Blobs: Mechanism for creating Blobs in browser process, then transferring to renderer.

content/browser/fileapi/chrome_blob_storage_context.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/fileapi/chrome_blob_storage_context.h"
 
 #include "base/bind.h"
+#include "base/guid.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
+#include "webkit/browser/blob/blob_data_handle.h"
 #include "webkit/browser/blob/blob_storage_context.h"
 
 using base::UserDataAdapter;
 using webkit_blob::BlobStorageContext;
 
 namespace content {
 
+class ChromeBlobHandle : public BlobHandle {

[michaeln, 2014/05/08 23:03:18]

The ChromeXXX naming convention is really archaic and doesn't fit at all
anymore. Lets call this BlobHandleImpl or something like that. wdyt?

Also this class should be in an annon namespace.

[tommycli, 2014/05/09 16:10:17]

Done.

+ public:
+  ChromeBlobHandle(scoped_ptr<webkit_blob::BlobDataHandle> handle)
+      : handle_(handle.Pass()) {
+  }
+
+  virtual ~ChromeBlobHandle() {}
+
+  virtual std::string uuid() OVERRIDE {
+    return handle_->uuid();
+  }
+
+ private:
+  scoped_ptr<webkit_blob::BlobDataHandle> handle_;
+};
+
 static const char* kBlobStorageContextKeyName = "content_blob_storage_context";
 
 ChromeBlobStorageContext::ChromeBlobStorageContext() {}
 
 ChromeBlobStorageContext* ChromeBlobStorageContext::GetFor(
     BrowserContext* context) {
   if (!context->GetUserData(kBlobStorageContextKeyName)) {
     scoped_refptr<ChromeBlobStorageContext> blob =
         new ChromeBlobStorageContext();
     context->SetUserData(
         kBlobStorageContextKeyName,
         new UserDataAdapter<ChromeBlobStorageContext>(blob.get()));
     // Check first to avoid memory leak in unittests.
     if (BrowserThread::IsMessageLoopValid(BrowserThread::IO)) {
       BrowserThread::PostTask(
           BrowserThread::IO, FROM_HERE,
           base::Bind(&ChromeBlobStorageContext::InitializeOnIOThread, blob));
     }
   }
 
   return UserDataAdapter<ChromeBlobStorageContext>::Get(
       context, kBlobStorageContextKeyName);
 }
 
 void ChromeBlobStorageContext::InitializeOnIOThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   context_.reset(new BlobStorageContext());
 }
 
+void ChromeBlobStorageContext::CreateMemoryBackedBlob(
+    const char* data, size_t length, const BlobCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  BrowserThread::PostTaskAndReplyWithResult(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&ChromeBlobStorageContext::CreateMemoryBackedBlobOnIOThread,
+                 this, data, length, callback),
+      callback);
+}
+
 ChromeBlobStorageContext::~ChromeBlobStorageContext() {}
 
+scoped_ptr<BlobHandle>
+ChromeBlobStorageContext::CreateMemoryBackedBlobOnIOThread(
+    const char* data, size_t length, const BlobCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  std::string uuid(base::GenerateGUID());
+  scoped_refptr<webkit_blob::BlobData> blob_data =
+      new webkit_blob::BlobData(uuid);
+  blob_data->AppendData(data, length);
+  scoped_ptr<BlobHandle> blob_handle(
+      new ChromeBlobHandle(context_->AddFinishedBlob(blob_data.get()).Pass()));
+  return blob_handle.Pass();
+}
+
 void ChromeBlobStorageContext::DeleteOnCorrectThread() const {
   if (BrowserThread::IsMessageLoopValid(BrowserThread::IO) &&
       !BrowserThread::CurrentlyOn(BrowserThread::IO)) {
     BrowserThread::DeleteSoon(BrowserThread::IO, FROM_HERE, this);
     return;
   }
   delete this;
 }
 
 }  // namespace content