[analysis_server] Record timings for recent LSP requests and show in server diagnostics

Change-Id: I1bfb03faa9ce3240c700c93cb4ab677dc1aff520
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/243820
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/lsp_protocol/protocol_special.dart

@@ -285,3 +285,14 @@ class LspJsonHandler<T> {
 abstract class ToJsonable {
   Object toJson();
 }
+
+extension IncomingMessageExtension on IncomingMessage {
+  /// Returns the amount of time (in milliseconds) since the client sent this
+  /// request or `null` if the client did not provide [clientRequestTime].
+  int? get timeSinceRequest {
+    var clientRequestTime = this.clientRequestTime;
+    return clientRequestTime != null
+        ? DateTime.now().millisecondsSinceEpoch - clientRequestTime
+        : null;
+  }
+}

pkg/analysis_server/lib/src/analysis_server_abstract.dart

@@ -14,6 +14,8 @@ import 'package:analysis_server/src/plugin/plugin_manager.dart';
 import 'package:analysis_server/src/plugin/plugin_watcher.dart';
 import 'package:analysis_server/src/server/crash_reporting_attachments.dart';
 import 'package:analysis_server/src/server/diagnostic_server.dart';
+import 'package:analysis_server/src/server/performance.dart';
+import 'package:analysis_server/src/services/completion/completion_performance.dart';
 import 'package:analysis_server/src/services/completion/dart/documentation_cache.dart';
 import 'package:analysis_server/src/services/correction/namespace.dart';
 import 'package:analysis_server/src/services/pub/pub_api.dart';
@@ -124,6 +126,9 @@ abstract class AbstractAnalysisServer {
   /// Performance information before initial analysis is complete.
   final ServerPerformance performanceDuringStartup = ServerPerformance();
 
+  /// Performance about recent requests.
+  final ServerRecentPerformance recentPerformance = ServerRecentPerformance();
+
   RequestStatisticsHelper? requestStatistics;
 
   PerformanceLog? analysisPerformanceLogger;
@@ -543,3 +548,18 @@ abstract class AbstractAnalysisServer {
     return null;
   }
 }
+
+class ServerRecentPerformance {
+  /// The maximum number of performance measurements to keep.
+  static const int performanceListMaxLength = 50;
+
+  /// A list of code completion performance measurements for the latest
+  /// completion operation up to [performanceListMaxLength] measurements.
+  final RecentBuffer<CompletionPerformance> completion =
+      RecentBuffer<CompletionPerformance>(performanceListMaxLength);
+
+  /// A [RecentBuffer] for performance information about the most recent
+  /// requests.
+  final RecentBuffer<RequestPerformance> requests =
+      RecentBuffer(performanceListMaxLength);
+}

pkg/analysis_server/lib/src/handler/legacy/completion_get_suggestions.dart

@@ -93,13 +93,13 @@ class CompletionGetSuggestionsHandler extends CompletionGetSuggestions2Handler {
         }
 
         final completionPerformance = CompletionPerformance(
-          operation: performance,
+          performance: performance,
           path: file,
           requestLatency: requestLatency,
           content: resolvedUnit.content,
           offset: offset,
         );
-        server.completionState.performanceList.add(completionPerformance);
+        server.recentPerformance.completion.add(completionPerformance);
 
         var declarationsTracker = server.declarationsTracker;
         if (declarationsTracker == null) {

pkg/analysis_server/lib/src/handler/legacy/completion_get_suggestions2.dart

@@ -176,13 +176,13 @@ class CompletionGetSuggestions2Handler extends CompletionHandler
         }
 
         final completionPerformance = CompletionPerformance(
-          operation: performance,
+          performance: performance,
           path: file,
           requestLatency: requestLatency,
           content: resolvedUnit.content,
           offset: offset,
         );
-        server.completionState.performanceList.add(completionPerformance);
+        server.recentPerformance.completion.add(completionPerformance);
 
         var analysisSession = resolvedUnit.analysisSession;
         var enclosingNode =

pkg/analysis_server/lib/src/lsp/handlers/handler_completion.dart

@@ -115,14 +115,14 @@ class CompletionHandler extends MessageHandler<CompletionParams, CompletionList>
         'request',
         (performance) async {
           final thisPerformance = CompletionPerformance(
-            operation: performance,
+            performance: performance,
             path: result.path,
             requestLatency: requestLatency,
             content: result.content,
             offset: offset,
           );
           completionPerformance = thisPerformance;
-          server.performanceStats.completion.add(thisPerformance);
+          server.recentPerformance.completion.add(thisPerformance);
 
