From c973bcc1039b64ec00acaf8e8d61b9f5229da56f Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Mon, 7 Oct 2019 15:26:32 +0200 Subject: Cleanup: move libutil related headers to "util" sub directory Signed-off-by: David Oberhollenzer --- include/util/str_table.h | 53 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 include/util/str_table.h (limited to 'include/util/str_table.h') diff --git a/include/util/str_table.h b/include/util/str_table.h new file mode 100644 index 0000000..60be1d1 --- /dev/null +++ b/include/util/str_table.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: LGPL-3.0-or-later */ +/* + * str_table.h + * + * Copyright (C) 2019 David Oberhollenzer + */ +#ifndef STR_TABLE_H +#define STR_TABLE_H + +#include "sqfs/predef.h" + +typedef struct str_bucket_t { + struct str_bucket_t *next; + char *str; + size_t index; + size_t refcount; +} str_bucket_t; + +/* Stores strings in a hash table and assigns an incremental, unique ID to + each string. Subsequent additions return the existing ID. The ID can be + used for (hopefully) constant time lookup of the original string. */ +typedef struct { + str_bucket_t **buckets; + size_t num_buckets; + + char **strings; + size_t num_strings; + size_t max_strings; +} str_table_t; + +/* `size` is the number of hash table buckets to use internally. */ +SQFS_INTERNAL int str_table_init(str_table_t *table, size_t size); + +SQFS_INTERNAL void str_table_cleanup(str_table_t *table); + +/* Resolve a string to an incremental, unique ID. */ +SQFS_INTERNAL +int str_table_get_index(str_table_t *table, const char *str, size_t *idx); + +/* Resolve a unique ID to the string it represents. + Returns NULL if the ID is unknown, i.e. out of bounds. */ +SQFS_INTERNAL +const char *str_table_get_string(str_table_t *table, size_t index); + +SQFS_INTERNAL void str_table_reset_ref_count(str_table_t *table); + +SQFS_INTERNAL void str_table_add_ref(str_table_t *table, size_t index); + +SQFS_INTERNAL void str_table_del_ref(str_table_t *table, size_t index); + +SQFS_INTERNAL size_t str_table_get_ref_count(str_table_t *table, size_t index); + +#endif /* STR_TABLE_H */ -- cgit v1.2.3