[lttng-tools.git] / src / common / buffer-view.h

/*
 * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#ifndef LTTNG_BUFFER_VIEW_H
#define LTTNG_BUFFER_VIEW_H

#include <stddef.h>
#include <stdint.h>
#include <common/macros.h>

struct lttng_dynamic_buffer;

struct lttng_buffer_view {
	const char *data;
	size_t size;
};

/**
 * Return a buffer view referencing a subset of the memory referenced by a raw
 * pointer.
 *
 * @src		Source buffer to reference
 * @offset	Offset to apply to the source memory buffer
 * @len		Length of the memory contents to reference.
 *
 * Note that a buffer view never assumes the ownership of the memory it
 * references.
 */
LTTNG_HIDDEN
struct lttng_buffer_view lttng_buffer_view_init(
		const char *src, size_t offset, ptrdiff_t len);

/**
 * Return a buffer view referencing a subset of the memory referenced by another
 * view.
 *
 * @src		Source view to reference
 * @offset	Offset to apply to the source memory content
 * @len		Length of the memory contents to reference. Passing -1 will
 *		cause the view to reference the whole view from the offset
 *		provided.
 *
 * Note that a buffer view never assumes the ownership of the memory it
 * references.
 */
LTTNG_HIDDEN
struct lttng_buffer_view lttng_buffer_view_from_view(
		const struct lttng_buffer_view *src, size_t offset,
		ptrdiff_t len);

/**
 * Return a buffer view referencing a subset of the memory referenced by a
 * dynamic buffer.
 *
 * @src		Source dynamic buffer to reference
 * @offset	Offset to apply to the source memory content
 * @len		Length of the memory contents to reference. Passing -1 will
 *		cause the view to reference the whole dynamic buffer from the
 *		offset provided.
 *
 * Note that a buffer view never assumes the ownership of the memory it
 * references.
 */
LTTNG_HIDDEN
struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
		const struct lttng_dynamic_buffer *src, size_t offset,
		ptrdiff_t len);

#endif /* LTTNG_BUFFER_VIEW_H */
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
	3	*
	4	* SPDX-License-Identifier: LGPL-2.1-only
	5	*
	6	*/
	7
	8	#ifndef LTTNG_BUFFER_VIEW_H
	9	#define LTTNG_BUFFER_VIEW_H
	10
	11	#include <stddef.h>
	12	#include <stdint.h>
	13	#include <common/macros.h>
	14
	15	struct lttng_dynamic_buffer;
	16
	17	struct lttng_buffer_view {
	18	const char *data;
	19	size_t size;
	20	};
	21
	22	/**
	23	* Return a buffer view referencing a subset of the memory referenced by a raw
	24	* pointer.
	25	*
	26	* @src Source buffer to reference
	27	* @offset Offset to apply to the source memory buffer
	28	* @len Length of the memory contents to reference.
	29	*
	30	* Note that a buffer view never assumes the ownership of the memory it
	31	* references.
	32	*/
	33	LTTNG_HIDDEN
	34	struct lttng_buffer_view lttng_buffer_view_init(
	35	const char *src, size_t offset, ptrdiff_t len);
	36
	37	/**
	38	* Return a buffer view referencing a subset of the memory referenced by another
	39	* view.
	40	*
	41	* @src Source view to reference
	42	* @offset Offset to apply to the source memory content
	43	* @len Length of the memory contents to reference. Passing -1 will
	44	* cause the view to reference the whole view from the offset
	45	* provided.
	46	*
	47	* Note that a buffer view never assumes the ownership of the memory it
	48	* references.
	49	*/
	50	LTTNG_HIDDEN
	51	struct lttng_buffer_view lttng_buffer_view_from_view(
	52	const struct lttng_buffer_view *src, size_t offset,
	53	ptrdiff_t len);
	54
	55	/**
	56	* Return a buffer view referencing a subset of the memory referenced by a
	57	* dynamic buffer.
	58	*
	59	* @src Source dynamic buffer to reference
	60	* @offset Offset to apply to the source memory content
	61	* @len Length of the memory contents to reference. Passing -1 will
	62	* cause the view to reference the whole dynamic buffer from the
	63	* offset provided.
	64	*
	65	* Note that a buffer view never assumes the ownership of the memory it
	66	* references.
	67	*/
	68	LTTNG_HIDDEN
	69	struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
	70	const struct lttng_dynamic_buffer *src, size_t offset,
	71	ptrdiff_t len);
	72
	73	#endif /* LTTNG_BUFFER_VIEW_H */