glib/cmph/compressed_rank.h

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#ifndef __CMPH_COMPRESSED_RANK_H__
#define __CMPH_COMPRESSED_RANK_H__
#include "select.h"
struct _compressed_rank_t
{
cmph_uint32 max_val;
cmph_uint32 n; // number of values stored in vals_rems
// The length in bits of each value is decomposed into two compnents: the lg(n) MSBs are stored in rank_select data structure
// the remaining LSBs are stored in a table of n cells, each one of rem_r bits.
cmph_uint32 rem_r;
select_t sel;
cmph_uint32 * vals_rems;
};
typedef struct _compressed_rank_t compressed_rank_t;
void compressed_rank_init(compressed_rank_t * cr);
void compressed_rank_destroy(compressed_rank_t * cr);
void compressed_rank_generate(compressed_rank_t * cr, cmph_uint32 * vals_table, cmph_uint32 n);
cmph_uint32 compressed_rank_query(compressed_rank_t * cr, cmph_uint32 idx);
cmph_uint32 compressed_rank_get_space_usage(compressed_rank_t * cr);
void compressed_rank_dump(compressed_rank_t * cr, char **buf, cmph_uint32 *buflen);
void compressed_rank_load(compressed_rank_t * cr, const char *buf, cmph_uint32 buflen);
/** \fn void compressed_rank_pack(compressed_rank_t *cr, void *cr_packed);
* \brief Support the ability to pack a compressed_rank structure into a preallocated contiguous memory space pointed by cr_packed.
* \param cr points to the compressed_rank structure
* \param cr_packed pointer to the contiguous memory area used to store the compressed_rank structure. The size of cr_packed must be at least @see compressed_rank_packed_size
*/
void compressed_rank_pack(compressed_rank_t *cr, void *cr_packed);
/** \fn cmph_uint32 compressed_rank_packed_size(compressed_rank_t *cr);
* \brief Return the amount of space needed to pack a compressed_rank structure.
* \return the size of the packed compressed_rank structure or zero for failures
*/
cmph_uint32 compressed_rank_packed_size(compressed_rank_t *cr);
/** \fn cmph_uint32 compressed_rank_query_packed(void * cr_packed, cmph_uint32 idx);
* \param cr_packed is a pointer to a contiguous memory area
* \param idx is an index to compute the rank
* \return an integer that represents the compressed_rank value.
*/
cmph_uint32 compressed_rank_query_packed(void * cr_packed, cmph_uint32 idx);
#endif