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/macros.h>
  22 #include <common/credentials.h>
  23 #include <common/compat/directory-handle.h>
  24 #include <stddef.h>
  25 #include <stdint.h>
  26 #include <stdbool.h>
  27
  28 /*
  29  * A trace chunk is a group of directories and files forming a (or a set of)
  30  * complete and independant trace(s). For instance, a trace archive chunk,
  31  * a snapshot, or a regular LTTng trace are all instances of a trace archive.
  32  *
  33  * A trace chunk is always contained within a session output directory.
  34  *
  35  * This facility is used by the session daemon, consumer daemon(s), and relay
  36  * daemon to:
  37  *   - Control file (data stream, metadata, and index) creation relative to
  38  *     a given output directory,
  39  *   - Track the use of an output directory by other objects in order to
  40  *     know if/when an output directory can be safely consumed, renamed,
  41  *     deleted, etc.
  42  *
  43  *
  44  * OWNER VS USER
  45  * ---
  46  *
  47  * A trace chunk can either be a owner or a user of its
  48  * "chunk output directory".
  49  *
  50  * A "user" trace chunk is provided with a handle to the chunk output directory
  51  * which can then be used to create subdirectories and files.
  52  *
  53  * An "owner" chunk, on top of being able to perform the operations of a "user"
  54  * chunk can perform operations on its chunk output directory, such as renaming
  55  * or deleting it.
  56  *
  57  * A trace chunk becomes an "owner" or "user" chunk based on which of
  58  * 'lttng_trace_chunk_set_as_owner()' or 'lttng_trace_chunk_set_as_user()' is
  59  * used. These methods are _exclusive_ and must only be used once on a
  60  * trace chunk.
  61  */
  62
  63 struct lttng_trace_chunk;
  64
  65 enum lttng_trace_chunk_status {
  66         LTTNG_TRACE_CHUNK_STATUS_OK,
  67         LTTNG_TRACE_CHUNK_STATUS_NONE,
  68         LTTNG_TRACE_CHUNK_STATUS_INVALID_ARGUMENT,
  69         LTTNG_TRACE_CHUNK_STATUS_INVALID_OPERATION,
  70         LTTNG_TRACE_CHUNK_STATUS_ERROR,
  71 };
  72
  73 enum lttng_trace_chunk_command_type {
  74         LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED = 0,
  75         LTTNG_TRACE_CHUNK_COMMAND_TYPE_MAX
  76 };
  77
  78 LTTNG_HIDDEN
  79 struct lttng_trace_chunk *lttng_trace_chunk_create_anonymous(void);
  80
  81 LTTNG_HIDDEN
  82 struct lttng_trace_chunk *lttng_trace_chunk_create(
  83                 uint64_t chunk_id,
  84                 time_t chunk_creation_time);
  85
  86 /*
  87  * Copy a trace chunk. The copy that is returned is always a _user_
  88  * mode chunk even if the source chunk was an _owner_ as there can never be
  89  * two _owners_ of the same trace output.
