[lttng-tools.git] / src / bin / lttng-relayd / viewer-stream.c

/*
 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
 *                      David Goulet <dgoulet@efficios.com>
 *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License, version 2 only, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _LGPL_SOURCE
#include <common/common.h>
#include <common/index/index.h>
#include <common/compat/string.h>
#include <common/utils.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include "lttng-relayd.h"
#include "viewer-stream.h"

static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
{
	free(vstream->path_name);
	free(vstream->channel_name);
	free(vstream);
}

static void viewer_stream_destroy_rcu(struct rcu_head *head)
{
	struct relay_viewer_stream *vstream =
		caa_container_of(head, struct relay_viewer_stream, rcu_node);

	viewer_stream_destroy(vstream);
}

struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
		struct lttng_trace_chunk *viewer_trace_chunk,
		enum lttng_viewer_seek seek_t)
{
	struct relay_viewer_stream *vstream = NULL;
	const bool acquired_reference = lttng_trace_chunk_get(
			viewer_trace_chunk);

	if (!acquired_reference) {
		goto error;
	}

	vstream = zmalloc(sizeof(*vstream));
	if (!vstream) {
		PERROR("relay viewer stream zmalloc");
		goto error;
	}

	vstream->stream_file.trace_chunk = viewer_trace_chunk;
	viewer_trace_chunk = NULL;
	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
	if (vstream->path_name == NULL) {
		PERROR("relay viewer path_name alloc");
		goto error;
	}
	vstream->channel_name = lttng_strndup(stream->channel_name,
			LTTNG_VIEWER_NAME_MAX);
	if (vstream->channel_name == NULL) {
		PERROR("relay viewer channel_name alloc");
		goto error;
	}

	if (!stream_get(stream)) {
		ERR("Cannot get stream");
		goto error;
	}
	vstream->stream = stream;

	pthread_mutex_lock(&stream->lock);

	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
		ERR("Cannot attach viewer metadata stream to trace (busy).");
		goto error_unlock;
	}

	switch (seek_t) {
	case LTTNG_VIEWER_SEEK_BEGINNING:
	{
		uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);

		if (seq_tail == -1ULL) {
			/*
			 * Tail may not be initialized yet. Nonetheless, we know
			 * we want to send the first index once it becomes
			 * available.
			 */
			seq_tail = 0;
		}
		vstream->current_tracefile_id =
			tracefile_array_get_file_index_tail(stream->tfa);
		vstream->index_sent_seqcount = seq_tail;
		break;
	}
	case LTTNG_VIEWER_SEEK_LAST:
		vstream->current_tracefile_id =
			tracefile_array_get_read_file_index_head(stream->tfa);
		/*
		 * We seek at the very end of each stream, awaiting for
		 * a future packet to eventually come in.
		 *
		 * We don't need to check the head position for -1ULL since the
		 * increment will set it to 0.
		 */
		vstream->index_sent_seqcount =
				tracefile_array_get_seq_head(stream->tfa) + 1;
		break;
	default:
		goto error_unlock;
	}

	/*
	 * If we never received an index for the current stream, delay
	 * the opening of the index, otherwise open it right now.
	 */
	if (stream->index_file == NULL) {
		vstream->index_file = NULL;
	} else {
		const uint32_t connection_major = stream->trace->session->major;
		const uint32_t connection_minor = stream->trace->session->minor;
		enum lttng_trace_chunk_status chunk_status;

		chunk_status = lttng_index_file_create_from_trace_chunk_read_only(
				vstream->stream_file.trace_chunk,
				stream->path_name,
				stream->channel_name, stream->tracefile_size,
				vstream->current_tracefile_id,
				lttng_to_index_major(connection_major,
						connection_minor),
				lttng_to_index_minor(connection_major,
						connection_minor),
				true, &vstream->index_file);
		if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
			if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_NO_FILE) {
				vstream->index_file = NULL;
			} else {
				goto error_unlock;
			}
		}
	}

	/*
	 * If we never received a data file for the current stream, delay the
	 * opening, otherwise open it right now.
	 */
	if (stream->file) {
		int ret;
		char file_path[LTTNG_PATH_MAX];
		enum lttng_trace_chunk_status status;

		ret = utils_stream_file_path(stream->path_name,
				stream->channel_name, stream->tracefile_size,
				vstream->current_tracefile_id, NULL, file_path,
				sizeof(file_path));
		if (ret < 0) {
			goto error_unlock;
		}

		status = lttng_trace_chunk_open_fs_handle(
				vstream->stream_file.trace_chunk, file_path,
				O_RDONLY, 0, &vstream->stream_file.handle,
				true);
		if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
			goto error_unlock;
		}
	}

