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         LTTNG_TRACE_CHUNK_STATUS_NO_FILE,
  72 };
  73
  74 enum lttng_trace_chunk_command_type {
  75         LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED = 0,
  76         LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION = 1,
  77         LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE = 2,
  78         LTTNG_TRACE_CHUNK_COMMAND_TYPE_MAX,
  79 };
  80
  81 LTTNG_HIDDEN
  82 struct lttng_trace_chunk *lttng_trace_chunk_create_anonymous(void);
  83
  84 LTTNG_HIDDEN
  85 struct lttng_trace_chunk *lttng_trace_chunk_create(
  86                 uint64_t chunk_id,
  87                 time_t chunk_creation_time);
  88
  89 /*
  90  * Copy a trace chunk. The copy that is returned is always a _user_
  91  * mode chunk even if the source chunk was an _owner_ as there can never be
  92  * two _owners_ of the same trace output.
  93  */
  94 LTTNG_HIDDEN
  95 struct lttng_trace_chunk *lttng_trace_chunk_copy(
  96                 struct lttng_trace_chunk *source_chunk);
  97
  98 LTTNG_HIDDEN
  99 enum lttng_trace_chunk_status lttng_trace_chunk_get_id(
 100                 struct lttng_trace_chunk *chunk, uint64_t *id);
 101
 102 LTTNG_HIDDEN
 103 enum lttng_trace_chunk_status lttng_trace_chunk_get_creation_timestamp(
 104                 struct lttng_trace_chunk *chunk, time_t *creation_ts);
 105
 106 LTTNG_HIDDEN
 107 enum lttng_trace_chunk_status lttng_trace_chunk_get_close_timestamp(
 108                 struct lttng_trace_chunk *chunk, time_t *close_ts);
 109
 110 LTTNG_HIDDEN
 111 enum lttng_trace_chunk_status lttng_trace_chunk_set_close_timestamp(
 112                 struct lttng_trace_chunk *chunk, time_t close_ts);
 113
 114 LTTNG_HIDDEN
 115 enum lttng_trace_chunk_status lttng_trace_chunk_get_name(
 116                 struct lttng_trace_chunk *chunk, const char **name,
 117                 bool *name_overridden);
 118
 119 LTTNG_HIDDEN
 120 enum lttng_trace_chunk_status lttng_trace_chunk_override_name(
 121                 struct lttng_trace_chunk *chunk, const char *name);
 122
 123 LTTNG_HIDDEN
 124 enum lttng_trace_chunk_status lttng_trace_chunk_get_credentials(
 125                 struct lttng_trace_chunk *chunk,
 126                 struct lttng_credentials *credentials);
 127
 128 LTTNG_HIDDEN
 129 enum lttng_trace_chunk_status lttng_trace_chunk_set_credentials(
 130                 struct lttng_trace_chunk *chunk,
 131                 const struct lttng_credentials *credentials);
 132
 133 LTTNG_HIDDEN
 134 enum lttng_trace_chunk_status lttng_trace_chunk_set_credentials_current_user(
 135                 struct lttng_trace_chunk *chunk);
 136
 137 LTTNG_HIDDEN
 138 enum lttng_trace_chunk_status lttng_trace_chunk_set_as_owner(
 139                 struct lttng_trace_chunk *chunk,
 140                 struct lttng_directory_handle *session_output_directory);
 141
 142 LTTNG_HIDDEN
 143 enum lttng_trace_chunk_status lttng_trace_chunk_set_as_user(
 144                 struct lttng_trace_chunk *chunk,
 145                 struct lttng_directory_handle *chunk_directory);
 146
 147 LTTNG_HIDDEN
 148 enum lttng_trace_chunk_status lttng_trace_chunk_borrow_chunk_directory_handle(
 149                 struct lttng_trace_chunk *chunk,
 150                 const struct lttng_directory_handle **handle);
 151
 152 LTTNG_HIDDEN
 153 enum lttng_trace_chunk_status lttng_trace_chunk_create_subdirectory(
 154                 struct lttng_trace_chunk *chunk,
 155                 const char *subdirectory_path);
 156
 157 LTTNG_HIDDEN
 158 enum lttng_trace_chunk_status lttng_trace_chunk_open_file(
 159                 struct lttng_trace_chunk *chunk, const char *filename,
 160                 int flags, mode_t mode, int *out_fd, bool expect_no_file);
 161
 162 LTTNG_HIDDEN
 163 int lttng_trace_chunk_unlink_file(struct lttng_trace_chunk *chunk,
 164                 const char *filename);
 165
 166 LTTNG_HIDDEN
 167 enum lttng_trace_chunk_status lttng_trace_chunk_get_close_command(
 168                 struct lttng_trace_chunk *chunk,
 169                 enum lttng_trace_chunk_command_type *command_type);
 170
 171 LTTNG_HIDDEN
 172 enum lttng_trace_chunk_status lttng_trace_chunk_set_close_command(
 173                 struct lttng_trace_chunk *chunk,
 174                 enum lttng_trace_chunk_command_type command_type);
 175
 176 LTTNG_HIDDEN
 177 const char *lttng_trace_chunk_command_type_get_name(
 178                 enum lttng_trace_chunk_command_type command);
 179
 180 /* Returns true on success. */
 181 LTTNG_HIDDEN
 182 bool lttng_trace_chunk_get(struct lttng_trace_chunk *chunk);
 183
 184 LTTNG_HIDDEN
 185 void lttng_trace_chunk_put(struct lttng_trace_chunk *chunk);
 186
 187 #endif /* LTTNG_TRACE_CHUNK_H */