  90  */
  91 LTTNG_HIDDEN
  92 struct lttng_trace_chunk *lttng_trace_chunk_copy(
  93                 struct lttng_trace_chunk *source_chunk);
  94
  95 LTTNG_HIDDEN
  96 enum lttng_trace_chunk_status lttng_trace_chunk_get_id(
  97                 struct lttng_trace_chunk *chunk, uint64_t *id);
  98
  99 LTTNG_HIDDEN
 100 enum lttng_trace_chunk_status lttng_trace_chunk_get_creation_timestamp(
 101                 struct lttng_trace_chunk *chunk, time_t *creation_ts);
 102
 103 LTTNG_HIDDEN
 104 enum lttng_trace_chunk_status lttng_trace_chunk_get_close_timestamp(
 105                 struct lttng_trace_chunk *chunk, time_t *close_ts);
 106
 107 LTTNG_HIDDEN
 108 enum lttng_trace_chunk_status lttng_trace_chunk_set_close_timestamp(
 109                 struct lttng_trace_chunk *chunk, time_t close_ts);
 110
 111 LTTNG_HIDDEN
 112 enum lttng_trace_chunk_status lttng_trace_chunk_get_name(
 113                 struct lttng_trace_chunk *chunk, const char **name,
 114                 bool *name_overridden);
 115
 116 LTTNG_HIDDEN
 117 enum lttng_trace_chunk_status lttng_trace_chunk_override_name(
 118                 struct lttng_trace_chunk *chunk, const char *name);
 119
 120 LTTNG_HIDDEN
 121 enum lttng_trace_chunk_status lttng_trace_chunk_get_credentials(
 122                 struct lttng_trace_chunk *chunk,
 123                 struct lttng_credentials *credentials);
 124
 125 LTTNG_HIDDEN
 126 enum lttng_trace_chunk_status lttng_trace_chunk_set_credentials(
 127                 struct lttng_trace_chunk *chunk,
 128                 const struct lttng_credentials *credentials);
 129
 130 LTTNG_HIDDEN
 131 enum lttng_trace_chunk_status lttng_trace_chunk_set_credentials_current_user(
 132                 struct lttng_trace_chunk *chunk);
 133
 134 /* session_output_directory ownership is transferred to the chunk on success. */
 135 LTTNG_HIDDEN
 136 enum lttng_trace_chunk_status lttng_trace_chunk_set_as_owner(
 137                 struct lttng_trace_chunk *chunk,
 138                 struct lttng_directory_handle *session_output_directory);
 139
 140 /* chunk_output_directory ownership is transferred to the chunk on success. */
 141 LTTNG_HIDDEN
 142 enum lttng_trace_chunk_status lttng_trace_chunk_set_as_user(
 143                 struct lttng_trace_chunk *chunk,
 144                 struct lttng_directory_handle *chunk_directory);
 145
 146 LTTNG_HIDDEN
 147 enum lttng_trace_chunk_status lttng_trace_chunk_get_chunk_directory_handle(
 148                 struct lttng_trace_chunk *chunk,
 149                 const struct lttng_directory_handle **handle);
 150
 151 LTTNG_HIDDEN
 152 enum lttng_trace_chunk_status lttng_trace_chunk_create_subdirectory(
 153                 struct lttng_trace_chunk *chunk,
 154                 const char *subdirectory_path);
 155
 156 LTTNG_HIDDEN
 157 enum lttng_trace_chunk_status lttng_trace_chunk_open_file(
 158                 struct lttng_trace_chunk *chunk, const char *filename,
 159                 int flags, mode_t mode, int *out_fd);
 160
 161 LTTNG_HIDDEN
 162 int lttng_trace_chunk_unlink_file(struct lttng_trace_chunk *chunk,
 163                 const char *filename);
 164
 165 LTTNG_HIDDEN
 166 enum lttng_trace_chunk_status lttng_trace_chunk_get_close_command(
 167                 struct lttng_trace_chunk *chunk,
 168                 enum lttng_trace_chunk_command_type *command_type);
 169
 170 LTTNG_HIDDEN
 171 enum lttng_trace_chunk_status lttng_trace_chunk_set_close_command(
 172                 struct lttng_trace_chunk *chunk,
 173                 enum lttng_trace_chunk_command_type command_type);
 174
 175 LTTNG_HIDDEN
 176 const char *lttng_trace_chunk_command_type_get_name(
 177                 enum lttng_trace_chunk_command_type command);
 178
 179 /* Returns true on success. */
 180 LTTNG_HIDDEN
 181 bool lttng_trace_chunk_get(struct lttng_trace_chunk *chunk);
 182
 183 LTTNG_HIDDEN
 184 void lttng_trace_chunk_put(struct lttng_trace_chunk *chunk);
 185
 186 #endif /* LTTNG_TRACE_CHUNK_H */