1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677 |
- #ifndef RINGBUFFER_H
- #define RINGBUFFER_H
- #include <stddef.h>
- #ifdef __cplusplus
- extern "C" {
- #endif
- typedef struct ll_ringbuffer ll_ringbuffer_t;
- typedef struct ll_ringbuffer_data {
- char *buf;
- size_t len;
- } ll_ringbuffer_data_t;
- /**
- * Create a new ringbuffer to hold at least `sz' elements of `elem_sz' bytes.
- * The number of elements is rounded up to the next power of two (even if it is
- * already a power of two, to ensure the requested amount can be written).
- */
- ll_ringbuffer_t *ll_ringbuffer_create(size_t sz, size_t elem_sz, int limit_writes);
- /** Free all data associated with the ringbuffer `rb'. */
- void ll_ringbuffer_free(ll_ringbuffer_t *rb);
- /** Reset the read and write pointers to zero. This is not thread safe. */
- void ll_ringbuffer_reset(ll_ringbuffer_t *rb);
- /**
- * The non-copying data reader. `vec' is an array of two places. Set the values
- * at `vec' to hold the current readable data at `rb'. If the readable data is
- * in one segment the second segment has zero length.
- */
- void ll_ringbuffer_get_read_vector(const ll_ringbuffer_t *rb, ll_ringbuffer_data_t vec[2]);
- /**
- * The non-copying data writer. `vec' is an array of two places. Set the values
- * at `vec' to hold the current writeable data at `rb'. If the writeable data
- * is in one segment the second segment has zero length.
- */
- void ll_ringbuffer_get_write_vector(const ll_ringbuffer_t *rb, ll_ringbuffer_data_t vec[2]);
- /**
- * Return the number of elements available for reading. This is the number of
- * elements in front of the read pointer and behind the write pointer.
- */
- size_t ll_ringbuffer_read_space(const ll_ringbuffer_t *rb);
- /**
- * The copying data reader. Copy at most `cnt' elements from `rb' to `dest'.
- * Returns the actual number of elements copied.
- */
- size_t ll_ringbuffer_read(ll_ringbuffer_t *rb, char *dest, size_t cnt);
- /**
- * The copying data reader w/o read pointer advance. Copy at most `cnt'
- * elements from `rb' to `dest'. Returns the actual number of elements copied.
- */
- size_t ll_ringbuffer_peek(ll_ringbuffer_t *rb, char *dest, size_t cnt);
- /** Advance the read pointer `cnt' places. */
- void ll_ringbuffer_read_advance(ll_ringbuffer_t *rb, size_t cnt);
- /**
- * Return the number of elements available for writing. This is the number of
- * elements in front of the write pointer and behind the read pointer.
- */
- size_t ll_ringbuffer_write_space(const ll_ringbuffer_t *rb);
- /**
- * The copying data writer. Copy at most `cnt' elements to `rb' from `src'.
- * Returns the actual number of elements copied.
- */
- size_t ll_ringbuffer_write(ll_ringbuffer_t *rb, const char *src, size_t cnt);
- /** Advance the write pointer `cnt' places. */
- void ll_ringbuffer_write_advance(ll_ringbuffer_t *rb, size_t cnt);
- #ifdef __cplusplus
- } /* extern "C" */
- #endif
- #endif /* RINGBUFFER_H */
|