LXR qemu/include/qemu/fifo8.h

   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_TEST(_field, _state, _test) {                  \
 152    .name         = (stringify(_field)),                             \
 153    .field_exists = (_test),                                         \
 154    .size         = sizeof(Fifo8),                                   \
 155    .vmsd         = &vmstate_fifo8,                                  \
 156    .flags        = VMS_STRUCT,                                      \
 157    .offset       = vmstate_offset_value(_state, _field, Fifo8),     \
 158}
 159
 160#define VMSTATE_FIFO8(_field, _state)                                \
 161    VMSTATE_FIFO8_TEST(_field, _state, NULL)
 162
 163#endif /* QEMU_FIFO8_H */
 164