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