diff options
Diffstat (limited to 'qemu/roms/u-boot/lib/circbuf.c')
-rw-r--r-- | qemu/roms/u-boot/lib/circbuf.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/lib/circbuf.c b/qemu/roms/u-boot/lib/circbuf.c new file mode 100644 index 000000000..9848da3b7 --- /dev/null +++ b/qemu/roms/u-boot/lib/circbuf.c @@ -0,0 +1,97 @@ +/* + * (C) Copyright 2003 + * Gerry Hamel, geh@ti.com, Texas Instruments + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#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; +} |