src/dictionary.c

   1 #include "common.h"
   2
   3 // ----------------------------------------------------------------------------
   4 // dictionary statistics
   5
   6 static inline void NETDATA_DICTIONARY_STATS_INSERTS_PLUS1(DICTIONARY *dict) {
   7         if(likely(dict->stats))
   8                 dict->stats->inserts++;
   9 }
  10 static inline void NETDATA_DICTIONARY_STATS_DELETES_PLUS1(DICTIONARY *dict) {
  11         if(likely(dict->stats))
  12                 dict->stats->deletes++;
  13 }
  14 static inline void NETDATA_DICTIONARY_STATS_SEARCHES_PLUS1(DICTIONARY *dict) {
  15         if(likely(dict->stats))
  16                 dict->stats->searches++;
  17 }
  18 static inline void NETDATA_DICTIONARY_STATS_ENTRIES_PLUS1(DICTIONARY *dict) {
  19         if(likely(dict->stats))
  20                 dict->stats->entries++;
  21 }
  22 static inline void NETDATA_DICTIONARY_STATS_ENTRIES_MINUS1(DICTIONARY *dict) {
  23         if(likely(dict->stats))
  24                 dict->stats->entries--;
  25 }
  26
  27
  28 // ----------------------------------------------------------------------------
  29 // dictionary locks
  30
  31 static inline void dictionary_read_lock(DICTIONARY *dict) {
  32         if(likely(dict->rwlock)) {
  33                 // debug(D_DICTIONARY, "Dictionary READ lock");
  34                 pthread_rwlock_rdlock(dict->rwlock);
  35         }
  36 }
  37
  38 static inline void dictionary_write_lock(DICTIONARY *dict) {
  39         if(likely(dict->rwlock)) {
  40                 // debug(D_DICTIONARY, "Dictionary WRITE lock");
  41                 pthread_rwlock_wrlock(dict->rwlock);
  42         }
  43 }
  44
  45 static inline void dictionary_unlock(DICTIONARY *dict) {
  46         if(likely(dict->rwlock)) {
  47                 // debug(D_DICTIONARY, "Dictionary UNLOCK lock");
  48                 pthread_rwlock_unlock(dict->rwlock);
  49         }
  50 }
  51
  52
  53 // ----------------------------------------------------------------------------
  54 // avl index
  55
  56 static int name_value_compare(void* a, void* b) {
  57         if(((NAME_VALUE *)a)->hash < ((NAME_VALUE *)b)->hash) return -1;
  58         else if(((NAME_VALUE *)a)->hash > ((NAME_VALUE *)b)->hash) return 1;
  59         else return strcmp(((NAME_VALUE *)a)->name, ((NAME_VALUE *)b)->name);
  60 }
  61
  62 #define dictionary_name_value_index_add_nolock(dict, nv) do { NETDATA_DICTIONARY_STATS_INSERTS_PLUS1(dict); avl_insert(&((dict)->values_index), (avl *)(nv)); } while(0)
  63 #define dictionary_name_value_index_del_nolock(dict, nv) do { NETDATA_DICTIONARY_STATS_DELETES_PLUS1(dict); avl_remove(&(dict->values_index), (avl *)(nv)); } while(0)
  64
  65 static inline NAME_VALUE *dictionary_name_value_index_find_nolock(DICTIONARY *dict, const char *name, uint32_t hash) {
  66         NAME_VALUE tmp;
  67         tmp.hash = (hash)?hash:simple_hash(name);
  68         tmp.name = (char *)name;
  69
  70         NETDATA_DICTIONARY_STATS_SEARCHES_PLUS1(dict);
  71         return (NAME_VALUE *)avl_search(&(dict->values_index), (avl *) &tmp);
  72 }
  73
  74 // ----------------------------------------------------------------------------
  75 // internal methods
  76
  77 static NAME_VALUE *dictionary_name_value_create_nolock(DICTIONARY *dict, const char *name, void *value, size_t value_len, uint32_t hash) {
  78         debug(D_DICTIONARY, "Creating name value entry for name '%s'.", name);
  79
  80         NAME_VALUE *nv = callocz(1, sizeof(NAME_VALUE));
  81
  82         if(dict->flags & DICTIONARY_FLAG_NAME_LINK_DONT_CLONE)
  83                 nv->name = (char *)name;
  84         else {
  85                 nv->name = strdupz(name);
  86         }
