src/common/trace-chunk.h

   1 /*
   2  * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #ifndef LTTNG_TRACE_CHUNK_H
   9 #define LTTNG_TRACE_CHUNK_H
  10
  11 #include <common/compat/directory-handle.h>
  12 #include <common/credentials.h>
  13 #include <common/fd-tracker/fd-tracker.h>
  14 #include <common/macros.h>
  15 #include <stdbool.h>
  16 #include <stddef.h>
  17 #include <stdint.h>
  18
  19 /*
  20  * A trace chunk is a group of directories and files forming a (or a set of)
  21  * complete and independant trace(s). For instance, a trace archive chunk,
  22  * a snapshot, or a regular LTTng trace are all instances of a trace archive.
  23  *
  24  * A trace chunk is always contained within a session output directory.
  25  *
  26  * This facility is used by the session daemon, consumer daemon(s), and relay
  27  * daemon to:
  28  *   - Control file (data stream, metadata, and index) creation relative to
  29  *     a given output directory,
  30  *   - Track the use of an output directory by other objects in order to
  31  *     know if/when an output directory can be safely consumed, renamed,
  32  *     deleted, etc.
  33  *
  34  *
  35  * OWNER VS USER
  36  * ---
  37  *
  38  * A trace chunk can either be a owner or a user of its
  39  * "chunk output directory".
  40  *
  41  * A "user" trace chunk is provided with a handle to the chunk output directory
  42  * which can then be used to create subdirectories and files.
  43  *
  44  * An "owner" chunk, on top of being able to perform the operations of a "user"
  45  * chunk can perform operations on its chunk output directory, such as renaming
  46  * or deleting it.
  47  *
  48  * A trace chunk becomes an "owner" or "user" chunk based on which of
  49  * 'lttng_trace_chunk_set_as_owner()' or 'lttng_trace_chunk_set_as_user()' is
  50  * used. These methods are _exclusive_ and must only be used once on a
  51  * trace chunk.
  52  */
  53
  54 struct lttng_trace_chunk;
  55 struct fd_tracker;
  56
  57 enum lttng_trace_chunk_status {
  58         LTTNG_TRACE_CHUNK_STATUS_OK,
  59         LTTNG_TRACE_CHUNK_STATUS_NONE,
  60         LTTNG_TRACE_CHUNK_STATUS_INVALID_ARGUMENT,
  61         LTTNG_TRACE_CHUNK_STATUS_INVALID_OPERATION,
  62         LTTNG_TRACE_CHUNK_STATUS_ERROR,
  63         LTTNG_TRACE_CHUNK_STATUS_NO_FILE,
  64 };
  65
  66 enum lttng_trace_chunk_command_type {
  67         LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED = 0,
  68         LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION = 1,
  69         LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE = 2,
  70         LTTNG_TRACE_CHUNK_COMMAND_TYPE_MAX,
  71 };
  72
  73 LTTNG_HIDDEN
  74 struct lttng_trace_chunk *lttng_trace_chunk_create_anonymous(void);
  75
  76 LTTNG_HIDDEN
  77 struct lttng_trace_chunk *lttng_trace_chunk_create(
  78                 uint64_t chunk_id,
  79                 time_t chunk_creation_time,
  80                 const char *path);
  81
  82 LTTNG_HIDDEN
  83 void lttng_trace_chunk_set_fd_tracker(struct lttng_trace_chunk *chunk,
  84                 struct fd_tracker *fd_tracker);
  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 bool lttng_trace_chunk_get_name_overridden(struct lttng_trace_chunk *chunk);
 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_rename_path(
 125                 struct lttng_trace_chunk *chunk, const char *path);
 126
 127 LTTNG_HIDDEN