           // `await` required for `performance.runAsync` to count time.
           return await _getServerDartItems(

pkg/analysis_server/lib/src/lsp/handlers/handlers.dart

@@ -183,7 +183,7 @@ abstract class MessageHandler<P, R>
 
     final params =
         paramsJson != null ? jsonHandler.convertParams(paramsJson) : null as P;
-    final messageInfo = MessageInfo(message.clientRequestTime);
+    final messageInfo = MessageInfo(timeSinceRequest: message.timeSinceRequest);
     return handle(params, messageInfo, token);
   }
 }
@@ -191,18 +191,11 @@ abstract class MessageHandler<P, R>
 /// Additional information about an incoming message (request or notification)
 /// provided to a handler.
 class MessageInfo {
-  final int? clientRequestTime;
-
-  MessageInfo(this.clientRequestTime);
-
   /// Returns the amount of time (in milliseconds) since the client sent this
   /// request or `null` if the client did not provide [clientRequestTime].
-  int? get timeSinceRequest {
-    var clientRequestTime = this.clientRequestTime;
-    return clientRequestTime != null
-        ? DateTime.now().millisecondsSinceEpoch - clientRequestTime
-        : null;
-  }
+  final int? timeSinceRequest;
+
+  MessageInfo({this.timeSinceRequest});
 }
 
 /// A message handler that handles all messages for a given server state.

pkg/analysis_server/lib/src/lsp/lsp_analysis_server.dart

@@ -9,7 +9,6 @@ import 'package:analysis_server/lsp_protocol/protocol_generated.dart';
 import 'package:analysis_server/lsp_protocol/protocol_special.dart';
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/analysis_server_abstract.dart';
-import 'package:analysis_server/src/collections.dart';
 import 'package:analysis_server/src/computer/computer_closingLabels.dart';
 import 'package:analysis_server/src/computer/computer_outline.dart';
 import 'package:analysis_server/src/context_manager.dart';
@@ -30,9 +29,7 @@ import 'package:analysis_server/src/protocol_server.dart' as protocol;
 import 'package:analysis_server/src/server/crash_reporting_attachments.dart';
 import 'package:analysis_server/src/server/diagnostic_server.dart';
 import 'package:analysis_server/src/server/error_notifier.dart';
-import 'package:analysis_server/src/services/completion/completion_performance.dart'
-    show CompletionPerformance;
-import 'package:analysis_server/src/services/completion/completion_state.dart';
+import 'package:analysis_server/src/server/performance.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
 import 'package:analysis_server/src/utilities/process.dart';
 import 'package:analyzer/dart/analysis/context_locator.dart';
@@ -47,6 +44,7 @@ import 'package:analyzer/src/dart/analysis/driver.dart' as analysis;
 import 'package:analyzer/src/dart/analysis/status.dart' as analysis;
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/util/file_paths.dart' as file_paths;
+import 'package:analyzer/src/util/performance/operation_performance.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart' as plugin;
 import 'package:analyzer_plugin/protocol/protocol_generated.dart' as plugin;
 import 'package:analyzer_plugin/src/protocol/protocol_internal.dart' as plugin;
@@ -99,8 +97,6 @@ class LspAnalysisServer extends AbstractAnalysisServer {
   ServerCapabilities? capabilities;
   late ServerCapabilitiesComputer capabilitiesComputer;
 
