move content/common_child to content/child

content/common_child/indexed_db/proxy_webidbcursor_impl.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/common_child/indexed_db/proxy_webidbcursor_impl.h"
-
-#include <vector>
-
-#include "content/common/child_thread.h"
-#include "content/common/indexed_db/indexed_db_messages.h"
-#include "content/common_child/indexed_db/indexed_db_dispatcher.h"
-
-using WebKit::WebData;
-using WebKit::WebIDBCallbacks;
-using WebKit::WebIDBKey;
-
-namespace content {
-
-RendererWebIDBCursorImpl::RendererWebIDBCursorImpl(int32 ipc_cursor_id)
-    : ipc_cursor_id_(ipc_cursor_id),
-      continue_count_(0),
-      used_prefetches_(0),
-      pending_onsuccess_callbacks_(0),
-      prefetch_amount_(kMinPrefetchAmount) {}
-
-RendererWebIDBCursorImpl::~RendererWebIDBCursorImpl() {
-  // It's not possible for there to be pending callbacks that address this
-  // object since inside WebKit, they hold a reference to the object which owns
-  // this object. But, if that ever changed, then we'd need to invalidate
-  // any such pointers.
-
-  if (ipc_cursor_id_ != kInvalidCursorId) {
-    // Invalid ID used in tests to avoid really sending this message.
-    IndexedDBDispatcher::Send(
-        new IndexedDBHostMsg_CursorDestroyed(ipc_cursor_id_));
-  }
-  IndexedDBDispatcher* dispatcher =
-      IndexedDBDispatcher::ThreadSpecificInstance();
-  dispatcher->CursorDestroyed(ipc_cursor_id_);
-}
-
-void RendererWebIDBCursorImpl::advance(unsigned long count,
-                                       WebIDBCallbacks* callbacks_ptr) {
-  IndexedDBDispatcher* dispatcher =
-      IndexedDBDispatcher::ThreadSpecificInstance();
-  scoped_ptr<WebIDBCallbacks> callbacks(callbacks_ptr);
-  ResetPrefetchCache();
-  dispatcher->RequestIDBCursorAdvance(
-      count, callbacks.release(), ipc_cursor_id_);
-}
-
-void RendererWebIDBCursorImpl::continueFunction(
-    const WebIDBKey& key,
-    WebIDBCallbacks* callbacks_ptr) {
-  IndexedDBDispatcher* dispatcher =
-      IndexedDBDispatcher::ThreadSpecificInstance();
-  scoped_ptr<WebIDBCallbacks> callbacks(callbacks_ptr);
-
-  if (key.type() == WebIDBKey::NullType) {
-    // No key, so this would qualify for a prefetch.
-    ++continue_count_;
-
-    if (!prefetch_keys_.empty()) {
-      // We have a prefetch cache, so serve the result from that.
-      CachedContinue(callbacks.get());
-      return;
-    }
-
-    if (continue_count_ > kPrefetchContinueThreshold) {
-      // Request pre-fetch.
-      ++pending_onsuccess_callbacks_;
-      dispatcher->RequestIDBCursorPrefetch(
-          prefetch_amount_, callbacks.release(), ipc_cursor_id_);
-
-      // Increase prefetch_amount_ exponentially.
-      prefetch_amount_ *= 2;
-      if (prefetch_amount_ > kMaxPrefetchAmount)
-        prefetch_amount_ = kMaxPrefetchAmount;
-
-      return;
-    }
-  } else {
-    // Key argument supplied. We couldn't prefetch this.
-    ResetPrefetchCache();
-  }
-
-  dispatcher->RequestIDBCursorContinue(
-      IndexedDBKey(key), callbacks.release(), ipc_cursor_id_);
-}
-
-void RendererWebIDBCursorImpl::postSuccessHandlerCallback() {
-  pending_onsuccess_callbacks_--;
-
-  // If the onsuccess callback called continue() on the cursor again,
-  // and that continue was served by the prefetch cache, then
-  // pending_onsuccess_callbacks_ would be incremented.
-  // If not, it means the callback did something else, or nothing at all,
-  // in which case we need to reset the cache.
-
-  if (pending_onsuccess_callbacks_ == 0)
-    ResetPrefetchCache();
-}
-
-void RendererWebIDBCursorImpl::SetPrefetchData(
-    const std::vector<IndexedDBKey>& keys,
-    const std::vector<IndexedDBKey>& primary_keys,
-    const std::vector<WebData>& values) {
-  prefetch_keys_.assign(keys.begin(), keys.end());
-  prefetch_primary_keys_.assign(primary_keys.begin(), primary_keys.end());
-  prefetch_values_.assign(values.begin(), values.end());
-
-  used_prefetches_ = 0;
-  pending_onsuccess_callbacks_ = 0;
-}
-
-void RendererWebIDBCursorImpl::CachedContinue(
-    WebKit::WebIDBCallbacks* callbacks) {
-  DCHECK_GT(prefetch_keys_.size(), 0ul);
-  DCHECK(prefetch_primary_keys_.size() == prefetch_keys_.size());
-  DCHECK(prefetch_values_.size() == prefetch_keys_.size());
-
-  IndexedDBKey key = prefetch_keys_.front();
-  IndexedDBKey primary_key = prefetch_primary_keys_.front();
-  // this could be a real problem.. we need 2 CachedContinues
-  WebData value = prefetch_values_.front();
-
-  prefetch_keys_.pop_front();
-  prefetch_primary_keys_.pop_front();
-  prefetch_values_.pop_front();
-  used_prefetches_++;
-
-  pending_onsuccess_callbacks_++;
-
-  callbacks->onSuccess(key, primary_key, value);
-}
-
-void RendererWebIDBCursorImpl::ResetPrefetchCache() {
-  continue_count_ = 0;
-  prefetch_amount_ = kMinPrefetchAmount;
-
-  if (!prefetch_keys_.size()) {
-    // No prefetch cache, so no need to reset the cursor in the back-end.
-    return;
-  }
-
-  IndexedDBDispatcher* dispatcher =
-      IndexedDBDispatcher::ThreadSpecificInstance();
-  dispatcher->RequestIDBCursorPrefetchReset(
-      used_prefetches_, prefetch_keys_.size(), ipc_cursor_id_);
-  prefetch_keys_.clear();
-  prefetch_primary_keys_.clear();
-  prefetch_values_.clear();
-
-  pending_onsuccess_callbacks_ = 0;
-}
-
-}  // namespace content