relayd: live: implement support for clear feature
[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>
b0d240a2
MD
24#include <common/utils.h>
25#include <sys/types.h>
26#include <sys/stat.h>
27#include <fcntl.h>
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DG
28
29#include "lttng-relayd.h"
30#include "viewer-stream.h"
31
7591bab1 32static 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);
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DG
37}
38
7591bab1 39static void viewer_stream_destroy_rcu(struct rcu_head *head)
2f8f53af 40{
7591bab1 41 struct relay_viewer_stream *vstream =
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DG
42 caa_container_of(head, struct relay_viewer_stream, rcu_node);
43
7591bab1 44 viewer_stream_destroy(vstream);
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DG
45}
46
47struct 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;
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
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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;
66 viewer_trace_chunk = NULL;
f5436bfc 67 vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
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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;
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122 break;
123 default:
a44ca2ca 124 goto error_unlock;
2f8f53af 125 }
2f8f53af 126
2f8f53af 127 /*
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MD
128 * If we never received an index for the current stream, delay
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;
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,
140 stream->path_name,
ebb29c10
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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 }
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DG
155 }
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 */
161 if (stream->stream_fd) {
162 int fd, ret;
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
174 status = lttng_trace_chunk_open_file(
175 vstream->stream_file.trace_chunk,
176 file_path, O_RDONLY, 0, &fd, true);
177 if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
178 goto error_unlock;
179 }
180 vstream->stream_file.fd = stream_fd_create(fd);
181 if (!vstream->stream_file.fd) {
182 if (close(fd)) {
183 PERROR("Failed to close viewer %sfile",
184 stream->is_metadata ? "metadata " : "");
185 }
186 goto error_unlock;
187 }
188 }
189
f8f3885c 190 if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
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DG
191 off_t lseek_ret;
192
f8f3885c 193 lseek_ret = lseek(vstream->index_file->fd, 0, SEEK_END);
2f8f53af 194 if (lseek_ret < 0) {
7591bab1 195 goto error_unlock;
2f8f53af 196 }
7591bab1 197 }
7591bab1
MD
198 if (stream->is_metadata) {
199 rcu_assign_pointer(stream->trace->viewer_metadata_stream,
200 vstream);
2f8f53af 201 }
a44ca2ca 202 pthread_mutex_unlock(&stream->lock);
2f8f53af 203
7591bab1
MD
204 /* Globally visible after the add unique. */
205 lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
7591bab1 206 urcu_ref_init(&vstream->ref);
c51b2177 207 lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
7591bab1 208
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209 return vstream;
210
7591bab1
MD
211error_unlock:
212 pthread_mutex_unlock(&stream->lock);
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213error:
214 if (vstream) {
7591bab1 215 viewer_stream_destroy(vstream);
2f8f53af 216 }
e4650a96 217 if (viewer_trace_chunk && acquired_reference) {
b66a15d1
JG
218 lttng_trace_chunk_put(viewer_trace_chunk);
219 }
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220 return NULL;
221}
222
7591bab1 223static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
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224{
225 int ret;
226 struct lttng_ht_iter iter;
227
7591bab1 228 iter.iter.node = &vstream->stream_n.node;
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229 ret = lttng_ht_del(viewer_streams_ht, &iter);
230 assert(!ret);
231}
232
7591bab1 233static void viewer_stream_release(struct urcu_ref *ref)
2f8f53af 234{
7591bab1
MD
235 struct relay_viewer_stream *vstream = caa_container_of(ref,
236 struct relay_viewer_stream, ref);
2a174661 237
7591bab1
MD
238 if (vstream->stream->is_metadata) {
239 rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
2a174661 240 }
2f8f53af 241
7591bab1
MD
242 viewer_stream_unpublish(vstream);
243
ebb29c10
JG
244 if (vstream->stream_file.fd) {
245 stream_fd_put(vstream->stream_file.fd);
246 vstream->stream_file.fd = NULL;
2f8f53af 247 }
f8f3885c
MD
248 if (vstream->index_file) {
249 lttng_index_file_put(vstream->index_file);
250 vstream->index_file = NULL;
7591bab1
MD
251 }
252 if (vstream->stream) {
253 stream_put(vstream->stream);
254 vstream->stream = NULL;
255 }
4c2717fc
JG
256 lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
257 vstream->stream_file.trace_chunk = NULL;
7591bab1
MD
258 call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
259}
260
261/* Must be called with RCU read-side lock held. */
262bool viewer_stream_get(struct relay_viewer_stream *vstream)
263{
ce4d4083 264 return urcu_ref_get_unless_zero(&vstream->ref);
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DG
265}
266
267/*
7591bab1 268 * Get viewer stream by id.
2f8f53af 269 *
7591bab1 270 * Return viewer stream if found else NULL.