-  LspPerformance performanceStats = LspPerformance();
-
   /// Whether or not the server is controlling the shutdown and will exit
   /// automatically.
   bool willExit = false;
@@ -355,15 +351,25 @@ class LspAnalysisServer extends AbstractAnalysisServer {
         if (message is ResponseMessage) {
           handleClientResponse(message);
         } else if (message is RequestMessage) {
-          final result = await messageHandler.handleMessage(message);
-          if (result.isError) {
-            sendErrorResponse(message, result.error);
-          } else {
-            channel.sendResponse(ResponseMessage(
-                id: message.id,
-                result: result.result,
-                jsonrpc: jsonRpcVersion));
-          }
+          // Record performance information for the request.
+          final performance = OperationPerformanceImpl('<root>');
+          await performance.runAsync('request', (performance) async {
+            final requestPerformance = RequestPerformance(
+              operation: message.method.toString(),
+              performance: performance,
+              requestLatency: message.timeSinceRequest,
+            );
+            recentPerformance.requests.add(requestPerformance);
+            final result = await messageHandler.handleMessage(message);
+            if (result.isError) {
+              sendErrorResponse(message, result.error);
+            } else {
+              channel.sendResponse(ResponseMessage(
+                  id: message.id,
+                  result: result.result,
+                  jsonrpc: jsonRpcVersion));
+            }
+          });
         } else if (message is NotificationMessage) {
           final result = await messageHandler.handleMessage(message);
           if (result.isError) {
@@ -857,14 +863,6 @@ class LspInitializationOptions {
         flutterOutline = options != null && options['flutterOutline'] == true;
 }
 
-class LspPerformance {
-  /// A list of code completion performance measurements for the latest
-  /// completion operation up to [performanceListMaxLength] measurements.
-  final RecentBuffer<CompletionPerformance> completion =
-      RecentBuffer<CompletionPerformance>(
-          CompletionState.performanceListMaxLength);
-}
-
 class LspServerContextManagerCallbacks extends ContextManagerCallbacks {
   // TODO(dantup): Lots of copy/paste from the Analysis Server one here.
 

pkg/analysis_server/lib/src/server/performance.dart

@@ -0,0 +1,19 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:analyzer/src/util/performance/operation_performance.dart';
+
+class RequestPerformance {
+  static var _nextId = 1;
+  final int id;
+  final OperationPerformance performance;
+  final int? requestLatency;
+  final String operation;
+
+  RequestPerformance({
+    required this.operation,
+    required this.performance,
+    this.requestLatency,
+  }) : id = _nextId++;
+}

pkg/analysis_server/lib/src/services/completion/completion_performance.dart

@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'package:analyzer/src/util/performance/operation_performance.dart';
+import 'package:analysis_server/src/server/performance.dart';
 
 /// Compute a string representing a code completion operation at the
 /// given source and location.
@@ -34,24 +34,20 @@ String _computeCompletionSnippet(String contents, int offset) {
 }
 
 /// Overall performance of a code completion operation.
-class CompletionPerformance {
-  static var _nextId = 1;
-  final int id;
-  final OperationPerformance operation;
+class CompletionPerformance extends RequestPerformance {
   final String path;
   final String snippet;
-  final int? requestLatency;
   int? computedSuggestionCount;
   int? transmittedSuggestionCount;
 
   CompletionPerformance({
-    required this.operation,
+    required super.performance,
     required this.path,
-    this.requestLatency,
+    super.requestLatency,
     required String content,
     required int offset,
-  })  : id = _nextId++,
-        snippet = _computeCompletionSnippet(content, offset);
+  })  : snippet = _computeCompletionSnippet(content, offset),
+        super(operation: 'Completion');
 
   String get computedSuggestionCountStr {
     if (computedSuggestionCount == null) return '';
@@ -59,7 +55,7 @@ class CompletionPerformance {
   }
 
   int get elapsedInMilliseconds {
-    return operation.elapsed.inMilliseconds;
+    return performance.elapsed.inMilliseconds;
   }
 
   String get transmittedSuggestionCountStr {

pkg/analysis_server/lib/src/services/completion/completion_state.dart

@@ -3,14 +3,9 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analysis_server/protocol/protocol_generated.dart';
-import 'package:analysis_server/src/collections.dart';
-import 'package:analysis_server/src/services/completion/completion_performance.dart';
 import 'package:analysis_server/src/services/completion/dart/completion_manager.dart';
 
 class CompletionState {
-  /// The maximum number of performance measurements to keep.
-  static const int performanceListMaxLength = 50;
-
   /// The time budget for a completion request.
   Duration budgetDuration = CompletionBudget.defaultDuration;
 
