common: index: remove redundant separator for empty channel string
[lttng-tools.git] / src / bin / lttng-relayd / viewer-stream.c
CommitLineData
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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>
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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
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21#include <common/common.h>
22#include <common/index/index.h>
f5436bfc 23#include <common/compat/string.h>
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24
25#include "lttng-relayd.h"
26#include "viewer-stream.h"
27
7591bab1 28static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
2f8f53af 29{
7591bab1
MD
30 free(vstream->path_name);
31 free(vstream->channel_name);
32 free(vstream);
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DG
33}
34
7591bab1 35static void viewer_stream_destroy_rcu(struct rcu_head *head)
2f8f53af 36{
7591bab1 37 struct relay_viewer_stream *vstream =
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38 caa_container_of(head, struct relay_viewer_stream, rcu_node);
39
7591bab1 40 viewer_stream_destroy(vstream);
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41}
42
43struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
b66a15d1 44 struct lttng_trace_chunk *viewer_trace_chunk,
7591bab1 45 enum lttng_viewer_seek seek_t)
2f8f53af 46{
ebb29c10
JG
47 struct relay_viewer_stream *vstream = NULL;
48 const bool acquired_reference = lttng_trace_chunk_get(
b66a15d1 49 viewer_trace_chunk);
ebb29c10
JG
50
51 if (!acquired_reference) {
52 goto error;
53 }
2f8f53af 54
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DG
55 vstream = zmalloc(sizeof(*vstream));
56 if (!vstream) {
57 PERROR("relay viewer stream zmalloc");
58 goto error;
59 }
60
b66a15d1
JG
61 vstream->stream_file.trace_chunk = viewer_trace_chunk;
62 viewer_trace_chunk = NULL;
f5436bfc 63 vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
b272577e
MD
64 if (vstream->path_name == NULL) {
65 PERROR("relay viewer path_name alloc");
66 goto error;
67 }
f5436bfc 68 vstream->channel_name = lttng_strndup(stream->channel_name,
2f8f53af 69 LTTNG_VIEWER_NAME_MAX);
b272577e
MD
70 if (vstream->channel_name == NULL) {
71 PERROR("relay viewer channel_name alloc");
72 goto error;
73 }
2f8f53af 74
a44ca2ca
MD
75 if (!stream_get(stream)) {
76 ERR("Cannot get stream");
77 goto error;
78 }
79 vstream->stream = stream;
80
81 pthread_mutex_lock(&stream->lock);
82
83 if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
84 ERR("Cannot attach viewer metadata stream to trace (busy).");
85 goto error_unlock;
86 }
87
2f8f53af 88 switch (seek_t) {
c4e361a4 89 case LTTNG_VIEWER_SEEK_BEGINNING:
a44ca2ca
MD
90 {
91 uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
92
93 if (seq_tail == -1ULL) {
94 /*
95 * Tail may not be initialized yet. Nonetheless, we know
96 * we want to send the first index once it becomes
97 * available.
98 */
99 seq_tail = 0;
100 }
101 vstream->current_tracefile_id =
102 tracefile_array_get_file_index_tail(stream->tfa);
103 vstream->index_sent_seqcount = seq_tail;
2f8f53af 104 break;
a44ca2ca 105 }
c4e361a4 106 case LTTNG_VIEWER_SEEK_LAST:
a44ca2ca 107 vstream->current_tracefile_id =
78118e3b 108 tracefile_array_get_read_file_index_head(stream->tfa);
a44ca2ca
MD
109 /*
110 * We seek at the very end of each stream, awaiting for
111 * a future packet to eventually come in.
112 *
113 * We don't need to check the head position for -1ULL since the
114 * increment will set it to 0.
115 */
116 vstream->index_sent_seqcount =
117 tracefile_array_get_seq_head(stream->tfa) + 1;
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118 break;
119 default:
a44ca2ca 120 goto error_unlock;
2f8f53af 121 }
2f8f53af 122
2f8f53af 123 /*
a44ca2ca
MD
124 * If we never received an index for the current stream, delay
125 * the opening of the index, otherwise open it right now.
