src/common/trace-chunk.h

   1 /*
   2  * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as 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 Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #ifndef LTTNG_TRACE_CHUNK_H
  19 #define LTTNG_TRACE_CHUNK_H
  20
  21 #include <common/compat/directory-handle.h>
  22 #include <common/credentials.h>
  23 #include <common/fd-tracker/fd-tracker.h>
  24 #include <common/macros.h>
  25 #include <stdbool.h>
  26 #include <stddef.h>
  27 #include <stdint.h>
  28
  29 /*
  30  * A trace chunk is a group of directories and files forming a (or a set of)
  31  * complete and independant trace(s). For instance, a trace archive chunk,
  32  * a snapshot, or a regular LTTng trace are all instances of a trace archive.
  33  *
  34  * A trace chunk is always contained within a session output directory.
  35  *
  36  * This facility is used by the session daemon, consumer daemon(s), and relay
  37  * daemon to:
  38  *   - Control file (data stream, metadata, and index) creation relative to
  39  *     a given output directory,
  40  *   - Track the use of an output directory by other objects in order to
  41  *     know if/when an output directory can be safely consumed, renamed,
  42  *     deleted, etc.
  43  *
  44  *
  45  * OWNER VS USER
  46  * ---
  47  *
  48  * A trace chunk can either be a owner or a user of its
  49  * "chunk output directory".
  50  *
  51  * A "user" trace chunk is provided with a handle to the chunk output directory
  52  * which can then be used to create subdirectories and files.
  53  *
  54  * An "owner" chunk, on top of being able to perform the operations of a "user"
  55  * chunk can perform operations on its chunk output directory, such as renaming
  56  * or deleting it.
  57  *
  58  * A trace chunk becomes an "owner" or "user" chunk based on which of
  59  * 'lttng_trace_chunk_set_as_owner()' or 'lttng_trace_chunk_set_as_user()' is
  60  * used. These methods are _exclusive_ and must only be used once on a
  61  * trace chunk.
  62  */
  63
  64 struct lttng_trace_chunk;
  65 struct fd_tracker;
  66
  67 enum lttng_trace_chunk_status {
  68         LTTNG_TRACE_CHUNK_STATUS_OK,
  69         LTTNG_TRACE_CHUNK_STATUS_NONE,
  70         LTTNG_TRACE_CHUNK_STATUS_INVALID_ARGUMENT,
  71         LTTNG_TRACE_CHUNK_STATUS_INVALID_OPERATION,
  72         LTTNG_TRACE_CHUNK_STATUS_ERROR,
  73         LTTNG_TRACE_CHUNK_STATUS_NO_FILE,
  74 };
  75
  76 enum lttng_trace_chunk_command_type {
  77         LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED = 0,
  78         LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION = 1,
  79         LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE = 2,
  80         LTTNG_TRACE_CHUNK_COMMAND_TYPE_MAX,
  81 };
  82
  83 LTTNG_HIDDEN
  84 struct lttng_trace_chunk *lttng_trace_chunk_create_anonymous(void);
  85
  86 LTTNG_HIDDEN
  87 struct lttng_trace_chunk *lttng_trace_chunk_create(
  88                 uint64_t chunk_id,
  89                 time_t chunk_creation_time,
  90                 const char *path);
  91
  92 LTTNG_HIDDEN
  93 void lttng_trace_chunk_set_fd_tracker(struct lttng_trace_chunk *chunk,
  94                 struct fd_tracker *fd_tracker);
  95
  96 /*
  97  * Copy a trace chunk. The copy that is returned is always a _user_
  98  * mode chunk even if the source chunk was an _owner_ as there can never be
  99  * two _owners_ of the same trace output.
