[lttng-tools.git] / src / bin / lttng-relayd / tracefile-array.h

#ifndef _TRACEFILE_ARRAY_H
#define _TRACEFILE_ARRAY_H

/*
 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#include <limits.h>
#include <inttypes.h>
#include <pthread.h>
#include <stdbool.h>

struct tracefile {
	/* Per-tracefile head/tail seq. */
	uint64_t seq_head;	/* Newest seqcount. Inclusive. */
	uint64_t seq_tail;	/* Oldest seqcount. Inclusive. */
};

enum tracefile_rotate_type {
	TRACEFILE_ROTATE_READ,
	TRACEFILE_ROTATE_WRITE,
};

/*
 * Represents an array of trace files in a stream.
 * head is the most recent file/trace packet.
 * tail is the oldest file/trace packet.
 *
 * There are two heads: a "read" head and a "write" head. The "write" head is
 * the position of the newest data file. The "read" head position is only moved
 * forward when the index is received.
 *
 * The viewer uses the "read" head position as upper bound, which
 * ensures it never attempts to open a non-existing index file.
 */
struct tracefile_array {
	struct tracefile *tf;
	size_t count;

	/* Current head/tail files. */
	uint64_t file_head_read;
	uint64_t file_head_write;
	uint64_t file_tail;

	/* Overall head/tail seq for the entire array. Inclusive. */
	uint64_t seq_head;
	uint64_t seq_tail;
};

struct tracefile_array *tracefile_array_create(size_t count);
void tracefile_array_destroy(struct tracefile_array *tfa);

void tracefile_array_file_rotate(struct tracefile_array *tfa, enum tracefile_rotate_type type);
void tracefile_array_commit_seq(struct tracefile_array *tfa,
		uint64_t new_seq_head);
void tracefile_array_reset(struct tracefile_array *tfa);

uint64_t tracefile_array_get_read_file_index_head(struct tracefile_array *tfa);
/* May return -1ULL in the case where we have not received any indexes yet. */
uint64_t tracefile_array_get_seq_head(struct tracefile_array *tfa);

uint64_t tracefile_array_get_file_index_tail(struct tracefile_array *tfa);
/* May return -1ULL in the case where we have not received any indexes yet. */
uint64_t tracefile_array_get_seq_tail(struct tracefile_array *tfa);

bool tracefile_array_seq_in_file(struct tracefile_array *tfa,
		uint64_t file_index, uint64_t seq);

#endif /* _STREAM_H */
Commit	Line	Data
a44ca2ca MD	1	#ifndef _TRACEFILE_ARRAY_H
	2	#define _TRACEFILE_ARRAY_H
	3
	4	/*
ab5be9fa	5	* Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
a44ca2ca	6	*
ab5be9fa	7	* SPDX-License-Identifier: GPL-2.0-only
a44ca2ca	8	*
a44ca2ca MD	9	*/
	10
	11	#include <limits.h>
	12	#include <inttypes.h>
	13	#include <pthread.h>
	14	#include <stdbool.h>
	15
	16	struct tracefile {
	17	/* Per-tracefile head/tail seq. */
	18	uint64_t seq_head; /* Newest seqcount. Inclusive. */
	19	uint64_t seq_tail; /* Oldest seqcount. Inclusive. */
	20	};
	21
78118e3b MD	22	enum tracefile_rotate_type {
	23	TRACEFILE_ROTATE_READ,
	24	TRACEFILE_ROTATE_WRITE,
	25	};
	26
a44ca2ca MD	27	/*
a44ca2ca MD	28	* Represents an array of trace files in a stream.
78118e3b MD	29	* head is the most recent file/trace packet.
	30	* tail is the oldest file/trace packet.
	31	*
	32	* There are two heads: a "read" head and a "write" head. The "write" head is
	33	* the position of the newest data file. The "read" head position is only moved
	34	* forward when the index is received.
	35	*
	36	* The viewer uses the "read" head position as upper bound, which
	37	* ensures it never attempts to open a non-existing index file.
a44ca2ca MD	38	*/
	39	struct tracefile_array {
	40	struct tracefile *tf;
	41	size_t count;
	42
	43	/* Current head/tail files. */
78118e3b MD	44	uint64_t file_head_read;
78118e3b MD	45	uint64_t file_head_write;
a44ca2ca MD	46	uint64_t file_tail;
	47
	48	/* Overall head/tail seq for the entire array. Inclusive. */
	49	uint64_t seq_head;
	50	uint64_t seq_tail;
	51	};
	52
	53	struct tracefile_array *tracefile_array_create(size_t count);
	54	void tracefile_array_destroy(struct tracefile_array *tfa);
	55
78118e3b	56	void tracefile_array_file_rotate(struct tracefile_array *tfa, enum tracefile_rotate_type type);
62f6e9ef MD	57	void tracefile_array_commit_seq(struct tracefile_array *tfa,
62f6e9ef MD	58	uint64_t new_seq_head);
c31a8092	59	void tracefile_array_reset(struct tracefile_array *tfa);
a44ca2ca	60
78118e3b	61	uint64_t tracefile_array_get_read_file_index_head(struct tracefile_array *tfa);
a44ca2ca MD	62	/* May return -1ULL in the case where we have not received any indexes yet. */
	63	uint64_t tracefile_array_get_seq_head(struct tracefile_array *tfa);
	64
	65	uint64_t tracefile_array_get_file_index_tail(struct tracefile_array *tfa);
	66	/* May return -1ULL in the case where we have not received any indexes yet. */
	67	uint64_t tracefile_array_get_seq_tail(struct tracefile_array *tfa);
	68
	69	bool tracefile_array_seq_in_file(struct tracefile_array *tfa,
	70	uint64_t file_index, uint64_t seq);
	71
	72	#endif /* _STREAM_H */