haiku/headers/private/kernel/util/ring_buffer.h
Ingo Weinhold 546f4e5e05 * Added create_ring_buffer_etc() which allows to re-create a ring buffer from
a given flat buffer.
* Added ring_buffer_peek() for random position reading from the ring buffer
  without changing its state.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35813 a95241bf-73f2-0310-859d-f6bbb57e9c96
2010-03-11 17:12:21 +00:00

50 lines
1.3 KiB
C

/*
* Copyright 2005, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
* Distributed under the terms of the MIT License.
*/
#ifndef RING_BUFFER_H
#define RING_BUFFER_H
#include <OS.h>
struct ring_buffer {
int32 first;
int32 in;
int32 size;
uint8 buffer[0];
};
// flags for create_ring_buffer_etc()
#define RING_BUFFER_INIT_FROM_BUFFER 0x01
#ifdef __cplusplus
extern "C" {
#endif
struct ring_buffer *create_ring_buffer(size_t size);
struct ring_buffer *create_ring_buffer_etc(void *memory, size_t size,
uint32 flags);
void delete_ring_buffer(struct ring_buffer *buffer);
void ring_buffer_clear(struct ring_buffer *buffer);
size_t ring_buffer_readable(struct ring_buffer *buffer);
size_t ring_buffer_writable(struct ring_buffer *buffer);
void ring_buffer_flush(struct ring_buffer *buffer, size_t bytes);
size_t ring_buffer_read(struct ring_buffer *buffer, uint8 *data, ssize_t length);
size_t ring_buffer_write(struct ring_buffer *buffer, const uint8 *data, ssize_t length);
ssize_t ring_buffer_user_read(struct ring_buffer *buffer, uint8 *data, ssize_t length);
ssize_t ring_buffer_user_write(struct ring_buffer *buffer, const uint8 *data, ssize_t length);
size_t ring_buffer_peek(struct ring_buffer *buffer, size_t offset, void *data,
size_t length);
#ifdef __cplusplus
}
#endif
#endif /* RING_BUFFER_H */