diff options
Diffstat (limited to 'kern/cbuf.h')
| -rw-r--r-- | kern/cbuf.h | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/kern/cbuf.h b/kern/cbuf.h index b675fd5d..0cac54ab 100644 --- a/kern/cbuf.h +++ b/kern/cbuf.h @@ -92,12 +92,25 @@ void cbuf_push(struct cbuf *cbuf, char byte); int cbuf_pop(struct cbuf *cbuf, char *bytep); /* - * Read a byte at a specific location. + * Write into a circular buffer at a specific location. * * If the given index is outside buffer boundaries, ERROR_INVAL is returned. - * Otherwise the byte is stored at the bytep address and 0 is returned. - * The buffer isn't changed by this operation. + * Otherwise size bytes are copied into the circular buffer. If the range + * in the circular buffer goes beyond its end, the end index is updated as + * appropriate. If the buffer is full when extending its end, the oldest + * bytes are overwritten and the start index is updated accordingly. */ -int cbuf_read(const struct cbuf *cbuf, size_t index, char *bytep); +int cbuf_write(struct cbuf *cbuf, size_t index, const char *buf, size_t size); + +/* + * Read from a circular buffer at a specific location. + * + * If the given index is outside buffer boundaries, ERROR_INVAL is returned. + * Otherwise at most *sizep bytes are copied into the given character buffer, + * and *sizep is updated to the number of bytes actually copied. + * + * The circular buffer isn't changed by this operation. + */ +int cbuf_read(const struct cbuf *cbuf, size_t index, char *buf, size_t *sizep); #endif /* _KERN_CBUF_H */ |