 128 enum lttng_trace_chunk_status lttng_trace_chunk_get_credentials(
 129                 struct lttng_trace_chunk *chunk,
 130                 struct lttng_credentials *credentials);
 131
 132 LTTNG_HIDDEN
 133 enum lttng_trace_chunk_status lttng_trace_chunk_set_credentials(
 134                 struct lttng_trace_chunk *chunk,
 135                 const struct lttng_credentials *credentials);
 136
 137 LTTNG_HIDDEN
 138 enum lttng_trace_chunk_status lttng_trace_chunk_set_credentials_current_user(
 139                 struct lttng_trace_chunk *chunk);
 140
 141 LTTNG_HIDDEN
 142 enum lttng_trace_chunk_status lttng_trace_chunk_set_as_owner(
 143                 struct lttng_trace_chunk *chunk,
 144                 struct lttng_directory_handle *session_output_directory);
 145
 146 LTTNG_HIDDEN
 147 enum lttng_trace_chunk_status lttng_trace_chunk_set_as_user(
 148                 struct lttng_trace_chunk *chunk,
 149                 struct lttng_directory_handle *chunk_directory);
 150
 151 LTTNG_HIDDEN
 152 enum lttng_trace_chunk_status
 153 lttng_trace_chunk_get_session_output_directory_handle(
 154                 struct lttng_trace_chunk *chunk,
 155                 struct lttng_directory_handle **handle);
 156
 157 LTTNG_HIDDEN
 158 enum lttng_trace_chunk_status lttng_trace_chunk_borrow_chunk_directory_handle(
 159                 struct lttng_trace_chunk *chunk,
 160                 const struct lttng_directory_handle **handle);
 161
 162 LTTNG_HIDDEN
 163 enum lttng_trace_chunk_status lttng_trace_chunk_create_subdirectory(
 164                 struct lttng_trace_chunk *chunk,
 165                 const char *subdirectory_path);
 166
 167 LTTNG_HIDDEN
 168 enum lttng_trace_chunk_status lttng_trace_chunk_open_file(
 169                 struct lttng_trace_chunk *chunk,
 170                 const char *filename,
 171                 int flags,
 172                 mode_t mode,
 173                 int *out_fd,
 174                 bool expect_no_file);
 175
 176 LTTNG_HIDDEN
 177 enum lttng_trace_chunk_status lttng_trace_chunk_open_fs_handle(
 178                 struct lttng_trace_chunk *chunk,
 179                 const char *filename,
 180                 int flags,
 181                 mode_t mode,
 182                 struct fs_handle **out_handle,
 183                 bool expect_no_file);
 184
 185 LTTNG_HIDDEN
 186 int lttng_trace_chunk_unlink_file(struct lttng_trace_chunk *chunk,
 187                 const char *filename);
 188
 189 LTTNG_HIDDEN
 190 enum lttng_trace_chunk_status lttng_trace_chunk_get_close_command(
 191                 struct lttng_trace_chunk *chunk,
 192                 enum lttng_trace_chunk_command_type *command_type);
 193
 194 LTTNG_HIDDEN
 195 enum lttng_trace_chunk_status lttng_trace_chunk_set_close_command(
 196                 struct lttng_trace_chunk *chunk,
 197                 enum lttng_trace_chunk_command_type command_type);
 198
 199 LTTNG_HIDDEN
 200 const char *lttng_trace_chunk_command_type_get_name(
 201                 enum lttng_trace_chunk_command_type command);
 202
 203 LTTNG_HIDDEN
 204 bool lttng_trace_chunk_ids_equal(const struct lttng_trace_chunk *chunk_a,
 205                 const struct lttng_trace_chunk *chunk_b);
 206
 207 /* Returns true on success. */
 208 LTTNG_HIDDEN
 209 bool lttng_trace_chunk_get(struct lttng_trace_chunk *chunk);
 210
 211 LTTNG_HIDDEN
 212 void lttng_trace_chunk_put(struct lttng_trace_chunk *chunk);
 213
 214 #endif /* LTTNG_TRACE_CHUNK_H */