1  #ifndef __CMPH_COMPRESSED_RANK_H__
       2  #define __CMPH_COMPRESSED_RANK_H__
       3  
       4  #include "select.h"
       5  
       6  struct _compressed_rank_t
       7  {
       8  	cmph_uint32 max_val;
       9  	cmph_uint32 n; // number of values stored in vals_rems
      10  	// The length in bits of each value is decomposed into two compnents: the lg(n) MSBs are stored in rank_select data structure
      11  	// the remaining LSBs are stored in a table of n cells, each one of rem_r bits.
      12  	cmph_uint32 rem_r;
      13  	select_t sel;
      14  	cmph_uint32 * vals_rems;
      15  };
      16  
      17  typedef struct _compressed_rank_t compressed_rank_t;
      18  
      19  void compressed_rank_init(compressed_rank_t * cr);
      20  
      21  void compressed_rank_destroy(compressed_rank_t * cr);
      22   
      23  void compressed_rank_generate(compressed_rank_t * cr, cmph_uint32 * vals_table, cmph_uint32 n);
      24  
      25  cmph_uint32 compressed_rank_query(compressed_rank_t * cr, cmph_uint32 idx);
      26  
      27  cmph_uint32 compressed_rank_get_space_usage(compressed_rank_t * cr);
      28  
      29  void compressed_rank_dump(compressed_rank_t * cr, char **buf, cmph_uint32 *buflen);
      30  
      31  void compressed_rank_load(compressed_rank_t * cr, const char *buf, cmph_uint32 buflen);
      32  
      33  
      34  /** \fn void compressed_rank_pack(compressed_rank_t *cr, void *cr_packed);
      35   *  \brief Support the ability to pack a compressed_rank structure into a preallocated contiguous memory space pointed by cr_packed.
      36   *  \param cr points to the compressed_rank structure
      37   *  \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 
      38   */
      39  void compressed_rank_pack(compressed_rank_t *cr, void *cr_packed);
      40  
      41  /** \fn cmph_uint32 compressed_rank_packed_size(compressed_rank_t *cr);
      42   *  \brief Return the amount of space needed to pack a compressed_rank structure.
      43   *  \return the size of the packed compressed_rank structure or zero for failures
      44   */ 
      45  cmph_uint32 compressed_rank_packed_size(compressed_rank_t *cr);
      46  
      47  
      48  /** \fn cmph_uint32 compressed_rank_query_packed(void * cr_packed, cmph_uint32 idx);
      49   *  \param cr_packed is a pointer to a contiguous memory area
      50   *  \param idx is an index to compute the rank
      51   *  \return an integer that represents the compressed_rank value.
      52   */
      53  cmph_uint32 compressed_rank_query_packed(void * cr_packed, cmph_uint32 idx);
      54  
      55  #endif