@@ -20,11 +15,6 @@ class CompletionState {
   /// The next completion response id.
   int nextCompletionId = 0;
 
-  /// A list of code completion performance measurements for the latest
-  /// completion operation up to [performanceListMaxLength] measurements.
-  final RecentBuffer<CompletionPerformance> performanceList =
-      RecentBuffer<CompletionPerformance>(performanceListMaxLength);
-
   /// The current request being processed or `null` if none.
   DartCompletionRequest? currentRequest;
 }

pkg/analysis_server/lib/src/status/diagnostics.dart

@@ -14,6 +14,7 @@ import 'package:analysis_server/src/lsp/lsp_analysis_server.dart'
     show LspAnalysisServer;
 import 'package:analysis_server/src/plugin/plugin_manager.dart';
 import 'package:analysis_server/src/server/http_server.dart';
+import 'package:analysis_server/src/server/performance.dart';
 import 'package:analysis_server/src/services/completion/completion_performance.dart';
 import 'package:analysis_server/src/socket_server.dart';
 import 'package:analysis_server/src/status/ast_writer.dart';
@@ -156,136 +157,6 @@ String writeOption(String name, dynamic value) {
   return '$name: <code>$value</code><br> ';
 }
 
-abstract class AbstractCompletionPage extends DiagnosticPageWithNav {
-  AbstractCompletionPage(DiagnosticsSite site)
-      : super(site, 'completion', 'Code Completion',
-            description: 'Latency statistics for code completion.');
-
-  path.Context get pathContext;
-
-  List<CompletionPerformance> get performanceItems;
-
-  @override
-  Future generateContent(Map<String, String> params) async {
-    var completions = performanceItems;
-
-    if (completions.isEmpty) {
-      blankslate('No completions recorded.');
-      return;
-    }
-
-    var fastCount =
-        completions.where((c) => c.elapsedInMilliseconds <= 100).length;
-    p('${completions.length} results; ${printPercentage(fastCount / completions.length)} within 100ms.');
-
-    // draw a chart
-    buf.writeln(
-        '<div id="chart-div" style="width: 700px; height: 300px;"></div>');
-    var rowData = StringBuffer();
-    for (var i = completions.length - 1; i >= 0; i--) {
-      if (rowData.isNotEmpty) {
-        rowData.write(',');
-      }
-      var latency = completions[i].requestLatency ?? 0;
-      var completionTime = completions[i].elapsedInMilliseconds;
-      // label, latency, time
-      // [' ', 21.0, 101.5]
-      rowData.write("[' ', $latency, $completionTime]");
-    }
-    buf.writeln('''
-      <script type="text/javascript">
-      google.charts.load('current', {'packages':['bar']});
-      google.charts.setOnLoadCallback(drawChart);
-      function drawChart() {
-        var data = google.visualization.arrayToDataTable([
-          [ 'Completion', 'Latency', 'Time' ],
-          $rowData
-        ]);
-        var options = {
-          bars: 'vertical',
-          vAxis: {format: 'decimal'},
-          height: 300,
-          isStacked: true,
-          series: {
-            0: { color: '#C0C0C0' },
-            1: { color: '#4285f4' },
-          }
-        };
-        var chart = new google.charts.Bar(document.getElementById('chart-div'));
-        chart.draw(data, google.charts.Bar.convertOptions(options));
-      }
-      </script>
-''');
-
-    // emit the data as a table
-    buf.writeln('<table>');
-    buf.writeln(
-        '<tr><th>Time</th><th>Computed Results</th><th>Transmitted Results</th><th>Source</th><th>Snippet</th></tr>');
-    for (var completion in completions) {
-      var shortName = pathContext.basename(completion.path);
-      buf.writeln('<tr>'
-          '<td class="pre right"><a href="/timing?id=${completion.id}">'
-          '${_formatTiming(completion)}'
-          '</a></td>'
-          '<td class="right">${completion.computedSuggestionCountStr}</td>'
-          '<td class="right">${completion.transmittedSuggestionCountStr}</td>'
-          '<td>${escape(shortName)}</td>'
-          '<td><code>${escape(completion.snippet)}</code></td>'
-          '</tr>');
-    }
-    buf.writeln('</table>');
-  }
-
-  String _formatTiming(CompletionPerformance completion) {
-    var buffer = StringBuffer();
-    buffer.write(printMilliseconds(completion.elapsedInMilliseconds));
-
-    var latency = completion.requestLatency;
-    if (latency != null) {
-      buffer
-        ..write(' <small class="subtle" title="client-to-server latency">(+ ')
-        ..write(printMilliseconds(latency))
-        ..write(')</small>');
-    }
-
-    return buffer.toString();
-  }
-}
-
-abstract class AbstractCompletionTimingPage extends DiagnosticPageWithNav {
-  AbstractCompletionTimingPage(DiagnosticsSite site)
-      : super(site, 'timing', 'Timing', description: 'Timing statistics.');
-
-  path.Context get pathContext;
-
-  List<CompletionPerformance> get performanceItems;
-
-  @override
-  bool get showInNav => false;
-
-  @override
-  Future generateContent(Map<String, String> params) async {
-    var id = int.parse(params['id'] ?? '');
-    var completionInfo =
-        performanceItems.firstWhereOrNull((info) => info.id == id);
-
-    if (completionInfo == null) {
-      blankslate('Unable to find completion data for $id. '
-          'Perhaps newer completion requests have pushed it out of the buffer?');
-      return;
-    }
-
-    var buffer = StringBuffer();
-    completionInfo.operation.write(buffer: buffer);
-    pre(() {
-      buf.write('<code>');
-      buf.write(escape('$buffer'));
-      buf.writeln('</code>');
-    });
-    return;
-  }
-}
-
 class AstPage extends DiagnosticPageWithNav {
   String? _description;
 
