/src/libzip/lib/zip_hash.c

Source
/*
  zip_hash.c -- hash table string -> uint64
  Copyright (C) 2015-2024 Dieter Baron and Thomas Klausner

  This file is part of libzip, a library to manipulate ZIP archives.
  The authors can be contacted at <info@libzip.org>

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.
  3. The names of the authors may not be used to endorse or promote
     products derived from this software without specific prior
     written permission.

  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include "zipint.h"
#include <stdlib.h>
#include <string.h>

/* parameter for the string hash function */
#define HASH_MULTIPLIER 33
#define HASH_START 5381

/* hash table's fill ratio is kept between these by doubling/halfing its size as necessary */
#define HASH_MAX_FILL .75
#define HASH_MIN_FILL .01

/* but hash table size is kept between these */
#define HASH_MIN_SIZE 256
#define HASH_MAX_SIZE 0x80000000ul

struct zip_hash_entry {
    const zip_uint8_t *name;
    zip_int64_t orig_index;
    zip_int64_t current_index;
    struct zip_hash_entry *next;
    zip_uint32_t hash_value;
};
typedef struct zip_hash_entry zip_hash_entry_t;

struct zip_hash {
    zip_uint32_t table_size;
    zip_uint64_t nentries;
    zip_hash_entry_t **table;
};


/* free list of entries */
static void free_list(zip_hash_entry_t *entry) {
    while (entry != NULL) {
        zip_hash_entry_t *next = entry->next;
        free(entry);
        entry = next;
    }
}


/* compute hash of string, full 32 bit value */
static zip_uint32_t hash_string(const zip_uint8_t *name) {
    zip_uint64_t value = HASH_START;

    if (name == NULL) {
        return 0;
    }

    while (*name != 0) {
        value = (zip_uint64_t)(((value * HASH_MULTIPLIER) + (zip_uint8_t)*name) % 0x100000000ul);
        name++;
    }

    return (zip_uint32_t)value;
}


/* resize hash table; new_size must be a power of 2, can be larger or smaller than current size */
static bool hash_resize(zip_hash_t *hash, zip_uint32_t new_size, zip_error_t *error) {
    zip_hash_entry_t **new_table;

    if (new_size == hash->table_size) {
        return true;
    }

    if ((new_table = (zip_hash_entry_t **)calloc(new_size, sizeof(zip_hash_entry_t *))) == NULL) {
        zip_error_set(error, ZIP_ER_MEMORY, 0);
        return false;
    }

    if (hash->nentries > 0) {
        zip_uint32_t i;

        for (i = 0; i < hash->table_size; i++) {
            zip_hash_entry_t *entry = hash->table[i];
            while (entry) {
                zip_hash_entry_t *next = entry->next;

                zip_uint32_t new_index = entry->hash_value % new_size;

                entry->next = new_table[new_index];
                new_table[new_index] = entry;

                entry = next;
            }
        }
    }

    free(hash->table);
    hash->table = new_table;
    hash->table_size = new_size;

    return true;
}


static zip_uint32_t size_for_capacity(zip_uint64_t capacity) {
    double needed_size = capacity / HASH_MAX_FILL;
    zip_uint32_t v;

    if (needed_size > ZIP_UINT32_MAX) {
        v = ZIP_UINT32_MAX;
    }
    else {
        v = (zip_uint32_t)needed_size;
    }

    if (v > HASH_MAX_SIZE) {
        return HASH_MAX_SIZE;
    }

    /* From Bit Twiddling Hacks by Sean Eron Anderson <seander@cs.stanford.edu>
     (http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2). */

    v--;
    v |= v >> 1;
    v |= v >> 2;
    v |= v >> 4;
    v |= v >> 8;
    v |= v >> 16;
    v++;

    return v;
}


zip_hash_t *_zip_hash_new(zip_error_t *error) {
    zip_hash_t *hash;

    if ((hash = (zip_hash_t *)malloc(sizeof(zip_hash_t))) == NULL) {
        zip_error_set(error, ZIP_ER_MEMORY, 0);
        return NULL;
    }

    hash->table_size = 0;
    hash->nentries = 0;
    hash->table = NULL;

    return hash;
}


void _zip_hash_free(zip_hash_t *hash) {
    zip_uint32_t i;

    if (hash == NULL) {
        return;
    }

    if (hash->table != NULL) {
        for (i = 0; i < hash->table_size; i++) {
            if (hash->table[i] != NULL) {
                free_list(hash->table[i]);
            }
        }
        free(hash->table);
    }
    free(hash);
}


