/src/libzip/lib/zip_hash.c

Source (jump to first uncovered line)
/*
  zip_hash.c -- hash table string -> uint64
  Copyright (C) 2015-2022 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: 2025-07-23 08:18

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