2f8f53af 271 */
7591bab1 272struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
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DG
273{
274 struct lttng_ht_node_u64 *node;
275 struct lttng_ht_iter iter;
7591bab1 276 struct relay_viewer_stream *vstream = NULL;
2f8f53af 277
7591bab1 278 rcu_read_lock();
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DG
279 lttng_ht_lookup(viewer_streams_ht, &id, &iter);
280 node = lttng_ht_iter_get_node_u64(&iter);
281 if (!node) {
282 DBG("Relay viewer stream %" PRIu64 " not found", id);
283 goto end;
284 }
7591bab1
MD
285 vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
286 if (!viewer_stream_get(vstream)) {
287 vstream = NULL;
288 }
2f8f53af 289end:
7591bab1
MD
290 rcu_read_unlock();
291 return vstream;
292}
293
294void viewer_stream_put(struct relay_viewer_stream *vstream)
295{
296 rcu_read_lock();
7591bab1 297 urcu_ref_put(&vstream->ref, viewer_stream_release);
7591bab1
MD
298 rcu_read_unlock();
299}
300
3087b021
MD
301void viewer_stream_close_files(struct relay_viewer_stream *vstream)
302{
303 if (vstream->index_file) {
304 lttng_index_file_put(vstream->index_file);
305 vstream->index_file = NULL;
306 }
307 if (vstream->stream_file.fd) {
308 stream_fd_put(vstream->stream_file.fd);
309 vstream->stream_file.fd = NULL;
310 }
311}
312
313void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream *vstream)
314{
315 const struct relay_stream *stream = vstream->stream;
316 uint64_t seq_tail;
317
318 vstream->current_tracefile_id = tracefile_array_get_file_index_tail(stream->tfa);
319 seq_tail = tracefile_array_get_seq_tail(stream->tfa);
320 if (seq_tail == -1ULL) {
321 seq_tail = 0;
322 }
323 vstream->index_sent_seqcount = seq_tail;
324}
325
2f8f53af
DG
326/*
327 * Rotate a stream to the next tracefile.
328 *
7591bab1 329 * Must be called with the rstream lock held.
b0d240a2 330 * Returns 0 on success, 1 on EOF.
2f8f53af 331 */
7591bab1 332int viewer_stream_rotate(struct relay_viewer_stream *vstream)
2f8f53af
DG
333{
334 int ret;
a44ca2ca 335 uint64_t new_id;
ebb29c10 336 const struct relay_stream *stream = vstream->stream;
2f8f53af 337
7591bab1 338 /* Detect the last tracefile to open. */
a44ca2ca
MD
339 if (stream->index_received_seqcount
340 == vstream->index_sent_seqcount
7591bab1
MD
341 && stream->trace->session->connection_closed) {
342 ret = 1;
2a174661
DG
343 goto end;
344 }
2f8f53af 345
7591bab1
MD
346 if (stream->tracefile_count == 0) {
347 /* Ignore rotation, there is none to do. */
348 ret = 0;
2f8f53af
DG
349 goto end;
350 }
351
a44ca2ca
MD
352 /*
353 * Try to move to the next file.
354 */
355 new_id = (vstream->current_tracefile_id + 1)
356 % stream->tracefile_count;
357 if (tracefile_array_seq_in_file(stream->tfa, new_id,
358 vstream->index_sent_seqcount)) {
359 vstream->current_tracefile_id = new_id;
2f8f53af 360 } else {
a44ca2ca
MD
361 uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
362
363 /*
364 * This can only be reached on overwrite, which implies there
365 * has been data written at some point, which will have set the
366 * tail.
367 */
368 assert(seq_tail != -1ULL);
369 /*
370 * We need to resync because we lag behind tail.
371 */
7591bab1 372 vstream->current_tracefile_id =
a44ca2ca
MD
373 tracefile_array_get_file_index_tail(stream->tfa);
374 vstream->index_sent_seqcount = seq_tail;
2f8f53af 375 }
b0d240a2
MD
376 viewer_stream_close_files(vstream);
377 ret = 0;
2f8f53af 378end:
2f8f53af
DG
379 return ret;
380}
7591bab1
MD
381
382void print_viewer_streams(void)
383{
384 struct lttng_ht_iter iter;
385 struct relay_viewer_stream *vstream;
386
ce3f3ba3
JG
387 if (!viewer_streams_ht) {
388 return;
389 }
390
7591bab1
MD
391 rcu_read_lock();
392 cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
393 stream_n.node) {
394 if (!viewer_stream_get(vstream)) {
395 continue;
396 }
397 DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
398 " session %" PRIu64,
399 vstream,
400 vstream->ref.refcount,
401 vstream->stream->stream_handle,
402 vstream->stream->trace->id,
403 vstream->stream->trace->session->id);
404 viewer_stream_put(vstream);
405 }
406 rcu_read_unlock();
407}
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