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