 100  */
 101 LTTNG_HIDDEN
 102 struct lttng_trace_chunk *lttng_trace_chunk_copy(
 103                 struct lttng_trace_chunk *source_chunk);
 104
 105 LTTNG_HIDDEN
 106 enum lttng_trace_chunk_status lttng_trace_chunk_get_id(
 107                 struct lttng_trace_chunk *chunk, uint64_t *id);
 108
 109 LTTNG_HIDDEN
 110 enum lttng_trace_chunk_status lttng_trace_chunk_get_creation_timestamp(
 111                 struct lttng_trace_chunk *chunk, time_t *creation_ts);
 112
 113 LTTNG_HIDDEN
 114 enum lttng_trace_chunk_status lttng_trace_chunk_get_close_timestamp(
 115                 struct lttng_trace_chunk *chunk, time_t *close_ts);
 116
 117 LTTNG_HIDDEN
 118 enum lttng_trace_chunk_status lttng_trace_chunk_set_close_timestamp(
 119                 struct lttng_trace_chunk *chunk, time_t close_ts);
 120
 121 LTTNG_HIDDEN
 122 enum lttng_trace_chunk_status lttng_trace_chunk_get_name(
 123                 struct lttng_trace_chunk *chunk, const char **name,
 124                 bool *name_overridden);
 125
 126 LTTNG_HIDDEN
 127 bool lttng_trace_chunk_get_name_overridden(struct lttng_trace_chunk *chunk);
 128
 129 LTTNG_HIDDEN
 130 enum lttng_trace_chunk_status lttng_trace_chunk_override_name(
 131                 struct lttng_trace_chunk *chunk, const char *name);
 132
 133 LTTNG_HIDDEN
 134 enum lttng_trace_chunk_status lttng_trace_chunk_rename_path(
 135                 struct lttng_trace_chunk *chunk, const char *path);
 136
 137 LTTNG_HIDDEN
 138 enum lttng_trace_chunk_status lttng_trace_chunk_get_credentials(
 139                 struct lttng_trace_chunk *chunk,
 140                 struct lttng_credentials *credentials);
 141
 142 LTTNG_HIDDEN
 143 enum lttng_trace_chunk_status lttng_trace_chunk_set_credentials(
 144                 struct lttng_trace_chunk *chunk,
 145                 const struct lttng_credentials *credentials);
 146
 147 LTTNG_HIDDEN
 148 enum lttng_trace_chunk_status lttng_trace_chunk_set_credentials_current_user(
 149                 struct lttng_trace_chunk *chunk);
 150
 151 LTTNG_HIDDEN
 152 enum lttng_trace_chunk_status lttng_trace_chunk_set_as_owner(
 153                 struct lttng_trace_chunk *chunk,
 154                 struct lttng_directory_handle *session_output_directory);
 155
 156 LTTNG_HIDDEN
 157 enum lttng_trace_chunk_status lttng_trace_chunk_set_as_user(
 158                 struct lttng_trace_chunk *chunk,
 159                 struct lttng_directory_handle *chunk_directory);
 160
 161 LTTNG_HIDDEN
 162 enum lttng_trace_chunk_status
 163 lttng_trace_chunk_get_session_output_directory_handle(
 164                 struct lttng_trace_chunk *chunk,
 165                 struct lttng_directory_handle **handle);
 166
 167 LTTNG_HIDDEN
 168 enum lttng_trace_chunk_status lttng_trace_chunk_borrow_chunk_directory_handle(
 169                 struct lttng_trace_chunk *chunk,
 170                 const struct lttng_directory_handle **handle);
 171
 172 LTTNG_HIDDEN
 173 enum lttng_trace_chunk_status lttng_trace_chunk_create_subdirectory(
 174                 struct lttng_trace_chunk *chunk,
 175                 const char *subdirectory_path);
 176
 177 LTTNG_HIDDEN
 178 enum lttng_trace_chunk_status lttng_trace_chunk_open_file(
 179                 struct lttng_trace_chunk *chunk,
 180                 const char *filename,
 181                 int flags,
 182                 mode_t mode,
 183                 int *out_fd,
 184                 bool expect_no_file);
 185
 186 LTTNG_HIDDEN
 187 enum lttng_trace_chunk_status lttng_trace_chunk_open_fs_handle(
 188                 struct lttng_trace_chunk *chunk,
 189                 const char *filename,
 190                 int flags,
 191                 mode_t mode,
 192                 struct fs_handle **out_handle,
 193                 bool expect_no_file);
 194
 195 LTTNG_HIDDEN
 196 int lttng_trace_chunk_unlink_file(struct lttng_trace_chunk *chunk,
 197                 const char *filename);
 198
 199 LTTNG_HIDDEN
 200 enum lttng_trace_chunk_status lttng_trace_chunk_get_close_command(
 201                 struct lttng_trace_chunk *chunk,
 202                 enum lttng_trace_chunk_command_type *command_type);
 203
 204 LTTNG_HIDDEN
 205 enum lttng_trace_chunk_status lttng_trace_chunk_set_close_command(
 206                 struct lttng_trace_chunk *chunk,
 207                 enum lttng_trace_chunk_command_type command_type);
 208
 209 LTTNG_HIDDEN
 210 const char *lttng_trace_chunk_command_type_get_name(
 211                 enum lttng_trace_chunk_command_type command);
 212
 213 /* Returns true on success. */
 214 LTTNG_HIDDEN
 215 bool lttng_trace_chunk_get(struct lttng_trace_chunk *chunk);
 216
 217 LTTNG_HIDDEN
 218 void lttng_trace_chunk_put(struct lttng_trace_chunk *chunk);
 219
 220 #endif /* LTTNG_TRACE_CHUNK_H */