	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
		off_t lseek_ret;

		lseek_ret = fs_handle_seek(
				vstream->index_file->file, 0, SEEK_END);
		if (lseek_ret < 0) {
			goto error_unlock;
		}
	}
	if (stream->is_metadata) {
		rcu_assign_pointer(stream->trace->viewer_metadata_stream,
				vstream);
	}
	pthread_mutex_unlock(&stream->lock);

	/* Globally visible after the add unique. */
	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
	urcu_ref_init(&vstream->ref);
	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);

	return vstream;

error_unlock:
	pthread_mutex_unlock(&stream->lock);
error:
	if (vstream) {
		viewer_stream_destroy(vstream);
	}
	if (viewer_trace_chunk && acquired_reference) {
		lttng_trace_chunk_put(viewer_trace_chunk);
	}
	return NULL;
}

static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
{
	int ret;
	struct lttng_ht_iter iter;

	iter.iter.node = &vstream->stream_n.node;
	ret = lttng_ht_del(viewer_streams_ht, &iter);
	assert(!ret);
}

static void viewer_stream_release(struct urcu_ref *ref)
{
	struct relay_viewer_stream *vstream = caa_container_of(ref,
			struct relay_viewer_stream, ref);

	if (vstream->stream->is_metadata) {
		rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
	}

	viewer_stream_unpublish(vstream);

	if (vstream->stream_file.handle) {
		fs_handle_close(vstream->stream_file.handle);
		vstream->stream_file.handle = NULL;
	}
	if (vstream->index_file) {
		lttng_index_file_put(vstream->index_file);
		vstream->index_file = NULL;
	}
	if (vstream->stream) {
		stream_put(vstream->stream);
		vstream->stream = NULL;
	}
	lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
	vstream->stream_file.trace_chunk = NULL;
	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
}

/* Must be called with RCU read-side lock held. */
bool viewer_stream_get(struct relay_viewer_stream *vstream)
{
	return urcu_ref_get_unless_zero(&vstream->ref);
}

/*
 * Get viewer stream by id.
 *
 * Return viewer stream if found else NULL.
 */
struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
{
	struct lttng_ht_node_u64 *node;
	struct lttng_ht_iter iter;
	struct relay_viewer_stream *vstream = NULL;

	rcu_read_lock();
	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	node = lttng_ht_iter_get_node_u64(&iter);
	if (!node) {
		DBG("Relay viewer stream %" PRIu64 " not found", id);
		goto end;
	}
	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	if (!viewer_stream_get(vstream)) {
		vstream = NULL;
	}
end:
	rcu_read_unlock();
	return vstream;
}

void viewer_stream_put(struct relay_viewer_stream *vstream)
{
	rcu_read_lock();
	urcu_ref_put(&vstream->ref, viewer_stream_release);
	rcu_read_unlock();
}

void viewer_stream_close_files(struct relay_viewer_stream *vstream)
{
	if (vstream->index_file) {
		lttng_index_file_put(vstream->index_file);
		vstream->index_file = NULL;
	}
	if (vstream->stream_file.handle) {
	        fs_handle_close(vstream->stream_file.handle);
		vstream->stream_file.handle = NULL;
	}
}

void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream *vstream)
{
	const struct relay_stream *stream = vstream->stream;
	uint64_t seq_tail;

	vstream->current_tracefile_id = tracefile_array_get_file_index_tail(stream->tfa);
	seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	if (seq_tail == -1ULL) {
		seq_tail = 0;
	}
	vstream->index_sent_seqcount = seq_tail;
}

/*
 * Rotate a stream to the next tracefile.
 *
 * Must be called with the rstream lock held.
 * Returns 0 on success, 1 on EOF.
 */
int viewer_stream_rotate(struct relay_viewer_stream *vstream)
{
	int ret;
	uint64_t new_id;
	const struct relay_stream *stream = vstream->stream;

	/* Detect the last tracefile to open. */
	if (stream->index_received_seqcount
			== vstream->index_sent_seqcount
			&& stream->trace->session->connection_closed) {
		ret = 1;
		goto end;
	}

	if (stream->tracefile_count == 0) {
		/* Ignore rotation, there is none to do. */
		ret = 0;
		goto end;
	}

