Update installed ServiceWorkers.

content/browser/service_worker/service_worker_storage.cc

Index: content/browser/service_worker/service_worker_storage.cc
diff --git a/content/browser/service_worker/service_worker_storage.cc b/content/browser/service_worker/service_worker_storage.cc
index ac8e3322de251e1a528a9f595ed7e3109754728d..ab73931ce614b32d33342a396969431d57f1555a 100644
--- a/content/browser/service_worker/service_worker_storage.cc
+++ b/content/browser/service_worker/service_worker_storage.cc
@@ -21,6 +21,7 @@
 #include "content/common/service_worker/service_worker_types.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/completion_callback.h"
+#include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "webkit/browser/quota/quota_manager_proxy.h"
 
@@ -72,6 +73,133 @@ ServiceWorkerStatusCode DatabaseStatusToStatusCode(
   }
 }
 
+class ResponseComparer : public base::RefCounted<ResponseComparer> {
+ public:
+  ResponseComparer(
+      base::WeakPtr<ServiceWorkerStorage> owner,
+      scoped_ptr<ServiceWorkerResponseReader> lhs,
+      scoped_ptr<ServiceWorkerResponseReader> rhs,
+      const ServiceWorkerStorage::CompareCallback& callback)
+      : owner_(owner),
+        completion_callback_(callback),
+        lhs_reader_(lhs.release()),
+        rhs_reader_(rhs.release()),
+        completion_count_(0),
+        previous_result_(0) {
+  }
+
+  void Start();
+
+ private:
+  friend class base::RefCounted<ResponseComparer>;
+
+  static const int kBufferSize = 16 * 1024;
+
+  ~ResponseComparer() {}
+  void ReadInfos();
+  void OnReadInfoComplete(int result);
+  void ReadSomeData();
+  void OnReadDataComplete(int result);
+
+  base::WeakPtr<ServiceWorkerStorage> owner_;
+  ServiceWorkerStorage::CompareCallback completion_callback_;
+  scoped_ptr<ServiceWorkerResponseReader> lhs_reader_;
+  scoped_refptr<HttpResponseInfoIOBuffer> lhs_info_;
+  scoped_refptr<net::IOBuffer> lhs_buffer_;
+  scoped_ptr<ServiceWorkerResponseReader> rhs_reader_;
+  scoped_refptr<HttpResponseInfoIOBuffer> rhs_info_;
+  scoped_refptr<net::IOBuffer> rhs_buffer_;
+  int completion_count_;
+  int previous_result_;
+  DISALLOW_COPY_AND_ASSIGN(ResponseComparer);
+};
+
+void ResponseComparer::Start() {
+  lhs_buffer_ = new net::IOBuffer(kBufferSize);
+  lhs_info_ = new HttpResponseInfoIOBuffer();
+  rhs_buffer_ = new net::IOBuffer(kBufferSize);
+  rhs_info_ = new HttpResponseInfoIOBuffer();
+
+  ReadInfos();
+}
+
+void ResponseComparer::ReadInfos() {
+  lhs_reader_->ReadInfo(
+      lhs_info_,
+      base::Bind(&ResponseComparer::OnReadInfoComplete,
+                 this));
+  rhs_reader_->ReadInfo(
+      rhs_info_,
+      base::Bind(&ResponseComparer::OnReadInfoComplete,
+                 this));
+}
+
+void ResponseComparer::OnReadInfoComplete(int result) {
+  if (completion_callback_.is_null() || !owner_)
+    return;
+  if (result < 0) {
+    completion_callback_.Run(SERVICE_WORKER_ERROR_FAILED, false);
+    completion_callback_.Reset();
+    return;
+  }
+  if (++completion_count_ != 2)
+    return;
+
+  if (lhs_info_->response_data_size != rhs_info_->response_data_size) {
+    completion_callback_.Run(SERVICE_WORKER_OK, false);
+    return;
+  }
+  ReadSomeData();
+}
+
+void ResponseComparer::ReadSomeData() {
+  completion_count_ = 0;
+  lhs_reader_->ReadData(
+      lhs_buffer_,
+      kBufferSize,
+      base::Bind(&ResponseComparer::OnReadDataComplete, this));
+  rhs_reader_->ReadData(
+      rhs_buffer_,
+      kBufferSize,
+      base::Bind(&ResponseComparer::OnReadDataComplete, this));
+}
+
+void ResponseComparer::OnReadDataComplete(int result) {
+  if (completion_callback_.is_null() || !owner_)
+    return;
+  if (result < 0) {
+    completion_callback_.Run(SERVICE_WORKER_ERROR_FAILED, false);
+    completion_callback_.Reset();
+    return;
+  }
+  if (++completion_count_ != 2) {
+    previous_result_ = result;
+    return;
+  }
+
+  // TODO(michaeln): Probably shouldn't assume that the amounts read from
+  // each reader will always be the same. This would wrongly signal false
+  // in that case.
+  if (result != previous_result_) {
+    completion_callback_.Run(SERVICE_WORKER_OK, false);
+    return;
+  }
+
+  if (result == 0) {
+    completion_callback_.Run(SERVICE_WORKER_OK, true);
+    return;
+  }
+
+  int compare_result =
+      memcmp(lhs_buffer_->data(), rhs_buffer_->data(), result);
+  if (compare_result != 0) {
+    completion_callback_.Run(SERVICE_WORKER_OK, false);
+    return;
+  }
+
+  ReadSomeData();
+}
+
 }  // namespace
 
 ServiceWorkerStorage::InitialData::InitialData()
@@ -391,6 +519,18 @@ void ServiceWorkerStorage::DoomUncommittedResponse(int64 id) {
   StartPurgingResources(std::vector<int64>(1, id));
 }
 
+void ServiceWorkerStorage::CompareScriptResources(
+    int64 lhs_id, int64 rhs_id,
+    const CompareCallback& callback) {
+  DCHECK(!callback.is_null());
+  scoped_refptr<ResponseComparer> comparer =
+      new ResponseComparer(weak_factory_.GetWeakPtr(),
+                           CreateResponseReader(lhs_id),
+                           CreateResponseReader(rhs_id),
+                           callback);
+  comparer->Start();  // It deletes itself when done.
+}
+
 void ServiceWorkerStorage::DeleteAndStartOver(const StatusCallback& callback) {
   Disable();
 
@@ -760,6 +900,10 @@ ServiceWorkerStorage::GetOrCreateRegistration(
     version->SetStatus(data.is_active ?
         ServiceWorkerVersion::ACTIVATED : ServiceWorkerVersion::INSTALLED);
     version->script_cache_map()->SetResources(resources);
+
+    // TODO(michaeln): need to activate a waiting version  that wasn't
+    // actrivated in an earlier session, maybe test for this condition
+    // (waitingversion and no activeversion) when navigating to a page?
   }
 
   if (version->status() == ServiceWorkerVersion::ACTIVATED)
@@ -768,8 +912,7 @@ ServiceWorkerStorage::GetOrCreateRegistration(
     registration->SetWaitingVersion(version);
   else
     NOTREACHED();
-  // TODO(michaeln): Hmmm, what if DeleteReg was invoked after
-  // the Find result we're returning here? NOTREACHED condition?
+
   return registration;
 }