Line data    Source code

       1             : /*
       2             :  *    Copyright (c) 2022 Project CHIP Authors
       3             :  *
       4             :  *    Licensed under the Apache License, Version 2.0 (the "License");
       5             :  *    you may not use this file except in compliance with the License.
       6             :  *    You may obtain a copy of the License at
       7             :  *
       8             :  *        http://www.apache.org/licenses/LICENSE-2.0
       9             :  *
      10             :  *    Unless required by applicable law or agreed to in writing, software
      11             :  *    distributed under the License is distributed on an "AS IS" BASIS,
      12             :  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      13             :  *    See the License for the specific language governing permissions and
      14             :  *    limitations under the License.
      15             :  */
      16             : #pragma once
      17             : 
      18             : #include <app/AttributePersistenceProvider.h>
      19             : #include <lib/support/ScopedBuffer.h>
      20             : #include <lib/support/Span.h>
      21             : #include <system/SystemClock.h>
      22             : 
      23             : namespace chip {
      24             : namespace app {
      25             : 
      26             : class DeferredAttribute
      27             : {
      28             : public:
      29             :     explicit DeferredAttribute(const ConcreteAttributePath & path) : mPath(path) {}
      30             : 
      31           0 :     bool Matches(const ConcreteAttributePath & path) const { return mPath == path; }
      32           0 :     bool IsArmed() const { return static_cast<bool>(mValue); }
      33           0 :     System::Clock::Timestamp GetFlushTime() const { return mFlushTime; }
      34             : 
      35             :     CHIP_ERROR PrepareWrite(System::Clock::Timestamp flushTime, const ByteSpan & value);
      36             :     void Flush(AttributePersistenceProvider & persister);
      37             : 
      38             : private:
      39             :     const ConcreteAttributePath mPath;
      40             :     System::Clock::Timestamp mFlushTime;
      41             :     Platform::ScopedMemoryBufferWithSize<uint8_t> mValue;
      42             : };
      43             : 
      44             : /**
      45             :  * Decorator class for the AttributePersistenceProvider implementation that
      46             :  * defers writes of selected attributes.
      47             :  *
      48             :  * This class is useful to increase the flash lifetime by reducing the number
      49             :  * of writes of fast-changing attributes, such as CurrentLevel attribute of the
      50             :  * LevelControl cluster.
      51             :  */
      52             : class DeferredAttributePersistenceProvider : public AttributePersistenceProvider
      53             : {
      54             : public:
      55             :     DeferredAttributePersistenceProvider(AttributePersistenceProvider & persister,
      56             :                                          const Span<DeferredAttribute> & deferredAttributes,
      57             :                                          System::Clock::Milliseconds32 writeDelay) :
      58             :         mPersister(persister),
      59             :         mDeferredAttributes(deferredAttributes), mWriteDelay(writeDelay)
      60             :     {}
      61             : 
      62             :     /*
      63             :      * If the written attribute is one of the deferred attributes specified in the constructor,
      64             :      * postpone the write operation by the configured delay. If this attribute changes within the
      65             :      * delay period, further postpone the operation so that the actual write happens once the
      66             :      * attribute has remained constant for the write delay period.
      67             :      *
      68             :      * For other attributes, immediately pass the write operation to the decorated persister.
      69             :      */
      70             :     CHIP_ERROR WriteValue(const ConcreteAttributePath & aPath, const ByteSpan & aValue) override;
      71             :     CHIP_ERROR ReadValue(const ConcreteAttributePath & aPath, const EmberAfAttributeMetadata * aMetadata,
      72             :                          MutableByteSpan & aValue) override;
      73             : 
      74             : private:
      75             :     void FlushAndScheduleNext();
      76             : 
      77             :     AttributePersistenceProvider & mPersister;
      78             :     const Span<DeferredAttribute> mDeferredAttributes;
      79             :     const System::Clock::Milliseconds32 mWriteDelay;
      80             : };
      81             : 
      82             : } // namespace app
      83             : } // namespace chip