You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
70 lines
1.9 KiB
70 lines
1.9 KiB
/*
|
|
* Copyright (C) 2017 The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "base/Compiler.h"
|
|
#include "base/Lock.h"
|
|
|
|
namespace android {
|
|
|
|
namespace base { class Stream; }
|
|
|
|
namespace snapshot {
|
|
|
|
// LazySnapshotObj is a base class for objects that use lazy strategy for
|
|
// snapshot loading. It separates heavy-weight loading / restoring operations
|
|
// and only triggers it when the object needs to be used.
|
|
// Please implement heavy-weight loading / restoring operations in restore()
|
|
// method and call "touch" before you need to use the object.
|
|
|
|
// An example is for texture lazy loading. On load it only reads the data from
|
|
// disk but does not load them into GPU. On restore it performs the heavy-weight
|
|
// GPU data loading.
|
|
|
|
template <class Derived>
|
|
class LazySnapshotObj {
|
|
DISALLOW_COPY_AND_ASSIGN(LazySnapshotObj);
|
|
public:
|
|
LazySnapshotObj() = default;
|
|
// Snapshot loader
|
|
LazySnapshotObj(base::Stream*) : mNeedRestore(true) {}
|
|
|
|
void touch() {
|
|
base::AutoLock lock(mMutex);
|
|
if (!mNeedRestore) {
|
|
return;
|
|
}
|
|
static_cast<Derived*>(this)->restore();
|
|
mNeedRestore = false;
|
|
}
|
|
|
|
bool needRestore() const {
|
|
base::AutoLock lock(mMutex);
|
|
return mNeedRestore;
|
|
}
|
|
|
|
protected:
|
|
~LazySnapshotObj() = default;
|
|
bool mNeedRestore = false;
|
|
|
|
private:
|
|
mutable base::Lock mMutex;
|
|
};
|
|
|
|
} // namespace snapshot
|
|
} // namespace android
|