Break large blobs into multiple ipcs during creation.

content/common/webblobregistry_impl.cc

 // Copyright (c) 2011 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/common/webblobregistry_impl.h"
 
 #include "base/memory/ref_counted.h"
+#include "base/shared_memory.h"
+#include "content/common/child_thread.h"
 #include "content/common/webblob_messages.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebBlobData.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebURL.h"
 #include "webkit/blob/blob_data.h"
+#include "webkit/glue/webkit_glue.h"
 
 using WebKit::WebBlobData;
 using WebKit::WebString;
 using WebKit::WebURL;
 
-WebBlobRegistryImpl::WebBlobRegistryImpl(IPC::Message::Sender* sender)
-    : sender_(sender) {
+WebBlobRegistryImpl::WebBlobRegistryImpl(ChildThread* child_thread)
+    : child_thread_(child_thread) {
 }
 
 WebBlobRegistryImpl::~WebBlobRegistryImpl() {
 }
 
 void WebBlobRegistryImpl::registerBlobURL(
     const WebURL& url, WebBlobData& data) {
-  scoped_refptr<webkit_blob::BlobData> blob_data(
-      new webkit_blob::BlobData(data));
-  sender_->Send(new BlobHostMsg_RegisterBlobUrl(url, blob_data));
+  child_thread_->Send(new BlobHostMsg_StartBuildingBlob(url));
+  size_t i = 0;
+  WebBlobData::Item data_item;
+  while (data.itemAt(i++, data_item)) {
+    webkit_blob::BlobData::Item item;
+    switch (data_item.type) {
+      case WebBlobData::Item::TypeData: {
+        // WebBlobData does not allow partial data items.
+        DCHECK(!data_item.offset && data_item.length == -1);
+        const size_t kLargeSizeThreshold = 250 * 1024;

[jam, 2011/10/15 01:53:15]

nit: constants usually go at the top of the file. it's also convention to
specify what units the constant is in, i.e. kLargeSizeThresholdKB

+        if (data_item.data.size() < kLargeSizeThreshold) {
+          item.SetToData(data_item.data.data(), data_item.data.size());
+          child_thread_->Send(new BlobHostMsg_AppendBlobDataItem(url, item));
+        } else {
+          // We handle larger amounts of data via SharedMemory instead of
+          // writing it directly to the IPC channel.
+          const size_t kMaxSharedMemorySize = 10 * 1024 * 1024;

[jam, 2011/10/15 01:53:15]

ditto

+          size_t data_size = data_item.data.size();
+          const char* data_ptr = data_item.data.data();
+          size_t shared_memory_size = std::min(data_size, kMaxSharedMemorySize);
+          scoped_ptr<base::SharedMemory> shared_memory(
+              child_thread_->AllocateSharedMemory(shared_memory_size));
+          CHECK(shared_memory.get());
+          while (data_size) {
+            size_t chunk_size = std::min(data_size, shared_memory_size);
+            memcpy(shared_memory->memory(), data_ptr, chunk_size);
+            child_thread_->Send(new BlobHostMsg_SyncAppendSharedMemory(
+                url, shared_memory->handle(), chunk_size));
+            data_size -= chunk_size;
+            data_ptr += chunk_size;
+          }
+        }
+        break;
+      }
+      case WebBlobData::Item::TypeFile:
+        item.SetToFile(
+            webkit_glue::WebStringToFilePath(data_item.filePath),
+            static_cast<uint64>(data_item.offset),
+            static_cast<uint64>(data_item.length),
+            base::Time::FromDoubleT(data_item.expectedModificationTime));
+        child_thread_->Send(new BlobHostMsg_AppendBlobDataItem(url, item));
+        break;
+      case WebBlobData::Item::TypeBlob:
+        if (data_item.length) {
+          item.SetToBlob(
+              data_item.blobURL,
+              static_cast<uint64>(data_item.offset),
+              static_cast<uint64>(data_item.length));
+        }
+        child_thread_->Send(new BlobHostMsg_AppendBlobDataItem(url, item));
+        break;
+      default:
+        NOTREACHED();
+    }
+  }
+  child_thread_->Send(new BlobHostMsg_FinishBuildingBlob(
+      url, data.contentType().utf8().data()));
 }
 
 void WebBlobRegistryImpl::registerBlobURL(
     const WebURL& url, const WebURL& src_url) {
-  sender_->Send(new BlobHostMsg_RegisterBlobUrlFrom(url, src_url));
+  child_thread_->Send(new BlobHostMsg_CloneBlob(url, src_url));
 }
 
 void WebBlobRegistryImpl::unregisterBlobURL(const WebURL& url) {
-  sender_->Send(new BlobHostMsg_UnregisterBlobUrl(url));
+  child_thread_->Send(new BlobHostMsg_RemoveBlob(url));
 }