@@ -416,32 +287,66 @@ class CommunicationsPage extends DiagnosticPageWithNav {
   }
 }
 
-class CompletionPage extends AbstractCompletionPage {
-  @override
-  AnalysisServer server;
+class CompletionPage extends DiagnosticPageWithNav with PerformanceChartMixin {
+  CompletionPage(DiagnosticsSite site)
+      : super(site, 'completion', 'Code Completion',
+            description: 'Latency statistics for code completion.');
 
-  CompletionPage(super.site, this.server);
-
-  @override
   path.Context get pathContext => server.resourceProvider.pathContext;
 
-  @override
   List<CompletionPerformance> get performanceItems =>
-      server.completionState.performanceList.items.toList();
-}
-
-class CompletionTimingPage extends AbstractCompletionTimingPage {
-  @override
-  AnalysisServer server;
-
-  CompletionTimingPage(super.site, this.server);
+      server.recentPerformance.completion.items.toList();
 
   @override
-  path.Context get pathContext => server.resourceProvider.pathContext;
+  Future generateContent(Map<String, String> params) async {
+    var completions = performanceItems;
 
-  @override
-  List<CompletionPerformance> get performanceItems =>
-      server.completionState.performanceList.items.toList();
+    if (completions.isEmpty) {
+      blankslate('No completions recorded.');
+      return;
+    }
+
+    var fastCount =
+        completions.where((c) => c.elapsedInMilliseconds <= 100).length;
+    p('${completions.length} results; ${printPercentage(fastCount / completions.length)} within 100ms.');
+
+    drawChart(completions);
+
+    // emit the data as a table
+    buf.writeln('<table>');
+    buf.writeln(
+        '<tr><th>Time</th><th>Computed Results</th><th>Transmitted Results</th><th>Source</th><th>Snippet</th></tr>');
+    for (var completion in completions) {
+      var shortName = pathContext.basename(completion.path);
+      buf.writeln(
+        '<tr>'
+        '<td class="pre right"><a href="/timing?id=${completion.id}&kind=completion">'
+        '${_formatTiming(completion)}'
+        '</a></td>'
+        '<td class="right">${completion.computedSuggestionCountStr}</td>'
+        '<td class="right">${completion.transmittedSuggestionCountStr}</td>'
+        '<td>${escape(shortName)}</td>'
+        '<td><code>${escape(completion.snippet)}</code></td>'
+        '</tr>',
+      );
+    }
+    buf.writeln('</table>');
+  }
+
+  String _formatTiming(CompletionPerformance completion) {
+    var buffer = StringBuffer();
+    buffer.write(printMilliseconds(completion.elapsedInMilliseconds));
+
+    var latency = completion.requestLatency;
+    if (latency != null) {
+      buffer
+        ..write(' <small class="subtle" title="client-to-server latency">(+ ')
+        ..write(printMilliseconds(latency))
+        ..write(')</small>');
+    }
+
+    return buffer.toString();
+  }
 }
 
