Coverage Report

Created: 2026-05-30 06:16

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/src/libzip/lib/zip_hash.c
Line
Count
Source
1
/*
2
  zip_hash.c -- hash table string -> uint64
3
  Copyright (C) 2015-2024 Dieter Baron and Thomas Klausner
4
5
  This file is part of libzip, a library to manipulate ZIP archives.
6
  The authors can be contacted at <info@libzip.org>
7
8
  Redistribution and use in source and binary forms, with or without
9
  modification, are permitted provided that the following conditions
10
  are met:
11
  1. Redistributions of source code must retain the above copyright
12
     notice, this list of conditions and the following disclaimer.
13
  2. Redistributions in binary form must reproduce the above copyright
14
     notice, this list of conditions and the following disclaimer in
15
     the documentation and/or other materials provided with the
16
     distribution.
17
  3. The names of the authors may not be used to endorse or promote
18
     products derived from this software without specific prior
19
     written permission.
20
21
  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
22
  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24
  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
25
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27
  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
29
  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30
  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
31
  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32
*/
33
34
#include "zipint.h"
35
#include <stdlib.h>
36
#include <string.h>
37
38
/* parameter for the string hash function */
39
212k
#define HASH_MULTIPLIER 33
40
26.1k
#define HASH_START 5381
41
42
/* hash table's fill ratio is kept between these by doubling/halfing its size as necessary */
43
16.4k
#define HASH_MAX_FILL .75
44
0
#define HASH_MIN_FILL .01
45
46
/* but hash table size is kept between these */
47
0
#define HASH_MIN_SIZE 256
48
3.43k
#define HASH_MAX_SIZE 0x80000000ul
49
50
struct zip_hash_entry {
51
    const zip_uint8_t *name;
52
    zip_int64_t orig_index;
53
    zip_int64_t current_index;
54
    struct zip_hash_entry *next;
55
    zip_uint32_t hash_value;
56
};
57
typedef struct zip_hash_entry zip_hash_entry_t;
58
59
struct zip_hash {
60
    zip_uint32_t table_size;
61
    zip_uint64_t nentries;
62
    zip_hash_entry_t **table;
63
};
64
65
66
/* free list of entries */
67
6.13k
static void free_list(zip_hash_entry_t *entry) {
68
13.3k
    while (entry != NULL) {
69
7.24k
        zip_hash_entry_t *next = entry->next;
70
7.24k
        free(entry);
71
7.24k
        entry = next;
72
7.24k
    }
73
6.13k
}
74
75
76
/* compute hash of string, full 32 bit value */
77
26.1k
static zip_uint32_t hash_string(const zip_uint8_t *name) {
78
26.1k
    zip_uint64_t value = HASH_START;
79
80
26.1k
    if (name == NULL) {
81
0
        return 0;
82
0
    }
83
84
238k
    while (*name != 0) {
85
212k
        value = (zip_uint64_t)(((value * HASH_MULTIPLIER) + (zip_uint8_t)*name) % 0x100000000ul);
86
212k
        name++;
87
212k
    }
88
89
26.1k
    return (zip_uint32_t)value;
90
26.1k
}
91
92
93
/* resize hash table; new_size must be a power of 2, can be larger or smaller than current size */
94
3.43k
static bool hash_resize(zip_hash_t *hash, zip_uint32_t new_size, zip_error_t *error) {
95
3.43k
    zip_hash_entry_t **new_table;
96
97
3.43k
    if (new_size == hash->table_size) {
98
0
        return true;
99
0
    }
100
101
3.43k
    if ((new_table = (zip_hash_entry_t **)calloc(new_size, sizeof(zip_hash_entry_t *))) == NULL) {
102
0
        zip_error_set(error, ZIP_ER_MEMORY, 0);
103
0
        return false;
104
0
    }
105
106
3.43k
    if (hash->nentries > 0) {
107
1.43k
        zip_uint32_t i;
108
109
2.92k
        for (i = 0; i < hash->table_size; i++) {
110
1.49k
            zip_hash_entry_t *entry = hash->table[i];
111
2.98k
            while (entry) {
112
1.49k
                zip_hash_entry_t *next = entry->next;
113
114
1.49k
                zip_uint32_t new_index = entry->hash_value % new_size;
115
116
1.49k
                entry->next = new_table[new_index];
117
1.49k
                new_table[new_index] = entry;
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119
1.49k
                entry = next;
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1.49k
            }
121
1.49k
        }
122
1.43k
    }
123
124
3.43k
    free(hash->table);
125
3.43k
    hash->table = new_table;
126
3.43k
    hash->table_size = new_size;
127
128
3.43k
    return true;
129
3.43k
}
130
131
132
2.00k
static zip_uint32_t size_for_capacity(zip_uint64_t capacity) {
