really create glitch-free branch

git-svn-id: file:///home/lennart/svn/public/pulseaudio/branches/glitch-free@2120 fefdeb5f-60dc-0310-8127-8f9354f1896f

1 files changed, 184 insertions, 0 deletions

diff --git a/src/pulsecore/strbuf.c b/src/pulsecore/strbuf.c
new file mode 100644
index 00000000..7c576c67
--- /dev/null
+++ b/src/pulsecore/strbuf.c
@@ -0,0 +1,184 @@
+/* $Id$ */
+
+/***
+  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 <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include <pulse/xmalloc.h>
+#include <pulsecore/macro.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) + PA_ALIGN(sizeof(struct chunk)))
+
+struct pa_strbuf {
+    size_t length;
+    struct chunk *head, *tail;
+};
+
+pa_strbuf *pa_strbuf_new(void) {
+    pa_strbuf *sb;
+
+    sb = pa_xnew(pa_strbuf, 1);
+    sb->length = 0;
+    sb->head = sb->tail = NULL;
+
+    return sb;
+}
+
+void pa_strbuf_free(pa_strbuf *sb) {
+    pa_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;
+
+    pa_assert(sb);
+
+    e = t = pa_xnew(char, sb->length+1);
+
+    for (c = sb->head; c; c = c->next) {
+        pa_assert((size_t) (e-t) <= sb->length);
+        memcpy(e, CHUNK_TO_TEXT(c), c->length);
+        e += c->length;
+    }
+
+    /* Trailing NUL */
+    *e = 0;
+
+    pa_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;
+
+    pa_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) {
+
+    pa_assert(sb);
+    pa_assert(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) {
+    pa_assert(sb);
+    pa_assert(c);
+
+    if (sb->tail) {
+        pa_assert(sb->head);
+        sb->tail->next = c;
+    } else {
+        pa_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;
+
+    pa_assert(sb);
+    pa_assert(t);
+
+    if (!l)
+       return;
+
+    c = pa_xmalloc(PA_ALIGN(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;
+
+    pa_assert(sb);
+    pa_assert(format);
+
+    for(;;) {
+        va_list ap;
+        int r;
+
+        c = pa_xrealloc(c, PA_ALIGN(sizeof(struct chunk)) + size);
+
+        va_start(ap, format);
+        r = vsnprintf(CHUNK_TO_TEXT(c), size, format, ap);
+        CHUNK_TO_TEXT(c)[size-1] = 0;
+        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;
+    }
+}