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mco_trace_message_handler_fn Callback

Callback function to handle trace messages.

For an overview see page Tracing Framework in C

When any database operation triggers a trace message a user-define callback function is called which has the following prototype:

 
    typedef int (*mco_trace_message_handler_fn)( mco_severity severity, 
                                mco_trace_module module, 
                                const char *file, 
                                int line, 
                                const char *fmt, ...);

Arguments

severity	The severity level of the message; possible levels (as defined in enum `mco_severity`) are: MCO_TRACE_FATAL MCO_TRACE_ERROR MCO_TRACE_WARNING MCO_TRACE_NOTICE MCO_TRACE_INFO MCO_TRACE_DEBUG MCO_TRACE_VERBOSE
module	The constant describing which eXtremeDB module where tracing is enabled. Modules are defined in enum `mco_trace_module`
file	The source code file where tracing has occurred
line	The source code line where tracing has occurred
fmt	A printf-like format for messages. Format specifiers are: %t - message time %m - module %i - thread id %s - severity %f - source code file %l - source code line %e - error text %r - pring errno %R - print errno with string representation
...	The arguments for substitution according to the format specification in argument `fmt`

Description

This function is when any database operation triggers a trace message. Note that this custom handler must be registered with function mco_trace_set_handler().

Return Codes

int	An integer value to indicate success (`MCO_S_OK`) or an error code