reviving xiang's cl as a stopgap for the memcache + serviceworker interop problem

Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 15 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include "config.h"
 #include "ServiceWorkerGlobalScope.h"
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8ThrowException.h"
+#include "core/fetch/MemoryCache.h"
 #include "core/fetch/ResourceLoaderOptions.h"
 #include "core/inspector/ScriptCallStack.h"
 #include "core/loader/ThreadableLoader.h"
 #include "core/workers/WorkerClients.h"
 #include "core/workers/WorkerThreadStartupData.h"
 #include "modules/CachePolyfill.h"
 #include "modules/CacheStoragePolyfill.h"
 #include "modules/EventTargetModules.h"
 #include "modules/serviceworkers/CacheStorage.h"
 #include "modules/serviceworkers/FetchManager.h"
@@ skipping 124 matching lines @@
     return EventTargetNames::ServiceWorkerGlobalScope;
 }
 
 void ServiceWorkerGlobalScope::trace(Visitor* visitor)
 {
     visitor->trace(m_clients);
     visitor->trace(m_caches);
     WorkerGlobalScope::trace(visitor);
 }
 
+void ServiceWorkerGlobalScope::importScripts(const Vector<String>& urls, ExceptionState& exceptionState)
+{
+    // Bust the MemoryCache to ensure script requests reach the browser-side
+    // and get added to and retrieved from the ServiceWorker's script cache.

[dominicc (has gone to gerrit), 2014/08/08 05:27:57]

I think the "and retrieved from" is a bit inaccurate? The point is primarily
that they're added to that cache.

[michaeln, 2014/08/08 19:51:42]

i think it's accurate, maybe less obvious. once the correct resource is cached,
it also has to be utilized for subsequent starts of the worker. one w/o the
other does not solve the problem of using the right script.

+    // FIXME: Revisit in light of the solution to crbug/388375.

[dominicc (has gone to gerrit), 2014/08/08 05:27:57]

I don't think you need this FIXME; I think CR388375 should be specifically about
not sharing between Service Workers/scopes/something in the memory cache.

[michaeln, 2014/08/08 19:51:42]

I don't want to leave the impression that this is a complete fix for this
problem because i don't this it is. It's a bit of a hack and as coded the wrong
resource could still be picked up albeit the window of opportunity is pretty
small. This is related to 388375 in that the resource that should be returned is
dependent on the context asking for it. The comment just says should be
revisited in light of what is done on behalf of CR388375.

+    for (Vector<String>::const_iterator it = urls.begin(); it != urls.end(); ++it)
+        MemoryCache::removeURLFromCache(this->executionContext(), completeURL(*it));
+    WorkerGlobalScope::importScripts(urls, exceptionState);
+}
+
 void ServiceWorkerGlobalScope::logExceptionToConsole(const String& errorMessage, const String& sourceURL, int lineNumber, int columnNumber, PassRefPtrWillBeRawPtr<ScriptCallStack> callStack)
 {
     WorkerGlobalScope::logExceptionToConsole(errorMessage, sourceURL, lineNumber, columnNumber, callStack);
     addMessageToWorkerConsole(JSMessageSource, ErrorMessageLevel, errorMessage, sourceURL, lineNumber, callStack, 0);
 }
 
 } // namespace blink