From 2087cc237cd0fe1ed29ebf891648bacb46f4833b Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Sun, 26 Jun 2022 16:45:52 +0200 Subject: Cleanup: move libutil headers to sub directory Move all the libutil stuff from the toplevel include/ to a util/ sub directory and fix up the includes that make use of them. Signed-off-by: David Oberhollenzer --- include/util/str_table.h | 63 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 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..206fa3a --- /dev/null +++ b/include/util/str_table.h @@ -0,0 +1,63 @@ +/* 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" +#include "array.h" +#include "hash_table.h" + +typedef struct { + size_t index; + size_t refcount; + char string[]; +} 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 { + /* an array that resolves index to bucket pointer */ + array_t bucket_ptrs; + + /* hash table with the string buckets attached */ + struct hash_table *ht; + + /* the next ID we are going to allocate */ + size_t next_index; +} str_table_t; + +/* the number of strings currently stored in the table */ +static SQFS_INLINE size_t str_table_count(const str_table_t *table) +{ + return table->next_index; +} + +/* `size` is the number of hash table buckets to use internally. */ +SQFS_INTERNAL int str_table_init(str_table_t *table); + +SQFS_INTERNAL void str_table_cleanup(str_table_t *table); + +SQFS_INTERNAL int str_table_copy(str_table_t *dst, const str_table_t *src); + +/* 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(const str_table_t *table, size_t index); + +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(const str_table_t *table, size_t index); + +#endif /* STR_TABLE_H */ -- cgit v1.2.3