vn-verdnaturachat/ios/Pods/MMKVCore/Core/MMKVMetaInfo.hpp

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2.2 KiB
C++

/*
* Tencent is pleased to support the open source community by making
* MMKV available.
*
* Copyright (C) 2018 THL A29 Limited, a Tencent company.
* All rights reserved.
*
* Licensed under the BSD 3-Clause License (the "License"); you may not use
* this file except in compliance with the License. You may obtain a copy of
* the License at
*
* https://opensource.org/licenses/BSD-3-Clause
*
* 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.
*/
#ifndef MMKV_MMKVMETAINFO_H
#define MMKV_MMKVMETAINFO_H
#ifdef __cplusplus
#include "aes/AESCrypt.h"
#include <cstdint>
#include <cstring>
namespace mmkv {
enum MMKVVersion : uint32_t {
MMKVVersionDefault = 0,
// record full write back count
MMKVVersionSequence = 1,
// store random iv for encryption
MMKVVersionRandomIV = 2,
// store actual size together with crc checksum, try to reduce file corruption
MMKVVersionActualSize = 3,
};
struct MMKVMetaInfo {
uint32_t m_crcDigest = 0;
uint32_t m_version = MMKVVersionSequence;
uint32_t m_sequence = 0; // full write-back count
uint8_t m_vector[AES_KEY_LEN] = {};
uint32_t m_actualSize = 0;
// confirmed info: it's been synced to file
struct {
uint32_t lastActualSize = 0;
uint32_t lastCRCDigest = 0;
uint32_t _reserved[16] = {};
} m_lastConfirmedMetaInfo;
void write(void *ptr) const {
MMKV_ASSERT(ptr);
memcpy(ptr, this, sizeof(MMKVMetaInfo));
}
void writeCRCAndActualSizeOnly(void *ptr) const {
MMKV_ASSERT(ptr);
auto other = (MMKVMetaInfo *) ptr;
other->m_crcDigest = m_crcDigest;
other->m_actualSize = m_actualSize;
}
void read(const void *ptr) {
MMKV_ASSERT(ptr);
memcpy(this, ptr, sizeof(MMKVMetaInfo));
}
};
static_assert(sizeof(MMKVMetaInfo) <= (4 * 1024), "MMKVMetaInfo lager than one pagesize");
} // namespace mmkv
#endif
#endif //MMKV_MMKVMETAINFO_H