/* insert into hash, return error on existence or memory issues */
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) {
    zip_uint32_t hash_value, table_index;
    zip_hash_entry_t *entry;

    if (hash == NULL || name == NULL || index > ZIP_INT64_MAX) {
        zip_error_set(error, ZIP_ER_INVAL, 0);
        return false;
    }

    if (hash->table_size == 0) {
        if (!hash_resize(hash, HASH_MIN_SIZE, error)) {
            return false;
        }
    }

    hash_value = hash_string(name);
    table_index = hash_value % hash->table_size;

    for (entry = hash->table[table_index]; entry != NULL; entry = entry->next) {
        if (entry->hash_value == hash_value && strcmp((const char *)name, (const char *)entry->name) == 0) {
            if (((flags & ZIP_FL_UNCHANGED) && entry->orig_index != -1) || entry->current_index != -1) {
                zip_error_set(error, ZIP_ER_EXISTS, 0);
                return false;
            }
            else {
                break;
            }
        }
    }

    if (entry == NULL) {
        if ((entry = (zip_hash_entry_t *)malloc(sizeof(zip_hash_entry_t))) == NULL) {
            zip_error_set(error, ZIP_ER_MEMORY, 0);
            return false;
        }
        entry->name = name;
        entry->next = hash->table[table_index];
        hash->table[table_index] = entry;
        entry->hash_value = hash_value;
        entry->orig_index = -1;
        hash->nentries++;
        if (hash->nentries > hash->table_size * HASH_MAX_FILL && hash->table_size < HASH_MAX_SIZE) {
            if (!hash_resize(hash, hash->table_size * 2, error)) {
                return false;
            }
        }
    }

    if (flags & ZIP_FL_UNCHANGED) {
        entry->orig_index = (zip_int64_t)index;
    }
    entry->current_index = (zip_int64_t)index;

    return true;
}


/* remove entry from hash, error if not found */
bool _zip_hash_delete(zip_hash_t *hash, const zip_uint8_t *name, zip_error_t *error) {
    zip_uint32_t hash_value, index;
    zip_hash_entry_t *entry, *previous;

    if (hash == NULL || name == NULL) {
        zip_error_set(error, ZIP_ER_INVAL, 0);
        return false;
    }

    if (hash->nentries > 0) {
        hash_value = hash_string(name);
        index = hash_value % hash->table_size;
        previous = NULL;
        entry = hash->table[index];
        while (entry) {
            if (entry->hash_value == hash_value && strcmp((const char *)name, (const char *)entry->name) == 0) {
                if (entry->orig_index == -1) {
                    if (previous) {
                        previous->next = entry->next;
                    }
                    else {
                        hash->table[index] = entry->next;
                    }
                    free(entry);
                    hash->nentries--;
                    if (hash->nentries < hash->table_size * HASH_MIN_FILL && hash->table_size > HASH_MIN_SIZE) {
                        if (!hash_resize(hash, hash->table_size / 2, error)) {
                            return false;
                        }
                    }
                }
                else {
                    entry->current_index = -1;
                }
                return true;
            }
            previous = entry;
            entry = entry->next;
        }
    }

    zip_error_set(error, ZIP_ER_NOENT, 0);
    return false;
}


/* find value for entry in hash, -1 if not found */
zip_int64_t _zip_hash_lookup(zip_hash_t *hash, const zip_uint8_t *name, zip_flags_t flags, zip_error_t *error) {
    zip_uint32_t hash_value, index;
    zip_hash_entry_t *entry;

    if (hash == NULL || name == NULL) {
        zip_error_set(error, ZIP_ER_INVAL, 0);
        return -1;
    }

    if (hash->nentries > 0) {
        hash_value = hash_string(name);
        index = hash_value % hash->table_size;
        for (entry = hash->table[index]; entry != NULL; entry = entry->next) {
            if (strcmp((const char *)name, (const char *)entry->name) == 0) {
                if (flags & ZIP_FL_UNCHANGED) {
                    if (entry->orig_index != -1) {
                        return entry->orig_index;
                    }
                }
                else {
                    if (entry->current_index != -1) {
                        return entry->current_index;
                    }
                }
                break;
            }
        }
    }

    zip_error_set(error, ZIP_ER_NOENT, 0);
    return -1;
}


bool _zip_hash_reserve_capacity(zip_hash_t *hash, zip_uint64_t capacity, zip_error_t *error) {
    zip_uint32_t new_size;

    if (capacity == 0) {
        return true;
    }

    new_size = size_for_capacity(capacity);

