Coverage Report

Created: 2025-11-11 06:52

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) 2015-2022 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
178k
#define HASH_MULTIPLIER 33
40
25.1k
#define HASH_START 5381
41
42
/* hash table's fill ratio is kept between these by doubling/halfing its size as necessary */
43
14.0k
#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
3.03k
#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
static void
68
5.23k
free_list(zip_hash_entry_t *entry) {
69
11.3k
    while (entry != NULL) {
70
6.13k
        zip_hash_entry_t *next = entry->next;
71
6.13k
        free(entry);
72
6.13k
        entry = next;
73
6.13k
    }
74
5.23k
}
75
76
77
/* compute hash of string, full 32 bit value */
78
static zip_uint32_t
79
25.1k
hash_string(const zip_uint8_t *name) {
80
25.1k
    zip_uint64_t value = HASH_START;
81
82
25.1k
    if (name == NULL) {
83
0
        return 0;
84
0
    }
85
86
204k
    while (*name != 0) {
87
178k
        value = (zip_uint64_t)(((value * HASH_MULTIPLIER) + (zip_uint8_t)*name) % 0x100000000ul);
88
178k
        name++;
89
178k
    }
90
91
25.1k
    return (zip_uint32_t)value;
92
25.1k
}
93
94
95
/* resize hash table; new_size must be a power of 2, can be larger or smaller than current size */
96
static bool
97
3.03k
hash_resize(zip_hash_t *hash, zip_uint32_t new_size, zip_error_t *error) {
98
3.03k
    zip_hash_entry_t **new_table;
99
100
3.03k
    if (new_size == hash->table_size) {
101
0
        return true;
102
0
    }
103
104
3.03k
    if ((new_table = (zip_hash_entry_t **)calloc(new_size, sizeof(zip_hash_entry_t *))) == NULL) {
105
0
        zip_error_set(error, ZIP_ER_MEMORY, 0);
106
0
        return false;
107
0
    }
108
109
3.03k
    if (hash->nentries > 0) {
110
1.23k
        zip_uint32_t i;
111
112
2.53k
        for (i = 0; i < hash->table_size; i++) {
113
1.29k
            zip_hash_entry_t *entry = hash->table[i];
114
2.59k
            while (entry) {
115
1.29k
                zip_hash_entry_t *next = entry->next;
116
117
1.29k
                zip_uint32_t new_index = entry->hash_value % new_size;
118
119
1.29k
                entry->next = new_table[new_index];
120
1.29k
                new_table[new_index] = entry;
121
122
1.29k
                entry = next;
123
1.29k
            }
124
1.29k
        }
125
1.23k
    }
126
127
3.03k
    free(hash->table);
128
3.03k
    hash->table = new_table;
129
3.03k
    hash->table_size = new_size;
130
131
3.03k
    return true;
132
3.03k
}
133
134
135
static zip_uint32_t
136
1.79k
size_for_capacity(zip_uint64_t capacity) {
137
1.79k
    double needed_size = capacity / HASH_MAX_FILL;
138
1.79k
    zip_uint32_t v;
139
140
1.79k
    if (needed_size > ZIP_UINT32_MAX) {
141
0
        v = ZIP_UINT32_MAX;
142
0
    }
143
1.79k
    else {
144
1.79k
        v = (zip_uint32_t)needed_size;
145
1.79k
    }
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147
1.79k
    if (v > HASH_MAX_SIZE) {
148
0
        return HASH_MAX_SIZE;
149
0
    }
150
151
    /* From Bit Twiddling Hacks by Sean Eron Anderson <seander@cs.stanford.edu>
152
     (http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2). */
153
154
1.79k
    v--;
155
1.79k
    v |= v >> 1;
156
1.79k
    v |= v >> 2;
157
1.79k
    v |= v >> 4;
158
1.79k
    v |= v >> 8;
159
1.79k
    v |= v >> 16;
160
1.79k
    v++;
161
162
1.79k
    return v;
163
1.79k
}
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165
166
zip_hash_t *
167
4.86k
_zip_hash_new(zip_error_t *error) {
168
4.86k
    zip_hash_t *hash;
169
170
4.86k
    if ((hash = (zip_hash_t *)malloc(sizeof(zip_hash_t))) == NULL) {
171
0
        zip_error_set(error, ZIP_ER_MEMORY, 0);
172
0
        return NULL;
173
0
    }
174
175
4.86k
    hash->table_size = 0;
176
4.86k
    hash->nentries = 0;
177
4.86k
    hash->table = NULL;
178
179
4.86k
    return hash;
180
4.86k
}
181
182
183
void
184
4.86k
_zip_hash_free(zip_hash_t *hash) {
185
4.86k
    zip_uint32_t i;
186
187
4.86k
