Add support for Siemens SX1 mobile phone;

[karo-tx-uboot.git] / common / circbuf.c

diff --git a/common/circbuf.c b/common/circbuf.c
new file mode 100644 (file)
index 0000000..2332c63
--- /dev/null
+++ b/common/circbuf.c
@@ -0,0 +1,110 @@
+/*
+ * (C) Copyright 2003
+ * Gerry Hamel, geh@ti.com, Texas Instruments
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307         USA
+ *
+ */
+
+#include <common.h>
+#include <malloc.h>
+
+#include <circbuf.h>
+
+
+int buf_init (circbuf_t * buf, unsigned int size)
+{
+       assert (buf != NULL);
+
+       buf->size = 0;
+       buf->totalsize = size;
+       buf->data = (char *) malloc (sizeof (char) * size);
+       assert (buf->data != NULL);
+
+       buf->top = buf->data;
+       buf->tail = buf->data;
+       buf->end = &(buf->data[size]);
+
+       return 1;
+}
+
+int buf_free (circbuf_t * buf)
+{
+       assert (buf != NULL);
+       assert (buf->data != NULL);
+
+       free (buf->data);
+       memset (buf, 0, sizeof (circbuf_t));
+
+       return 1;
+}
+
+int buf_pop (circbuf_t * buf, char *dest, unsigned int len)
+{
+       unsigned int i;
+       char *p = buf->top;
+
+       assert (buf != NULL);
+       assert (dest != NULL);
+
+       /* Cap to number of bytes in buffer */
+       if (len > buf->size)
+               len = buf->size;
+
+       for (i = 0; i < len; i++) {
+               dest[i] = *p++;
+               /* Bounds check. */
+               if (p == buf->end) {
+                       p = buf->data;
+               }
+       }
+
+       /* Update 'top' pointer */
+       buf->top = p;
+       buf->size -= len;
+
+       return len;
+}
+
+int buf_push (circbuf_t * buf, const char *src, unsigned int len)
+{
+       /* NOTE:  this function allows push to overwrite old data. */
+       unsigned int i;
+       char *p = buf->tail;
+
+       assert (buf != NULL);
+       assert (src != NULL);
+
+       for (i = 0; i < len; i++) {
+               *p++ = src[i];
+               if (p == buf->end) {
+                       p = buf->data;
+               }
+               /* Make sure pushing too much data just replaces old data */
+               if (buf->size < buf->totalsize) {
+                       buf->size++;
+               } else {
+                       buf->top++;
+                       if (buf->top == buf->end) {
+                               buf->top = buf->data;
+                       }
+               }
+       }
+
+       /* Update 'tail' pointer */
+       buf->tail = p;
+
+       return len;
+}