relayd tracefile array: add tracefile_array_reset
[lttng-tools.git] / src / bin / lttng-relayd / tracefile-array.c
1 /*
2 * Copyright (C) 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License, version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _LGPL_SOURCE
19 #include <assert.h>
20 #include <common/common.h>
21 #include <common/utils.h>
22 #include <common/defaults.h>
23
24 #include "tracefile-array.h"
25
26 struct tracefile_array *tracefile_array_create(size_t count)
27 {
28 struct tracefile_array *tfa = NULL;
29 int i;
30
31 tfa = zmalloc(sizeof(*tfa));
32 if (!tfa) {
33 goto error;
34 }
35 tfa->tf = zmalloc(sizeof(*tfa->tf) * count);
36 if (!tfa->tf) {
37 goto error;
38 }
39 tfa->count = count;
40 for (i = 0; i < count; i++) {
41 tfa->tf[i].seq_head = -1ULL;
42 tfa->tf[i].seq_tail = -1ULL;
43 }
44 tfa->seq_head = -1ULL;
45 tfa->seq_tail = -1ULL;
46 return tfa;
47
48 error:
49 if (tfa) {
50 free(tfa->tf);
51 }
52 free(tfa);
53 return NULL;
54 }
55
56 void tracefile_array_destroy(struct tracefile_array *tfa)
57 {
58 if (!tfa) {
59 return;
60 }
61 free(tfa->tf);
62 free(tfa);
63 }
64
65 void tracefile_array_reset(struct tracefile_array *tfa)
66 {
67 size_t count, i;
68
69 count = tfa->count;
70 for (i = 0; i < count; i++) {
71 tfa->tf[i].seq_head = -1ULL;
72 tfa->tf[i].seq_tail = -1ULL;
73 }
74 tfa->seq_head = -1ULL;
75 tfa->seq_tail = -1ULL;
76 tfa->file_head_read = 0;
77 tfa->file_head_write = 0;
78 tfa->file_tail = 0;
79 }
80
81 void tracefile_array_file_rotate(struct tracefile_array *tfa,
82 enum tracefile_rotate_type type)
83 {
84 uint64_t *headp, *tailp;
85
86 if (!tfa->count) {
87 /* Not in tracefile rotation mode. */
88 return;
89 }
90 switch (type) {
91 case TRACEFILE_ROTATE_READ:
92 /*
93 * Rotate read head to write head position, thus allowing
94 * reader to consume the newly rotated head file.
95 */
96 tfa->file_head_read = tfa->file_head_write;
97 break;
98 case TRACEFILE_ROTATE_WRITE:
99 /* Rotate write head to next file, pushing tail if needed. */
100 tfa->file_head_write = (tfa->file_head_write + 1) % tfa->count;
101 if (tfa->file_head_write == tfa->file_tail) {
102 /* Move tail. */
103 tfa->file_tail = (tfa->file_tail + 1) % tfa->count;
104 }
105 headp = &tfa->tf[tfa->file_head_write].seq_head;
106 tailp = &tfa->tf[tfa->file_head_write].seq_tail;
107 /*
108 * If we overwrite a file with content, we need to push the tail
109 * to the position following the content we are overwriting.
110 */
111 if (*headp != -1ULL) {
112 tfa->seq_tail = tfa->tf[tfa->file_tail].seq_tail;
113 }
114 /* Reset this file head/tail (overwrite). */
115 *headp = -1ULL;
116 *tailp = -1ULL;
117 break;
118 default:
119 abort();
120 }
121 }
122
123 void tracefile_array_commit_seq(struct tracefile_array *tfa)
124 {
125 uint64_t *headp, *tailp;
126
127 /* Increment overall head. */
128 tfa->seq_head++;
129 /* If we are committing our first index overall, set tail to 0. */
130 if (tfa->seq_tail == -1ULL) {
131 tfa->seq_tail = 0;
132 }
133 if (!tfa->count) {
134 /* Not in tracefile rotation mode. */
135 return;
136 }
137 headp = &tfa->tf[tfa->file_head_write].seq_head;
138 tailp = &tfa->tf[tfa->file_head_write].seq_tail;
139 /* Update head tracefile seq_head. */
140 *headp = tfa->seq_head;
141 /*
142 * If we are committing our first index in this packet, set tail
143 * to this index seq count.
144 */
145 if (*tailp == -1ULL) {
146 *tailp = tfa->seq_head;
147 }
148 }
149
150 uint64_t tracefile_array_get_read_file_index_head(struct tracefile_array *tfa)
151 {
152 return tfa->file_head_read;
153 }
154
155 uint64_t tracefile_array_get_seq_head(struct tracefile_array *tfa)
156 {
157 return tfa->seq_head;
158 }
159
160 uint64_t tracefile_array_get_file_index_tail(struct tracefile_array *tfa)
161 {
162 return tfa->file_tail;
163 }
164
165 uint64_t tracefile_array_get_seq_tail(struct tracefile_array *tfa)
166 {
167 return tfa->seq_tail;
168 }
169
170 bool tracefile_array_seq_in_file(struct tracefile_array *tfa,
171 uint64_t file_index, uint64_t seq)
172 {
173 if (!tfa->count) {
174 /*
175 * Not in tracefile rotation mode; we are guaranteed to have the
176 * index in this file.
177 */
178 return true;
179 }
180 assert(file_index < tfa->count);
181 if (seq == -1ULL) {
182 return false;
183 }
184 if (seq >= tfa->tf[file_index].seq_tail
185 && seq <= tfa->tf[file_index].seq_head) {
186 return true;
187 } else {
188 return false;
189 }
190 }
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