    if (new_size <= hash->table_size) {
        return true;
    }

    if (!hash_resize(hash, new_size, error)) {
        return false;
    }

    return true;
}


bool _zip_hash_revert(zip_hash_t *hash, zip_error_t *error) {
    zip_uint32_t i;
    zip_hash_entry_t *entry, *previous;

    for (i = 0; i < hash->table_size; i++) {
        previous = NULL;
        entry = hash->table[i];
        while (entry) {
            if (entry->orig_index == -1) {
                zip_hash_entry_t *p;
                if (previous) {
                    previous->next = entry->next;
                }
                else {
                    hash->table[i] = entry->next;
                }
                p = entry;
                entry = entry->next;
                /* previous does not change */
                free(p);
                hash->nentries--;
            }
            else {
                entry->current_index = entry->orig_index;
                previous = entry;
                entry = entry->next;
            }
        }
    }

    if (hash->nentries < hash->table_size * HASH_MIN_FILL && hash->table_size > HASH_MIN_SIZE) {
        zip_uint32_t new_size = hash->table_size / 2;
        while (hash->nentries < new_size * HASH_MIN_FILL && new_size > HASH_MIN_SIZE) {
            new_size /= 2;
        }
        if (!hash_resize(hash, new_size, error)) {
            return false;
        }
    }