  87
  88         nv->hash = (hash)?hash:simple_hash(nv->name);
  89
  90         if(dict->flags & DICTIONARY_FLAG_VALUE_LINK_DONT_CLONE)
  91                 nv->value = value;
  92         else {
  93                 nv->value = mallocz(value_len);
  94                 memcpy(nv->value, value, value_len);
  95         }
  96
  97         // index it
  98         dictionary_name_value_index_add_nolock(dict, nv);
  99         NETDATA_DICTIONARY_STATS_ENTRIES_PLUS1(dict);
 100
 101         return nv;
 102 }
 103
 104 static void dictionary_name_value_destroy_nolock(DICTIONARY *dict, NAME_VALUE *nv) {
 105         debug(D_DICTIONARY, "Destroying name value entry for name '%s'.", nv->name);
 106
 107         dictionary_name_value_index_del_nolock(dict, nv);
 108
 109         NETDATA_DICTIONARY_STATS_ENTRIES_MINUS1(dict);
 110
 111         if(!(dict->flags & DICTIONARY_FLAG_VALUE_LINK_DONT_CLONE)) {
 112                 debug(D_REGISTRY, "Dictionary freeing value of '%s'", nv->name);
 113                 freez(nv->value);
 114         }
 115
 116         if(!(dict->flags & DICTIONARY_FLAG_NAME_LINK_DONT_CLONE)) {
 117                 debug(D_REGISTRY, "Dictionary freeing name '%s'", nv->name);
 118                 freez(nv->name);
 119         }
 120
 121         freez(nv);
 122 }
 123
 124 // ----------------------------------------------------------------------------
 125 // API - basic methods
 126
 127 DICTIONARY *dictionary_create(uint8_t flags) {
 128         debug(D_DICTIONARY, "Creating dictionary.");
 129
 130         DICTIONARY *dict = callocz(1, sizeof(DICTIONARY));
 131
 132         if(flags & DICTIONARY_FLAG_WITH_STATISTICS)
 133                 dict->stats = callocz(1, sizeof(struct dictionary_stats));
 134
 135         if(!(flags & DICTIONARY_FLAG_SINGLE_THREADED)) {
 136                 dict->rwlock = callocz(1, sizeof(pthread_rwlock_t));
 137                 pthread_rwlock_init(dict->rwlock, NULL);
 138         }
 139
 140         avl_init(&dict->values_index, name_value_compare);
 141         dict->flags = flags;
 142
 143         return dict;
 144 }
 145
 146 void dictionary_destroy(DICTIONARY *dict) {
 147         debug(D_DICTIONARY, "Destroying dictionary.");
 148
 149         dictionary_write_lock(dict);
 150
 151         while(dict->values_index.root)
 152                 dictionary_name_value_destroy_nolock(dict, (NAME_VALUE *)dict->values_index.root);
 153
 154         dictionary_unlock(dict);
 155
 156         if(dict->stats)
 157                 freez(dict->stats);
 158
 159         if(dict->rwlock)
 160                 freez(dict->rwlock);
 161
 162         freez(dict);
 163 }
 164
 165 // ----------------------------------------------------------------------------
 166
 167 void *dictionary_set(DICTIONARY *dict, const char *name, void *value, size_t value_len) {
 168         debug(D_DICTIONARY, "SET dictionary entry with name '%s'.", name);
 169
 170         uint32_t hash = simple_hash(name);
 171
 172         dictionary_write_lock(dict);
 173
 174         NAME_VALUE *nv = dictionary_name_value_index_find_nolock(dict, name, hash);
 175         if(unlikely(!nv)) {
 176                 debug(D_DICTIONARY, "Dictionary entry with name '%s' not found. Creating a new one.", name);
 177
 178                 nv = dictionary_name_value_create_nolock(dict, name, value, value_len, hash);
 179                 if(unlikely(!nv))
 180                         fatal("Cannot create name_value.");
 181         }
 182         else {
 183                 debug(D_DICTIONARY, "Dictionary entry with name '%s' found. Changing its value.", name);
 184
 185                 if(dict->flags & DICTIONARY_FLAG_VALUE_LINK_DONT_CLONE) {
