| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236 | #ifndef _LIBMAPLE_RING_BUFFER_H_#define _LIBMAPLE_RING_BUFFER_H_typedef unsigned char    u8;      // 无符号8位整型变量typedef signed   char    int8;       // 有符号8位整型变量typedef unsigned short   u16;     // 无符号16位整型变量typedef signed   short   int16;      // 有符号16位整型变量typedef unsigned int     u32;     // 无符号32位整型变量typedef signed   int     int32;      // 有符号32位整型变量#ifdef __cplusplusextern "C" {#endif/** * Ring buffer type. * * The buffer is empty when head == tail. * * The buffer is full when the head is one byte in front of the tail, * modulo buffer length. * * One byte is left free to distinguish empty from full. */typedef struct ring_buffer {    volatile u8 *buf; /**< Buffer items are stored into */    u16 head;         /**< Index of the next item to remove */    u16 tail;         /**< Index where the next item will get inserted */    u16 size;         /**< Buffer capacity minus one */} ring_buffer;typedef struct ring_buffer16 {    volatile u16 *buf; /**< Buffer items are stored into */    u16 head;         /**< Index of the next item to remove */    u16 tail;         /**< Index where the next item will get inserted */    u16 size;         /**< Buffer capacity minus one */} ring_buffer16;/** * Initialise a ring buffer. * *  @param rb   Instance to initialise * *  @param size Number of items in buf.  The ring buffer will always *              leave one element unoccupied, so the maximum number of *              elements it can store will be size - 1.  Thus, size *              must be at least 2. * *  @param buf  Buffer to store items into */static inline void rb_init(ring_buffer *rb, u16 size, u8 *buf) {    rb->head = 0;    rb->tail = 0;    rb->size = size - 1;    rb->buf = buf;}static inline void rb_init16(ring_buffer16 *rb, u16 size, u16 *buf) {    rb->head = 0;    rb->tail = 0;    rb->size = size - 1;    rb->buf = buf;}/** * @brief Return the number of elements stored in the ring buffer. * @param rb Buffer whose elements to count. */static inline u16 rb_full_count(ring_buffer *rb) {    volatile ring_buffer *arb = rb;    u32 size = arb->tail - arb->head;    if (arb->tail < arb->head) {        size += arb->size + 1;    }    return (u16)size;}static inline u16 rb_full_count16(ring_buffer16 *rb) {    volatile ring_buffer16 *arb = rb;    u32 size = arb->tail - arb->head;    if (arb->tail < arb->head) {        size += arb->size + 1;    }    return (u16)size;}/** * @brief Returns true if and only if the ring buffer is full. * @param rb Buffer to test. */static inline int rb_is_full(ring_buffer *rb) {    return (rb->tail + 1 == rb->head) ||           (rb->tail == rb->size && rb->head == 0);}static inline int rb_is_full16(ring_buffer16 *rb) {    return (rb->tail + 1 == rb->head) ||           (rb->tail == rb->size && rb->head == 0);}/** * @brief Returns true if and only if the ring buffer is empty. * @param rb Buffer to test. */static inline int rb_is_empty(ring_buffer *rb) {    return rb->head == rb->tail;}static inline int rb_is_empty16(ring_buffer16 *rb) {    return rb->head == rb->tail;}/** * Append element onto the end of a ring buffer. * @param rb Buffer to append onto. * @param element Value to append. */static inline void rb_insert(ring_buffer *rb, u8 element) {    rb->buf[rb->tail] = element;    rb->tail = (rb->tail == rb->size) ? 0 : rb->tail + 1;}static inline void rb_insert16(ring_buffer16 *rb, u16 element) {    rb->buf[rb->tail] = element;    rb->tail = (rb->tail == rb->size) ? 0 : rb->tail + 1;}/** * @brief Remove and return the first item from a ring buffer. * @param rb Buffer to remove from, must contain at least one element. */static inline u8 rb_remove(ring_buffer *rb) {    u8 ch = rb->buf[rb->head];    rb->head = (rb->head == rb->size) ? 0 : rb->head + 1;    return ch;}static inline u16 rb_remove16(ring_buffer16 *rb) {    u8 ch = rb->buf[rb->head];    rb->head = (rb->head == rb->size) ? 0 : rb->head + 1;    return ch;}static inline u8 rb_peek(ring_buffer *rb) {    u8 ch = rb->buf[rb->head];    return ch;}static inline u8 rb_peek_byCount(ring_buffer *rb,u8 str[]) {    u8 x;    x=0;    if (rb->buf[rb->head]==0x7E && rb_full_count(rb)>rb->buf[rb->head+1])    {        for(int i=0; i<rb->buf[rb->head+1]; i++)        {            str[i] = rb->buf[rb->head+i];            x++;        }    }    return x;}static inline u16 rb_peek16(ring_buffer16 *rb) {    u8 ch = rb->buf[rb->head];    return ch;}/** * @brief Attempt to remove the first item from a ring buffer. * * If the ring buffer is nonempty, removes and returns its first item. * If it is empty, does nothing and returns a negative value. * * @param rb Buffer to attempt to remove from. */static inline int16 rb_safe_remove(ring_buffer *rb) {    return rb_is_empty(rb) ? -1 : rb_remove(rb);}static inline int16 rb_safe_remove16(ring_buffer16 *rb) {    return rb_is_empty16(rb) ? -1 : rb_remove16(rb);}/** * @brief Attempt to insert an element into a ring buffer. * * @param rb Buffer to insert into. * @param element Value to insert into rb. * @sideeffect If rb is not full, appends element onto buffer. * @return If element was appended, then true; otherwise, false. */static inline int rb_safe_insert(ring_buffer *rb, u8 element) {    if (rb_is_full(rb)) {        return 0;    }    rb_insert(rb, element);    return 1;}static inline int rb_safe_insert16(ring_buffer16 *rb, u16 element) {    if (rb_is_full16(rb)) {        return 0;    }    rb_insert16(rb, element);    return 1;}/** * @brief Append an item onto the end of a non-full ring buffer. * * If the buffer is full, removes its first item, then inserts the new * element at the end. * * @param rb Ring buffer to insert into. * @param element Value to insert into ring buffer. * @return On success, returns -1.  If an element was popped, returns *         the popped value. */static inline int rb_push_insert(ring_buffer *rb, u8 element) {    int ret = -1;    if (rb_is_full(rb)) {        ret = rb_remove(rb);    }    rb_insert(rb, element);    return ret;}static inline int rb_push_insert16(ring_buffer16 *rb, u16 element) {    int ret = -1;    if (rb_is_full16(rb)) {        ret = rb_remove16(rb);    }    rb_insert16(rb, element);    return ret;}/** * @brief Discard all items from a ring buffer. * @param rb Ring buffer to discard all items from. */static inline void rb_reset(ring_buffer *rb) {    rb->tail = rb->head;}static inline void rb_reset16(ring_buffer16 *rb) {    rb->tail = rb->head;}#ifdef __cplusplus} // extern "C"#endif#endif
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