    return true;
}

Coverage Report

Created: 2026-07-30 07:17

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	274k	#define HASH_MULTIPLIER 33
40	13.6k	#define HASH_START 5381
41
42		/* hash table's fill ratio is kept between these by doubling/halfing its size as necessary */
43	15.8k	#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	832	#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	6.20k	static void free_list(zip_hash_entry_t *entry) {
68	13.6k	while (entry != NULL) {
69	7.48k	zip_hash_entry_t *next = entry->next;
70	7.48k	free(entry);
71	7.48k	entry = next;
72	7.48k	}
73	6.20k	}
74
75
76		/* compute hash of string, full 32 bit value */
77	13.6k	static zip_uint32_t hash_string(const zip_uint8_t *name) {
78	13.6k	zip_uint64_t value = HASH_START;
79
80	13.6k	if (name == NULL) {
81	0	return 0;
82	0	}
83
84	287k	while (*name != 0) {
85	274k	value = (zip_uint64_t)(((value * HASH_MULTIPLIER) + (zip_uint8_t)*name) % 0x100000000ul);
86	274k	name++;
87	274k	}
88
89	13.6k	return (zip_uint32_t)value;
90	13.6k	}
91
92
93		/* resize hash table; new_size must be a power of 2, can be larger or smaller than current size */
94	832	static bool hash_resize(zip_hash_t hash, zip_uint32_t new_size, zip_error_t error) {
95	832	zip_hash_entry_t **new_table;
96
97	832	if (new_size == hash->table_size) {
98	0	return true;
99	0	}
100
101	832	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	832	if (hash->nentries > 0) {
107	0	zip_uint32_t i;
108
109	0	for (i = 0; i < hash->table_size; i++) {
110	0	zip_hash_entry_t *entry = hash->table[i];
111	0	while (entry) {
112	0	zip_hash_entry_t *next = entry->next;
113
114	0	zip_uint32_t new_index = entry->hash_value % new_size;
115
116	0	entry->next = new_table[new_index];
117	0	new_table[new_index] = entry;
118
119	0	entry = next;
120	0	}
121	0	}
122	0	}
123
124	832	free(hash->table);
125	832	hash->table = new_table;
126	832	hash->table_size = new_size;
127
128	832	return true;
129	832	}
130
131
132	832	static zip_uint32_t size_for_capacity(zip_uint64_t capacity) {
133	832	double needed_size = capacity / HASH_MAX_FILL;
134	832	zip_uint32_t v;
135
136	832	if (needed_size > ZIP_UINT32_MAX) {
137	0	v = ZIP_UINT32_MAX;
138	0	}
139	832	else {
140	832	v = (zip_uint32_t)needed_size;
141	832	}
142
143	832	if (v > HASH_MAX_SIZE) {
144	0	return HASH_MAX_SIZE;
145	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	832	v--;
151	832	v \|= v >> 1;
152	832	v \|= v >> 2;
153	832	v \|= v >> 4;
154	832	v \|= v >> 8;
155	832	v \|= v >> 16;
156	832	v++;
157
158	832	return v;
159	832	}
160
161
162	1.16k	zip_hash_t _zip_hash_new(zip_error_t error) {
163	1.16k	zip_hash_t *hash;
164
165	1.16k	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	1.16k	hash->table_size = 0;
171	1.16k	hash->nentries = 0;
172	1.16k	hash->table = NULL;
173
174	1.16k	return hash;
175	1.16k	}
176
177
178	1.16k	void _zip_hash_free(zip_hash_t *hash) {
179	1.16k	zip_uint32_t i;
180
181	1.16k	if (hash == NULL) {
182	0	return;
183	0	}
184
185	1.16k	if (hash->table != NULL) {
186	14.1k	for (i = 0; i < hash->table_size; i++) {
187	13.3k	if (hash->table[i] != NULL) {
188	6.20k	free_list(hash->table[i]);
189	6.20k	}
190	13.3k	}
191	832	free(hash->table);
192	832	}
193	1.16k	free(hash);
194	1.16k	}
195
196
197		/* insert into hash, return error on existence or memory issues */
198	7.48k	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	7.48k	zip_uint32_t hash_value, table_index;
200	7.48k	zip_hash_entry_t *entry;
201
202	7.48k	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	7.48k	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	7.48k	hash_value = hash_string(name);
214	7.48k	table_index = hash_value % hash->table_size;
215
216	8.79k	for (entry = hash->table[table_index]; entry != NULL; entry = entry->next) {
217	1.30k	if (entry->hash_value == hash_value && strcmp((const char )name, (const char )entry->name) == 0) {
218	2	if (((flags & ZIP_FL_UNCHANGED) && entry->orig_index != -1) \|\| entry->current_index != -1) {
219	2	zip_error_set(error, ZIP_ER_EXISTS, 0);
220	2	return false;
221	2	}
222	0	else {
223	0	break;
224	0	}
225	2	}
226	1.30k	}
227
228	7.48k	if (entry == NULL) {
229	7.48k	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	7.48k	entry->name = name;
234	7.48k	entry->next = hash->table[table_index];
235	7.48k	hash->table[table_index] = entry;
236	7.48k	entry->hash_value = hash_value;
237	7.48k	entry->orig_index = -1;
238	7.48k	hash->nentries++;
239	7.48k	if (hash->nentries > hash->table_size * HASH_MAX_FILL && hash->table_size < HASH_MAX_SIZE) {
240	0	if (!hash_resize(hash, hash->table_size * 2, error)) {
241	0	return false;
242	0	}
243	0	}
244	7.48k	}
245
246	7.48k	if (flags & ZIP_FL_UNCHANGED) {
247	7.48k	entry->orig_index = (zip_int64_t)index;
248	7.48k	}
249	7.48k	entry->current_index = (zip_int64_t)index;
250
251	7.48k	return true;
252	7.48k	}
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	6.15k	zip_int64_t _zip_hash_lookup(zip_hash_t hash, const zip_uint8_t name, zip_flags_t flags, zip_error_t *error) {
304	6.15k	zip_uint32_t hash_value, index;
305	6.15k	zip_hash_entry_t *entry;
306
307	6.15k	if (hash == NULL \|\| name == NULL) {
308	0	zip_error_set(error, ZIP_ER_INVAL, 0);
309	0	return -1;
310	0	}
311
312	6.15k	if (hash->nentries > 0) {
313	6.15k	hash_value = hash_string(name);
314	6.15k	index = hash_value % hash->table_size;
315	9.93k	for (entry = hash->table[index]; entry != NULL; entry = entry->next) {
316	5.72k	if (strcmp((const char )name, (const char )entry->name) == 0) {
317	1.94k	if (flags & ZIP_FL_UNCHANGED) {
318	1.94k	if (entry->orig_index != -1) {
319	1.94k	return entry->orig_index;
320	1.94k	}
321	1.94k	}
322	0	else {
323	0	if (entry->current_index != -1) {
324	0	return entry->current_index;
325	0	}
326	0	}
327	0	break;
328	1.94k	}
329	5.72k	}
330	6.15k	}
331
332	4.21k	zip_error_set(error, ZIP_ER_NOENT, 0);
333	4.21k	return -1;
334	6.15k	}
335
336
337	832	bool _zip_hash_reserve_capacity(zip_hash_t hash, zip_uint64_t capacity, zip_error_t error) {
338	832	zip_uint32_t new_size;
339
340	832	if (capacity == 0) {
341	0	return true;
342	0	}
343
344	832	new_size = size_for_capacity(capacity);
345
346	832	if (new_size <= hash->table_size) {
347	0	return true;
348	0	}
349
350	832	if (!hash_resize(hash, new_size, error)) {
351	0	return false;
352	0	}
353
354	832	return true;
355	832	}
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	}