1 files changed, 91 insertions, 0 deletions
diff --git a/lib/sbuf.c b/lib/sbuf.c
new file mode 100644
index 0000000..2762e44
--- /dev/null
+++ b/lib/sbuf.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Simple string buffer
+ *
+ * Copyright (C) 2017 Christian Franke
+ */
+#include <zebra.h>
+
+#include "printfrr.h"
+#include "sbuf.h"
+#include "memory.h"
+
+void sbuf_init(struct sbuf *dest, char *buf, size_t size)
+{
+	dest->fixed = (size > 0);
+	if (dest->fixed) {
+		dest->buf = buf;
+		dest->size = size;
+	} else {
+		dest->buf = XMALLOC(MTYPE_TMP, SBUF_DEFAULT_SIZE);
+		dest->size = SBUF_DEFAULT_SIZE;
+	}
+
+	dest->pos = 0;
+	dest->buf[0] = '\0';
+}
+
+void sbuf_reset(struct sbuf *dest)
+{
+	dest->pos = 0;
+	dest->buf[0] = '\0';
+}
+
+const char *sbuf_buf(struct sbuf *buf)
+{
+	return buf->buf;
+}
+
+void sbuf_free(struct sbuf *buf)
+{
+	if (!buf->fixed)
+		XFREE(MTYPE_TMP, buf->buf);
+}
+
+void sbuf_push(struct sbuf *buf, int indent, const char *format, ...)
+{
+	va_list args;
+	int written;
+
+	if (!buf->fixed) {
+		int written1, written2;
+		size_t new_size;
+
+		written1 = indent;
+		va_start(args, format);
+		written2 = vsnprintfrr(NULL, 0, format, args);
+		va_end(args);
+
+		new_size = buf->size;
+		if (written1 >= 0 && written2 >= 0) {
+			while (buf->pos + written1 + written2 >= new_size)
+				new_size *= 2;
+			if (new_size > buf->size) {
+				buf->buf =
+					XREALLOC(MTYPE_TMP, buf->buf, new_size);
+				buf->size = new_size;
+			}
+		}
+	}
+
+	written = snprintf(buf->buf + buf->pos, buf->size - buf->pos, "%*s",
+			   indent, "");
+
+	if (written >= 0)
+		buf->pos += written;
+	if (buf->pos > buf->size)
+		buf->pos = buf->size;
+
+	va_start(args, format);
+	written = vsnprintfrr(buf->buf + buf->pos, buf->size - buf->pos,
+			      format, args);
+	va_end(args);
+
+	if (written >= 0)
+		buf->pos += written;
+	if (buf->pos > buf->size)
+		buf->pos = buf->size;
+
+	if (buf->pos == buf->size)
+		assert(!"Buffer filled up!");
+}