src/common/config/session-config.h

   1 /*
   2  * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #ifndef _CONFIG_H
   9 #define _CONFIG_H
  10
  11 #include <common/config/ini.h>
  12 #include <common/config/config-session-abi.h>
  13 #include <common/macros.h>
  14 #include <stdint.h>
  15
  16 #ifdef __cplusplus
  17 extern "C" {
  18 #endif
  19
  20 struct config_entry {
  21         /* section is NULL if the entry is not in a section */
  22         const char *section;
  23         const char *name;
  24         const char *value;
  25 };
  26
  27 struct config_load_session_override_attr {
  28         char *path_url;
  29         char *ctrl_url;
  30         char *data_url;
  31         char *session_name;
  32 };
  33
  34 /* Instance of a configuration writer. */
  35 struct config_writer;
  36
  37 /*
  38  * A config_entry_handler_cb receives config_entry structures belonging to the
  39  * sections the handler has been registered to.
  40  *
  41  * The config_entry and its members are only valid for the duration of the call
  42  * and must not be freed.
  43  *
  44  * config_entry_handler_cb may return negative value to indicate an error in
  45  * the configuration file.
  46  */
  47 typedef int (*config_entry_handler_cb)(const struct config_entry *, void *);
  48
  49 /*
  50  * Read a section's entries in an INI configuration file.
  51  *
  52  * path may be NULL, in which case the following paths will be tried:
  53  *      1) $HOME/.lttng/lttng.conf
  54  *      2) /etc/lttng/lttng.conf
  55  *
  56  * handler will only be called with entries belonging to the provided section.
  57  * If section is NULL, all entries will be relayed to handler. If section is
  58  * "", only the global entries are relayed.
  59  *
  60  * Returns 0 on success. Negative values are error codes. If the return value
  61  * is positive, it represents the line number on which a parsing error occurred.
  62  */
  63 int config_get_section_entries(const char *path, const char *section,
  64                 config_entry_handler_cb handler, void *user_data);
  65
  66 /*
  67  * Parse a configuration value.
  68  *
  69  * This function expects either an unsigned integer or a boolean text option.
  70  * The following strings are recognized: true, yes, on, false, no and off.
  71  *
  72  * Returns either the value of the parsed integer, or 0/1 if a boolean text
  73  * string was recognized. Negative values indicate an error.
  74  */
  75 int config_parse_value(const char *value);
  76
  77 /*
  78  * Create an instance of a configuration writer.
  79  *
  80  * fd_output File to which the XML content must be written. fd_output is
  81  * owned by the caller.
  82  *
  83  * indent If other than 0 the XML will be pretty printed
  84  * with indentation and newline.
  85  *
  86  * Returns an instance of a configuration writer on success, NULL on
  87  * error.
  88  */
  89 struct config_writer *config_writer_create(int fd_output, int indent);
  90
  91 /*
  92  * Destroy an instance of a configuration writer.
  93  *
  94  * writer An instance of a configuration writer.
  95  *
  96  * Returns zero if the XML document could be closed cleanly. Negative values
  97  * indicate an error.
  98  */
  99 int config_writer_destroy(struct config_writer *writer);
 100
 101 /*
 102  * Open an element tag.
 103  *
 104  * writer An instance of a configuration writer.
 105  *
 106  * element_name Element tag name.
 107  *
 108  * Returns zero if the XML element could be opened.
 109  * Negative values indicate an error.
 110  */
 111 int config_writer_open_element(struct config_writer *writer,
 112                 const char *element_name);
 113
 114 /*
 115  * Write an element tag attribute.
 116  *
 117  * writer An instance of a configuration writer.
 118  *
 119  * name Attribute name.
 120  *
 121  * Returns zero if the XML element's attribute could be written.
 122  * Negative values indicate an error.
 123  */
 124 int config_writer_write_attribute(struct config_writer *writer,
 125                 const char *name, const char *value);
 126
 127 /*
 128  * Close the current element tag.
 129  *
 130  * writer An instance of a configuration writer.
 131  *
 132  * Returns zero if the XML document could be closed cleanly.
 133  * Negative values indicate an error.
 134  */
 135 int config_writer_close_element(struct config_writer *writer);
 136
 137 /*
 138  * Write an element of type unsigned int.
 139  *
 140  * writer An instance of a configuration writer.
 141  *
 142  * element_name Element name.
 143  *
 144  * value Unsigned int value of the element
 145  *
 146  * Returns zero if the element's value could be written.
 147  * Negative values indicate an error.
 148  */
 149 int config_writer_write_element_unsigned_int(struct config_writer *writer,
 150                 const char *element_name, uint64_t value);
 151
 152 /*
 153  * Write an element of type signed int.
 154  *
 155  * writer An instance of a configuration writer.
 156  *
 157  * element_name Element name.
 158  *
 159  * value Signed int value of the element
 160  *
 161  * Returns zero if the element's value could be written.
 162  * Negative values indicate an error.
 163  */
 164 int config_writer_write_element_signed_int(struct config_writer *writer,
 165                 const char *element_name, int64_t value);
 166
 167 /*
 168  * Write an element of type boolean.
 169  *
 170  * writer An instance of a configuration writer.
 171  *
 172  * element_name Element name.
 173  *
 174  * value Boolean value of the element
 175  *
 176  * Returns zero if the element's value could be written.
 177  * Negative values indicate an error.
 178  */
 179 int config_writer_write_element_bool(struct config_writer *writer,
 180                 const char *element_name, int value);
 181
 182 /*
 183  * Write an element of type string.
 184  *
 185  * writer An instance of a configuration writer.
 186  *
 187  * element_name Element name.
 188  *
 189  * value String value of the element
 190  *
 191  * Returns zero if the element's value could be written.
 192  * Negative values indicate an error.
 193  */
 194 int config_writer_write_element_string(struct config_writer *writer,
 195                 const char *element_name, const char *value);
 196
 197 /*
 198  * Write an element of type double.
 199  *
 200  * writer An instance of a configuration writer.
 201  *
 202  * element_name Element name.
 203  *
 204  * value Double value of the element
 205  *
 206  * Returns zero if the element's value could be written.
 207  * Negative values indicate an error.
 208  */
 209 int config_writer_write_element_double(struct config_writer *writer,
 210                 const char *element_name,
 211                 double 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 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 #ifdef __cplusplus
 237 }
 238 #endif
 239
 240 #endif /* _CONFIG_H */