1 #ifndef QEMU_FIFO8_H 2 #define QEMU_FIFO8_H 3 4 #include "migration/vmstate.h" 5 6 typedef struct { 7 /* All fields are private */ 8 uint8_t *data; 9 uint32_t capacity; 10 uint32_t head; 11 uint32_t num; 12 } Fifo8; 13 14 /** 15 * fifo8_create: 16 * @fifo: struct Fifo8 to initialise with new FIFO 17 * @capacity: capacity of the newly created FIFO 18 * 19 * Create a FIFO of the specified size. Clients should call fifo8_destroy() 20 * when finished using the fifo. The FIFO is initially empty. 21 */ 22 23 void fifo8_create(Fifo8 *fifo, uint32_t capacity); 24 25 /** 26 * fifo8_destroy: 27 * @fifo: FIFO to cleanup 28 * 29 * Cleanup a FIFO created with fifo8_create(). Frees memory created for FIFO 30 *storage. The FIFO is no longer usable after this has been called. 31 */ 32 33 void fifo8_destroy(Fifo8 *fifo); 34 35 /** 36 * fifo8_push: 37 * @fifo: FIFO to push to 38 * @data: data byte to push 39 * 40 * Push a data byte to the FIFO. Behaviour is undefined if the FIFO is full. 41 * Clients are responsible for checking for fullness using fifo8_is_full(). 42 */ 43 44 void fifo8_push(Fifo8 *fifo, uint8_t data); 45 46 /** 47 * fifo8_push_all: 48 * @fifo: FIFO to push to 49 * @data: data to push 50 * @size: number of bytes to push 51 * 52 * Push a byte array to the FIFO. Behaviour is undefined if the FIFO is full. 53 * Clients are responsible for checking the space left in the FIFO using 54 * fifo8_num_free(). 55 */ 56 57 void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num); 58 59 /** 60 * fifo8_pop: 61 * @fifo: fifo to pop from 62 * 63 * Pop a data byte from the FIFO. Behaviour is undefined if the FIFO is empty. 64 * Clients are responsible for checking for emptyness using fifo8_is_empty(). 65 * 66 * Returns: The popped data byte. 67 */ 68 69 uint8_t fifo8_pop(Fifo8 *fifo); 70 71 /** 72 * fifo8_pop_buf: 73 * @fifo: FIFO to pop from 74 * @max: maximum number of bytes to pop 75 * @num: actual number of returned bytes 76 * 77 * Pop a number of elements from the FIFO up to a maximum of max. The buffer 78 * containing the popped data is returned. This buffer points directly into 79 * the FIFO backing store and data is invalidated once any of the fifo8_* APIs 80 * are called on the FIFO. 81 * 82 * The function may return fewer bytes than requested when the data wraps 83 * around in the ring buffer; in this case only a contiguous part of the data 84 * is returned. 85 * 86 * The number of valid bytes returned is populated in *num; will always return 87 * at least 1 byte. max must not be 0 or greater than the number of bytes in 88 * the FIFO. 89 * 90 * Clients are responsible for checking the availability of requested data 91 * using fifo8_num_used(). 92 * 93 * Returns: A pointer to popped data. 94 */ 95 const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num); 96 97 /** 98 * fifo8_reset: 99 * @fifo: FIFO to reset 100 * 101 * Reset a FIFO. All data is discarded and the FIFO is emptied. 102 */ 103 104 void fifo8_reset(Fifo8 *fifo); 105 106 /** 107 * fifo8_is_empty: 108 * @fifo: FIFO to check 109 * 110 * Check if a FIFO is empty. 111 * 112 * Returns: True if the fifo is empty, false otherwise. 113 */ 114 115 bool fifo8_is_empty(Fifo8 *fifo); 116 117 /** 118 * fifo8_is_full: 119 * @fifo: FIFO to check 120 * 121 * Check if a FIFO is full. 122 * 123 * Returns: True if the fifo is full, false otherwise. 124 */ 125 126 bool fifo8_is_full(Fifo8 *fifo); 127 128 /** 129 * fifo8_num_free: 130 * @fifo: FIFO to check 131 * 132 * Return the number of free bytes in the FIFO. 133 * 134 * Returns: Number of free bytes. 135 */ 136 137 uint32_t fifo8_num_free(Fifo8 *fifo); 138 139 /** 140 * fifo8_num_used: 141 * @fifo: FIFO to check 142 * 143 * Return the number of used bytes in the FIFO. 144 * 145 * Returns: Number of used bytes. 146 */ 147 148 uint32_t fifo8_num_used(Fifo8 *fifo); 149 150 extern const VMStateDescription vmstate_fifo8; 151 152 #define VMSTATE_FIFO8(_field, _state) { \ 153 .name = (stringify(_field)), \ 154 .size = sizeof(Fifo8), \ 155 .vmsd = &vmstate_fifo8, \ 156 .flags = VMS_STRUCT, \ 157 .offset = vmstate_offset_value(_state, _field, Fifo8), \ 158 } 159 160 #endif /* QEMU_FIFO8_H */ 161