diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/qemu/fifo8.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/qemu/fifo8.h b/include/qemu/fifo8.h index d0d02bc73d..c6295c6ff0 100644 --- a/include/qemu/fifo8.h +++ b/include/qemu/fifo8.h @@ -94,6 +94,33 @@ uint8_t fifo8_pop(Fifo8 *fifo); const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr); /** + * fifo8_peek_buf: read upto max bytes from the fifo + * @fifo: FIFO to read from + * @max: maximum number of bytes to peek + * @numptr: pointer filled with number of bytes returned (can be NULL) + * + * Peek into a number of elements from the FIFO up to a maximum of max. + * The buffer containing the data peeked into is returned. This buffer points + * directly into the FIFO backing store. Since data is invalidated once any + * of the fifo8_* APIs are called on the FIFO, it is the caller responsibility + * to access it before doing further API calls. + * + * The function may return fewer bytes than requested when the data wraps + * around in the ring buffer; in this case only a contiguous part of the data + * is returned. + * + * The number of valid bytes returned is populated in *numptr; will always + * return at least 1 byte. max must not be 0 or greater than the number of + * bytes in the FIFO. + * + * Clients are responsible for checking the availability of requested data + * using fifo8_num_used(). + * + * Returns: A pointer to peekable data. + */ +const uint8_t *fifo8_peek_buf(Fifo8 *fifo, uint32_t max, uint32_t *numptr); + +/** * fifo8_reset: * @fifo: FIFO to reset * |