	/*
	 * Try to move to the next file.
	 */
	new_id = (vstream->current_tracefile_id + 1)
			% stream->tracefile_count;
	if (tracefile_array_seq_in_file(stream->tfa, new_id,
			vstream->index_sent_seqcount)) {
		vstream->current_tracefile_id = new_id;
	} else {
		uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);

		/*
		 * This can only be reached on overwrite, which implies there
		 * has been data written at some point, which will have set the
		 * tail.
		 */
		assert(seq_tail != -1ULL);
		/*
		 * We need to resync because we lag behind tail.
		 */
		vstream->current_tracefile_id =
			tracefile_array_get_file_index_tail(stream->tfa);
		vstream->index_sent_seqcount = seq_tail;
	}
	viewer_stream_close_files(vstream);
	ret = 0;
end:
	return ret;
}

void print_viewer_streams(void)
{
	struct lttng_ht_iter iter;
	struct relay_viewer_stream *vstream;

	if (!viewer_streams_ht) {
		return;
	}

	rcu_read_lock();
	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
			stream_n.node) {
		if (!viewer_stream_get(vstream)) {
			continue;
		}
		DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
			" session %" PRIu64,
			vstream,
			vstream->ref.refcount,
			vstream->stream->stream_handle,
			vstream->stream->trace->id,
			vstream->stream->trace->session->id);
		viewer_stream_put(vstream);
	}
	rcu_read_unlock();
}
Commit	Line	Data
2f8f53af DG	1	/*
	2	* Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
	3	* David Goulet <dgoulet@efficios.com>
7591bab1	4	* 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2f8f53af DG	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License, version 2 only, as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along with
	16	* this program; if not, write to the Free Software Foundation, Inc., 51
	17	* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	18	*/
	19
6c1c0768	20	#define _LGPL_SOURCE
2f8f53af DG	21	#include <common/common.h>
2f8f53af DG	22	#include <common/index/index.h>
f5436bfc	23	#include <common/compat/string.h>
b0d240a2 MD	24	#include <common/utils.h>
	25	#include <sys/types.h>
	26	#include <sys/stat.h>
	27	#include <fcntl.h>
2f8f53af DG	28
	29	#include "lttng-relayd.h"
	30	#include "viewer-stream.h"
	31
7591bab1	32	static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
2f8f53af	33	{
7591bab1 MD	34	free(vstream->path_name);
	35	free(vstream->channel_name);
	36	free(vstream);
2f8f53af DG	37	}
2f8f53af DG	38
7591bab1	39	static void viewer_stream_destroy_rcu(struct rcu_head *head)
2f8f53af	40	{
7591bab1	41	struct relay_viewer_stream *vstream =
2f8f53af DG	42	caa_container_of(head, struct relay_viewer_stream, rcu_node);
2f8f53af DG	43
7591bab1	44	viewer_stream_destroy(vstream);
2f8f53af DG	45	}
	46
	47	struct relay_viewer_stream viewer_stream_create(struct relay_stream stream,
b66a15d1	48	struct lttng_trace_chunk *viewer_trace_chunk,
7591bab1	49	enum lttng_viewer_seek seek_t)
2f8f53af	50	{
ebb29c10 JG	51	struct relay_viewer_stream *vstream = NULL;
ebb29c10 JG	52	const bool acquired_reference = lttng_trace_chunk_get(
b66a15d1	53	viewer_trace_chunk);
ebb29c10 JG	54
	55	if (!acquired_reference) {
	56	goto error;
	57	}
2f8f53af	58
2f8f53af DG	59	vstream = zmalloc(sizeof(*vstream));
	60	if (!vstream) {
	61	PERROR("relay viewer stream zmalloc");
	62	goto error;
	63	}
	64
b66a15d1 JG	65	vstream->stream_file.trace_chunk = viewer_trace_chunk;
b66a15d1 JG	66	viewer_trace_chunk = NULL;
f5436bfc	67	vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
b272577e MD	68	if (vstream->path_name == NULL) {
	69	PERROR("relay viewer path_name alloc");
	70	goto error;
	71	}
f5436bfc	72	vstream->channel_name = lttng_strndup(stream->channel_name,
