pawengine/hashmap.c

#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include "log.h"

#define HASH_MASK 0b111111
#define TYPE uint32_t

struct Node_ui32 {
  TYPE v;
  struct Node_ui32 *next;
};
struct Bucket_ui32 {
  struct Node_ui32 *nodes;
};
struct Hashmap_ui32 {
  struct Bucket_ui32 buckets[HASH_MASK + 1];
};

struct Hashmap_ui32 *create_hashmap_ui32() {
  struct Hashmap_ui32 *map = malloc(sizeof(struct Hashmap_ui32));
  for (int i = 0; i <= HASH_MASK; i++) {
    map->buckets[i].nodes = NULL;
  }
  return map;
}
void destroy_hashmap_ui32(struct Hashmap_ui32 *map) {
  for (int i = 0; i <= HASH_MASK; i++) {
    struct Node_ui32 *node = map->buckets[i].nodes;
    while (node != NULL) {
      struct Node_ui32 *tmp = node;
      node = tmp->next;
      free(tmp);
    }
  }
  memset(map, 0, sizeof(struct Hashmap_ui32));
  free(map);
}
int hash(TYPE v) { return v & HASH_MASK; }
void insert_hashmap_ui32(struct Hashmap_ui32 *map, TYPE v) {
  int h = hash(v);
  struct Node_ui32 *node = map->buckets[h].nodes;
  while (node != NULL) {
    if (node->v == v) {
      meow("%d was already in hashmap", v);
      return;
    }
    node = node->next;
  }
  struct Node_ui32 *n = malloc(sizeof(struct Node_ui32));
  n->v = v;
  n->next = map->buckets[h].nodes;
  map->buckets[h].nodes = n;
}
void remove_hashmap_ui32(struct Hashmap_ui32 *map, TYPE v) {
  int h = hash(v);
  struct Node_ui32 *prev = NULL;
  struct Node_ui32 *node = map->buckets[h].nodes;
  while (node != NULL) {
    if (node->v == v) {
      if (prev == NULL) {
        if (node->next == NULL) {
          map->buckets[h].nodes = NULL;
        } else {
          map->buckets[h].nodes = node->next;
        }
      } else {
        prev->next = node->next;
      }
      free(node);
      return;
    }
    node = node->next;
  }
  meow("did not find %d in hashmap", v);
}
bool get_hashmap_ui32(struct Hashmap_ui32 *map, TYPE v) {
  int h = hash(v);
  struct Node_ui32 *node = map->buckets[h].nodes;
  while (node != NULL) {
    if (node->v == v) {
      return true;
    }
    node = node->next;
  }
  return false;
}