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// 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/renderer/renderer_webidbcursor_impl.h"
#include "content/common/indexed_db_messages.h"
#include "content/renderer/indexed_db_dispatcher.h"
#include "content/renderer/render_thread_impl.h"
using WebKit::WebExceptionCode;
using WebKit::WebIDBCallbacks;
using WebKit::WebIDBKey;
using WebKit::WebSerializedScriptValue;
RendererWebIDBCursorImpl::RendererWebIDBCursorImpl(int32 idb_cursor_id)
: idb_cursor_id_(idb_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 wich owns
// this object. But, if that ever changed, then we'd need to invalidate
// any such pointers.
ChildThread::current()->Send(new IndexedDBHostMsg_CursorDestroyed(
idb_cursor_id_));
IndexedDBDispatcher* dispatcher =
IndexedDBDispatcher::ThreadSpecificInstance();
dispatcher->CursorDestroyed(idb_cursor_id_);
}
unsigned short RendererWebIDBCursorImpl::direction() const {
int direction;
ChildThread::current()->Send(
new IndexedDBHostMsg_CursorDirection(idb_cursor_id_, &direction));
return direction;
}
WebIDBKey RendererWebIDBCursorImpl::key() const {
return key_;
}
WebIDBKey RendererWebIDBCursorImpl::primaryKey() const {
return primary_key_;
}
WebSerializedScriptValue RendererWebIDBCursorImpl::value() const {
return value_;
}
void RendererWebIDBCursorImpl::update(const WebSerializedScriptValue& value,
WebIDBCallbacks* callbacks,
WebExceptionCode& ec) {
IndexedDBDispatcher* dispatcher =
IndexedDBDispatcher::ThreadSpecificInstance();
dispatcher->RequestIDBCursorUpdate(
content::SerializedScriptValue(value), callbacks, idb_cursor_id_, &ec);
}
void RendererWebIDBCursorImpl::continueFunction(const WebIDBKey& key,
WebIDBCallbacks* callbacks,
WebExceptionCode& ec) {
IndexedDBDispatcher* dispatcher =
IndexedDBDispatcher::ThreadSpecificInstance();
if (key.type() == WebIDBKey::InvalidType) {
// 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);
return;
}
if (continue_count_ > kPrefetchContinueThreshold) {
// Request pre-fetch.
dispatcher->RequestIDBCursorPrefetch(prefetch_amount_, callbacks,
idb_cursor_id_, &ec);
// 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,
idb_cursor_id_, &ec);
}
void RendererWebIDBCursorImpl::deleteFunction(WebIDBCallbacks* callbacks,
WebExceptionCode& ec) {
IndexedDBDispatcher* dispatcher =
IndexedDBDispatcher::ThreadSpecificInstance();
dispatcher->RequestIDBCursorDelete(callbacks, idb_cursor_id_, &ec);
}
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::SetKeyAndValue(
const IndexedDBKey& key,
const IndexedDBKey& primary_key,
const content::SerializedScriptValue& value) {
key_ = key;
primary_key_ = primary_key;
value_ = value;
}
void RendererWebIDBCursorImpl::SetPrefetchData(
const std::vector<IndexedDBKey>& keys,
const std::vector<IndexedDBKey>& primary_keys,
const std::vector<content::SerializedScriptValue>& 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(prefetch_keys_.size() > 0);
DCHECK(prefetch_primary_keys_.size() == prefetch_keys_.size());
DCHECK(prefetch_values_.size() == prefetch_keys_.size());
key_ = prefetch_keys_.front();
primary_key_ = prefetch_primary_keys_.front();
value_ = prefetch_values_.front();
prefetch_keys_.pop_front();
prefetch_primary_keys_.pop_front();
prefetch_values_.pop_front();
used_prefetches_++;
pending_onsuccess_callbacks_++;
callbacks->onSuccessWithContinuation();
}
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(),
idb_cursor_id_);
prefetch_keys_.clear();
prefetch_primary_keys_.clear();
prefetch_values_.clear();
pending_onsuccess_callbacks_ = 0;
}
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