2f8f53af	73	LTTNG_VIEWER_NAME_MAX);
b272577e MD	74	if (vstream->channel_name == NULL) {
	75	PERROR("relay viewer channel_name alloc");
	76	goto error;
	77	}
2f8f53af	78
a44ca2ca MD	79	if (!stream_get(stream)) {
	80	ERR("Cannot get stream");
	81	goto error;
	82	}
	83	vstream->stream = stream;
	84
	85	pthread_mutex_lock(&stream->lock);
	86
	87	if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
	88	ERR("Cannot attach viewer metadata stream to trace (busy).");
	89	goto error_unlock;
	90	}
	91
2f8f53af	92	switch (seek_t) {
c4e361a4	93	case LTTNG_VIEWER_SEEK_BEGINNING:
a44ca2ca MD	94	{
	95	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	96
	97	if (seq_tail == -1ULL) {
	98	/*
	99	* Tail may not be initialized yet. Nonetheless, we know
	100	* we want to send the first index once it becomes
	101	* available.
	102	*/
	103	seq_tail = 0;
	104	}
	105	vstream->current_tracefile_id =
	106	tracefile_array_get_file_index_tail(stream->tfa);
	107	vstream->index_sent_seqcount = seq_tail;
2f8f53af	108	break;
a44ca2ca	109	}
c4e361a4	110	case LTTNG_VIEWER_SEEK_LAST:
a44ca2ca	111	vstream->current_tracefile_id =
78118e3b	112	tracefile_array_get_read_file_index_head(stream->tfa);
a44ca2ca MD	113	/*
	114	* We seek at the very end of each stream, awaiting for
	115	* a future packet to eventually come in.
	116	*
	117	* We don't need to check the head position for -1ULL since the
	118	* increment will set it to 0.
	119	*/
	120	vstream->index_sent_seqcount =
	121	tracefile_array_get_seq_head(stream->tfa) + 1;
2f8f53af DG	122	break;
2f8f53af DG	123	default:
a44ca2ca	124	goto error_unlock;
2f8f53af	125	}
2f8f53af	126
2f8f53af	127	/*
a44ca2ca MD	128	* If we never received an index for the current stream, delay
a44ca2ca MD	129	* the opening of the index, otherwise open it right now.
2f8f53af	130	*/
b0d240a2	131	if (stream->index_file == NULL) {
f8f3885c	132	vstream->index_file = NULL;
2f8f53af	133	} else {
ebb29c10 JG	134	const uint32_t connection_major = stream->trace->session->major;
ebb29c10 JG	135	const uint32_t connection_minor = stream->trace->session->minor;
3ff5c5db	136	enum lttng_trace_chunk_status chunk_status;
ebb29c10	137
3ff5c5db	138	chunk_status = lttng_index_file_create_from_trace_chunk_read_only(
b66a15d1 JG	139	vstream->stream_file.trace_chunk,
b66a15d1 JG	140	stream->path_name,
ebb29c10 JG	141	stream->channel_name, stream->tracefile_size,
	142	vstream->current_tracefile_id,
	143	lttng_to_index_major(connection_major,
	144	connection_minor),
	145	lttng_to_index_minor(connection_major,
3ff5c5db MD	146	connection_minor),
	147	true, &vstream->index_file);
	148	if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
	149	if (chunk_status == LTTNG_TRACE_CHUNK_STATUS_NO_FILE) {
	150	vstream->index_file = NULL;
	151	} else {
	152	goto error_unlock;
	153	}
2f8f53af	154	}
2f8f53af DG	155	}
2f8f53af DG	156
b0d240a2 MD	157	/*
	158	* If we never received a data file for the current stream, delay the
	159	* opening, otherwise open it right now.
	160	*/
8bb66c3c JG	161	if (stream->file) {
8bb66c3c JG	162	int ret;
b0d240a2 MD	163	char file_path[LTTNG_PATH_MAX];
	164	enum lttng_trace_chunk_status status;
	165
	166	ret = utils_stream_file_path(stream->path_name,
	167	stream->channel_name, stream->tracefile_size,
	168	vstream->current_tracefile_id, NULL, file_path,
	169	sizeof(file_path));
	170	if (ret < 0) {
	171	goto error_unlock;
	172	}
	173
8bb66c3c JG	174	status = lttng_trace_chunk_open_fs_handle(
	175	vstream->stream_file.trace_chunk, file_path,
	176	O_RDONLY, 0, &vstream->stream_file.handle,
	177	true);
b0d240a2 MD	178	if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
