Coverage Report

Created: 2025-07-23 06:33

/src/libzip/lib/zip_hash.c
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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
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5
  This file is part of libzip, a library to manipulate ZIP archives.
6
  The authors can be contacted at <info@libzip.org>
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8
  Redistribution and use in source and binary forms, with or without
9
  modification, are permitted provided that the following conditions
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  are met:
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  1. Redistributions of source code must retain the above copyright
12
     notice, this list of conditions and the following disclaimer.
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  2. Redistributions in binary form must reproduce the above copyright
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     notice, this list of conditions and the following disclaimer in
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     the documentation and/or other materials provided with the
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     distribution.
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  3. The names of the authors may not be used to endorse or promote
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     products derived from this software without specific prior
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     written permission.
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  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
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  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
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  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
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  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
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  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "zipint.h"
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#include <stdlib.h>
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#include <string.h>
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38
/* parameter for the string hash function */
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269k
#define HASH_MULTIPLIER 33
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24.7k
#define HASH_START 5381
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42
/* hash table's fill ratio is kept between these by doubling/halfing its size as necessary */
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12.5k
#define HASH_MAX_FILL .75
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0
#define HASH_MIN_FILL .01
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/* but hash table size is kept between these */
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0
#define HASH_MIN_SIZE 256
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3.28k
#define HASH_MAX_SIZE 0x80000000ul
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struct zip_hash_entry {
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    const zip_uint8_t *name;
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    zip_int64_t orig_index;
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    zip_int64_t current_index;
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    struct zip_hash_entry *next;
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    zip_uint32_t hash_value;
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};
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typedef struct zip_hash_entry zip_hash_entry_t;
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struct zip_hash {
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    zip_uint32_t table_size;
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    zip_uint64_t nentries;
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    zip_hash_entry_t **table;
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};
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/* free list of entries */
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static void
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4.49k
free_list(zip_hash_entry_t *entry) {
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9.78k
    while (entry != NULL) {
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5.29k
        zip_hash_entry_t *next = entry->next;
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5.29k
        free(entry);
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5.29k
        entry = next;
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5.29k
    }
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4.49k
}
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/* compute hash of string, full 32 bit value */
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static zip_uint32_t
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24.7k
hash_string(const zip_uint8_t *name) {
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24.7k
    zip_uint64_t value = HASH_START;
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82
24.7k
    if (name == NULL) {
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0
        return 0;
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0
    }
85
86
294k
    while (*name != 0) {
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269k
        value = (zip_uint64_t)(((value * HASH_MULTIPLIER) + (zip_uint8_t)*name) % 0x100000000ul);
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269k
        name++;
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269k
    }
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24.7k
    return (zip_uint32_t)value;
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24.7k
}
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/* resize hash table; new_size must be a power of 2, can be larger or smaller than current size */
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static bool
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3.28k
hash_resize(zip_hash_t *hash, zip_uint32_t new_size, zip_error_t *error) {
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3.28k
    zip_hash_entry_t **new_table;
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100
3.28k
    if (new_size == hash->table_size) {
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0
        return true;
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0
    }
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3.28k
    if ((new_table = (zip_hash_entry_t **)calloc(new_size, sizeof(zip_hash_entry_t *))) == NULL) {
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0
        zip_error_set(error, ZIP_ER_MEMORY, 0);
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0
        return false;
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0
    }
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109
3.28k
    if (hash->nentries > 0) {
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1.36k
        zip_uint32_t i;
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112
2.80k
        for (i = 0; i < hash->table_size; i++) {
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1.43k
            zip_hash_entry_t *entry = hash->table[i];
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2.87k
            while (entry) {
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1.43k
                zip_hash_entry_t *next = entry->next;
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1.43k
                zip_uint32_t new_index = entry->hash_value % new_size;
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1.43k
                entry->next = new_table[new_index];
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1.43k
                new_table[new_index] = entry;
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1.43k
                entry = next;
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1.43k
            }
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1.43k
        }
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1.36k
    }
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3.28k
    free(hash->table);
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3.28k
    hash->table = new_table;
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3.28k
    hash->table_size = new_size;
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3.28k
    return true;
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3.28k
