sdm/include/core/buffer_allocator.h

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/*! @file buffer_allocator.h
  @brief Interface file for platform specific buffer allocator.

  @details This interface is used by SDM to allocate internal buffers.
*/

#ifndef __BUFFER_ALLOCATOR_H__
#define __BUFFER_ALLOCATOR_H__

#include <core/layer_buffer.h>

namespace sdm {
/*! @brief Input configuration set by the client for buffer allocation.

  @sa BufferInfo::BufferConfig
*/

struct BufferConfig {
  uint32_t width;            //!< Specifies buffer width for buffer allocation.
  uint32_t height;           //!< Specifies buffer height for buffer allocation.
  LayerBufferFormat format;  //!< Specifies buffer format for buffer allocation.
  uint32_t buffer_count;     //!< Specifies number of buffers to be allocated.
  bool secure;               //!< Specifies buffer to be allocated from secure region.
  bool cache;                //!< Specifies whether the buffer needs to be cache.

  BufferConfig() : width(0), height(0), format(kFormatInvalid), buffer_count(0), secure(false),
                  cache(false) { }
};

/*! @brief Holds the information about the allocated buffer.

  @sa BufferAllocator::AllocateBuffer
  @sa BufferAllocator::FreeBuffer
*/
struct AllocatedBufferInfo {
  int fd;                    //!< Specifies the fd of the allocated buffer.
  uint32_t stride;           //!< Specifies aligned buffer width of the allocated buffer.
  uint32_t size;             //!< Specifies the size of the allocated buffer.

  AllocatedBufferInfo() : fd(-1), stride(0), size(0) { }
};

/*! @brief Holds the information about the input/output configuration of an output buffer.

  @sa BufferAllocator::AllocateBuffer
  @sa BufferAllocator::FreeBuffer
*/
struct BufferInfo {
  BufferConfig buffer_config;             //!< Specifies configuration of a buffer to be allocated.
  AllocatedBufferInfo alloc_buffer_info;  //!< Specifies buffer information of allocated buffer.

  void *private_data;                      //!< Pointer to private data.

  BufferInfo() : private_data(NULL) { }
};

/*! @brief Buffer allocator implemented by the client

  @details This class declares prototype for BufferAllocator methods which must be
  implemented by the client. Buffer manager in display manager will use these methods to
  allocate/deallocate buffers for display manager.

  @sa CoreInterface::CreateCore
*/
class BufferAllocator {
 public:
  /*! @brief Method to allocate ouput buffer for the given input configuration.

    @details This method allocates memory based on input configuration.

    @param[in] buffer_info \link BufferInfo \endlink

    @return \link DisplayError \endlink
  */
  virtual DisplayError AllocateBuffer(BufferInfo *buffer_info) = 0;


  /*! @brief Method to deallocate the ouput buffer.

    @details This method deallocates the memory allocated using AllocateBuffer method.

    @param[in] buffer_info \link BufferInfo \endlink

    @return \link DisplayError \endlink
  */
  virtual DisplayError FreeBuffer(BufferInfo *buffer_info) = 0;

 protected:
  virtual ~BufferAllocator() { }
};

}  // namespace sdm

#endif  // __BUFFER_ALLOCATOR_H__