1 #ifndef QEMU_FIFO8_H 2 #define QEMU_FIFO8_H 3 4 5 typedef 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 22 void 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 32 void 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 43 void 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 56 void 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 68 uint8_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 */ 94 const 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 */ 102 103 void 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 */ 113 114 bool 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 */ 124 125 bool 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 */ 135 136 uint32_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 */ 146 147 uint32_t fifo8_num_used(Fifo8 *fifo); 148 149 extern 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