}
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static zip_uint32_t
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1.92k
size_for_capacity(zip_uint64_t capacity) {
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1.92k
    double needed_size = capacity / HASH_MAX_FILL;
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1.92k
    zip_uint32_t v;
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1.92k
    if (needed_size > ZIP_UINT32_MAX) {
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0
        v = ZIP_UINT32_MAX;
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0
    }
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1.92k
    else {
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1.92k
        v = (zip_uint32_t)needed_size;
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1.92k
    }
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1.92k
    if (v > HASH_MAX_SIZE) {
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0
        return HASH_MAX_SIZE;
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0
    }
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    /* From Bit Twiddling Hacks by Sean Eron Anderson <seander@cs.stanford.edu>
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     (http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2). */
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1.92k
    v--;
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1.92k
    v |= v >> 1;
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1.92k
    v |= v >> 2;
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1.92k
    v |= v >> 4;
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1.92k
    v |= v >> 8;
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1.92k
    v |= v >> 16;
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1.92k
    v++;
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1.92k
    return v;
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1.92k
}
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zip_hash_t *
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4.91k
_zip_hash_new(zip_error_t *error) {
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4.91k
    zip_hash_t *hash;
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4.91k
    if ((hash = (zip_hash_t *)malloc(sizeof(zip_hash_t))) == NULL) {
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0
        zip_error_set(error, ZIP_ER_MEMORY, 0);
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0
        return NULL;
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0
    }
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4.91k
    hash->table_size = 0;
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4.91k
    hash->nentries = 0;
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4.91k
    hash->table = NULL;
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4.91k
    return hash;
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4.91k
}
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182
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void
184
4.91k
_zip_hash_free(zip_hash_t *hash) {
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4.91k
    zip_uint32_t i;
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187
4.91k
    if (hash == NULL) {
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0
        return;
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0
    }
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191
4.91k
    if (hash->table != NULL) {
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51.9k
        for (i = 0; i < hash->table_size; i++) {
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50.0k
            if (hash->table[i] != NULL) {
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4.49k
                free_list(hash->table[i]);
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4.49k
            }
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50.0k
        }
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1.92k
        free(hash->table);
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1.92k
    }
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4.91k
    free(hash);
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4.91k
}
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/* insert into hash, return error on existence or memory issues */
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bool
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24.7k
_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
24.7k
    zip_uint32_t hash_value, table_index;
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24.7k
    zip_hash_entry_t *entry;
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209
24.7k
    if (hash == NULL || name == NULL || index > ZIP_INT64_MAX) {
210
0
        zip_error_set(error, ZIP_ER_INVAL, 0);
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0
        return false;
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0
    }
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214
24.7k
    if (hash->table_size == 0) {
215
0
        if (!hash_resize(hash, HASH_MIN_SIZE, error)) {
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0
            return false;
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0
        }
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0
    }
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220
24.7k
    hash_value = hash_string(name);
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24.7k
    table_index = hash_value % hash->table_size;
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26.2k
    for (entry = hash->table[table_index]; entry != NULL; entry = entry->next) {
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20.9k
        if (entry->hash_value == hash_value && strcmp((const char *)name, (const char *)entry->name) == 0) {
225
19.4k
            if (((flags & ZIP_FL_UNCHANGED) && entry->orig_index != -1) || entry->current_index != -1) {
226
19.4k
                zip_error_set(error, ZIP_ER_EXISTS, 0);
227
19.4k
                return false;
228
19.4k
            }
229
0
            else {
230
0
                break;
231
0
            }
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19.4k
        }
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20.9k
    }
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235
5.29k
    if (entry == NULL) {
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5.29k
        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;
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0
        }
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5.29k
        entry->name = name;
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5.29k
        entry->next = hash->table[table_index];
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5.29k
        hash->table[table_index] = entry;
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5.29k
        entry->hash_value = hash_value;
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5.29k
        entry->orig_index = -1;
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5.29k
        hash->nentries++;
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5.29k
        if (hash->nentries > hash->table_size * HASH_MAX_FILL && hash->table_size < HASH_MAX_SIZE) {
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1.36k
            if (!hash_resize(hash, hash->table_size * 2, error)) {
248
0
                return false;
249
0
            }
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1.36k
        }
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5.29k
    }
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253
5.29k
    if (flags & ZIP_FL_UNCHANGED) {
254
5.29k
        entry->orig_index = (zip_int64_t)index;
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5.29k
    }
256
5.29k
    entry->current_index = (zip_int64_t)index;
257
258
5.29k
    return true;
259
5.29k
}
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
2.22k
_zip_hash_reserve_capacity(zip_hash_t *hash, zip_uint64_t capacity, zip_error_t *error) {
348
2.22k
    zip_uint32_t new_size;
349
350
2.22k
    if (capacity == 0) {
351
305
        return true;
352
305
    }
353
354
1.92k
    new_size = size_for_capacity(capacity);
355
356
1.92k
    if (new_size <= hash->table_size) {
357
0
        return true;
358
0
    }
359
360
1.92k
    if (!hash_resize(hash, new_size, error)) {
361
0
        return false;
362
0
    }
363
364
1.92k
    return true;
365
1.92k
}
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
}