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(

[jsbell, 2014/04/17 18:37:59]

It seems like it would be nice to propagate the IndexedDBValue (bits+blobs)
pattern throughout Chromium/IPC/Blink API/WebCore to reduce the number of
parameters everywhere and provide more encapsulation. I suppose that could be
done later.

[ericu, 2014/04/17 21:56:02]

Agreed; will add a TODO to my notes.

+    WebData* web_value,
+    const std::string& value,
+    const std::vector<IndexedDBMsg_BlobOrFileInfo>& blob_info,
+    blink::WebVector<WebBlobInfo>* web_blob_info) {

[jsbell, 2014/04/17 18:37:59]

Parameter order here looks odd - web_value, value, blob_info, web_blob_info.

[ericu, 2014/04/17 21:56:02]

Huh.  Yeah, that's terrible.  Fixed to value, blob_info, *web_value,
*web_blob_info.

+
+  if (!value.empty()) {

[jsbell, 2014/04/17 18:37:59]

Make this an early exit, to reduce indentation?

[ericu, 2014/04/17 21:56:02]

Done.

+    web_value->assign(&*value.begin(), value.size());
+    blink::WebVector<WebBlobInfo> local_blob_info(blob_info.size());
+    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(
+      &web_value, params.value, params.blob_or_file_info, &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(
+      &web_value, params.value, params.blob_or_file_info, &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(
+      &web_value, p.value, p.blob_or_file_info, &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(
+      &web_value, value, p.blob_or_file_info, &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());

[jsbell, 2014/04/17 18:37:59]

Bleah - sending same-sized vectors through is an antipattern. We should really
define a struct and pass a vector of those through.

(I think I started on a patch for that at one point, but don't have it any
more.)

It's browser->renderer so it's not a security issue, at least.)

[ericu, 2014/04/17 21:56:02]

Added a TODO to indexed_db_messages.h for this message.

+  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(
+        &values[i], p.values[i], p.blob_or_file_infos[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