NAME

       mongoc_logging - Logging

       MongoDB C driver Logging Abstraction

SYNOPSIS

          typedef enum {
             MONGOC_LOG_LEVEL_ERROR,
             MONGOC_LOG_LEVEL_CRITICAL,
             MONGOC_LOG_LEVEL_WARNING,
             MONGOC_LOG_LEVEL_MESSAGE,
             MONGOC_LOG_LEVEL_INFO,
             MONGOC_LOG_LEVEL_DEBUG,
             MONGOC_LOG_LEVEL_TRACE,
          } mongoc_log_level_t;

          #define MONGOC_ERROR(...)
          #define MONGOC_CRITICAL(...)
          #define MONGOC_WARNING(...)
          #define MONGOC_MESSAGE(...)
          #define MONGOC_INFO(...)
          #define MONGOC_DEBUG(...)

          typedef void (*mongoc_log_func_t) (mongoc_log_level_t log_level,
                                             const char *log_domain,
                                             const char *message,
                                             void *user_data);

          void
          mongoc_log_set_handler (mongoc_log_func_t log_func, void *user_data);
          void
          mongoc_log (mongoc_log_level_t log_level,
                      const char *log_domain,
                      const char *format,
                      ...) BSON_GNUC_PRINTF (3, 4);
          const char *
          mongoc_log_level_str (mongoc_log_level_t log_level);
          void
          mongoc_log_default_handler (mongoc_log_level_t log_level,
                                      const char *log_domain,
                                      const char *message,
                                      void *user_data);
          void
          mongoc_log_trace_enable (void);
          void
          mongoc_log_trace_disable (void);

       The  MongoDB  C  driver  comes  with  an  abstraction for logging that you can use in your
       application, or integrate with an existing logging system.

MACROS

       To make logging a little less  painful,  various  helper  macros  are  provided.  See  the
       following example.

          #undef MONGOC_LOG_DOMAIN
          #define MONGOC_LOG_DOMAIN "my-custom-domain"

          MONGOC_WARNING ("An error occurred: %s", strerror (errno));

CUSTOM LOG HANDLERS

       The default log handler prints a timestamp and the log message to stdout, or to stderr for
       warnings, critical messages, and errors.
              You can override the handler with mongoc_log_set_handler().  Your handler  function
              is called in a mutex for thread safety.

       For  example,  you  could register a custom handler to suppress messages at INFO level and
       below:

          void
          my_logger (mongoc_log_level_t log_level,
                     const char *log_domain,
                     const char *message,
                     void *user_data)
          {
             /* smaller values are more important */
             if (log_level < MONGOC_LOG_LEVEL_INFO) {
                mongoc_log_default_handler (log_level, log_domain, message, user_data);
             }
          }

          int
          main (int argc, char *argv[])
          {
             mongoc_log_set_handler (my_logger, NULL);
             mongoc_init ();

             /* ... your code ...  */

             mongoc_cleanup ();
             return 0;
          }

       Note that in the example above mongoc_log_set_handler() is  called  before  mongoc_init().
       Otherwise, some log traces could not be processed by the log handler.

       To restore the default handler:

          mongoc_log_set_handler (mongoc_log_default_handler, NULL);

DISABLE LOGGING

       To disable all logging, including warnings, critical messages and errors, provide an empty
       log handler:

          mongoc_log_set_handler (NULL, NULL);

TRACING

       If  compiling  your  own  copy  of  the  MongoDB  C  driver,  consider  configuring   with
       -DENABLE_TRACING=ON  to enable function tracing and hex dumps of network packets to STDERR
       and STDOUT during development and debugging.

       This is especially useful when debugging what may be going on internally in the driver.

       Trace messages can be  enabled  and  disabled  by  calling  mongoc_log_trace_enable()  and
       mongoc_log_trace_disable()

       NOTE:
          Compiling  the  driver  with -DENABLE_TRACING=ON will affect its performance. Disabling
          tracing with mongoc_log_trace_disable() significantly reduces the overhead, but  cannot
          remove it completely.

AUTHOR

       MongoDB, Inc

COPYRIGHT

       2017-present, MongoDB, Inc