[PATCH 3/3] util/fifo8: Introduce fifo8_change_capacity()

[Philippe Mathieu-Daudé]

FIFOs can be resized at runtime. Introduce the
fifo8_change_capacity() method to do that.
When capacity is changed, the FIFO must be reset.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/qemu/fifo8.h | 10 ++++++++++
 util/fifo8.c         |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/include/qemu/fifo8.h b/include/qemu/fifo8.h
index c6295c6ff0..9fe0555a24 100644
--- a/include/qemu/fifo8.h
+++ b/include/qemu/fifo8.h
@@ -31,6 +31,16 @@ void fifo8_create(Fifo8 *fifo, uint32_t capacity);
 
 void fifo8_destroy(Fifo8 *fifo);
 
+/**
+ * fifo8_change_capacity:
+ * @fifo: struct Fifo8 to change the capacity
+ * @capacity: new capacity of the FIFO
+ *
+ * Change a FIFO capacity to the specified size. The FIFO is reset.
+ */
+
+void fifo8_change_capacity(Fifo8 *fifo, uint32_t capacity);
+
 /**
  * fifo8_push:
  * @fifo: FIFO to push to
diff --git a/util/fifo8.c b/util/fifo8.c
index 2925fe5611..c453afd774 100644
--- a/util/fifo8.c
+++ b/util/fifo8.c
@@ -34,6 +34,13 @@ void fifo8_destroy(Fifo8 *fifo)
     g_free(fifo->data);
 }
 
+void fifo8_change_capacity(Fifo8 *fifo, uint32_t capacity)
+{
+    fifo->data = g_renew(uint8_t, fifo->data, capacity);
+    fifo->capacity = capacity;
+    fifo8_reset(fifo);
+}
+
 void fifo8_push(Fifo8 *fifo, uint8_t data)
 {
     assert(fifo->num < fifo->capacity);
-- 
2.41.0