[Wind] Ace notes (1)-Log message management

ACE provides flexible and convenient log management and message output functions. The following describes some simple and direct functions.

Ace_debug common output messages
Ace_error provides some low-level messages about program errors.

The usage of the two macros is consistent.
Ace_debug (error level, "Format String", variable 1... Variable N)

Some Error-level systems are defined as follows:
Lm_shutdown = 01, system crash level
Lm_trace = 02, Trace Level
Lm_debug = 04, debug level
Lm_info = 010, general information level
Lm_notice = 020, Attention Level
Lm_warning = 040, warning level
Lm_startup = 0100, startup level
Lm_error = 0200, error level
Lm_critical = 0400, critical level
Lm_alert = 01000, recoverable Warning Level
Lm_emergency = 02000, Global Warning Level
Some format strings are used as follows:
Similar to the use of printf in C
% N-current program name of the table
% T-current thread Number of the table
% P-Table pointer
% S-string
 
Ace manages and controls the output through the Global Single Instance ace_log_msg. We can use this instance to redirect the output to the file or to the flag output.
The following table lists the levels of messages that can be output:

Ace_log_msg-> set_flags (ace_log_msg: stderr );
Set output to standard error output
Ace_log_msg-> clr_flags (ace_log_msg: stderr );
Disable output to flag error output
Ace_log_msg-> set_flags (ace_log_msg: ostream );
Ofstream mystream (filename, IOS: Out | IOs: trunc );
Ace_log_msg-> msg_ostream (& mystream );
Set output to file
U_long priority_mask = ace_log_msg-> priority_mask (ace_log_msg: process );
Ace_set_bits (priority_mask, lm_debug | lm_info );
Set to only record messages at the lm_debug or lm_info level
Ace_clr_bits (priority_mask, lm_debug | lm_info );
Clear setting conditions
Ace_log_msg also has a very interesting function, which can output blocks in the memory in hexadecimal mode. The simple usage is as follows:
Ace_log_msg-> log_hexdump (lm_debug,
(Char *) array,
Sizeof array );

The following is an example. The example is from the example program in the ace package.
# Include "ACE/OS _main.h"
# Include "ACE/streams. H"
# Include "ACE/log_msg.h"
Int
Ace_tmain (INT, ace_tchar * [])
{
// The message will be output to stderr.
Ace_debug (lm_debug,
"First message/N "));
Ace_log_msg-> clr_flags (ace_log_msg: stderr );
// The message will not be output because the flag is cleared.
Ace_debug (lm_debug,
"Second message/N "));
Ace_log_msg-> set_flags (ace_log_msg: ostream );
// The message will not be output because the stream entity has not been defined
Ace_debug (lm_debug,
"Third message/N "));
// Create a stream object pointing to the D:/output. Log File
Const char * filename = "D: // output. log ";
Ofstream mystream (filename, IOS: Out | IOs: trunc );
If (mystream. Bad ())
Return 1;
// Set output to stream
Ace_log_msg-> msg_ostream (& mystream );
// The message will be output to the file.
Ace_debug (lm_debug,
"Fourth message/N "));
Ace_log_msg-> set_flags (ace_log_msg: stderr );
// This message will be output to both the file and stderr.
Ace_debug (lm_debug,
"Th message/N "));
Return 0;
}
 
Well, there are more functions in the ace diary management function,
I will write in ACE skills and ACE application articles;
For example, you can use command line parameters to configure log parameter output and how to configure logs through configuration files.