2f8f53af 126 */
a44ca2ca 127 if (stream->index_received_seqcount == 0) {
f8f3885c 128 vstream->index_file = NULL;
2f8f53af 129 } else {
ebb29c10
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130 const uint32_t connection_major = stream->trace->session->major;
131 const uint32_t connection_minor = stream->trace->session->minor;
132
133 vstream->index_file = lttng_index_file_create_from_trace_chunk_read_only(
b66a15d1
JG
134 vstream->stream_file.trace_chunk,
135 stream->path_name,
ebb29c10
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136 stream->channel_name, stream->tracefile_size,
137 vstream->current_tracefile_id,
138 lttng_to_index_major(connection_major,
139 connection_minor),
140 lttng_to_index_minor(connection_major,
141 connection_minor));
f8f3885c 142 if (!vstream->index_file) {
7591bab1 143 goto error_unlock;
2f8f53af 144 }
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145 }
146
f8f3885c 147 if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
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148 off_t lseek_ret;
149
f8f3885c 150 lseek_ret = lseek(vstream->index_file->fd, 0, SEEK_END);
2f8f53af 151 if (lseek_ret < 0) {
7591bab1 152 goto error_unlock;
2f8f53af 153 }
7591bab1 154 }
7591bab1
MD
155 if (stream->is_metadata) {
156 rcu_assign_pointer(stream->trace->viewer_metadata_stream,
157 vstream);
2f8f53af 158 }
a44ca2ca 159 pthread_mutex_unlock(&stream->lock);
2f8f53af 160
7591bab1
MD
161 /* Globally visible after the add unique. */
162 lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
7591bab1 163 urcu_ref_init(&vstream->ref);
c51b2177 164 lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
7591bab1 165
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166 return vstream;
167
7591bab1
MD
168error_unlock:
169 pthread_mutex_unlock(&stream->lock);
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170error:
171 if (vstream) {
7591bab1 172 viewer_stream_destroy(vstream);
2f8f53af 173 }
e4650a96 174 if (viewer_trace_chunk && acquired_reference) {
b66a15d1
JG
175 lttng_trace_chunk_put(viewer_trace_chunk);
176 }
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177 return NULL;
178}
179
7591bab1 180static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
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181{
182 int ret;
183 struct lttng_ht_iter iter;
184
7591bab1 185 iter.iter.node = &vstream->stream_n.node;
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186 ret = lttng_ht_del(viewer_streams_ht, &iter);
187 assert(!ret);
188}
189
7591bab1 190static void viewer_stream_release(struct urcu_ref *ref)
2f8f53af 191{
7591bab1
MD
192 struct relay_viewer_stream *vstream = caa_container_of(ref,
193 struct relay_viewer_stream, ref);
2a174661 194
7591bab1
MD
195 if (vstream->stream->is_metadata) {
196 rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
2a174661 197 }
2f8f53af 198
7591bab1
MD
199 viewer_stream_unpublish(vstream);
200
ebb29c10
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201 if (vstream->stream_file.fd) {
202 stream_fd_put(vstream->stream_file.fd);
203 vstream->stream_file.fd = NULL;
2f8f53af 204 }
f8f3885c
MD
205 if (vstream->index_file) {
206 lttng_index_file_put(vstream->index_file);
207 vstream->index_file = NULL;
7591bab1
MD
208 }
209 if (vstream->stream) {
210 stream_put(vstream->stream);
211 vstream->stream = NULL;
212 }
4c2717fc
JG
213 lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
214 vstream->stream_file.trace_chunk = NULL;
7591bab1
MD
215 call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
216}
217
218/* Must be called with RCU read-side lock held. */
219bool viewer_stream_get(struct relay_viewer_stream *vstream)
220{
ce4d4083 221 return urcu_ref_get_unless_zero(&vstream->ref);
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DG
222}
223
224/*
7591bab1 225 * Get viewer stream by id.
2f8f53af 226 *
7591bab1 227 * Return viewer stream if found else NULL.
2f8f53af 228 */
7591bab1 229struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
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DG
230{
231 struct lttng_ht_node_u64 *node;
232 struct lttng_ht_iter iter;
7591bab1 233 struct relay_viewer_stream *vstream = NULL;
2f8f53af 234
7591bab1 235 rcu_read_lock();
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DG
236 lttng_ht_lookup(viewer_streams_ht, &id, &iter);
237 node = lttng_ht_iter_get_node_u64(&iter);
238 if (!node) {
239 DBG("Relay viewer stream %" PRIu64 " not found", id);
240 goto end;
241 }
7591bab1
MD
242 vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
243 if (!viewer_stream_get(vstream)) {
244 vstream = NULL;
245 }
2f8f53af 246end:
7591bab1
MD
247 rcu_read_unlock();
248 return vstream;
249}
250
251void viewer_stream_put(struct relay_viewer_stream *vstream)
252{
253 rcu_read_lock();
7591bab1 254 urcu_ref_put(&vstream->ref, viewer_stream_release);
7591bab1
MD
255 rcu_read_unlock();
256}
257
2f8f53af
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258/*
259 * Rotate a stream to the next tracefile.
