1 files changed, 160 insertions, 0 deletions
diff --git a/src/include/qemu/fifo8.h b/src/include/qemu/fifo8.h
new file mode 100644
index 0000000..8820780
--- /dev/null
+++ b/src/include/qemu/fifo8.h
@@ -0,0 +1,160 @@
+#ifndef FIFO_H
+#define FIFO_H
+
+#include "migration/vmstate.h"
+
+typedef struct {
+    /* All fields are private */
+    uint8_t *data;
+    uint32_t capacity;
+    uint32_t head;
+    uint32_t num;
+} Fifo8;
+
+/**
+ * fifo8_create:
+ * @fifo: struct Fifo8 to initialise with new FIFO
+ * @capacity: capacity of the newly created FIFO
+ *
+ * Create a FIFO of the specified size. Clients should call fifo8_destroy()
+ * when finished using the fifo. The FIFO is initially empty.
+ */
+
+void fifo8_create(Fifo8 *fifo, uint32_t capacity);
+
+/**
+ * fifo8_destroy:
+ * @fifo: FIFO to cleanup
+ *
+ * Cleanup a FIFO created with fifo8_create(). Frees memory created for FIFO
+  *storage. The FIFO is no longer usable after this has been called.
+ */
+
+void fifo8_destroy(Fifo8 *fifo);
+
+/**
+ * fifo8_push:
+ * @fifo: FIFO to push to
+ * @data: data byte to push
+ *
+ * Push a data byte to the FIFO. Behaviour is undefined if the FIFO is full.
+ * Clients are responsible for checking for fullness using fifo8_is_full().
+ */
+
+void fifo8_push(Fifo8 *fifo, uint8_t data);
+
+/**
+ * fifo8_push_all:
+ * @fifo: FIFO to push to
+ * @data: data to push
+ * @size: number of bytes to push
+ *
+ * Push a byte array to the FIFO. Behaviour is undefined if the FIFO is full.
+ * Clients are responsible for checking the space left in the FIFO using
+ * fifo8_num_free().
+ */
+
+void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num);
+
+/**
+ * fifo8_pop:
+ * @fifo: fifo to pop from
+ *
+ * Pop a data byte from the FIFO. Behaviour is undefined if the FIFO is empty.
+ * Clients are responsible for checking for emptyness using fifo8_is_empty().
+ *
+ * Returns: The popped data byte.
+ */
+
+uint8_t fifo8_pop(Fifo8 *fifo);
+
+/**
+ * fifo8_pop_buf:
+ * @fifo: FIFO to pop from
+ * @max: maximum number of bytes to pop
+ * @num: actual number of returned bytes
+ *
+ * Pop a number of elements from the FIFO up to a maximum of max. The buffer
+ * containing the popped data is returned. This buffer points directly into
+ * the FIFO backing store and data is invalidated once any of the fifo8_* APIs
+ * are called on the FIFO.
+ *
+ * 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 *num; 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 popped data.
+ */
+const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num);
+
+/**
+ * fifo8_reset:
+ * @fifo: FIFO to reset
+ *
+ * Reset a FIFO. All data is discarded and the FIFO is emptied.
+ */
+
+void fifo8_reset(Fifo8 *fifo);
+
+/**
+ * fifo8_is_empty:
+ * @fifo: FIFO to check
+ *
+ * Check if a FIFO is empty.
+ *
+ * Returns: True if the fifo is empty, false otherwise.
+ */
+
+bool fifo8_is_empty(Fifo8 *fifo);
+
+/**
+ * fifo8_is_full:
+ * @fifo: FIFO to check
+ *
+ * Check if a FIFO is full.
+ *
+ * Returns: True if the fifo is full, false otherwise.
+ */
+
+bool fifo8_is_full(Fifo8 *fifo);
+
+/**
+ * fifo8_num_free:
+ * @fifo: FIFO to check
+ *
+ * Return the number of free bytes in the FIFO.
+ *
+ * Returns: Number of free bytes.
+ */
+
+uint32_t fifo8_num_free(Fifo8 *fifo);
+
+/**
+ * fifo8_num_used:
+ * @fifo: FIFO to check
+ *
+ * Return the number of used bytes in the FIFO.
+ *
+ * Returns: Number of used bytes.
+ */
+
+uint32_t fifo8_num_used(Fifo8 *fifo);
+
+extern const VMStateDescription vmstate_fifo8;
+
+#define VMSTATE_FIFO8(_field, _state) {                              \
+    .name       = (stringify(_field)),                               \
+    .size       = sizeof(Fifo8),                                     \
+    .vmsd       = &vmstate_fifo8,                                    \
+    .flags      = VMS_STRUCT,                                        \
+    .offset     = vmstate_offset_value(_state, _field, Fifo8),       \
+}
+
+#endif /* FIFO_H */