aboutsummaryrefslogtreecommitdiff
path: root/include/qemu/fifo8.h
blob: 489c35429111b726e9fc3f6b899c7c90502edd7f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
#ifndef QEMU_FIFO8_H
#define QEMU_FIFO8_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 /* QEMU_FIFO8_H */