    if (hash == NULL) {
188
0
        return;
189
0
    }
190
191
4.86k
    if (hash->table != NULL) {
192
52.6k
        for (i = 0; i < hash->table_size; i++) {
193
50.8k
            if (hash->table[i] != NULL) {
194
5.23k
                free_list(hash->table[i]);
195
5.23k
            }
196
50.8k
        }
197
1.79k
        free(hash->table);
198
1.79k
    }
199
4.86k
    free(hash);
200
4.86k
}
201
202
203
/* insert into hash, return error on existence or memory issues */
204
bool
205
25.1k
_zip_hash_add(zip_hash_t *hash, const zip_uint8_t *name, zip_uint64_t index, zip_flags_t flags, zip_error_t *error) {
206
25.1k
    zip_uint32_t hash_value, table_index;
207
25.1k
    zip_hash_entry_t *entry;
208
209
25.1k
    if (hash == NULL || name == NULL || index > ZIP_INT64_MAX) {
210
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
211
0
        return false;
212
0
    }
213
214
25.1k
    if (hash->table_size == 0) {
215
0
        if (!hash_resize(hash, HASH_MIN_SIZE, error)) {
216
0
            return false;
217
0
        }
218
0
    }
219
220
25.1k
    hash_value = hash_string(name);
221
25.1k
    table_index = hash_value % hash->table_size;
222
223
26.3k
    for (entry = hash->table[table_index]; entry != NULL; entry = entry->next) {
224
20.2k
        if (entry->hash_value == hash_value && strcmp((const char *)name, (const char *)entry->name) == 0) {
225
19.0k
            if (((flags & ZIP_FL_UNCHANGED) && entry->orig_index != -1) || entry->current_index != -1) {
226
19.0k
                zip_error_set(error, ZIP_ER_EXISTS, 0);
227
19.0k
                return false;
228
19.0k
            }
229
0
            else {
230
0
                break;
231
0
            }
232
19.0k
        }
233
20.2k
    }
234
235
6.13k
    if (entry == NULL) {
236
6.13k
        if ((entry = (zip_hash_entry_t *)malloc(sizeof(zip_hash_entry_t))) == NULL) {
237
0
            zip_error_set(error, ZIP_ER_MEMORY, 0);
238
0
            return false;
239
0
        }
240
6.13k
        entry->name = name;
241
6.13k
        entry->next = hash->table[table_index];
242
6.13k
        hash->table[table_index] = entry;
243
6.13k
        entry->hash_value = hash_value;
244
6.13k
        entry->orig_index = -1;
245
6.13k
        hash->nentries++;
246
6.13k
        if (hash->nentries > hash->table_size * HASH_MAX_FILL && hash->table_size < HASH_MAX_SIZE) {
247
1.23k
            if (!hash_resize(hash, hash->table_size * 2, error)) {
248
0
                return false;
249
0
            }
250
1.23k
        }
251
6.13k
    }
252
253
6.13k
    if (flags & ZIP_FL_UNCHANGED) {
254
6.13k
        entry->orig_index = (zip_int64_t)index;
255
6.13k
    }
256
6.13k
    entry->current_index = (zip_int64_t)index;
257
258
6.13k
    return true;
259
6.13k
}
260
261
262
/* remove entry from hash, error if not found */
263
bool
264
0
_zip_hash_delete(zip_hash_t *hash, const zip_uint8_t *name, zip_error_t *error) {
265
0
    zip_uint32_t hash_value, index;
266
0
    zip_hash_entry_t *entry, *previous;
267
268
0
    if (hash == NULL || name == NULL) {
269
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
270
0
        return false;
271
0
    }
272
273
0
    if (hash->nentries > 0) {
274
0
        hash_value = hash_string(name);
275
0
        index = hash_value % hash->table_size;
276
0
        previous = NULL;
277
0
        entry = hash->table[index];
278
0
        while (entry) {
279
0
            if (entry->hash_value == hash_value && strcmp((const char *)name, (const char *)entry->name) == 0) {
280
0
                if (entry->orig_index == -1) {
281
0
                    if (previous) {
282
0
                        previous->next = entry->next;
283
0
                    }
284
0
                    else {
285
0
                        hash->table[index] = entry->next;
286
0
                    }
287
0
                    free(entry);
288
0
                    hash->nentries--;
289
0
                    if (hash->nentries < hash->table_size * HASH_MIN_FILL && hash->table_size > HASH_MIN_SIZE) {