260 *
7591bab1 261 * Must be called with the rstream lock held.
2f8f53af
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262 * Returns 0 on success, 1 on EOF, a negative value on error.
263 */
7591bab1 264int viewer_stream_rotate(struct relay_viewer_stream *vstream)
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DG
265{
266 int ret;
a44ca2ca 267 uint64_t new_id;
ebb29c10
JG
268 const struct relay_stream *stream = vstream->stream;
269 const uint32_t connection_major = stream->trace->session->major;
270 const uint32_t connection_minor = stream->trace->session->minor;
2f8f53af 271
7591bab1 272 /* Detect the last tracefile to open. */
a44ca2ca
MD
273 if (stream->index_received_seqcount
274 == vstream->index_sent_seqcount
7591bab1
MD
275 && stream->trace->session->connection_closed) {
276 ret = 1;
2a174661
DG
277 goto end;
278 }
2f8f53af 279
7591bab1
MD
280 if (stream->tracefile_count == 0) {
281 /* Ignore rotation, there is none to do. */
282 ret = 0;
2f8f53af
DG
283 goto end;
284 }
285
a44ca2ca
MD
286 /*
287 * Try to move to the next file.
288 */
289 new_id = (vstream->current_tracefile_id + 1)
290 % stream->tracefile_count;
291 if (tracefile_array_seq_in_file(stream->tfa, new_id,
292 vstream->index_sent_seqcount)) {
293 vstream->current_tracefile_id = new_id;
2f8f53af 294 } else {
a44ca2ca
MD
295 uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
296
297 /*
298 * This can only be reached on overwrite, which implies there
299 * has been data written at some point, which will have set the
300 * tail.
301 */
302 assert(seq_tail != -1ULL);
303 /*
304 * We need to resync because we lag behind tail.
305 */
7591bab1 306 vstream->current_tracefile_id =
a44ca2ca
MD
307 tracefile_array_get_file_index_tail(stream->tfa);
308 vstream->index_sent_seqcount = seq_tail;
2f8f53af 309 }
2f8f53af 310
f8f3885c
MD
311 if (vstream->index_file) {
312 lttng_index_file_put(vstream->index_file);
313 vstream->index_file = NULL;
2f8f53af 314 }
ebb29c10
JG
315 if (vstream->stream_file.fd) {
316 stream_fd_put(vstream->stream_file.fd);
317 vstream->stream_file.fd = NULL;
2f8f53af 318 }
ebb29c10
JG
319 vstream->index_file =
320 lttng_index_file_create_from_trace_chunk_read_only(
b66a15d1
JG
321 vstream->stream_file.trace_chunk,
322 stream->path_name,
ebb29c10
JG
323 stream->channel_name,
324 stream->tracefile_size,
325 vstream->current_tracefile_id,
326 lttng_to_index_major(connection_major,
327 connection_minor),
328 lttng_to_index_minor(connection_major,
329 connection_minor));
f8f3885c
MD
330 if (!vstream->index_file) {
331 ret = -1;
7591bab1 332 goto end;
7591bab1 333 } else {
f8f3885c 334 ret = 0;
2f8f53af 335 }
2f8f53af 336end:
2f8f53af
DG
337 return ret;
338}
7591bab1
MD
339
340void print_viewer_streams(void)
341{
342 struct lttng_ht_iter iter;
343 struct relay_viewer_stream *vstream;
344
ce3f3ba3
JG
345 if (!viewer_streams_ht) {
346 return;
347 }
348
7591bab1
MD
349 rcu_read_lock();
350 cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
351 stream_n.node) {
352 if (!viewer_stream_get(vstream)) {
353 continue;
354 }
355 DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
356 " session %" PRIu64,
357 vstream,
358 vstream->ref.refcount,
359 vstream->stream->stream_handle,
360 vstream->stream->trace->id,
361 vstream->stream->trace->session->id);
362 viewer_stream_put(vstream);
363 }
364 rcu_read_unlock();
365}
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