133
2.00k
    double needed_size = capacity / HASH_MAX_FILL;
134
2.00k
    zip_uint32_t v;
135
136
2.00k
    if (needed_size > ZIP_UINT32_MAX) {
137
0
        v = ZIP_UINT32_MAX;
138
0
    }
139
2.00k
    else {
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2.00k
        v = (zip_uint32_t)needed_size;
141
2.00k
    }
142
143
2.00k
    if (v > HASH_MAX_SIZE) {
144
0
        return HASH_MAX_SIZE;
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0
    }
146
147
    /* From Bit Twiddling Hacks by Sean Eron Anderson <seander@cs.stanford.edu>
148
     (http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2). */
149
150
2.00k
    v--;
151
2.00k
    v |= v >> 1;
152
2.00k
    v |= v >> 2;
153
2.00k
    v |= v >> 4;
154
2.00k
    v |= v >> 8;
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2.00k
    v |= v >> 16;
156
2.00k
    v++;
157
158
2.00k
    return v;
159
2.00k
}
160
161
162
5.06k
zip_hash_t *_zip_hash_new(zip_error_t *error) {
163
5.06k
    zip_hash_t *hash;
164
165
5.06k
    if ((hash = (zip_hash_t *)malloc(sizeof(zip_hash_t))) == NULL) {
166
0
        zip_error_set(error, ZIP_ER_MEMORY, 0);
167
0
        return NULL;
168
0
    }
169
170
5.06k
    hash->table_size = 0;
171
5.06k
    hash->nentries = 0;
172
5.06k
    hash->table = NULL;
173
174
5.06k
    return hash;
175
5.06k
}
176
177
178
5.06k
void _zip_hash_free(zip_hash_t *hash) {
179
5.06k
    zip_uint32_t i;
180
181
5.06k
    if (hash == NULL) {
182
0
        return;
183
0
    }
184
185
5.06k
    if (hash->table != NULL) {
186
54.8k
        for (i = 0; i < hash->table_size; i++) {
187
52.8k
            if (hash->table[i] != NULL) {
188
6.13k
                free_list(hash->table[i]);
189
6.13k
            }
190
52.8k
        }
191
2.00k
        free(hash->table);
192
2.00k
    }
193
5.06k
    free(hash);
194
5.06k
}
195
196
197
/* insert into hash, return error on existence or memory issues */
198
26.1k
bool _zip_hash_add(zip_hash_t *hash, const zip_uint8_t *name, zip_uint64_t index, zip_flags_t flags, zip_error_t *error) {
199
26.1k
    zip_uint32_t hash_value, table_index;
200
26.1k
    zip_hash_entry_t *entry;
201
202
26.1k
    if (hash == NULL || name == NULL || index > ZIP_INT64_MAX) {
203
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
204
0
        return false;
205
0
    }
206
207
26.1k
    if (hash->table_size == 0) {
208
0
        if (!hash_resize(hash, HASH_MIN_SIZE, error)) {
209
0
            return false;
210
0
        }
211
0
    }
212
213
26.1k
    hash_value = hash_string(name);
214
26.1k
    table_index = hash_value % hash->table_size;
215
216
27.7k
    for (entry = hash->table[table_index]; entry != NULL; entry = entry->next) {
217
20.5k
        if (entry->hash_value == hash_value && strcmp((const char *)name, (const char *)entry->name) == 0) {
218
18.9k
            if (((flags & ZIP_FL_UNCHANGED) && entry->orig_index != -1) || entry->current_index != -1) {
219
18.9k
                zip_error_set(error, ZIP_ER_EXISTS, 0);
220
18.9k
                return false;
221
18.9k
            }
222
0
            else {
223
0
                break;
224
0
            }
225
18.9k
        }
226
20.5k
    }
227
228
7.24k
    if (entry == NULL) {
229
7.24k
        if ((entry = (zip_hash_entry_t *)malloc(sizeof(zip_hash_entry_t))) == NULL) {
230
0
            zip_error_set(error, ZIP_ER_MEMORY, 0);
231
0
            return false;
232
0
        }
233
7.24k
        entry->name = name;
234
7.24k
        entry->next = hash->table[table_index];
235
7.24k
        hash->table[table_index] = entry;
236
7.24k
        entry->hash_value = hash_value;
237
7.24k
        entry->orig_index = -1;
238
7.24k
        hash->nentries++;
239
7.24k
        if (hash->nentries > hash->table_size * HASH_MAX_FILL && hash->table_size < HASH_MAX_SIZE) {
240
1.43k
            if (!hash_resize(hash, hash->table_size * 2, error)) {
241
0
                return false;
242
0
            }
243
1.43k
        }
244
7.24k
    }
245
246
7.24k
    if (flags & ZIP_FL_UNCHANGED) {
247
7.24k
        entry->orig_index = (zip_int64_t)index;
248
7.24k
    }
249
7.24k
    entry->current_index = (zip_int64_t)index;
250
251
7.24k
    return true;
252
7.24k
}
253
254
255
/* remove entry from hash, error if not found */
256
0
bool _zip_hash_delete(zip_hash_t *hash, const zip_uint8_t *name, zip_error_t *error) {
257
0
    zip_uint32_t hash_value, index;
258
0
    zip_hash_entry_t *entry, *previous;
259
260
0
    if (hash == NULL || name == NULL) {
261
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
262
0
        return false;
263
0
    }
264
265
0
    if (hash->nentries > 0) {
266
0
        hash_value = hash_string(name);
267
0
