summaryrefslogtreecommitdiff
path: root/src/pulsecore/strbuf.c
blob: a3ddc1144c3cae330722668ab68418cdd072d59c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/* $Id$ */

/***
  This file is part of PulseAudio.

  Copyright 2004-2006 Lennart Poettering

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.

  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/types.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>

#include <pulse/xmalloc.h>

#include "strbuf.h"

/* A chunk of the linked list that makes up the string */
struct chunk {
    struct chunk *next;
    size_t length;
};

#define CHUNK_TO_TEXT(c) ((char*) (c) + sizeof(struct chunk))

struct pa_strbuf {
    size_t length;
    struct chunk *head, *tail;
};

pa_strbuf *pa_strbuf_new(void) {
    pa_strbuf *sb = pa_xmalloc(sizeof(pa_strbuf));
    sb->length = 0;
    sb->head = sb->tail = NULL;
    return sb;
}

void pa_strbuf_free(pa_strbuf *sb) {
    assert(sb);
    while (sb->head) {
        struct chunk *c = sb->head;
        sb->head = sb->head->next;
        pa_xfree(c);
    }

    pa_xfree(sb);
}

/* Make a C string from the string buffer. The caller has to free
 * string with pa_xfree(). */
char *pa_strbuf_tostring(pa_strbuf *sb) {
    char *t, *e;
    struct chunk *c;
    assert(sb);

    e = t = pa_xmalloc(sb->length+1);

    for (c = sb->head; c; c = c->next) {
        assert((size_t) (e-t) <= sb->length);
        memcpy(e, CHUNK_TO_TEXT(c), c->length);
        e += c->length;
    }

    /* Trailing NUL */
    *e = 0;

    assert(e == t+sb->length);

    return t;
}

/* Combination of pa_strbuf_free() and pa_strbuf_tostring() */
char *pa_strbuf_tostring_free(pa_strbuf *sb) {
    char *t;
    assert(sb);
    t = pa_strbuf_tostring(sb);
    pa_strbuf_free(sb);
    return t;
}

/* Append a string to the string buffer */
void pa_strbuf_puts(pa_strbuf *sb, const char *t) {
    assert(sb && t);
    pa_strbuf_putsn(sb, t, strlen(t));
}

/* Append a new chunk to the linked list */
static void append(pa_strbuf *sb, struct chunk *c) {
    assert(sb && c);

    if (sb->tail) {
        assert(sb->head);
        sb->tail->next = c;
    } else {
        assert(!sb->head);
        sb->head = c;
    }

    sb->tail = c;
    sb->length += c->length;
    c->next = NULL;
}

/* Append up to l bytes of a string to the string buffer */
void pa_strbuf_putsn(pa_strbuf *sb, const char *t, size_t l) {
    struct chunk *c;
    assert(sb && t);

    if (!l)
       return;

    c = pa_xmalloc(sizeof(struct chunk)+l);
    c->length = l;
    memcpy(CHUNK_TO_TEXT(c), t, l);

    append(sb, c);
}

/* Append a printf() style formatted string to the string buffer. */
/* The following is based on an example from the GNU libc documentation */
int pa_strbuf_printf(pa_strbuf *sb, const char *format, ...) {
    int size = 100;
    struct chunk *c = NULL;

    assert(sb);

    for(;;) {
        va_list ap;
        int r;

        c = pa_xrealloc(c, sizeof(struct chunk)+size);

        va_start(ap, format);
        r = vsnprintf(CHUNK_TO_TEXT(c), size, format, ap);
        va_end(ap);

        if (r > -1 && r < size) {
            c->length = r;
            append(sb, c);
            return r;
        }

        if (r > -1)    /* glibc 2.1 */
            size = r+1;
        else           /* glibc 2.0 */
            size *= 2;
    }
}