Coverage Report

Created: 2025-10-10 06:38

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
637k
#define HASH_MULTIPLIER 33
40
48.1k
#define HASH_START 5381
41
42
/* hash table's fill ratio is kept between these by doubling/halfing its size as necessary */
43
27.7k
#define HASH_MAX_FILL .75
44
0
#define HASH_MIN_FILL .01
45
46
/* but hash table size is kept between these */
47
973
#define HASH_MIN_SIZE 256
48
5.37k
#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
10.3k
free_list(zip_hash_entry_t *entry) {
69
22.6k
    while (entry != NULL) {
70
12.2k
        zip_hash_entry_t *next = entry->next;
71
12.2k
        free(entry);
72
12.2k
        entry = next;
73
12.2k
    }
74
10.3k
}
75
76
77
/* compute hash of string, full 32 bit value */
78
static zip_uint32_t
79
48.1k
hash_string(const zip_uint8_t *name) {
80
48.1k
    zip_uint64_t value = HASH_START;
81
82
48.1k
    if (name == NULL) {
83
0
        return 0;
84
0
    }
85
86
685k
    while (*name != 0) {
87
637k
        value = (zip_uint64_t)(((value * HASH_MULTIPLIER) + (zip_uint8_t)*name) % 0x100000000ul);
88
637k
        name++;
89
637k
    }
90
91
48.1k
    return (zip_uint32_t)value;
92
48.1k
}
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
6.35k
hash_resize(zip_hash_t *hash, zip_uint32_t new_size, zip_error_t *error) {
98
6.35k
    zip_hash_entry_t **new_table;
99
100
6.35k
    if (new_size == hash->table_size) {
101
0
        return true;
102
0
    }
103
104
6.35k
    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
6.35k
    if (hash->nentries > 0) {
110
2.21k
        zip_uint32_t i;
111
112
4.54k
        for (i = 0; i < hash->table_size; i++) {
113
2.33k
            zip_hash_entry_t *entry = hash->table[i];
114
4.66k
            while (entry) {
115
2.33k
                zip_hash_entry_t *next = entry->next;
116
117
2.33k
                zip_uint32_t new_index = entry->hash_value % new_size;
118
119
2.33k
                entry->next = new_table[new_index];
120
2.33k
                new_table[new_index] = entry;
121
122
2.33k
                entry = next;
123
2.33k
            }
124
2.33k
        }
125
2.21k
    }
126
127
6.35k
    free(hash->table);
128
6.35k
    hash->table = new_table;
129
6.35k
    hash->table_size = new_size;
130
131
6.35k
    return true;
132
6.35k
}
133
134
135
static zip_uint32_t
136
3.16k
size_for_capacity(zip_uint64_t capacity) {
137
3.16k
    double needed_size = capacity / HASH_MAX_FILL;
138
3.16k
    zip_uint32_t v;
139
140
3.16k
    if (needed_size > ZIP_UINT32_MAX) {
141
0
        v = ZIP_UINT32_MAX;
142
0
    }
143
3.16k
    else {
144
3.16k
        v = (zip_uint32_t)needed_size;
145
3.16k
    }
146
147
3.16k
    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
3.16k
    v--;
155
3.16k
    v |= v >> 1;
156
3.16k
    v |= v >> 2;
157
3.16k
    v |= v >> 4;
158
3.16k
    v |= v >> 8;
159
3.16k
    v |= v >> 16;
160
3.16k
    v++;
161
162
3.16k
    return v;
163
3.16k
}
164
165
166
zip_hash_t *
167
10.1k
_zip_hash_new(zip_error_t *error) {
168
10.1k
    zip_hash_t *hash;
169
170
10.1k
    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
10.1k
    hash->table_size = 0;
176
10.1k
    hash->nentries = 0;
177
10.1k
    hash->table = NULL;
178
179
10.1k
    return hash;
180
10.1k
}
181
182
183
void
184
10.1k
_zip_hash_free(zip_hash_t *hash) {
185
10.1k
    zip_uint32_t i;
186
187
10.1k
    if (hash == NULL) {
188
0
        return;
189
0
    }
190
191
10.1k
    if (hash->table != NULL) {
192