 class ContentsPage extends DiagnosticPageWithNav {
@@ -844,15 +749,13 @@ class DiagnosticsSite extends Site implements AbstractGetHandler {
     if (server != null) {
       pages.add(PluginsPage(this, server));
     }
+    pages.add(CompletionPage(this));
     if (server is AnalysisServer) {
-      pages.add(CompletionPage(this, server));
-      pages.add(CompletionTimingPage(this, server));
       pages.add(SubscriptionsPage(this, server));
     } else if (server is LspAnalysisServer) {
-      pages.add(LspCompletionPage(this, server));
-      pages.add(LspCompletionTimingPage(this, server));
       pages.add(LspCapabilitiesPage(this, server));
     }
+    pages.add(TimingPage(this));
 
     var profiler = ProcessProfiler.getProfilerForPlatform();
     if (profiler != null) {
@@ -1110,34 +1013,6 @@ class LspCapabilitiesPage extends DiagnosticPageWithNav {
 //   }
 // }
 
-class LspCompletionPage extends AbstractCompletionPage {
-  @override
-  LspAnalysisServer server;
-
-  LspCompletionPage(super.site, this.server);
-
-  @override
-  path.Context get pathContext => server.resourceProvider.pathContext;
-
-  @override
-  List<CompletionPerformance> get performanceItems =>
-      server.performanceStats.completion.items.toList();
-}
-
-class LspCompletionTimingPage extends AbstractCompletionTimingPage {
-  @override
-  LspAnalysisServer server;
-
-  LspCompletionTimingPage(super.site, this.server);
-
-  @override
-  path.Context get pathContext => server.resourceProvider.pathContext;
-
-  @override
-  List<CompletionPerformance> get performanceItems =>
-      server.performanceStats.completion.items.toList();
-}
-
 class MemoryAndCpuPage extends DiagnosticPageWithNav {
   final ProcessProfiler profiler;
 
@@ -1255,7 +1130,7 @@ class PluginsPage extends DiagnosticPageWithNav {
             var requestName = entry.key;
             var data = entry.value;
             // TODO(brianwilkerson) Consider displaying these times as a graph,
-            //  similar to the one in AbstractCompletionPage.generateContent.
+            //  similar to the one in CompletionPage.generateContent.
             var buffer = StringBuffer();
             buffer.write(requestName);
             buffer.write(' ');
@@ -1356,3 +1231,84 @@ class SubscriptionsPage extends DiagnosticPageWithNav {
     });
   }
 }
+
+class TimingPage extends DiagnosticPageWithNav with PerformanceChartMixin {
+  TimingPage(DiagnosticsSite site)
+      : super(site, 'timing', 'Timing', description: 'Timing statistics.');
+
+  @override
+  Future generateContent(Map<String, String> params) async {
+    var kind = params['kind'];
+
+    List<RequestPerformance> items;
+    if (kind == 'completion') {
+      items = server.recentPerformance.completion.items.toList();
+    } else {
+      items = server.recentPerformance.requests.items.toList();
+    }
+
+    var id = int.tryParse(params['id'] ?? '');
+    if (id == null) {
+      return _generateList(items);
+    } else {
+      return _generateDetails(id, items);
+    }
+  }
+
+  String _formatTiming(RequestPerformance item) {
+    var buffer = StringBuffer();
+    buffer.write(printMilliseconds(item.performance.elapsed.inMilliseconds));
+
+    var latency = item.requestLatency;
+    if (latency != null) {
+      buffer
+        ..write(' <small class="subtle" title="client-to-server latency">(+ ')
+        ..write(printMilliseconds(latency))
+        ..write(')</small>');
+    }
+
+    return buffer.toString();
+  }
+
+  void _generateDetails(int id, List<RequestPerformance> items) {
+    var item = items.firstWhereOrNull((info) => info.id == id);
+
+    if (item == null) {
+      blankslate('Unable to find data for $id. '
+          'Perhaps newer requests have pushed it out of the buffer?');
+      return;
+    }
+
+    var buffer = StringBuffer();
+    item.performance.write(buffer: buffer);
+    pre(() {
+      buf.write('<code>');
+      buf.write(escape('$buffer'));
+      buf.writeln('</code>');
+    });
+  }
+
+  void _generateList(List<RequestPerformance> items) {
+    if (items.isEmpty) {
+      blankslate('No requests recorded.');
+      return;
+    }
+
+    drawChart(items);
+
+    // emit the data as a table
+    buf.writeln('<table>');
+    buf.writeln('<tr><th>Time</th><th>Request</th></tr>');
+    for (var item in items) {
+      buf.writeln(
+        '<tr>'
+        '<td class="pre right"><a href="/timing?id=${item.id}">'
+        '${_formatTiming(item)}'
+        '</a></td>'
+        '<td>${escape(item.operation)}</td>'
+        '</tr>',
+      );
+    }
+    buf.writeln('</table>');
+  }
+}