	179	goto error_unlock;
	180	}
b0d240a2 MD	181	}
b0d240a2 MD	182
f8f3885c	183	if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
2f8f53af DG	184	off_t lseek_ret;
2f8f53af DG	185
8bb66c3c JG	186	lseek_ret = fs_handle_seek(
8bb66c3c JG	187	vstream->index_file->file, 0, SEEK_END);
2f8f53af	188	if (lseek_ret < 0) {
7591bab1	189	goto error_unlock;
2f8f53af	190	}
7591bab1	191	}
7591bab1 MD	192	if (stream->is_metadata) {
	193	rcu_assign_pointer(stream->trace->viewer_metadata_stream,
	194	vstream);
2f8f53af	195	}
a44ca2ca	196	pthread_mutex_unlock(&stream->lock);
2f8f53af	197
7591bab1 MD	198	/* Globally visible after the add unique. */
7591bab1 MD	199	lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
7591bab1	200	urcu_ref_init(&vstream->ref);
c51b2177	201	lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
7591bab1	202
2f8f53af DG	203	return vstream;
2f8f53af DG	204
7591bab1 MD	205	error_unlock:
7591bab1 MD	206	pthread_mutex_unlock(&stream->lock);
2f8f53af DG	207	error:
2f8f53af DG	208	if (vstream) {
7591bab1	209	viewer_stream_destroy(vstream);
2f8f53af	210	}
e4650a96	211	if (viewer_trace_chunk && acquired_reference) {
b66a15d1 JG	212	lttng_trace_chunk_put(viewer_trace_chunk);
b66a15d1 JG	213	}
2f8f53af DG	214	return NULL;
	215	}
	216
7591bab1	217	static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
2f8f53af DG	218	{
	219	int ret;
	220	struct lttng_ht_iter iter;
	221
7591bab1	222	iter.iter.node = &vstream->stream_n.node;
2f8f53af DG	223	ret = lttng_ht_del(viewer_streams_ht, &iter);
	224	assert(!ret);
	225	}
	226
7591bab1	227	static void viewer_stream_release(struct urcu_ref *ref)
2f8f53af	228	{
7591bab1 MD	229	struct relay_viewer_stream *vstream = caa_container_of(ref,
7591bab1 MD	230	struct relay_viewer_stream, ref);
2a174661	231
7591bab1 MD	232	if (vstream->stream->is_metadata) {
7591bab1 MD	233	rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
2a174661	234	}
2f8f53af	235
7591bab1 MD	236	viewer_stream_unpublish(vstream);
7591bab1 MD	237
8bb66c3c JG	238	if (vstream->stream_file.handle) {
	239	fs_handle_close(vstream->stream_file.handle);
	240	vstream->stream_file.handle = NULL;
2f8f53af	241	}
f8f3885c MD	242	if (vstream->index_file) {
	243	lttng_index_file_put(vstream->index_file);
	244	vstream->index_file = NULL;
7591bab1 MD	245	}
	246	if (vstream->stream) {
	247	stream_put(vstream->stream);
	248	vstream->stream = NULL;
	249	}
4c2717fc JG	250	lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
4c2717fc JG	251	vstream->stream_file.trace_chunk = NULL;
7591bab1 MD	252	call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
	253	}
	254
	255	/* Must be called with RCU read-side lock held. */
	256	bool viewer_stream_get(struct relay_viewer_stream *vstream)
	257	{
ce4d4083	258	return urcu_ref_get_unless_zero(&vstream->ref);
2f8f53af DG	259	}
	260
	261	/*
7591bab1	262	* Get viewer stream by id.
2f8f53af	263	*
7591bab1	264	* Return viewer stream if found else NULL.
2f8f53af	265	*/
7591bab1	266	struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
2f8f53af DG	267	{
	268	struct lttng_ht_node_u64 *node;
	269	struct lttng_ht_iter iter;
7591bab1	270	struct relay_viewer_stream *vstream = NULL;
2f8f53af	271
7591bab1	272	rcu_read_lock();
2f8f53af DG	273	lttng_ht_lookup(viewer_streams_ht, &id, &iter);
	274	node = lttng_ht_iter_get_node_u64(&iter);
	275	if (!node) {
	276	DBG("Relay viewer stream %" PRIu64 " not found", id);
	277	goto end;
	278	}
7591bab1 MD	279	vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
	280	if (!viewer_stream_get(vstream)) {
	281	vstream = NULL;
	282	}
2f8f53af	283	end:
