uwx_str.c revision 160157 
1/*
2Copyright (c) 2003-2006 Hewlett-Packard Development Company, L.P.
3Permission is hereby granted, free of charge, to any person
4obtaining a copy of this software and associated documentation
5files (the "Software"), to deal in the Software without
6restriction, including without limitation the rights to use,
7copy, modify, merge, publish, distribute, sublicense, and/or sell
8copies of the Software, and to permit persons to whom the
9Software is furnished to do so, subject to the following
10conditions:
11
12The above copyright notice and this permission notice shall be
13included in all copies or substantial portions of the Software.
14
15THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
17OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
19HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
20WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22OTHER DEALINGS IN THE SOFTWARE.
23*/
24
25#include <string.h>
26
27#include "uwx_env.h"
28#include "uwx_str.h"
29
30/*
31 *  uwx_str.c
32 *
33 *  This file contains the routines for maintaining a string
34 *  pool for the unwind environment. We preallocate enough
35 *  space for most purposes so that no memory allocation is
36 *  necessary during a normal unwind. If we do need more,
37 *  we use the allocate callback, if one is provided.
38 *
39 *  The string pool is reused with each call to step(),
40 *  and is completely freed when the unwind environment is
41 *  freed.
42 */
43
44
45int uwx_init_str_pool(struct uwx_env *env, struct uwx_str_pool *pool)
46{
47    if (pool == 0)
48	return UWX_ERR_NOMEM;
49
50    pool->next = 0;
51    pool->size = STRPOOLSIZE;
52    pool->used = 0;
53
54    env->string_pool = pool;
55
56    return UWX_OK;
57}
58
59void uwx_free_str_pool(struct uwx_env *env)
60{
61    struct uwx_str_pool *pool;
62    struct uwx_str_pool *next;
63
64    /* The first pool is preallocated as part of the uwx_env. Don't free it! */
65    pool = env->string_pool;
66    if (pool != 0)
67	pool = pool->next;
68    for (; pool != 0; pool = next) {
69	next = pool->next;
70	if (env->free_cb == 0)
71	    free(pool);
72	else
73	    (*env->free_cb)(pool);
74    }
75}
76
77char *uwx_alloc_str(struct uwx_env *env, char *str)
78{
79    int len;
80    int size;
81    struct uwx_str_pool *pool;
82    struct uwx_str_pool *prev;
83    char *p;
84
85    len = strlen(str) + 1;
86    prev = 0;
87    for (pool = env->string_pool; pool != 0; pool = pool->next) {
88	prev = pool;
89	if (pool->size - pool->used >= len)
90	    break;
91    }
92    if (pool == 0) {
93	size = STRPOOLSIZE;
94	if (len > size)
95	    size = len;
96	size += sizeof(struct uwx_str_pool) - STRPOOLSIZE;
97	if (env->allocate_cb == 0)
98	    pool = (struct uwx_str_pool *) malloc(size);
99	else
100	    pool = (struct uwx_str_pool *) (*env->allocate_cb)(size);
101	if (env->string_pool == 0)
102	    return 0;
103	pool->next = 0;
104	pool->size = size;
105	pool->used = 0;
106	prev->next = pool;
107    }
108    p = pool->pool + pool->used;
109    strcpy(p, str);
110    pool->used += len;
111    return p;
112}
113
114void uwx_reset_str_pool(struct uwx_env *env)
115{
116    struct uwx_str_pool *pool;
117
118    for (pool = env->string_pool; pool != 0; pool = pool->next)
119	pool->used = 0;
120}
121