Add find_timeouts and caching to tools/gardening

tools/gardening/lib/src/buildbot_loading.dart

Index: tools/gardening/lib/src/buildbot_loading.dart
diff --git a/tools/gardening/lib/src/buildbot_loading.dart b/tools/gardening/lib/src/buildbot_loading.dart
new file mode 100644
index 0000000000000000000000000000000000000000..35cf6d7c09ff799470ad077bc86ea2358469b355
--- /dev/null
+++ b/tools/gardening/lib/src/buildbot_loading.dart
@@ -0,0 +1,140 @@
+// Copyright (c) 2017, 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 'dart:async';
+import 'dart:io';
+import 'util.dart';
+
+import 'buildbot_structures.dart';
+import 'cache.dart';
+import 'logdog.dart';
+
+const String BUILDBOT_BUILDNUMBER = ' BUILDBOT_BUILDNUMBER: ';
+
+/// Read the build result for [buildUri].
+///
+/// The data is loaded from the cache, if available, otherwise [read] is called
+/// to fetch the data and stored in the cache afterwards.
+Future<BuildResult> _readBuildResult(
+    BuildUri buildUri, Future<String> read()) async {
+  if (buildUri.buildNumber < 0) {
+    String text = await read();
+    BuildResult result = parseTestStepResult(buildUri, text);
+    if (result.buildNumber != null) {
+      cache.write(result.buildUri.logdogPath, text);
+    }
+    return result;
+  } else {
+    return parseTestStepResult(
+        buildUri, await cache.read(buildUri.logdogPath, read));
+  }
+}
+
+/// Fetches test data for [buildUri] through the buildbot stdio.
+Future<BuildResult> readBuildResult(
+    HttpClient client, BuildUri buildUri) async {
+  Future<String> read() async {
+    Uri uri = buildUri.toUri();
+    log('Reading buildbot results: $uri');
+    return await readUriAsText(client, uri);
+  }
+
+  return _readBuildResult(buildUri, read);
+}
+
+/// Fetches test data for [buildUri] through logdog.
+///
+/// The build number of [buildUri] most be non-negative.
+Future<BuildResult> readLogDogResult(BuildUri buildUri) {
+  Future<String> read() async {
+    log('Reading logdog results: $buildUri');
+    return cat(buildUri.logdogPath);
+  }
+
+  return _readBuildResult(buildUri, read);
+}
+
+/// Parses a test status line of the from
+/// `Done <config-name> <arch-name> <test-name>: <status>`.
+///
+/// If [line] is not of the correct form, `null` is returned.
+TestStatus parseTestStatus(String line) {
+  try {
+    List<String> parts = split(line, ['Done ', ' ', ' ', ': ']);
+    String testName = parts[3];
+    String configName = parts[1];
+    String archName = parts[2];
+    String status = parts[4];
+    return new TestStatus(
+        new TestConfiguration(configName, archName, testName), status);
+  } catch (_) {
+    return null;
+  }
+}
+
+/// Parses the [buildUri] test log and creates a [BuildResult] for it.
+BuildResult parseTestStepResult(BuildUri buildUri, String text) {
+  log('Parsing results: $buildUri (${text.length} bytes)');
+  int buildNumber;
+  List<String> currentFailure;
+  bool parsingTimingBlock = false;
+
+  List<TestStatus> results = <TestStatus>[];
+  List<TestFailure> failures = <TestFailure>[];
+  List<Timing> timings = <Timing>[];
+  for (String line in text.split('\n')) {
+    if (line.startsWith(BUILDBOT_BUILDNUMBER)) {
+      buildNumber =
+          int.parse(line.substring(BUILDBOT_BUILDNUMBER.length).trim());
+    }
+    if (currentFailure != null) {
+      if (line.startsWith('Done ')) {
+        TestStatus status = parseTestStatus(line);
+        if (status != null) {
+          results.add(status);
+          failures.add(new TestFailure(buildUri, currentFailure));
+          currentFailure = null;
+        }
+      } else {
+        currentFailure.add(line);
+      }
+    } else if (line.startsWith('FAILED:')) {
+      currentFailure = <String>[];
+      currentFailure.add(line);
+    }
+    if (line.startsWith('--- Total time:')) {
+      parsingTimingBlock = true;
+    } else if (parsingTimingBlock) {
+      if (line.startsWith('0:')) {
+        timings.addAll(parseTimings(buildUri, line));
+      } else {
+        parsingTimingBlock = false;
+      }
+    }
+  }
+  return new BuildResult(buildUri, buildNumber, results, failures, timings);
+}
+
+/// Create the [Timing]s for the [line] as found in the top-20 timings of a
+/// build step stdio log.
+List<Timing> parseTimings(BuildUri uri, String line) {
+  List<String> parts = split(line, [' - ', ' - ', ' ']);
+  String time = parts[0];
+  String stepName = parts[1];
+  String configName = parts[2];
+  String testNames = parts[3];
+  List<Timing> timings = <Timing>[];
+  for (String name in testNames.split(',')) {
+    name = name.trim();
+    int slashPos = name.indexOf('/');
+    String archName = name.substring(0, slashPos);
+    String testName = name.substring(slashPos + 1);
+    timings.add(new Timing(
+        uri,
+        time,
+        new TestStep(
+            stepName, new TestConfiguration(configName, archName, testName))));
+  }
+  return timings;
+}