7591bab1 MD	284	rcu_read_unlock();
	285	return vstream;
	286	}
	287
	288	void viewer_stream_put(struct relay_viewer_stream *vstream)
	289	{
	290	rcu_read_lock();
7591bab1	291	urcu_ref_put(&vstream->ref, viewer_stream_release);
7591bab1 MD	292	rcu_read_unlock();
	293	}
	294
3087b021 MD	295	void viewer_stream_close_files(struct relay_viewer_stream *vstream)
	296	{
	297	if (vstream->index_file) {
	298	lttng_index_file_put(vstream->index_file);
	299	vstream->index_file = NULL;
	300	}
8bb66c3c JG	301	if (vstream->stream_file.handle) {
	302	fs_handle_close(vstream->stream_file.handle);
	303	vstream->stream_file.handle = NULL;
3087b021 MD	304	}
	305	}
	306
	307	void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream *vstream)
	308	{
	309	const struct relay_stream *stream = vstream->stream;
	310	uint64_t seq_tail;
	311
	312	vstream->current_tracefile_id = tracefile_array_get_file_index_tail(stream->tfa);
	313	seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	314	if (seq_tail == -1ULL) {
	315	seq_tail = 0;
	316	}
	317	vstream->index_sent_seqcount = seq_tail;
	318	}
	319
2f8f53af DG	320	/*
	321	* Rotate a stream to the next tracefile.
	322	*
7591bab1	323	* Must be called with the rstream lock held.
b0d240a2	324	* Returns 0 on success, 1 on EOF.
2f8f53af	325	*/
7591bab1	326	int viewer_stream_rotate(struct relay_viewer_stream *vstream)
2f8f53af DG	327	{
2f8f53af DG	328	int ret;
a44ca2ca	329	uint64_t new_id;
ebb29c10	330	const struct relay_stream *stream = vstream->stream;
2f8f53af	331
7591bab1	332	/* Detect the last tracefile to open. */
a44ca2ca MD	333	if (stream->index_received_seqcount
a44ca2ca MD	334	== vstream->index_sent_seqcount
7591bab1 MD	335	&& stream->trace->session->connection_closed) {
7591bab1 MD	336	ret = 1;
2a174661 DG	337	goto end;
2a174661 DG	338	}
2f8f53af	339
7591bab1 MD	340	if (stream->tracefile_count == 0) {
	341	/* Ignore rotation, there is none to do. */
	342	ret = 0;
2f8f53af DG	343	goto end;
	344	}
	345
a44ca2ca MD	346	/*
	347	* Try to move to the next file.
	348	*/
	349	new_id = (vstream->current_tracefile_id + 1)
	350	% stream->tracefile_count;
	351	if (tracefile_array_seq_in_file(stream->tfa, new_id,
	352	vstream->index_sent_seqcount)) {
	353	vstream->current_tracefile_id = new_id;
2f8f53af	354	} else {
a44ca2ca MD	355	uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
	356
	357	/*
	358	* This can only be reached on overwrite, which implies there
	359	* has been data written at some point, which will have set the
	360	* tail.
	361	*/
	362	assert(seq_tail != -1ULL);
	363	/*
	364	* We need to resync because we lag behind tail.
	365	*/
7591bab1	366	vstream->current_tracefile_id =
a44ca2ca MD	367	tracefile_array_get_file_index_tail(stream->tfa);
a44ca2ca MD	368	vstream->index_sent_seqcount = seq_tail;
2f8f53af	369	}
b0d240a2 MD	370	viewer_stream_close_files(vstream);
b0d240a2 MD	371	ret = 0;
2f8f53af	372	end:
2f8f53af DG	373	return ret;
2f8f53af DG	374	}
7591bab1 MD	375
	376	void print_viewer_streams(void)
	377	{
	378	struct lttng_ht_iter iter;
	379	struct relay_viewer_stream *vstream;
	380
ce3f3ba3 JG	381	if (!viewer_streams_ht) {
	382	return;
	383	}
	384
7591bab1 MD	385	rcu_read_lock();
	386	cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
	387	stream_n.node) {
	388	if (!viewer_stream_get(vstream)) {
	389	continue;
	390	}
	391	DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
	392	" session %" PRIu64,
	393	vstream,
	394	vstream->ref.refcount,
	395	vstream->stream->stream_handle,
	396	vstream->stream->trace->id,
	397	vstream->stream->trace->session->id);
	398	viewer_stream_put(vstream);
	399	}
	400	rcu_read_unlock();
	401	}