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 LTTNG_HIDDEN
  60 int config_get_section_entries(const char *path, const char *section,
  61                 config_entry_handler_cb handler, void *user_data);
  62
  63 /*
  64  * Parse a configuration value.
  65  *
  66  * This function expects either an unsigned integer or a boolean text option.
  67  * The following strings are recognized: true, yes, on, false, no and off.
  68  *
  69  * Returns either the value of the parsed integer, or 0/1 if a boolean text
  70  * string was recognized. Negative values indicate an error.
  71  */
  72 LTTNG_HIDDEN
  73 int config_parse_value(const char *value);
  74
  75 /*
  76  * Create an instance of a configuration writer.
  77  *
  78  * fd_output File to which the XML content must be written. fd_output is
  79  * owned by the caller.
  80  *
  81  * indent If other than 0 the XML will be pretty printed
  82  * with indentation and newline.
  83  *
  84  * Returns an instance of a configuration writer on success, NULL on
  85  * error.
  86  */
  87 LTTNG_HIDDEN
  88 struct config_writer *config_writer_create(int fd_output, int indent);
  89
  90 /*
  91  * Destroy an instance of a configuration writer.
  92  *
  93  * writer An instance of a configuration writer.
  94  *
  95  * Returns zero if the XML document could be closed cleanly. Negative values
  96  * indicate an error.
  97  */
  98 LTTNG_HIDDEN
  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 LTTNG_HIDDEN
 112 int config_writer_open_element(struct config_writer *writer,
 113                 const char *element_name);
 114
 115 /*
 116  * Write an element tag attribute.
 117  *
 118  * writer An instance of a configuration writer.
 119  *
 120  * name Attribute name.
 121  *
 122  * Returns zero if the XML element's attribute could be written.
 123  * Negative values indicate an error.
 124  */
 125 LTTNG_HIDDEN
 126 int config_writer_write_attribute(struct config_writer *writer,
 127                 const char *name, const char *value);
 128
 129 /*
 130  * Close the current element tag.
 131  *
 132  * writer An instance of a configuration writer.
 133  *
 134  * Returns zero if the XML document could be closed cleanly.
 135  * Negative values indicate an error.
 136  */
 137 LTTNG_HIDDEN
 138 int config_writer_close_element(struct config_writer *writer);
 139
 140 /*
 141  * Write an element of type unsigned int.
 142  *
 143  * writer An instance of a configuration writer.
 144  *
 145  * element_name Element name.
 146  *
 147  * value Unsigned int value of the element
 148  *
 149  * Returns zero if the element's value could be written.
 150  * Negative values indicate an error.
 151  */
 152 LTTNG_HIDDEN
 153 int config_writer_write_element_unsigned_int(struct config_writer *writer,
 154                 const char *element_name, uint64_t value);
 155
 156 /*
 157  * Write an element of type signed int.
 158  *
 159  * writer An instance of a configuration writer.
 160  *
 161  * element_name Element name.
 162  *
 163  * value Signed int value of the element
 164  *
 165  * Returns zero if the element's value could be written.
 166  * Negative values indicate an error.
 167  */LTTNG_HIDDEN
 168 int config_writer_write_element_signed_int(struct config_writer *writer,
 169                 const char *element_name, int64_t value);
 170
 171 /*
 172  * Write an element of type boolean.
 173  *
 174  * writer An instance of a configuration writer.
 175  *
 176  * element_name Element name.
 177  *
 178  * value Boolean value of the element
 179  *
 180  * Returns zero if the element's value could be written.
 181  * Negative values indicate an error.
 182  */
 183 LTTNG_HIDDEN
 184 int config_writer_write_element_bool(struct config_writer *writer,
 185                 const char *element_name, int value);
 186
 187 /*
 188  * Write an element of type string.
 189  *
 190  * writer An instance of a configuration writer.
 191  *
 192  * element_name Element name.
 193  *
 194  * value String value of the element
 195  *
 196  * Returns zero if the element's value could be written.
 197  * Negative values indicate an error.
 198  */
 199 LTTNG_HIDDEN
 200 int config_writer_write_element_string(struct config_writer *writer,
 201                 const char *element_name, const char *value);
 202
 203 /*
 204  * Load session configurations from a file.
 205  *
 206  * path Path to an LTTng session configuration file. All *.lttng files
 207  * will be loaded if path is a directory. If path is NULL, the default
 208  * paths will be searched in the following order:
 209  *      1) $HOME/.lttng/sessions
 210  *      2) /etc/lttng/sessions
 211  *
 212  * session_name Name of the session to load. Will load all
 213  * sessions from path if NULL.
 214  *
 215  * overwrite Overwrite current session configuration if it exists.
 216  * autoload Tell to load the auto session(s).
 217  * overrides The override attribute structure specifying override parameters.
 218  *
 219  * Returns zero if the session could be loaded successfully. Returns
 220  * a negative LTTNG_ERR code on error.
 221  */
 222 LTTNG_HIDDEN
 223 int config_load_session(const char *path, const char *session_name,
 224                 int overwrite, unsigned int autoload,
 225                 const struct config_load_session_override_attr *overrides);
 226
 227 #endif /* _CONFIG_H */