Spdk/include/spdk/reduce.h

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/** \file
 * SPDK block compression
 */

#ifndef SPDK_REDUCE_H_
#define SPDK_REDUCE_H_

#include "spdk/uuid.h"

/**
 * Describes the parameters of an spdk_reduce_vol.
 */
struct spdk_reduce_vol_params {
	/**
	 * Size in bytes of the IO unit for the backing device.  This
	 *  is the unit in which space is allocated from the backing
	 *  device, and the unit in which data is read from of written
	 *  to the backing device.  Must be greater than 0.
	 */
	uint32_t		backing_io_unit_size;

	/**
	 * Size in bytes of a chunk on the compressed volume.  This
	 *  is the unit in which data is compressed.  Must be an even
	 *  multiple of backing_io_unit_size.  Must be greater than 0.
	 */
	uint32_t		chunk_size;

	/**
	 * Total size in bytes of the compressed volume.  Must be
	 *  an even multiple of chunk_size.  Must be greater than 0.
	 */
	uint64_t		vol_size;
};

/**
 * Get the required size for the pm file for a compressed volume.
 *
 * \param params Parameters for the compressed volume
 * \return Size of the required pm file (in bytes) needed to create the
 *         compressed volume.  Returns -EINVAL if params is invalid.
 */
int64_t spdk_reduce_get_pm_file_size(struct spdk_reduce_vol_params *params);

/**
 * Get the required size for the backing device for a compressed volume.
 *
 * \param params Parameters for the compressed volume
 * \return Size of the required backing device (in bytes) needed to create
 *         the compressed volume.  Returns -EINVAL if params is invalid.
 */
int64_t spdk_reduce_get_backing_device_size(struct spdk_reduce_vol_params *params);

#endif /* SPDK_REDUCE_H_ */