sc/map

Hashmap

Overview

• Open addressing hashmap with linear probing.
• Key and value types can be integers(32bit/64bit) or pointers only. This is
  required for good performance.
• Naming requires prefixes, it's ugly but macros are necessary to avoid
  copy/compare function pointers, memcpy calls etc..
• Other types can be added but must be scalar types, not structs.
• Comes with predefined key value pairs :

                  name  key type      value type
  sc_map_of_scalar(32,  uint32_t,     uint32_t)
  sc_map_of_scalar(64,  uint64_t,     uint64_t)
  sc_map_of_scalar(64v, uint64_t,     void *)
  sc_map_of_scalar(64s, uint64_t,     const char *)
  sc_map_of_strkey(str, const char *, const char *)
  sc_map_of_strkey(sv,  const char *, void*)
  sc_map_of_strkey(s64, const char *, uint64_t)

• This is a very fast hashmap.
  • Single array allocation for all data.
  • Linear probing over an array.
  • Deletion without tombstones
  • Macros generate functions in sc_map.h and sc_map.c, it doesn't force
    compiler to inline. Inlining is upto the compiler.

Usage

#include "sc_map.h"

#include <stdio.h>

int main(int argc, char *argv[])
{
    const char *key, *value;
    struct sc_map_str map;

    sc_map_init_str(&map, 0, 0);

    sc_map_put_str(&map, "jack", "chicago");
    sc_map_put_str(&map, "jane", "new york");
    sc_map_put_str(&map, "janie", "atlanta");

    sc_map_foreach (&map, key, value) {
        printf("Key:[%s], Value:[%s] \n", key, value);
    }

    sc_map_term_str(&map);

    return 0;
}