        index = hash_value % hash->table_size;
268
0
        previous = NULL;
269
0
        entry = hash->table[index];
270
0
        while (entry) {
271
0
            if (entry->hash_value == hash_value && strcmp((const char *)name, (const char *)entry->name) == 0) {
272
0
                if (entry->orig_index == -1) {
273
0
                    if (previous) {
274
0
                        previous->next = entry->next;
275
0
                    }
276
0
                    else {
277
0
                        hash->table[index] = entry->next;
278
0
                    }
279
0
                    free(entry);
280
0
                    hash->nentries--;
281
0
                    if (hash->nentries < hash->table_size * HASH_MIN_FILL && hash->table_size > HASH_MIN_SIZE) {
282
0
                        if (!hash_resize(hash, hash->table_size / 2, error)) {
283
0
                            return false;
284
0
                        }
285
0
                    }
286
0
                }
287
0
                else {
288
0
                    entry->current_index = -1;
289
0
                }
290
0
                return true;
291
0
            }
292
0
            previous = entry;
293
0
            entry = entry->next;
294
0
        }
295
0
    }
296
297
0
    zip_error_set(error, ZIP_ER_NOENT, 0);
298
0
    return false;
299
0
}
300
301
302
/* find value for entry in hash, -1 if not found */
303
0
zip_int64_t _zip_hash_lookup(zip_hash_t *hash, const zip_uint8_t *name, zip_flags_t flags, zip_error_t *error) {
304
0
    zip_uint32_t hash_value, index;
305
0
    zip_hash_entry_t *entry;
306
307
0
    if (hash == NULL || name == NULL) {
308
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
309
0
        return -1;
310
0
    }
311
312
0
    if (hash->nentries > 0) {
313
0
        hash_value = hash_string(name);
314
0
        index = hash_value % hash->table_size;
315
0
        for (entry = hash->table[index]; entry != NULL; entry = entry->next) {
316
0
            if (strcmp((const char *)name, (const char *)entry->name) == 0) {
317
0
                if (flags & ZIP_FL_UNCHANGED) {
318
0
                    if (entry->orig_index != -1) {
319
0
                        return entry->orig_index;
320
0
                    }
321
0
                }
322
0
                else {
323
0
                    if (entry->current_index != -1) {
324
0
                        return entry->current_index;
325
0
                    }
326
0
                }
327
0
                break;
328
0
            }
329
0
        }
330
0
    }
331
332
0
    zip_error_set(error, ZIP_ER_NOENT, 0);
333
0
    return -1;
334
0
}
335
336
337
2.30k
bool _zip_hash_reserve_capacity(zip_hash_t *hash, zip_uint64_t capacity, zip_error_t *error) {
338
2.30k
    zip_uint32_t new_size;
339
340
2.30k
    if (capacity == 0) {
341
302
        return true;
342
302
    }
343
344
2.00k
    new_size = size_for_capacity(capacity);
345
346
2.00k
    if (new_size <= hash->table_size) {
347
0
        return true;
348
0
    }
349
350
2.00k
    if (!hash_resize(hash, new_size, error)) {
351
0
        return false;
352
0
    }
353
354
2.00k
    return true;
355
2.00k
}
356
357
358
0
bool _zip_hash_revert(zip_hash_t *hash, zip_error_t *error) {
359
0
    zip_uint32_t i;
360
0
    zip_hash_entry_t *entry, *previous;
361
362
0
    for (i = 0; i < hash->table_size; i++) {
363
0
        previous = NULL;
364
0
        entry = hash->table[i];
365
0
        while (entry) {
366
0
            if (entry->orig_index == -1) {
367
0
                zip_hash_entry_t *p;
368
0
                if (previous) {
369
0
                    previous->next = entry->next;
370
0
                }
371
0
                else {
372
0
                    hash->table[i] = entry->next;
373
0
                }
374
0
                p = entry;
375
0
                entry = entry->next;
376
                /* previous does not change */
377
0
                free(p);
378
0
                hash->nentries--;
379
0
            }
380
0
            else {
381
0
                entry->current_index = entry->orig_index;
382
0
                previous = entry;
383
0
                entry = entry->next;
384
0
            }
385
0
        }
386
0
    }
387
388
0
    if (hash->nentries < hash->table_size * HASH_MIN_FILL && hash->table_size > HASH_MIN_SIZE) {
389
0
        zip_uint32_t new_size = hash->table_size / 2;
390
0
        while (hash->nentries < new_size * HASH_MIN_FILL && new_size > HASH_MIN_SIZE) {
391
0
            new_size /= 2;
392
0
        }
393
0
        if (!hash_resize(hash, new_size, error)) {
394
0
            return false;
395
0
        }
396
0
    }
397
398
0
    return true;
399
0
}