The chromium-side backchannel plumbing for blobs in IDB.

content/child/indexed_db/indexed_db_dispatcher.cc

 // Copyright 2013 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/child/indexed_db/indexed_db_dispatcher.h"
 
 #include <utility>
 
 #include "base/format_macros.h"
 #include "base/lazy_instance.h"
@@ skipping 502 matching lines @@
     int32 ipc_callbacks_id,
     const std::vector<base::string16>& value) {
   DCHECK_EQ(ipc_thread_id, CurrentWorkerId());
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(ipc_callbacks_id);
   if (!callbacks)
     return;
   callbacks->onSuccess(WebVector<WebString>(value));
   pending_callbacks_.Remove(ipc_callbacks_id);
 }
 
+static void PrepareWebValueAndBlobInfo(
+    const std::string& value,
+    const std::vector<IndexedDBMsg_BlobOrFileInfo>& blob_info,
+    WebData* web_value,
+    blink::WebVector<WebBlobInfo>* web_blob_info) {
+
+  if (value.empty())
+    return;
+
+  web_value->assign(&*value.begin(), value.size());
+  blink::WebVector<WebBlobInfo> local_blob_info(blob_info.size());

[cmumford, 2014/04/17 22:26:53]

Why create a local array and then swap at the end? Why not just construct
directly into web_blob_info?

[ericu, 2014/04/17 22:33:11]

Outside of the constructor, you can't set the size of a WebVector without
overwriting the whole thing.  You can't even append to it.  It's a very simple
class, just used as a wrapper to pass things through the API boundary.

I could see if folks were OK with making WebVector just a little bit more
complicated [adding a resize to it], but this seemed simple enough, so I thought
I'd just use the local+swap.

+  for (size_t i = 0; i < blob_info.size(); ++i) {
+    const IndexedDBMsg_BlobOrFileInfo& info = blob_info[i];
+    if (info.is_file) {
+      local_blob_info[i] = WebBlobInfo(WebString::fromUTF8(info.uuid.c_str()),
+                                       info.file_path,
+                                       info.file_name,
+                                       info.mime_type,
+                                       info.last_modified,
+                                       info.size);
+    } else {
+      local_blob_info[i] = WebBlobInfo(
+          WebString::fromUTF8(info.uuid.c_str()), info.mime_type, info.size);
+    }
+  }
+  web_blob_info->swap(local_blob_info);
+}
+
 void IndexedDBDispatcher::OnSuccessValue(
-    const IndexedDBMsg_CallbacksSuccessValue_Params& p) {
-  DCHECK_EQ(p.ipc_thread_id, CurrentWorkerId());
-  WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(p.ipc_callbacks_id);
+    const IndexedDBMsg_CallbacksSuccessValue_Params& params) {
+  DCHECK_EQ(params.ipc_thread_id, CurrentWorkerId());
+  WebIDBCallbacks* callbacks =
+      pending_callbacks_.Lookup(params.ipc_callbacks_id);
   if (!callbacks)
     return;
   WebData web_value;
-  if (!p.value.empty())
-    web_value.assign(&*p.value.begin(), p.value.size());
-  callbacks->onSuccess(web_value);
-  pending_callbacks_.Remove(p.ipc_callbacks_id);
-  cursor_transaction_ids_.erase(p.ipc_callbacks_id);
+  WebVector<WebBlobInfo> web_blob_info;
+  PrepareWebValueAndBlobInfo(
+      params.value, params.blob_or_file_info, &web_value, &web_blob_info);
+  callbacks->onSuccess(web_value, web_blob_info);
+  pending_callbacks_.Remove(params.ipc_callbacks_id);
+  cursor_transaction_ids_.erase(params.ipc_callbacks_id);
 }
 
 void IndexedDBDispatcher::OnSuccessValueWithKey(
-    const IndexedDBMsg_CallbacksSuccessValueWithKey_Params& p) {
-  DCHECK_EQ(p.ipc_thread_id, CurrentWorkerId());
-  WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(p.ipc_callbacks_id);
+    const IndexedDBMsg_CallbacksSuccessValueWithKey_Params& params) {
+  DCHECK_EQ(params.ipc_thread_id, CurrentWorkerId());
+  WebIDBCallbacks* callbacks =
+      pending_callbacks_.Lookup(params.ipc_callbacks_id);
   if (!callbacks)
     return;
   WebData web_value;
-  if (p.value.size())
-    web_value.assign(&*p.value.begin(), p.value.size());
+  WebVector<WebBlobInfo> web_blob_info;
+  PrepareWebValueAndBlobInfo(
+      params.value, params.blob_or_file_info, &web_value, &web_blob_info);
   callbacks->onSuccess(web_value,
-                       WebIDBKeyBuilder::Build(p.primary_key),
-                       WebIDBKeyPathBuilder::Build(p.key_path));
-  pending_callbacks_.Remove(p.ipc_callbacks_id);
+                       web_blob_info,
+                       WebIDBKeyBuilder::Build(params.primary_key),
+                       WebIDBKeyPathBuilder::Build(params.key_path));
+  pending_callbacks_.Remove(params.ipc_callbacks_id);
 }
 
 void IndexedDBDispatcher::OnSuccessInteger(int32 ipc_thread_id,
                                            int32 ipc_callbacks_id,
                                            int64 value) {
   DCHECK_EQ(ipc_thread_id, CurrentWorkerId());
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(ipc_callbacks_id);
   if (!callbacks)
     return;
   callbacks->onSuccess(value);
@@ skipping 11 matching lines @@
 }
 
