequest.env_for('/', params: { 'performance_bar' => 'memory' }) }
+
+        before do
+          allow(env).to receive(:[]).and_call_original
+          allow(app).to receive(:call).and_return(empty_memory_report)
+        end
+
+        let(:empty_memory_report) do
+          report = MemoryProfiler::Results.new
+          report.register_results(MemoryProfiler::StatHash.new, MemoryProfiler::StatHash.new, 1)
+        end
+
+        it 'returns a memory report' do
+          expect(MemoryProfiler).to receive(:report).and_yield
+
+          status, headers, body = middleware.call(env)
+
+          expect(status).to eq(200)
+          expect(headers).to eq({ 'Content-Type' => 'text/plain' })
+          expect(body.first).to include('Total allocated: 0 B')
+        end
+
+        context 'when something goes wrong with creating the report' do
+          before do
+            expect(MemoryProfiler).to receive(:report).and_raise(StandardError, 'something went terribly wrong!')
+          end
+
+          it 'logs the error' do
+            expect(::Gitlab::ErrorTracking).to receive(:track_exception)
+
+            middleware.call(env)
+          end
+
+          it 'returns the error' do
+            status, headers, body = middleware.call(env)
+
+            expect(status).to eq(500)
+            expect(headers).to eq({ 'Content-Type' => 'text/plain' })
+            expect(body.first).to include('Could not generate memory report: something went terribly wrong!')
+          end
+        end
+      end
+    end
+  end
+end