347k
        for (i = 0; i < hash->table_size; i++) {
193
343k
            if (hash->table[i] != NULL) {
194
10.3k
                free_list(hash->table[i]);
195
10.3k
            }
196
343k
        }
197
4.14k
        free(hash->table);
198
4.14k
    }
199
10.1k
    free(hash);
200
10.1k
}
201
202
203
/* insert into hash, return error on existence or memory issues */
204
bool
205
48.1k
_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
48.1k
    zip_uint32_t hash_value, table_index;
207
48.1k
    zip_hash_entry_t *entry;
208
209
48.1k
    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
48.1k
    if (hash->table_size == 0) {
215
973
        if (!hash_resize(hash, HASH_MIN_SIZE, error)) {
216
0
            return false;
217
0
        }
218
973
    }
219
220
48.1k
    hash_value = hash_string(name);
221
48.1k
    table_index = hash_value % hash->table_size;
222
223
51.1k
    for (entry = hash->table[table_index]; entry != NULL; entry = entry->next) {
224
38.8k
        if (entry->hash_value == hash_value && strcmp((const char *)name, (const char *)entry->name) == 0) {
225
35.8k
            if (((flags & ZIP_FL_UNCHANGED) && entry->orig_index != -1) || entry->current_index != -1) {
226
35.8k
                zip_error_set(error, ZIP_ER_EXISTS, 0);
227
35.8k
                return false;
228
35.8k
            }
229
0
            else {
230
0
                break;
231
0
            }
232
35.8k
        }
233
38.8k
    }
234
235
12.2k
    if (entry == NULL) {
236
12.2k
        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
12.2k
        entry->name = name;
241
12.2k
        entry->next = hash->table[table_index];
242
12.2k
        hash->table[table_index] = entry;
243
12.2k
        entry->hash_value = hash_value;
244
12.2k
        entry->orig_index = -1;
245
12.2k
        hash->nentries++;
246
12.2k
        if (hash->nentries > hash->table_size * HASH_MAX_FILL && hash->table_size < HASH_MAX_SIZE) {
247
2.21k
            if (!hash_resize(hash, hash->table_size * 2, error)) {
248
0
                return false;
249
0
            }
250
2.21k
        }
251
12.2k
    }
252
253
12.2k
    if (flags & ZIP_FL_UNCHANGED) {
254
11.3k
        entry->orig_index = (zip_int64_t)index;
255
11.3k
    }
256
12.2k
    entry->current_index = (zip_int64_t)index;
257
258
12.2k
    return true;
259
12.2k
}
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
1.94k
_zip_hash_lookup(zip_hash_t *hash, const zip_uint8_t *name, zip_flags_t flags, zip_error_t *error) {
313
1.94k
    zip_uint32_t hash_value, index;
314
1.94k
    zip_hash_entry_t *entry;
315
316
1.94k
    if (hash == NULL || name == NULL) {
317
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
318
0
        return -1;
319
0
    }
320
321
1.94k
    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
1.94k
    zip_error_set(error, ZIP_ER_NOENT, 0);
342
1.94k
    return -1;
343
1.94k
}
344
345
346
bool
347
3.78k
_zip_hash_reserve_capacity(zip_hash_t *hash, zip_uint64_t capacity, zip_error_t *error) {
348
3.78k
    zip_uint32_t new_size;
349
350
3.78k
    if (capacity == 0) {
351
617
        return true;
352
617
    }
353
354
3.16k
    new_size = size_for_capacity(capacity);
355
356
3.16k
    if (new_size <= hash->table_size) {
357
0
        return true;
358
0
    }
359
360
3.16k
    if (!hash_resize(hash, new_size, error)) {
361
0
        return false;
362
0
    }
363
364
3.16k
    return true;
365
3.16k
}
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
}