1/***
2  This file is part of PulseAudio.
3
4  Copyright 2004-2006 Lennart Poettering
5
6  PulseAudio is free software; you can redistribute it and/or modify
7  it under the terms of the GNU Lesser General Public License as published
8  by the Free Software Foundation; either version 2.1 of the License,
9  or (at your option) any later version.
10
11  PulseAudio is distributed in the hope that it will be useful, but
12  WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  General Public License for more details.
15
16  You should have received a copy of the GNU Lesser General Public License
17  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
18***/
19
20#ifdef HAVE_CONFIG_H
21#include <config.h>
22#endif
23
24#include <sys/types.h>
25#include <stdlib.h>
26#include <string.h>
27#include <stdarg.h>
28#include <stdio.h>
29
30#include <pulse/xmalloc.h>
31#include <pulsecore/macro.h>
32
33#include "strbuf.h"
34
35/* A chunk of the linked list that makes up the string */
36struct chunk {
37    struct chunk *next;
38    size_t length;
39};
40
41#define CHUNK_TO_TEXT(c) ((char*) (c) + PA_ALIGN(sizeof(struct chunk)))
42
43struct pa_strbuf {
44    size_t length;
45    struct chunk *head, *tail;
46};
47
48pa_strbuf *pa_strbuf_new(void) {
49    pa_strbuf *sb;
50
51    sb = pa_xnew(pa_strbuf, 1);
52    sb->length = 0;
53    sb->head = sb->tail = NULL;
54
55    return sb;
56}
57
58void pa_strbuf_free(pa_strbuf *sb) {
59    pa_assert(sb);
60
61    while (sb->head) {
62        struct chunk *c = sb->head;
63        sb->head = sb->head->next;
64        pa_xfree(c);
65    }
66
67    pa_xfree(sb);
68}
69
70/* Make a C string from the string buffer. The caller has to free
71 * string with pa_xfree(). */
72char *pa_strbuf_to_string(pa_strbuf *sb) {
73    char *t, *e;
74    struct chunk *c;
75
76    pa_assert(sb);
77
78    e = t = pa_xmalloc(sb->length+1);
79
80    for (c = sb->head; c; c = c->next) {
81        pa_assert((size_t) (e-t) <= sb->length);
82        memcpy(e, CHUNK_TO_TEXT(c), c->length);
83        e += c->length;
84    }
85
86    /* Trailing NUL */
87    *e = 0;
88
89    pa_assert(e == t+sb->length);
90
91    return t;
92}
93
94/* Combination of pa_strbuf_free() and pa_strbuf_to_string() */
95char *pa_strbuf_to_string_free(pa_strbuf *sb) {
96    char *t;
97
98    pa_assert(sb);
99    t = pa_strbuf_to_string(sb);
100    pa_strbuf_free(sb);
101
102    return t;
103}
104
105/* Append a string to the string buffer */
106void pa_strbuf_puts(pa_strbuf *sb, const char *t) {
107
108    pa_assert(sb);
109    pa_assert(t);
110
111    pa_strbuf_putsn(sb, t, strlen(t));
112}
113
114/* Append a character to the string buffer */
115void pa_strbuf_putc(pa_strbuf *sb, char c) {
116    pa_assert(sb);
117
118    pa_strbuf_putsn(sb, &c, 1);
119}
120
121/* Append a new chunk to the linked list */
122static void append(pa_strbuf *sb, struct chunk *c) {
123    pa_assert(sb);
124    pa_assert(c);
125
126    if (sb->tail) {
127        pa_assert(sb->head);
128        sb->tail->next = c;
129    } else {
130        pa_assert(!sb->head);
131        sb->head = c;
132    }
133
134    sb->tail = c;
135    sb->length += c->length;
136    c->next = NULL;
137}
138
139/* Append up to l bytes of a string to the string buffer */
140void pa_strbuf_putsn(pa_strbuf *sb, const char *t, size_t l) {
141    struct chunk *c;
142
143    pa_assert(sb);
144    pa_assert(t);
145
146    if (!l)
147        return;
148
149    c = pa_xmalloc(PA_ALIGN(sizeof(struct chunk)) + l);
150    c->length = l;
151    memcpy(CHUNK_TO_TEXT(c), t, l);
152
153    append(sb, c);
154}
155
156/* Append a printf() style formatted string to the string buffer. */
157/* The following is based on an example from the GNU libc documentation */
158size_t pa_strbuf_printf(pa_strbuf *sb, const char *format, ...) {
159    size_t size = 100;
160    struct chunk *c = NULL;
161
162    pa_assert(sb);
163    pa_assert(format);
164
165    for(;;) {
166        va_list ap;
167        int r;
168
169        c = pa_xrealloc(c, PA_ALIGN(sizeof(struct chunk)) + size);
170
171        va_start(ap, format);
172        r = vsnprintf(CHUNK_TO_TEXT(c), size, format, ap);
173        CHUNK_TO_TEXT(c)[size-1] = 0;
174        va_end(ap);
175
176        if (r > -1 && (size_t) r < size) {
177            c->length = (size_t) r;
178            append(sb, c);
179            return (size_t) r;
180        }
181
182        if (r > -1)    /* glibc 2.1 */
183            size = (size_t) r+1;
184        else           /* glibc 2.0 */
185            size *= 2;
186    }
187}
188
189bool pa_strbuf_isempty(pa_strbuf *sb) {
190    pa_assert(sb);
191
192    return sb->length <= 0;
193}
194