1#ifndef QEMU_FIFO8_H
2#define QEMU_FIFO8_H
3
4
5typedef struct {
6 /* All fields are private */
7 uint8_t *data;
8 uint32_t capacity;
9 uint32_t head;
10 uint32_t num;
11} Fifo8;
12
13/**
14 * fifo8_create:
15 * @fifo: struct Fifo8 to initialise with new FIFO
16 * @capacity: capacity of the newly created FIFO
17 *
18 * Create a FIFO of the specified size. Clients should call fifo8_destroy()
19 * when finished using the fifo. The FIFO is initially empty.
20 */
21
22void fifo8_create(Fifo8 *fifo, uint32_t capacity);
23
24/**
25 * fifo8_destroy:
26 * @fifo: FIFO to cleanup
27 *
28 * Cleanup a FIFO created with fifo8_create(). Frees memory created for FIFO
29 *storage. The FIFO is no longer usable after this has been called.
30 */
31
32void fifo8_destroy(Fifo8 *fifo);
33
34/**
35 * fifo8_push:
36 * @fifo: FIFO to push to
37 * @data: data byte to push
38 *
39 * Push a data byte to the FIFO. Behaviour is undefined if the FIFO is full.
40 * Clients are responsible for checking for fullness using fifo8_is_full().
41 */
42
43void fifo8_push(Fifo8 *fifo, uint8_t data);
44
45/**
46 * fifo8_push_all:
47 * @fifo: FIFO to push to
48 * @data: data to push
49 * @size: number of bytes to push
50 *
51 * Push a byte array to the FIFO. Behaviour is undefined if the FIFO is full.
52 * Clients are responsible for checking the space left in the FIFO using
53 * fifo8_num_free().
54 */
55
56void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num);
57
58/**
59 * fifo8_pop:
60 * @fifo: fifo to pop from
61 *
62 * Pop a data byte from the FIFO. Behaviour is undefined if the FIFO is empty.
63 * Clients are responsible for checking for emptyness using fifo8_is_empty().
64 *
65 * Returns: The popped data byte.
66 */
67
68uint8_t fifo8_pop(Fifo8 *fifo);
69
70/**
71 * fifo8_pop_buf:
72 * @fifo: FIFO to pop from
73 * @max: maximum number of bytes to pop
74 * @num: actual number of returned bytes
75 *
76 * Pop a number of elements from the FIFO up to a maximum of max. The buffer
77 * containing the popped data is returned. This buffer points directly into
78 * the FIFO backing store and data is invalidated once any of the fifo8_* APIs
79 * are called on the FIFO.
80 *
81 * The function may return fewer bytes than requested when the data wraps
82 * around in the ring buffer; in this case only a contiguous part of the data
83 * is returned.
84 *
85 * The number of valid bytes returned is populated in *num; will always return
86 * at least 1 byte. max must not be 0 or greater than the number of bytes in
87 * the FIFO.
88 *
89 * Clients are responsible for checking the availability of requested data
90 * using fifo8_num_used().
91 *
92 * Returns: A pointer to popped data.
93 */
94const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num);
95
96/**
97 * fifo8_reset:
98 * @fifo: FIFO to reset
99 *
100 * Reset a FIFO. All data is discarded and the FIFO is emptied.
101 */
102
103void fifo8_reset(Fifo8 *fifo);
104
105/**
106 * fifo8_is_empty:
107 * @fifo: FIFO to check
108 *
109 * Check if a FIFO is empty.
110 *
111 * Returns: True if the fifo is empty, false otherwise.
112 */
113
114bool fifo8_is_empty(Fifo8 *fifo);
115
116/**
117 * fifo8_is_full:
118 * @fifo: FIFO to check
119 *
120 * Check if a FIFO is full.
121 *
122 * Returns: True if the fifo is full, false otherwise.
123 */
124
125bool fifo8_is_full(Fifo8 *fifo);
126
127/**
128 * fifo8_num_free:
129 * @fifo: FIFO to check
130 *
131 * Return the number of free bytes in the FIFO.
132 *
133 * Returns: Number of free bytes.
134 */
135
136uint32_t fifo8_num_free(Fifo8 *fifo);
137
138/**
139 * fifo8_num_used:
140 * @fifo: FIFO to check
141 *
142 * Return the number of used bytes in the FIFO.
143 *
144 * Returns: Number of used bytes.
145 */
146
147uint32_t fifo8_num_used(Fifo8 *fifo);
148
149extern const VMStateDescription vmstate_fifo8;
150
151#define VMSTATE_FIFO8(_field, _state) { \
152 .name = (stringify(_field)), \
153 .size = sizeof(Fifo8), \
154 .vmsd = &vmstate_fifo8, \
155 .flags = VMS_STRUCT, \
156 .offset = vmstate_offset_value(_state, _field, Fifo8), \
157}
158
159#endif /* QEMU_FIFO8_H */
160