 void IndexedDBDispatcher::OnSuccessOpenCursor(
     const IndexedDBMsg_CallbacksSuccessIDBCursor_Params& p) {
   DCHECK_EQ(p.ipc_thread_id, CurrentWorkerId());
   int32 ipc_callbacks_id = p.ipc_callbacks_id;
   int32 ipc_object_id = p.ipc_cursor_id;
   const IndexedDBKey& key = p.key;
   const IndexedDBKey& primary_key = p.primary_key;
   WebData web_value;
-  if (p.value.size())
-    web_value.assign(&*p.value.begin(), p.value.size());
+  WebVector<WebBlobInfo> web_blob_info;
+  PrepareWebValueAndBlobInfo(
+      p.value, p.blob_or_file_info, &web_value, &web_blob_info);
 
   DCHECK(cursor_transaction_ids_.find(ipc_callbacks_id) !=
          cursor_transaction_ids_.end());
   int64 transaction_id = cursor_transaction_ids_[ipc_callbacks_id];
   cursor_transaction_ids_.erase(ipc_callbacks_id);
 
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(ipc_callbacks_id);
   if (!callbacks)
     return;
 
   WebIDBCursorImpl* cursor = new WebIDBCursorImpl(
       ipc_object_id, transaction_id, thread_safe_sender_.get());
   cursors_[ipc_object_id] = cursor;
-  callbacks->onSuccess(cursor, WebIDBKeyBuilder::Build(key),
-                       WebIDBKeyBuilder::Build(primary_key), web_value);
+  callbacks->onSuccess(cursor,
+                       WebIDBKeyBuilder::Build(key),
+                       WebIDBKeyBuilder::Build(primary_key),
+                       web_value,
+                       web_blob_info);
 
   pending_callbacks_.Remove(ipc_callbacks_id);
 }
 
 void IndexedDBDispatcher::OnSuccessCursorContinue(
     const IndexedDBMsg_CallbacksSuccessCursorContinue_Params& p) {
   DCHECK_EQ(p.ipc_thread_id, CurrentWorkerId());
   int32 ipc_callbacks_id = p.ipc_callbacks_id;
   int32 ipc_cursor_id = p.ipc_cursor_id;
   const IndexedDBKey& key = p.key;
   const IndexedDBKey& primary_key = p.primary_key;
   const std::string& value = p.value;
 
   WebIDBCursorImpl* cursor = cursors_[ipc_cursor_id];
   DCHECK(cursor);
 
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(ipc_callbacks_id);
   if (!callbacks)
     return;
 
   WebData web_value;
-  if (value.size())
-    web_value.assign(&*value.begin(), value.size());
+  WebVector<WebBlobInfo> web_blob_info;
+  PrepareWebValueAndBlobInfo(
+      value, p.blob_or_file_info, &web_value, &web_blob_info);
   callbacks->onSuccess(WebIDBKeyBuilder::Build(key),
-                       WebIDBKeyBuilder::Build(primary_key), web_value);
+                       WebIDBKeyBuilder::Build(primary_key),
+                       web_value,
+                       web_blob_info);
 
   pending_callbacks_.Remove(ipc_callbacks_id);
 }
 
 void IndexedDBDispatcher::OnSuccessCursorPrefetch(
     const IndexedDBMsg_CallbacksSuccessCursorPrefetch_Params& p) {
   DCHECK_EQ(p.ipc_thread_id, CurrentWorkerId());
   int32 ipc_callbacks_id = p.ipc_callbacks_id;
   int32 ipc_cursor_id = p.ipc_cursor_id;
   const std::vector<IndexedDBKey>& keys = p.keys;
   const std::vector<IndexedDBKey>& primary_keys = p.primary_keys;
   std::vector<WebData> values(p.values.size());
+  DCHECK_EQ(p.values.size(), p.blob_or_file_infos.size());
+  std::vector<WebVector<WebBlobInfo> > blob_infos(p.blob_or_file_infos.size());
   for (size_t i = 0; i < p.values.size(); ++i) {
-    if (p.values[i].size())
-      values[i].assign(&*p.values[i].begin(), p.values[i].size());
+    PrepareWebValueAndBlobInfo(
+        p.values[i], p.blob_or_file_infos[i], &values[i], &blob_infos[i]);
   }
   WebIDBCursorImpl* cursor = cursors_[ipc_cursor_id];
   DCHECK(cursor);
-  cursor->SetPrefetchData(keys, primary_keys, values);
+  cursor->SetPrefetchData(keys, primary_keys, values, blob_infos);
 
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(ipc_callbacks_id);
   DCHECK(callbacks);
   cursor->CachedContinue(callbacks);
   pending_callbacks_.Remove(ipc_callbacks_id);
 }
 
 void IndexedDBDispatcher::OnIntBlocked(int32 ipc_thread_id,
                                        int32 ipc_callbacks_id,
                                        int64 existing_version) {
@@ skipping 95 matching lines @@
   typedef std::map<int32, WebIDBCursorImpl*>::iterator Iterator;
   for (Iterator i = cursors_.begin(); i != cursors_.end(); ++i) {
     if (i->first == ipc_exception_cursor_id ||
         i->second->transaction_id() != transaction_id)
       continue;
     i->second->ResetPrefetchCache();
   }
 }
 
 }  // namespace content