290
0
                        if (!hash_resize(hash, hash->table_size / 2, error)) {
291
0
                            return false;
292
0
                        }
293
0
                    }
294
0
                }
295
0
                else {
296
0
                    entry->current_index = -1;
297
0
                }
298
0
                return true;
299
0
            }
300
0
            previous = entry;
301
0
            entry = entry->next;
302
0
        }
303
0
    }
304
305
0
    zip_error_set(error, ZIP_ER_NOENT, 0);
306
0
    return false;
307
0
}
308
309
310
/* find value for entry in hash, -1 if not found */
311
zip_int64_t
312
0
_zip_hash_lookup(zip_hash_t *hash, const zip_uint8_t *name, zip_flags_t flags, zip_error_t *error) {
313
0
    zip_uint32_t hash_value, index;
314
0
    zip_hash_entry_t *entry;
315
316
0
    if (hash == NULL || name == NULL) {
317
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
318
0
        return -1;
319
0
    }
320
321
0
    if (hash->nentries > 0) {
322
0
        hash_value = hash_string(name);
323
0
        index = hash_value % hash->table_size;
324
0
        for (entry = hash->table[index]; entry != NULL; entry = entry->next) {
325
0
            if (strcmp((const char *)name, (const char *)entry->name) == 0) {
326
0
                if (flags & ZIP_FL_UNCHANGED) {
327
0
                    if (entry->orig_index != -1) {
328
0
                        return entry->orig_index;
329
0
                    }
330
0
                }
331
0
                else {
332
0
                    if (entry->current_index != -1) {
333
0
                        return entry->current_index;
334
0
                    }
335
0
                }
336
0
                break;
337
0
            }
338
0
        }
339
0
    }
340
341
0
    zip_error_set(error, ZIP_ER_NOENT, 0);
342
0
    return -1;
343
0
}
344
345
346
bool
347
2.09k
_zip_hash_reserve_capacity(zip_hash_t *hash, zip_uint64_t capacity, zip_error_t *error) {
348
2.09k
    zip_uint32_t new_size;
349
350
2.09k
    if (capacity == 0) {
351
305
        return true;
352
305
    }
353
354
1.79k
    new_size = size_for_capacity(capacity);
355
356
1.79k
    if (new_size <= hash->table_size) {
357
0
        return true;
358
0
    }
359
360
1.79k
    if (!hash_resize(hash, new_size, error)) {
361
0
        return false;
362
0
    }
363
364
1.79k
    return true;
365
1.79k
}
366
367
368
bool
369
0
_zip_hash_revert(zip_hash_t *hash, zip_error_t *error) {
370
0
    zip_uint32_t i;
371
0
    zip_hash_entry_t *entry, *previous;
372
373
0
    for (i = 0; i < hash->table_size; i++) {
374
0
        previous = NULL;
375
0
        entry = hash->table[i];
376
0
        while (entry) {
377
0
            if (entry->orig_index == -1) {
378
0
                zip_hash_entry_t *p;
379
0
                if (previous) {
380
0
                    previous->next = entry->next;
381
0
                }
382
0
                else {
383
0
                    hash->table[i] = entry->next;
384
0
                }
385
0
                p = entry;
386
0
                entry = entry->next;
387
                /* previous does not change */
388
0
                free(p);
389
0
                hash->nentries--;
390
0
            }
391
0
            else {
392
0
                entry->current_index = entry->orig_index;
393
0
                previous = entry;
394
0
                entry = entry->next;
395
0
            }
396
0
        }
397
0
    }
398
399
0
    if (hash->nentries < hash->table_size * HASH_MIN_FILL && hash->table_size > HASH_MIN_SIZE) {
400
0
        zip_uint32_t new_size = hash->table_size / 2;
401
0
        while (hash->nentries < new_size * HASH_MIN_FILL && new_size > HASH_MIN_SIZE) {
402
0
            new_size /= 2;
403
0
        }
404
0
        if (!hash_resize(hash, new_size, error)) {
405
0
            return false;
406
0
        }
407
0
    }
408
409
0
    return true;
410
0
}