src/common/config/session-config.h

   1 /*
   2  * Copyright (C) 2013 - 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 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 #ifndef _CONFIG_H
  19 #define _CONFIG_H
  20
  21 #include <common/config/ini.h>
  22 #include <common/config/config-session-abi.h>
  23 #include <common/macros.h>
  24 #include <stdint.h>
  25
  26 struct config_entry {
  27         /* section is NULL if the entry is not in a section */
  28         const char *section;
  29         const char *name;
  30         const char *value;
  31 };
  32
  33 struct config_load_session_override_attr {
  34         char *path_url;
  35         char *ctrl_url;
  36         char *data_url;
  37         char *session_name;
  38 };
  39
  40 /* Instance of a configuration writer. */
  41 struct config_writer;
  42
  43 /*
  44  * A config_entry_handler_cb receives config_entry structures belonging to the
  45  * sections the handler has been registered to.
  46  *
  47  * The config_entry and its members are only valid for the duration of the call
  48  * and must not be freed.
  49  *
  50  * config_entry_handler_cb may return negative value to indicate an error in
  51  * the configuration file.
  52  */
  53 typedef int (*config_entry_handler_cb)(const struct config_entry *, void *);
  54
  55 /*
  56  * Read a section's entries in an INI configuration file.
  57  *
  58  * path may be NULL, in which case the following paths will be tried:
  59  *      1) $HOME/.lttng/lttng.conf
  60  *      2) /etc/lttng/lttng.conf
  61  *
  62  * handler will only be called with entries belonging to the provided section.
  63  * If section is NULL, all entries will be relayed to handler. If section is
  64  * "", only the global entries are relayed.
  65  *
  66  * Returns 0 on success. Negative values are error codes. If the return value
  67  * is positive, it represents the line number on which a parsing error occurred.
  68  */
  69 LTTNG_HIDDEN
  70 int config_get_section_entries(const char *path, const char *section,
  71                 config_entry_handler_cb handler, void *user_data);
  72
  73 /*
  74  * Parse a configuration value.
  75  *
  76  * This function expects either an unsigned integer or a boolean text option.
  77  * The following strings are recognized: true, yes, on, false, no and off.
  78  *
  79  * Returns either the value of the parsed integer, or 0/1 if a boolean text
  80  * string was recognized. Negative values indicate an error.
  81  */
  82 LTTNG_HIDDEN
  83 int config_parse_value(const char *value);
  84
  85 /*
  86  * Create an instance of a configuration writer.
  87  *
  88  * fd_output File to which the XML content must be written. fd_output is
  89  * owned by the caller.
  90  *
  91  * indent If other than 0 the XML will be pretty printed
  92  * with indentation and newline.
  93  *
  94  * Returns an instance of a configuration writer on success, NULL on
  95  * error.
  96  */
  97 LTTNG_HIDDEN
  98 struct config_writer *config_writer_create(int fd_output, int indent);
  99
 100 /*
 101  * Destroy an instance of a configuration writer.
 102  *
 103  * writer An instance of a configuration writer.
 104  *
 105  * Returns zero if the XML document could be closed cleanly. Negative values
 106  * indicate an error.
 107  */
 108 LTTNG_HIDDEN
 109 int config_writer_destroy(struct config_writer *writer);
 110
 111 /*
 112  * Open an element tag.
 113  *
 114  * writer An instance of a configuration writer.
 115  *
 116  * element_name Element tag name.
 117  *
 118  * Returns zero if the XML element could be opened.
 119  * Negative values indicate an error.
 120  */
 121 LTTNG_HIDDEN
 122 int config_writer_open_element(struct config_writer *writer,
 123                 const char *element_name);
 124
 125 /*
 126  * Write an element tag attribute.
 127  *
 128  * writer An instance of a configuration writer.
 129  *
 130  * name Attribute name.
 131  *
 132  * Returns zero if the XML element's attribute could be written.
 133  * Negative values indicate an error.
 134  */
 135 LTTNG_HIDDEN
 136 int config_writer_write_attribute(struct config_writer *writer,
 137                 const char *name, const char *value);
 138
 139 /*
 140  * Close the current element tag.
 141  *
 142  * writer An instance of a configuration writer.
 143  *
 144  * Returns zero if the XML document could be closed cleanly.
 145  * Negative values indicate an error.
 146  */
 147 LTTNG_HIDDEN
 148 int config_writer_close_element(struct config_writer *writer);
 149
 150 /*
 151  * Write an element of type unsigned int.
 152  *
 153  * writer An instance of a configuration writer.
 154  *
 155  * element_name Element name.
 156  *
 157  * value Unsigned int value of the element
 158  *
 159  * Returns zero if the element's value could be written.
 160  * Negative values indicate an error.
 161  */
 162 LTTNG_HIDDEN
 163 int config_writer_write_element_unsigned_int(struct config_writer *writer,
 164                 const char *element_name, uint64_t value);
 165
 166 /*
 167  * Write an element of type signed int.
 168  *
 169  * writer An instance of a configuration writer.
 170  *
 171  * element_name Element name.
 172  *
 173  * value Signed int value of the element
 174  *
 175  * Returns zero if the element's value could be written.
 176  * Negative values indicate an error.
 177  */LTTNG_HIDDEN
 178 int config_writer_write_element_signed_int(struct config_writer *writer,
 179                 const char *element_name, int64_t value);
 180
 181 /*
 182  * Write an element of type boolean.
 183  *
 184  * writer An instance of a configuration writer.
 185  *
 186  * element_name Element name.
 187  *
 188  * value Boolean value of the element
 189  *
 190  * Returns zero if the element's value could be written.
 191  * Negative values indicate an error.
 192  */
 193 LTTNG_HIDDEN
 194 int config_writer_write_element_bool(struct config_writer *writer,
 195                 const char *element_name, int value);
 196
 197 /*
 198  * Write an element of type string.
 199  *
 200  * writer An instance of a configuration writer.
 201  *
 202  * element_name Element name.
 203  *
 204  * value String value of the element
 205  *
 206  * Returns zero if the element's value could be written.
 207  * Negative values indicate an error.
 208  */
 209 LTTNG_HIDDEN
 210 int config_writer_write_element_string(struct config_writer *writer,
 211                 const char *element_name, const char *value);
 212
 213 /*
 214  * Load session configurations from a file.
 215  *
 216  * path Path to an LTTng session configuration file. All *.lttng files
 217  * will be loaded if path is a directory. If path is NULL, the default
 218  * paths will be searched in the following order:
 219  *      1) $HOME/.lttng/sessions
 220  *      2) /etc/lttng/sessions
 221  *
 222  * session_name Name of the session to load. Will load all
 223  * sessions from path if NULL.
 224  *
 225  * overwrite Overwrite current session configuration if it exists.
 226  * autoload Tell to load the auto session(s).
 227  * overrides The override attribute structure specifying override parameters.
 228  *
 229  * Returns zero if the session could be loaded successfully. Returns
 230  * a negative LTTNG_ERR code on error.
 231  */
 232 LTTNG_HIDDEN
 233 int config_load_session(const char *path, const char *session_name,
 234                 int overwrite, unsigned int autoload,
 235                 const struct config_load_session_override_attr *overrides);
 236
 237 #endif /* _CONFIG_H */