 186                         debug(D_REGISTRY, "Dictionary: linking value to '%s'", name);
 187                         nv->value = value;
 188                 }
 189                 else {
 190                         debug(D_REGISTRY, "Dictionary: cloning value to '%s'", name);
 191
 192                         // copy the new value without breaking
 193                         // any other thread accessing the same entry
 194                         void *new = mallocz(value_len),
 195                                         *old = nv->value;
 196
 197                         memcpy(new, value, value_len);
 198                         nv->value = new;
 199
 200                         debug(D_REGISTRY, "Dictionary: freeing old value of '%s'", name);
 201                         freez(old);
 202                 }
 203         }
 204
 205         dictionary_unlock(dict);
 206
 207         return nv->value;
 208 }
 209
 210 void *dictionary_get(DICTIONARY *dict, const char *name) {
 211         debug(D_DICTIONARY, "GET dictionary entry with name '%s'.", name);
 212
 213         dictionary_read_lock(dict);
 214         NAME_VALUE *nv = dictionary_name_value_index_find_nolock(dict, name, 0);
 215         dictionary_unlock(dict);
 216
 217         if(unlikely(!nv)) {
 218                 debug(D_DICTIONARY, "Not found dictionary entry with name '%s'.", name);
 219                 return NULL;
 220         }
 221
 222         debug(D_DICTIONARY, "Found dictionary entry with name '%s'.", name);
 223         return nv->value;
 224 }
 225
 226 int dictionary_del(DICTIONARY *dict, const char *name) {
 227         int ret;
 228
 229         debug(D_DICTIONARY, "DEL dictionary entry with name '%s'.", name);
 230
 231         dictionary_write_lock(dict);
 232
 233         NAME_VALUE *nv = dictionary_name_value_index_find_nolock(dict, name, 0);
 234         if(unlikely(!nv)) {
 235                 debug(D_DICTIONARY, "Not found dictionary entry with name '%s'.", name);
 236                 ret = -1;
 237         }
 238         else {
 239                 debug(D_DICTIONARY, "Found dictionary entry with name '%s'.", name);
 240                 dictionary_name_value_destroy_nolock(dict, nv);
 241                 ret = 0;
 242         }
 243
 244         dictionary_unlock(dict);
 245
 246         return ret;
 247 }
 248
 249
 250 // ----------------------------------------------------------------------------
 251 // API - walk through the dictionary
 252 // the dictionary is locked for reading while this happens
 253 // do not user other dictionary calls while walking the dictionary - deadlock!
 254
 255 static int dictionary_walker(avl *a, int (*callback)(void *entry, void *data), void *data) {
 256         int total = 0, ret = 0;
 257
 258         if(a->avl_link[0]) {
 259                 ret = dictionary_walker(a->avl_link[0], callback, data);
 260                 if(ret < 0) return ret;
 261                 total += ret;
 262         }
 263
 264         ret = callback(((NAME_VALUE *)a)->value, data);
 265         if(ret < 0) return ret;
 266         total += ret;
 267
 268         if(a->avl_link[1]) {
 269                 ret = dictionary_walker(a->avl_link[1], callback, data);
 270                 if (ret < 0) return ret;
 271                 total += ret;
 272         }
 273
 274         return total;
 275 }
 276
 277 int dictionary_get_all(DICTIONARY *dict, int (*callback)(void *entry, void *data), void *data) {
 278         int ret = 0;
 279
 280         dictionary_read_lock(dict);
 281
 282         if(likely(dict->values_index.root))
 283                 ret = dictionary_walker(dict->values_index.root, callback, data);
 284
 285         dictionary_unlock(dict);
 286
 287         return ret;
 288 }