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/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
* str_table.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "config.h"
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "sqfs/error.h"
#include "str_table.h"
#include "util.h"
/* R5 hash function (borrowed from reiserfs) */
static sqfs_u32 strhash(const char *s)
{
const signed char *str = (const signed char *)s;
sqfs_u32 a = 0;
while (*str != '\0') {
a += *str << 4;
a += *str >> 4;
a *= 11;
str++;
}
return a;
}
static bool key_equals_function(void *user, const void *a, const void *b)
{
(void)user;
return strcmp(a, b) == 0;
}
int str_table_init(str_table_t *table)
{
memset(table, 0, sizeof(*table));
if (array_init(&table->bucket_ptrs, sizeof(str_bucket_t *), 0))
goto fail_arr;
table->ht = hash_table_create(NULL, key_equals_function);
if (table->ht == NULL)
goto fail_ht;
return 0;
fail_ht:
array_cleanup(&table->bucket_ptrs);
fail_arr:
memset(table, 0, sizeof(*table));
return SQFS_ERROR_ALLOC;
}
int str_table_copy(str_table_t *dst, const str_table_t *src)
{
str_bucket_t *bucket, **array;
int ret;
ret = array_init_copy(&dst->bucket_ptrs, &src->bucket_ptrs);
if (ret != 0)
return ret;
dst->ht = hash_table_clone(src->ht);
if (dst->ht == NULL) {
array_cleanup(&dst->bucket_ptrs);
return SQFS_ERROR_ALLOC;
}
array = (str_bucket_t **)dst->bucket_ptrs.data;
hash_table_foreach(dst->ht, ent) {
bucket = alloc_flex(sizeof(*bucket), 1, strlen(ent->key) + 1);
if (bucket == NULL) {
str_table_cleanup(dst);
return SQFS_ERROR_ALLOC;
}
memcpy(bucket, ent->data,
sizeof(*bucket) + strlen(ent->key) + 1);
ent->data = bucket;
ent->key = bucket->string;
array[bucket->index] = bucket;
}
return 0;
}
void str_table_cleanup(str_table_t *table)
{
hash_table_foreach(table->ht, ent) {
free(ent->data);
ent->data = NULL;
ent->key = NULL;
}
hash_table_destroy(table->ht, NULL);
array_cleanup(&table->bucket_ptrs);
memset(table, 0, sizeof(*table));
}
int str_table_get_index(str_table_t *table, const char *str, size_t *idx)
{
struct hash_entry *ent;
str_bucket_t *new;
sqfs_u32 hash;
hash = strhash(str);
ent = hash_table_search_pre_hashed(table->ht, hash, str);
if (ent != NULL) {
*idx = ((str_bucket_t *)ent->data)->index;
return 0;
}
new = alloc_flex(sizeof(*new), 1, strlen(str) + 1);
if (new == NULL)
return SQFS_ERROR_ALLOC;
new->index = table->next_index;
strcpy(new->string, str);
ent = hash_table_insert_pre_hashed(table->ht, hash, str, new);
if (ent == NULL) {
free(new);
return SQFS_ERROR_ALLOC;
}
ent->key = new->string;
if (array_append(&table->bucket_ptrs, &new) != 0) {
free(new);
ent->key = NULL;
ent->data = NULL;
return SQFS_ERROR_ALLOC;
}
*idx = table->next_index++;
return 0;
}
static str_bucket_t *bucket_by_index(const str_table_t *table, size_t index)
{
if (index >= table->bucket_ptrs.used)
return NULL;
return ((str_bucket_t **)table->bucket_ptrs.data)[index];
}
const char *str_table_get_string(const str_table_t *table, size_t index)
{
str_bucket_t *bucket = bucket_by_index(table, index);
return bucket == NULL ? NULL : bucket->string;
}
void str_table_add_ref(str_table_t *table, size_t index)
{
str_bucket_t *bucket = bucket_by_index(table, index);
if (bucket != NULL && bucket->refcount < ~((size_t)0))
bucket->refcount += 1;
}
void str_table_del_ref(str_table_t *table, size_t index)
{
str_bucket_t *bucket = bucket_by_index(table, index);
if (bucket != NULL && bucket->refcount > 0)
bucket->refcount -= 1;
}
size_t str_table_get_ref_count(const str_table_t *table, size_t index)
{
str_bucket_t *bucket = bucket_by_index(table, index);
return bucket != NULL ? bucket->refcount : 0;
}
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