Line data    Source code

       1              : /*
       2              :  *
       3              :  *    Copyright (c) 2022 Project CHIP Authors
       4              :  *
       5              :  *    Licensed under the Apache License, Version 2.0 (the "License");
       6              :  *    you may not use this file except in compliance with the License.
       7              :  *    You may obtain a copy of the License at
       8              :  *
       9              :  *        http://www.apache.org/licenses/LICENSE-2.0
      10              :  *
      11              :  *    Unless required by applicable law or agreed to in writing, software
      12              :  *    distributed under the License is distributed on an "AS IS" BASIS,
      13              :  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      14              :  *    See the License for the specific language governing permissions and
      15              :  *    limitations under the License.
      16              :  */
      17              : #pragma once
      18              : 
      19              : #include <lib/core/CHIPPersistentStorageDelegate.h>
      20              : #include <lib/core/TLV.h>
      21              : #include <lib/support/DefaultStorageKeyAllocator.h>
      22              : 
      23              : namespace chip {
      24              : 
      25              : /// @brief Interface to Persistent Storage Delegate allowing storage of data of variable size such as TLV.
      26              : /// @tparam kMaxSerializedSize size of the mBuffer necessary to retrieve an entry from the storage. Varies with the type of data
      27              : /// stored. Will be allocated on the stack so the implementation needs to be aware of this when choosing this value.
      28              : template <size_t kMaxSerializedSize>
      29              : struct PersistentData
      30              : {
      31         1948 :     PersistentData(PersistentStorageDelegate * storage = nullptr) : mStorage(storage) {}
      32         1948 :     virtual ~PersistentData() = default;
      33              : 
      34              :     virtual CHIP_ERROR UpdateKey(StorageKeyName & key)          = 0;
      35              :     virtual CHIP_ERROR Serialize(TLV::TLVWriter & writer) const = 0;
      36              :     virtual CHIP_ERROR Deserialize(TLV::TLVReader & reader)     = 0;
      37              :     virtual void Clear()                                        = 0;
      38              : 
      39            0 :     virtual CHIP_ERROR Save() { return this->Save(this->mStorage); }
      40              : 
      41          568 :     virtual CHIP_ERROR Save(PersistentStorageDelegate * storage)
      42              :     {
      43          568 :         VerifyOrReturnError(nullptr != storage, CHIP_ERROR_INVALID_ARGUMENT);
      44              : 
      45          568 :         StorageKeyName key = StorageKeyName::Uninitialized();
      46          568 :         ReturnErrorOnFailure(UpdateKey(key));
      47              : 
      48              :         // Serialize the data
      49          568 :         TLV::TLVWriter writer;
      50          568 :         writer.Init(mBuffer, sizeof(mBuffer));
      51              : 
      52          568 :         ReturnErrorOnFailure(Serialize(writer));
      53              : 
      54              :         // Save serialized data
      55          568 :         return storage->SyncSetKeyValue(key.KeyName(), mBuffer, static_cast<uint16_t>(writer.GetLengthWritten()));
      56          568 :     }
      57              : 
      58            0 :     virtual CHIP_ERROR Load() { return this->Load(this->mStorage); }
      59              : 
      60         2242 :     virtual CHIP_ERROR Load(PersistentStorageDelegate * storage)
      61              :     {
      62         2242 :         VerifyOrReturnError(nullptr != storage, CHIP_ERROR_INVALID_ARGUMENT);
      63              : 
      64         2242 :         StorageKeyName key = StorageKeyName::Uninitialized();
      65              : 
      66              :         // Update storage key
      67         2242 :         ReturnErrorOnFailure(UpdateKey(key));
      68              : 
      69              :         // Set data to defaults
      70         2240 :         Clear();
      71              : 
      72              :         // Load the serialized data
      73         2240 :         uint16_t size  = static_cast<uint16_t>(sizeof(mBuffer));
      74         2240 :         CHIP_ERROR err = storage->SyncGetKeyValue(key.KeyName(), mBuffer, size);
      75         2240 :         VerifyOrReturnError(CHIP_ERROR_PERSISTED_STORAGE_VALUE_NOT_FOUND != err, CHIP_ERROR_NOT_FOUND);
      76         2161 :         ReturnErrorOnFailure(err);
      77              : 
      78              :         // Decode serialized data
      79         2161 :         TLV::TLVReader reader;
      80         2161 :         reader.Init(mBuffer, size);
      81         2161 :         return Deserialize(reader);
      82         2242 :     }
      83              : 
      84          131 :     virtual CHIP_ERROR Delete(PersistentStorageDelegate * storage)
      85              :     {
      86          131 :         VerifyOrReturnError(nullptr != storage, CHIP_ERROR_INVALID_ARGUMENT);
      87              : 
      88          131 :         StorageKeyName key = StorageKeyName::Uninitialized();
      89          131 :         ReturnErrorOnFailure(UpdateKey(key));
      90              : 
      91          131 :         return storage->SyncDeleteKeyValue(key.KeyName());
      92          131 :     }
      93              : 
      94              :     PersistentStorageDelegate * mStorage = nullptr;
      95              :     uint8_t mBuffer[kMaxSerializedSize]  = { 0 };
      96              : };
      97              : 
      98              : } // namespace chip