1 /**
2 * \file lib/rpmhash.c
3 * Hash table implemenation
4 */
5
6 #include "system.h"
7 #include <stdio.h>
8 #include "debug.h"
9
10 #define Bucket JOIN(HASHTYPE,Buket)
11 #define Bucket_s JOIN(HASHTYPE,Buket_s)
12
13 typedef struct Bucket_s * Bucket;
14
15 /**
16 */
17 struct Bucket_s {
18 Bucket next; /*!< pointer to next item in bucket */
19 HTKEYTYPE key; /*!< hash key */
20 #ifdef HTDATATYPE
21 int dataCount; /*!< data entries */
22 HTDATATYPE data[1]; /*!< data - grows by resizing whole bucket */
23 #endif
24 };
25
26 /**
27 */
28 struct HASHSTRUCT {
29 int numBuckets; /*!< number of hash buckets */
30 Bucket * buckets; /*!< hash bucket array */
31 hashFunctionType fn; /*!< generate hash value for key */
32 hashEqualityType eq; /*!< compare hash keys for equality */
33 hashFreeKey freeKey;
34 int bucketCount; /*!< number of used buckets */
35 int keyCount; /*!< number of keys */
36 #ifdef HTDATATYPE
37 int dataCount; /*!< number of data entries */
38 hashFreeData freeData;
39 #endif
40 };
41
42 /**
43 * Find entry in hash table.
44 * @param ht pointer to hash table
45 * @param key pointer to key value
46 * @param keyHash key hash
47 * @return pointer to hash bucket of key (or NULL)
48 */
49 static
HASHPREFIX(findEntry)50 Bucket HASHPREFIX(findEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash)
51 {
52 unsigned int hash = keyHash % ht->numBuckets;
53 Bucket b = ht->buckets[hash];
54
55 while (b && ht->eq(b->key, key))
56 b = b->next;
57
58 return b;
59 }
60
HASHPREFIX(Create)61 HASHTYPE HASHPREFIX(Create)(int numBuckets,
62 hashFunctionType fn, hashEqualityType eq,
63 hashFreeKey freeKey
64 #ifdef HTDATATYPE
65 , hashFreeData freeData
66 #endif
67 )
68 {
69 HASHTYPE ht;
70
71 ht = xmalloc(sizeof(*ht));
72 ht->numBuckets = numBuckets > 11 ? numBuckets : 11;
73 ht->buckets = xcalloc(ht->numBuckets, sizeof(*ht->buckets));
74 ht->freeKey = freeKey;
75 #ifdef HTDATATYPE
76 ht->freeData = freeData;
77 ht->dataCount = 0;
78 #endif
79 ht->fn = fn;
80 ht->eq = eq;
81 ht->bucketCount = ht->keyCount = 0;
82 return ht;
83 }
84
HASHPREFIX(Resize)85 static void HASHPREFIX(Resize)(HASHTYPE ht, int numBuckets) {
86 Bucket * buckets = xcalloc(numBuckets, sizeof(*ht->buckets));
87
88 for (int i=0; i<ht->numBuckets; i++) {
89 Bucket b = ht->buckets[i];
90 Bucket nextB;
91 while (b != NULL) {
92 unsigned int hash = ht->fn(b->key) % numBuckets;
93 nextB = b->next;
94 b->next = buckets[hash];
95 buckets[hash] = b;
96 b = nextB;
97 }
98 }
99 free(ht->buckets);
100 ht->buckets = buckets;
101 ht->numBuckets = numBuckets;
102 }
103
HASHPREFIX(KeyHash)104 unsigned int HASHPREFIX(KeyHash)(HASHTYPE ht, HTKEYTYPE key)
105 {
106 return ht->fn(key);
107 }
108
HASHPREFIX(AddHEntry)109 void HASHPREFIX(AddHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash
110 #ifdef HTDATATYPE
111 , HTDATATYPE data
112 #endif
113 )
114 {
115 unsigned int hash = keyHash % ht->numBuckets;
116 Bucket b = ht->buckets[hash];
117 #ifdef HTDATATYPE
118 Bucket * b_addr = ht->buckets + hash;
119 #endif
120
121 if (b == NULL) {
122 ht->bucketCount += 1;
123 }
124
125 while (b && ht->eq(b->key, key)) {
126 #ifdef HTDATATYPE
127 b_addr = &(b->next);
128 #endif
129 b = b->next;
130 }
131
132 if (b == NULL) {
133 ht->keyCount += 1;
134 b = xmalloc(sizeof(*b));
135 b->key = key;
136 #ifdef HTDATATYPE
137 b->dataCount = 1;
138 b->data[0] = data;
139 #endif
140 b->next = ht->buckets[hash];
141 ht->buckets[hash] = b;
142 }
143 #ifdef HTDATATYPE
144 else {
145 if (ht->freeKey)
146 ht->freeKey(key);
147 // resizing bucket TODO: increase exponentially
148 // Bucket_s already contains space for one dataset
149 b = *b_addr = xrealloc(
150 b, sizeof(*b) + sizeof(b->data[0]) * (b->dataCount));
151 // though increasing dataCount after the resize
152 b->data[b->dataCount++] = data;
