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