1/*
2 * regional.h -- region based memory allocator.
3 *
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
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 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36/**
37 * \file
38 * Regional allocator. Allocates small portions of of larger chunks.
39 * Based on region-allocator from NSD, but rewritten to be light.
40 *
41 * Different from (nsd) region-allocator.h
42 * 	o does not have recycle bin
43 * 	o does not collect stats; just enough to answer get_mem() in use.
44 * 	o does not keep cleanup list
45 * 	o does not have function pointers to setup
46 * 	o allocs the regional struct inside the first block.
47 * 	o can take a block to create regional from.
48 * 	o blocks and large allocations are kept on singly linked lists.
49 */
50
51#ifndef UTIL_REGIONAL_H_
52#define UTIL_REGIONAL_H_
53
54/**
55 * the regional* is the first block*.
56 * every block has a ptr to the next in first bytes.
57 * and so does the regional struct, which is the first block.
58 */
59struct regional
60{
61	/**
62	 * next chunk. NULL if first chunk is the only chunk.
63	 * first inside that chunk is the char* next pointer.
64	 * When regional_free_all() has been called this value is NULL.
65	 */
66	char* next;
67	/** first large object, cast to char** to obtain next ptr */
68	char* large_list;
69	/** total large size */
70	size_t total_large;
71	/** initial chunk size */
72	size_t first_size;
73	/** number of bytes available in the current chunk. */
74	size_t available;
75	/** current chunk data position. */
76	char* data;
77};
78
79/**
80 * Create a new regional.
81 * @return: newly allocated regional.
82 */
83struct regional* regional_create(void);
84
85/**
86 * Create a new region, with custom settings.
87 * @param size: length of first block.
88 * @return: newly allocated regional.
89 */
90struct regional* regional_create_custom(size_t size);
91
92/**
93 * Free all memory associated with regional. Only keeps the first block with
94 * the regional inside it.
95 * @param r: the region.
96 */
97void regional_free_all(struct regional *r);
98
99/**
100 * Destroy regional.  All memory associated with regional is freed as if
101 * regional_free_all was called, as well as destroying the regional struct.
102 * @param r: to delete.
103 */
104void regional_destroy(struct regional *r);
105
106/**
107 * Allocate size bytes of memory inside regional.  The memory is
108 * deallocated when region_free_all is called for this region.
109 * @param r: the region.
110 * @param size: number of bytes.
111 * @return: pointer to memory allocated.
112 */
113void *regional_alloc(struct regional *r, size_t size);
114
115/**
116 * Allocate size bytes of memory inside regional and copy INIT into it.
117 * The memory is deallocated when region_free_all is called for this
118 * region.
119 * @param r: the region.
120 * @param init: to copy.
121 * @param size: number of bytes.
122 * @return: pointer to memory allocated.
123 */
124void *regional_alloc_init(struct regional* r, const void *init, size_t size);
125
126/**
127 * Allocate size bytes of memory inside regional that are initialized to
128 * 0.  The memory is deallocated when region_free_all is called for
129 * this region.
130 * @param r: the region.
131 * @param size: number of bytes.
132 * @return: pointer to memory allocated.
133 */
134void *regional_alloc_zero(struct regional *r, size_t size);
135
136/**
137 * Duplicate string and allocate the result in regional.
138 * @param r: the region.
139 * @param string: null terminated string.
140 * @return: pointer to memory allocated.
141 */
142char *regional_strdup(struct regional *r, const char *string);
143
144/** Debug print regional statistics to log */
145void regional_log_stats(struct regional *r);
146
147/** get total memory size in use by region */
148size_t regional_get_mem(struct regional* r);
149
150#endif /* UTIL_REGIONAL_H_ */
151