Add fifo32_peek() that returns the first element from the queue
without popping it.
Signed-off-by: Octavian Purdila <ta...@google.com>
---
include/qemu/fifo32.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/include/qemu/fifo32.h b/include/qemu/fifo32.h
index 4e9fd1b5ef..77aab488ae 100644
--- a/include/qemu/fifo32.h
+++ b/include/qemu/fifo32.h
@@ -140,6 +140,34 @@ static inline uint32_t fifo32_pop(Fifo32 *fifo)
return ret;
}
+/**
+ * fifo32_peek:
+ * @fifo: fifo to peek at
+ *
+ * Returns the value from the FIFO's head without poping it. Behaviour
+ * is undefined if the FIFO is empty. Clients are responsible for
+ * checking for emptiness using fifo32_is_empty().
+ *
+ * Returns: the value from the FIFO's head
+ */
+
+static inline uint32_t fifo32_peek(Fifo32 *fifo)
+{
+ uint32_t ret = 0, num;
+ const uint8_t *buf;
+
+ buf = fifo8_peek_buf(&fifo->fifo, 4, &num);
+ if (num != 4) {
+ return ret;
+ }
+
+ for (int i = 0; i < sizeof(uint32_t); i++) {
+ ret |= buf[i] << (i * 8);
+ }
+
+ return ret;
+}
+
/**
* There is no fifo32_pop_buf() because the data is not stored in the buffer
* as a set of native-order words.
--
2.46.0.184.g6999bdac58-goog