pkg/analysis_server/lib/src/status/pages.dart

@@ -5,6 +5,8 @@
 import 'dart:convert';
 import 'dart:io';
 
+import 'package:analysis_server/src/server/performance.dart';
+
 String escape(String? text) => text == null ? '' : htmlEscape.convert(text);
 
 String printMilliseconds(int value) => '$value ms';
@@ -130,6 +132,48 @@ abstract class Page {
   }
 }
 
+mixin PerformanceChartMixin on Page {
+  void drawChart(List<RequestPerformance> items) {
+    buf.writeln(
+        '<div id="chart-div" style="width: 700px; height: 300px; padding-bottom: 30px;"></div>');
+    var rowData = StringBuffer();
+    for (var i = items.length - 1; i >= 0; i--) {
+      if (rowData.isNotEmpty) {
+        rowData.write(',');
+      }
+      var latency = items[i].requestLatency ?? 0;
+      var time = items[i].performance.elapsed.inMilliseconds;
+      // label, latency, time
+      // [' ', 21.0, 101.5]
+      rowData.write("[' ', $latency, $time]");
+    }
+    buf.writeln('''
+      <script type="text/javascript">
+      google.charts.load('current', {'packages':['bar']});
+      google.charts.setOnLoadCallback(drawChart);
+      function drawChart() {
+        var data = google.visualization.arrayToDataTable([
+          [ 'Request', 'Latency', 'Time' ],
+          $rowData
+        ]);
+        var options = {
+          bars: 'vertical',
+          vAxis: {format: 'decimal'},
+          height: 300,
+          isStacked: true,
+          series: {
+            0: { color: '#C0C0C0' },
+            1: { color: '#4285f4' },
+          }
+        };
+        var chart = new google.charts.Bar(document.getElementById('chart-div'));
+        chart.draw(data, google.charts.Bar.convertOptions(options));
+      }
+      </script>
+''');
+  }
+}
+
 /// Contains a collection of Pages.
 abstract class Site {
   final String title;

pkg/analysis_server/test/lsp/server_test.dart

@@ -36,6 +36,19 @@ class ServerTest extends AbstractLspAnalysisServerTest {
     expect(server.performanceDuringStartup.latencyCount, isPositive);
   }
 
+  Future<void> test_capturesRequestPerformance() async {
+    await initialize(includeClientRequestTime: true);
+    await openFile(mainFileUri, '');
+    await expectLater(
+      getHover(mainFileUri, startOfDocPos),
+      completes,
+    );
+    final performanceItems = server.recentPerformance.requests.items;
+    final hoverItems = performanceItems.where(
+        (item) => item.operation == Method.textDocument_hover.toString());
+    expect(hoverItems, hasLength(1));
+  }
+
   Future<void> test_inconsistentStateError() async {
     await initialize(
       // Error is expected and checked below.