Dev compiler debugger related tweaks.

pkg/dev_compiler/web/web_command.dart

Index: pkg/dev_compiler/web/web_command.dart
diff --git a/pkg/dev_compiler/web/web_command.dart b/pkg/dev_compiler/web/web_command.dart
index 1df3255ec61bf74ce53e0bccdf0b22b16f40c8b0..d5eef15cc48a182485e73890387a55d5daf54080 100644
--- a/pkg/dev_compiler/web/web_command.dart
+++ b/pkg/dev_compiler/web/web_command.dart
@@ -7,6 +7,7 @@ library dev_compiler.web.web_command;
 import 'dart:async';
 import 'dart:convert';
 import 'dart:html' show HttpRequest;
+import 'dart:typed_data';
 
 import 'package:analyzer/dart/element/element.dart'
     show
@@ -37,6 +38,21 @@ typedef void MessageHandler(Object message);
 
 @JS()
 @anonymous
+class JSIterator<V> {}
+
+@JS('Map')
+class JSMap<K, V> {
+  external V get(K v);
+  external set(K k, V v);
+  external JSIterator<K> keys();
+  external JSIterator<V> values();
+}
+
+@JS('Array.from')
+external List<V> iteratorToList<V>(JSIterator<V> iterator);
+
+@JS()
+@anonymous
 class CompileResult {
   external factory CompileResult(
       {String code, List<String> errors, bool isValid});
@@ -45,6 +61,51 @@ class CompileResult {
 typedef CompileModule(String imports, String body, String libraryName,
     String existingLibrary, String fileName);
 
+/// Version of HttpRequest.request that retries on 502 errors.
+Future<HttpRequest> httpRequestRetry502Error(String url,
+    {String responseType, String mimeType}) {
+  var completer = new Completer<HttpRequest>();
+
+  var xhr = new HttpRequest();
+  xhr.open('GET', url, async: true);
+
+  if (responseType != null) {
+    xhr.responseType = responseType;
+  }
+
+  if (mimeType != null) {
+    xhr.overrideMimeType(mimeType);
+  }
+
+  xhr.onLoad.listen((e) {
+    var accepted = xhr.status >= 200 && xhr.status < 300;
+    var fileUri = xhr.status == 0; // file:// URIs have status of 0.
+    var notModified = xhr.status == 304;
+    // Redirect status is specified up to 307, but others have been used in
+    // practice. Notably Google Drive uses 308 Resume Incomplete for
+    // resumable uploads, and it's also been used as a redirect. The
+    // redirect case will be handled by the browser before it gets to us,
+    // so if we see it we should pass it through to the user.
+    var unknownRedirect = xhr.status > 307 && xhr.status < 400;
+
+    if (accepted || fileUri || notModified || unknownRedirect) {
+      completer.complete(xhr);
+    } else {
+      if (xhr.status == 502) {
+        print("Retrying due to 502 error for $url");
+        return HttpRequest.request(url,
+            responseType: responseType, mimeType: mimeType);
+      }
+      completer.completeError(e);
+    }
+  });
+
+  xhr.onError.listen(completer.completeError);
+
+  xhr.send();
+  return completer.future;
+}
+
 /// The command for invoking the modular compiler.
 class WebCompileCommand extends Command {
   get name => 'compile';
@@ -63,35 +124,43 @@ class WebCompileCommand extends Command {
     return requestSummaries;
   }
 
-  void requestSummaries(String summaryRoot, String sdkUrl,
-      List<String> summaryUrls, Function onCompileReady, Function onError) {
-    HttpRequest
-        .request(sdkUrl,
-            responseType: "arraybuffer", mimeType: "application/octet-stream")
-        .then((sdkRequest) {
-      var sdkBytes = sdkRequest.response.asUint8List();
-
-      // Map summary URLs to HttpRequests.
-      var summaryRequests = summaryUrls.map((summary) => new Future(() =>
-          HttpRequest.request(summaryRoot + summary,
-              responseType: "arraybuffer",
-              mimeType: "application/octet-stream")));
-
-      Future.wait(summaryRequests).then((summaryResponses) {
-        // Map summary responses to summary bytes.
-        var summaryBytes = <List<int>>[];
-        for (var response in summaryResponses) {
-          summaryBytes.add(response.response.asUint8List());
-        }
+  Future<Null> requestSummaries(String sdkUrl, JSMap<String, String> summaryMap,
+      Function onCompileReady, Function onError) async {
+    var sdkRequest;
+    try {
+      sdkRequest = await httpRequestRetry502Error(sdkUrl,
+          responseType: "arraybuffer", mimeType: "application/octet-stream");
+    } catch (error) {
+      onError('Dart sdk summaries failed to load: $error. url: $sdkUrl');
+      return null;
+    }
 
-        onCompileReady(setUpCompile(sdkBytes, summaryBytes, summaryUrls));
-      }).catchError((error) => onError('Summaries failed to load: $error'));
-    }).catchError((error) =>
-            onError('Dart sdk summaries failed to load: $error. url: $sdkUrl'));
+    var sdkBytes = (sdkRequest.response as ByteBuffer).asUint8List();
+
+    // Map summary URLs to HttpRequests.
+    var summaryRequests = iteratorToList(summaryMap.values())
+        .map((String summaryUrl) => httpRequestRetry502Error(summaryUrl,
+            responseType: "arraybuffer", mimeType: "application/octet-stream"))
+        .toList();
+    var summaryResponses;
+    try {
+      summaryResponses = await Future.wait(summaryRequests);
+    } catch (error) {
+      print('Summaries failed to load: $error');
+      onError('Summaries failed to load: $error');
+      return null;
+    }
+    // Map summary responses to summary bytes.
+    List<List<int>> summaryBytes = summaryResponses
+        .map((response) => (response.response as ByteBuffer).asUint8List())
+        .toList();
+    print("Summaries loaded");
+    onCompileReady(setUpCompile(
+        sdkBytes, summaryBytes, iteratorToList(summaryMap.keys())));
   }
 
   List<Function> setUpCompile(List<int> sdkBytes, List<List<int>> summaryBytes,
-      List<String> summaryUrls) {
+      List<String> moduleIds) {
     var dartSdkSummaryPath = '/dart-sdk/lib/_internal/web_sdk.sum';
 
     var resourceProvider = new MemoryResourceProvider()
@@ -106,9 +175,17 @@ class WebCompileCommand extends Command {
         resourceProvider: resourceProvider, recordDependencyInfo: true);
     for (var i = 0; i < summaryBytes.length; i++) {
       var bytes = summaryBytes[i];
-      var url = '/' + summaryUrls[i];
-      var summaryBundle = new PackageBundle.fromBuffer(bytes);
-      summaryDataStore.addBundle(url, summaryBundle);
+      // Packages with no dart source files will have empty summaries which is fine.
+      if (bytes.length == 0) continue;
+      var url = '/${moduleIds[i]}.api.ds';
+      try {
+        var summaryBundle = new PackageBundle.fromBuffer(bytes);
+        summaryDataStore.addBundle(url, summaryBundle);
+      } catch (e) {
+        print(
+            "XXX failed to load summary for $i, ${moduleIds[i]}, len = ${summaryBytes[i].length}");
+        continue;
+      }
     }
     var summaryResolver =
         new InSummaryUriResolver(resourceProvider, summaryDataStore);