From 78acc472d9719316f22e002a009a998d9ceec29d Mon Sep 17 00:00:00 2001 From: Peter Tyser Date: Mon, 12 Apr 2010 22:28:05 -0500 Subject: Rename lib_generic/ to lib/ Now that the other architecture-specific lib directories have been moved out of the top-level directory there's not much reason to have the '_generic' suffix on the common lib directory. Signed-off-by: Peter Tyser --- lib/circbuf.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 lib/circbuf.c (limited to 'lib/circbuf.c') diff --git a/lib/circbuf.c b/lib/circbuf.c new file mode 100644 index 0000000000..2332c63717 --- /dev/null +++ b/lib/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 +#include + +#include + + +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; +} -- cgit v1.2.1