diff --git a/kernel-src/include/ringbuffer.h b/kernel-src/include/ringbuffer.h index f53a3f63..9164f8d5 100644 --- a/kernel-src/include/ringbuffer.h +++ b/kernel-src/include/ringbuffer.h @@ -11,13 +11,36 @@ typedef struct { void *data; } ringbuffer_t; +// initializes a ring buffer with a specific size +// returns an errno or 0 if successful int ringbuffer_init(ringbuffer_t *ringbuffer, size_t size); + +// destroys the ring buffer and frees the memory void ringbuffer_destroy(ringbuffer_t *ringbuffer); + +// reads count bytes from ring buffer into buffer +// returns -1 if it was unable to read (due to EFAULT when copying a user page) +// otherwise returns the number of bytes read size_t ringbuffer_read(ringbuffer_t* ringbuffer, void *buffer, size_t count); + +// writes count bytes from buffer into ring buffer +// returns -1 if it was unable to write (due to EFAULT when copying a user page) +// otherwise returns the number of bytes read size_t ringbuffer_write(ringbuffer_t* ringbuffer, void *buffer, size_t count); + +// removes count bytes from the read end (read goes forward) +// returns the number of bytes truncated size_t ringbuffer_truncate(ringbuffer_t *ringbuffer, size_t count); + +// same as ringbuffer_read, but accepts an offset and does not update the read pointer +// returns -1 if it was unable to read (due to EFAULT when copying a user page) +// otherwise returns the number of bytes read size_t ringbuffer_peek(ringbuffer_t *ringbuffer, void *buffer, uintmax_t offset, size_t count); +// removes count bytes from the write end (write goes backwards) +// returns the number of bytes removed +size_t ringbuffer_remove(ringbuffer_t *ringbuffer, size_t count); + #define RINGBUFFER_DATACOUNT(x) ((x)->write - (x)->read) #define RINGBUFFER_SIZE(x) (x)->size #define RINGBUFFER_FREESPACE(x) (RINGBUFFER_SIZE(x) - RINGBUFFER_DATACOUNT(x)) diff --git a/kernel-src/lib/ringbuffer.c b/kernel-src/lib/ringbuffer.c index d8d870c6..c81e1bfc 100644 --- a/kernel-src/lib/ringbuffer.c +++ b/kernel-src/lib/ringbuffer.c @@ -86,3 +86,9 @@ size_t ringbuffer_write(ringbuffer_t *ringbuffer, void *buffer, size_t count) { ringbuffer->write += count; return count; } + +size_t ringbuffer_remove(ringbuffer_t *ringbuffer, size_t count) { + size_t true_count = min(RINGBUFFER_DATACOUNT(ringbuffer), count); + ringbuffer->write -= true_count; + return true_count; +}