ucx/map.c

Fri, 25 May 2012 17:39:27 +0200

author
Olaf Wintermann <olaf.wintermann@gmail.com>
date
Fri, 25 May 2012 17:39:27 +0200
changeset 31
91ac86557290
parent 30
23bb65cbf7a4
child 38
35f67a8ef875
permissions
-rw-r--r--

added map iterator

     1 /*
     2  *
     3  */
     5 #include <stdlib.h>
     6 #include <string.h>
     8 #include "map.h"
    10 UcxMap *ucx_map_new(size_t size) {
    11     UcxMap *map = (UcxMap*)malloc(sizeof(UcxMap));
    12     if(map == NULL) {
    13         return NULL;
    14     }
    16     map->map = (UcxMapElement**)calloc(size, sizeof(UcxMapElement*));
    17     if(map->map == NULL) {
    18         free(map);
    19         return NULL;
    20     }
    21     map->size = size;
    23     return map;
    24 }
    26 void ucx_map_free(UcxMap *map) {
    27     for (size_t n = 0 ; n < map->size ; n++) {
    28         UcxMapElement *elem = map->map[n];
    29         if (elem != NULL) {
    30             do {
    31                 UcxMapElement *next = elem->next;
    32                 free(elem->key.data);
    33                 free(elem);
    34                 elem = next;
    35             } while (elem != NULL);
    36         }
    37     }
    38     free(map->map);
    39     free(map);
    40 }
    42 int ucx_map_put(UcxMap *map, UcxKey key, void *data) {
    43     if(key.hash == 0) {
    44         key.hash = ucx_hash((char*)key.data, key.len);
    45     }
    47     size_t slot = key.hash%map->size;
    48     UcxMapElement *elm = map->map[slot];
    49     UcxMapElement *prev = NULL;
    51     while (elm != NULL && elm->key.hash < key.hash) {
    52         prev = elm;
    53         elm = elm->next;
    54     }
    56     if (elm == NULL || elm->key.hash != key.hash) {
    57         UcxMapElement *e = (UcxMapElement*)malloc(sizeof(UcxMapElement));
    58         if(e == NULL) {
    59             return -1;
    60         }
    61         e->key.data = NULL;
    62         if (prev == NULL) {
    63             map->map[slot] = e;
    64         } else {
    65             prev->next = e;
    66         }
    67         e->next = elm;
    68         elm = e;
    69     }
    71     if(elm->key.data == NULL) {
    72         void *kd = malloc(key.len);
    73         if (kd == NULL) {
    74             return -1;
    75         }
    76         memcpy(kd, key.data, key.len);
    77         key.data = kd;
    78         elm->key = key;
    79     }
    80     elm->data = data;
    82     return 0;
    83 }
    85 void* ucx_map_get(UcxMap *map, UcxKey key) {
    86     if(key.hash == 0) {
    87         key.hash = ucx_hash((char*)key.data, key.len);
    88     }
    90     UcxMapElement *elm = map->map[key.hash%map->size];
    91     while (elm != NULL && elm->key.hash <= key.hash) {
    92         if(elm->key.hash == key.hash) {
    93             int n = (key.len > elm->key.len) ? elm->key.len : key.len;
    94             if (memcmp(elm->key.data, key.data, n) == 0) {
    95                 return elm->data;
    96             }
    97         }
    98         elm = elm->next;
    99     }
   101     return NULL;
   102 }
   104 UcxKey ucx_key(void *data, size_t len) {
   105     UcxKey key;
   106     key.data = data;
   107     key.len = len;
   108     key.hash = ucx_hash(data, len);
   109     return key;
   110 }
   113 int ucx_hash(char *data, size_t len) {
   114     /* murmur hash 2 */
   116     int m = 0x5bd1e995;
   117     int r = 24;
   119     int h = 25 ^ len;
   121     int i = 0;
   122     while (len >= 4) {
   123         int k = data[i + 0] & 0xFF;
   124         k |= (data[i + 1] & 0xFF) << 8;
   125         k |= (data[i + 2] & 0xFF) << 16;
   126         k |= (data[i + 3] & 0xFF) << 24;
   128         k *= m;
   129         k ^= k >> r;
   130         k *= m;
   132         h *= m;
   133         h ^= k;
   135         i += 4;
   136         len -= 4;
   137     }
   139     switch (len) {
   140         case 3: h ^= (data[i + 2] & 0xFF) << 16;
   141         case 2: h ^= (data[i + 1] & 0xFF) << 8;
   142         case 1: h ^= (data[i + 0] & 0xFF); h *= m;
   143     }
   145     h ^= h >> 13;
   146     h *= m;
   147     h ^= h >> 15;
   149     return h;
   150 }
   152 UcxMapIterator ucx_map_iterator(UcxMap *map) {
   153     UcxMapIterator i;
   154     i.map = map;
   155     i.cur = NULL;
   156     i.index = 0;
   157     return i;
   158 }
   160 int ucx_map_iter_next(UcxMapIterator *i, void **elm) {
   161     UcxMapElement *e = i->cur;
   163     if(e == NULL) {
   164         e = i->map->map[0];
   165     } else {
   166         e = e->next;
   167     }
   169     while(i->index < i->map->size) {
   170         if(e != NULL) {
   171             if(e->data != NULL) {
   172                 i->cur = e;
   173                 *elm = e->data;
   174                 return 0;
   175             }
   177             e = e->next;
   178         } else {
   179             i->index++;
   181             if(i->index < i->map->size) {
   182                 e = i->map->map[i->index];
   183             }
   184         }
   185     }
   187     return 1;
   188 }

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