[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 <common/macros.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.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);

/**
 * Checks if a buffer view is safe to access.
 *
 * After calling the buffer view creation functions, callers should verify
 * if the resquested length (if any is explicitly provided) could be mapped
 * to a new view.
 *
 * @view	Buffer view to validate
 */
LTTNG_HIDDEN
bool lttng_buffer_view_is_valid(const struct lttng_buffer_view *view);

/**
 * 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);

/**
 * Verify that `buf` contains a string starting at `str` of length
 * `len_with_null_terminator`.
 *
 * @buf				The buffer view
 * @str				The start of the string
 * @len_with_null_terminator	Expected length of the string, including the
 * 				NULL terminator.
 */
LTTNG_HIDDEN
bool lttng_buffer_view_contains_string(const struct lttng_buffer_view *buf,
		const char *str,
		size_t len_with_null_terminator);

#endif /* LTTNG_BUFFER_VIEW_H */
Commit	Line	Data
01dc0eed	1	/*
ab5be9fa	2	* Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
01dc0eed	3	*
ab5be9fa	4	* SPDX-License-Identifier: LGPL-2.1-only
01dc0eed	5	*
01dc0eed JG	6	*/
	7
	8	#ifndef LTTNG_BUFFER_VIEW_H
	9	#define LTTNG_BUFFER_VIEW_H
	10
67d8e2ef SM	11	#include <common/macros.h>
67d8e2ef SM	12	#include <stdbool.h>
01dc0eed JG	13	#include <stddef.h>
	14	#include <stdint.h>
	15
	16	struct lttng_dynamic_buffer;
	17
	18	struct lttng_buffer_view {
	19	const char *data;
	20	size_t size;
	21	};
	22
b35aac84 JG	23	/**
	24	* Return a buffer view referencing a subset of the memory referenced by a raw
	25	* pointer.
	26	*
	27	* @src Source buffer to reference
	28	* @offset Offset to apply to the source memory buffer
	29	* @len Length of the memory contents to reference.
	30	*
	31	* Note that a buffer view never assumes the ownership of the memory it
	32	* references.
	33	*/
	34	LTTNG_HIDDEN
	35	struct lttng_buffer_view lttng_buffer_view_init(
	36	const char *src, size_t offset, ptrdiff_t len);
	37
3e6e0df2 JG	38	/**
	39	* Checks if a buffer view is safe to access.
	40	*
	41	* After calling the buffer view creation functions, callers should verify
	42	* if the resquested length (if any is explicitly provided) could be mapped
	43	* to a new view.
b2530e4d JG	44	*
b2530e4d JG	45	* @view Buffer view to validate
3e6e0df2 JG	46	*/
	47	LTTNG_HIDDEN
	48	bool lttng_buffer_view_is_valid(const struct lttng_buffer_view *view);
	49
01dc0eed JG	50	/**
	51	* Return a buffer view referencing a subset of the memory referenced by another
	52	* view.
	53	*
	54	* @src Source view to reference
	55	* @offset Offset to apply to the source memory content
	56	* @len Length of the memory contents to reference. Passing -1 will
	57	* cause the view to reference the whole view from the offset
	58	* provided.
	59	*
	60	* Note that a buffer view never assumes the ownership of the memory it
	61	* references.
	62	*/
ff28f865	63	LTTNG_HIDDEN
01dc0eed JG	64	struct lttng_buffer_view lttng_buffer_view_from_view(
	65	const struct lttng_buffer_view *src, size_t offset,
	66	ptrdiff_t len);
	67
	68	/**
	69	* Return a buffer view referencing a subset of the memory referenced by a
	70	* dynamic buffer.
	71	*
	72	* @src Source dynamic buffer to reference
	73	* @offset Offset to apply to the source memory content
	74	* @len Length of the memory contents to reference. Passing -1 will
	75	* cause the view to reference the whole dynamic buffer from the
	76	* offset provided.
	77	*
	78	* Note that a buffer view never assumes the ownership of the memory it
	79	* references.
	80	*/
ff28f865	81	LTTNG_HIDDEN
01dc0eed JG	82	struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
	83	const struct lttng_dynamic_buffer *src, size_t offset,
	84	ptrdiff_t len);
	85
67d8e2ef SM	86	/**
	87	* Verify that `buf` contains a string starting at `str` of length
	88	* `len_with_null_terminator`.
	89	*
	90	* @buf The buffer view
	91	* @str The start of the string
	92	* @len_with_null_terminator Expected length of the string, including the
	93	* NULL terminator.
	94	*/
	95	LTTNG_HIDDEN
	96	bool lttng_buffer_view_contains_string(const struct lttng_buffer_view *buf,
	97	const char *str,
	98	size_t len_with_null_terminator);
	99
01dc0eed	100	#endif /* LTTNG_BUFFER_VIEW_H */