153 }
154 ht->dataCount += 1;
155 #endif
156 if (ht->keyCount > ht->numBuckets) {
157 HASHPREFIX(Resize)(ht, ht->numBuckets * 2);
158 }
159 }
160
HASHPREFIX(AddEntry)161 void HASHPREFIX(AddEntry)(HASHTYPE ht, HTKEYTYPE key
162 #ifdef HTDATATYPE
163 , HTDATATYPE data
164 #endif
165 )
166 {
167 #ifdef HTDATATYPE
168 HASHPREFIX(AddHEntry)(ht, key, ht->fn(key), data);
169 #else
170 HASHPREFIX(AddHEntry)(ht, key, ht->fn(key));
171 #endif
172 }
173
HASHPREFIX(Empty)174 void HASHPREFIX(Empty)( HASHTYPE ht)
175 {
176 Bucket b, n;
177 int i;
178
179 if (ht->bucketCount == 0) return;
180
181 for (i = 0; i < ht->numBuckets; i++) {
182 b = ht->buckets[i];
183 if (b == NULL)
184 continue;
185 ht->buckets[i] = NULL;
186
187 do {
188 n = b->next;
189 if (ht->freeKey)
190 b->key = ht->freeKey(b->key);
191 #ifdef HTDATATYPE
192 if (ht->freeData) {
193 int j;
194 for (j=0; j < b->dataCount; j++ ) {
195 b->data[j] = ht->freeData(b->data[j]);
196 }
197 }
198 #endif
199 b = _free(b);
200 } while ((b = n) != NULL);
201 }
202 ht->bucketCount = 0;
203 ht->keyCount = 0;
204 #ifdef HTDATATYPE
205 ht->dataCount = 0;
206 #endif
207 }
208
HASHPREFIX(Free)209 HASHTYPE HASHPREFIX(Free)(HASHTYPE ht)
210 {
211 if (ht==NULL)
212 return ht;
213 HASHPREFIX(Empty)(ht);
214 ht->buckets = _free(ht->buckets);
215 ht = _free(ht);
216
217 return NULL;
218 }
219
HASHPREFIX(HasHEntry)220 int HASHPREFIX(HasHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash)
221 {
222 Bucket b;
223
224 if (!(b = HASHPREFIX(findEntry)(ht, key, keyHash))) return 0; else return 1;
225 }
226
HASHPREFIX(HasEntry)227 int HASHPREFIX(HasEntry)(HASHTYPE ht, HTKEYTYPE key)
228 {
229 return HASHPREFIX(HasHEntry)(ht, key, ht->fn(key));
230 }
231
HASHPREFIX(GetHEntry)232 int HASHPREFIX(GetHEntry)(HASHTYPE ht, HTKEYTYPE key, unsigned int keyHash,
233 #ifdef HTDATATYPE
234 HTDATATYPE** data, int * dataCount,
235 #endif
236 HTKEYTYPE* tableKey)
237 {
238 Bucket b;
239 int rc = ((b = HASHPREFIX(findEntry)(ht, key, keyHash)) != NULL);
240
241 #ifdef HTDATATYPE
242 if (data)
243 *data = rc ? b->data : NULL;
244 if (dataCount)
245 *dataCount = rc ? b->dataCount : 0;
246 #endif
247 if (tableKey && rc)
248 *tableKey = b->key;
249
250 return rc;
251 }
252
HASHPREFIX(GetEntry)253 int HASHPREFIX(GetEntry)(HASHTYPE ht, HTKEYTYPE key,
254 #ifdef HTDATATYPE
255 HTDATATYPE** data, int * dataCount,
256 #endif
257 HTKEYTYPE* tableKey)
258 {
259 return HASHPREFIX(GetHEntry)(ht, key, ht->fn(key),
260 #ifdef HTDATATYPE
261 data, dataCount,
262 #endif
263 tableKey);
264 }
265
HASHPREFIX(NumBuckets)266 unsigned int HASHPREFIX(NumBuckets)(HASHTYPE ht) {
267 return ht->numBuckets;
268 }
269
HASHPREFIX(UsedBuckets)270 unsigned int HASHPREFIX(UsedBuckets)(HASHTYPE ht) {
271 return ht->bucketCount;
272 }
273
HASHPREFIX(NumKeys)274 unsigned int HASHPREFIX(NumKeys)(HASHTYPE ht) {
275 return ht->keyCount;
276 }
277
278 #ifdef HTDATATYPE
HASHPREFIX(NumData)279 unsigned int HASHPREFIX(NumData)(HASHTYPE ht) {
280 return ht->dataCount;
281 }
282 #endif
283
284
HASHPREFIX(PrintStats)285 void HASHPREFIX(PrintStats)(HASHTYPE ht) {
286 int i;
287 Bucket bucket;
288
289 int hashcnt=0, bucketcnt=0, datacnt=0;
290 int maxbuckets=0;
291
292 for (i=0; i<ht->numBuckets; i++) {
293 int buckets = 0;
294 for (bucket=ht->buckets[i]; bucket; bucket=bucket->next){
295 buckets++;
296 #ifdef HTDATATYPE
297 datacnt += bucket->dataCount;
298 #endif
299 }
300 if (maxbuckets < buckets) maxbuckets = buckets;
301 if (buckets) hashcnt++;
302 bucketcnt += buckets;
303 }
304 fprintf(stderr, "Hashsize: %i\n", ht->numBuckets);
305 fprintf(stderr, "Hashbuckets: %i\n", hashcnt);
306 fprintf(stderr, "Keys: %i\n", bucketcnt);
307 fprintf(stderr, "Values: %i\n", datacnt);
308 fprintf(stderr, "Max Keys/Bucket: %i\n", maxbuckets);
309 }
310