+// :vi sw=4 ts=4 noet:
+/*
+==================================================================================
+ Copyright (c) 2019-2020 Nokia
+ Copyright (c) 2018-2020 AT&T Intellectual Property.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+==================================================================================
+*/
+/*
+ Mnemonic: logging.c
+ Abstract: Implements a common logging interface.
+
+ Some thoughts and theory....
+ Libraries should write human readable messages to standard error
+ when errors, warnings, or general information messages are called
+ for. These messages should NEVER be written to standard output,
+ and should never be mixed with an application's log messages which
+ are assumed to contain potentially sensitive information, such as
+ user names, and should not be written to standard error.
+
+ For libraries such as RMR, where speed and latency are absolutely
+ critical, logging should only be done from non-critical path code,
+ or when an error has already compromised the ability to be performant.
+ Thus, it is expected that most calls to the functions here are of
+ the form:
+ if( DEBUG ) rmr_logger( vlevel, fmt, parms);
+
+ such that the call to rmr_logger() is removed from the code unless
+ compiled with the DEBUG flag set. Code such as
+ if( vlevel >= WARNING ) {
+ rmr_logger( fmt, parms )
+ }
+
+ is unacceptable because it adds unnecessary checking for the current
+ verbosity level setting in line.
+
+
+ With respect to formatting messages written to stderr: they should NOT
+ be written with json, or anyother form of mark up. Idealy, they should
+ use a syntax similar to system log:
+ <timestamp> <pid> <situation> <message>
+
+ where timestamp is UNIX time, pid is the process id, situation is error,
+ warning, etc, and message is obviously the text.
+
+ Thus, the default messages geneated are "plain." Because some might feel
+ that messages need to be formatted, the code here provides for the gross
+ encapsulation of standard error text into json (best wishes for the poor
+ sap who is left having to read the output on some dark and stormy night).
+ To enable this, the environment veriable RMR_HRLOG=0 must be set to
+ turn off human readable logs.
+
+ Author: E. Scott Daniels
+ Date: 27 January 2020
+*/
+
+#ifndef _logger_static_c
+#define _logger_static_c
+
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strings.h>
+#include <errno.h>
+#include <string.h>
+#include <stdint.h>
+#include <time.h>
+
+
+#include <rmr.h>
+#include <rmr_agnostic.h>
+#include <rmr_logging.h>
+
+static int log_initialised = 0;
+static int log_vlevel = RMR_VL_ERR;
+static int log_hrlogging = 1;
+static int log_pid = 0;
+static char* log_situations[RMR_VL_DEBUG+1];
+
+/*
+ Initialise logging. Returns the current log level.
+*/
+extern int rmr_vlog_init( ) {
+ char* data;
+
+ if( (data = getenv( ENV_LOG_HR )) != NULL ) {
+ log_hrlogging = atoi( data );
+ }
+
+ if( (data = getenv( ENV_LOG_VLEVEL )) != NULL ) {
+ log_vlevel = atoi( data );
+ if( log_vlevel < 0 ) {
+ log_vlevel = 0;
+ } else {
+ if( log_vlevel > RMR_VL_DEBUG ) {
+ log_vlevel = RMR_VL_DEBUG;
+ }
+ }
+ }
+
+ log_pid = getpid();
+ log_situations[RMR_VL_DEBUG] = LOG_DEBUG;
+ log_situations[RMR_VL_INFO] = LOG_INFO;
+ log_situations[RMR_VL_WARN] = LOG_WARN;
+ log_situations[RMR_VL_ERR] = LOG_ERROR;
+ log_situations[RMR_VL_CRIT] = LOG_CRIT;
+
+ log_initialised = 1;
+
+ return log_vlevel;
+}
+
+/*
+ Write a variable message formatted in the same vein as *printf.
+ We add a header to each log message with time, pid and message
+ situation (error, warning, etc.).
+*/
+extern void rmr_vlog( int write_level, char* fmt, ... ) {
+ va_list argp; // first arg in our parms which is variable
+ char msg[4096];
+ int hlen;
+ char* body; // pointer into msg, past header
+
+ if( write_level > log_vlevel ) { // write too big, skip
+ return;
+ }
+
+ if( ! log_initialised ) {
+ rmr_vlog_init();
+ }
+
+ if( write_level > RMR_VL_DEBUG || write_level < 0 ) {
+ write_level = RMR_VL_DEBUG;
+ }
+
+ hlen = snprintf( msg, sizeof( msg ), "%ld %d/RMR [%s] ", (long) time( NULL ), log_pid, log_situations[write_level] );
+ body = msg + hlen;
+
+ va_start( argp, fmt ); // suss out parm past fmt
+
+ vsnprintf( body, sizeof( msg ) - (hlen+2), fmt, argp ); // add in user message formatting it along the way
+ fprintf( stderr, "%s", msg ); // we grew from printfs so all existing msg have \n; assume there
+}
+
+/*
+ This ensures that the message is written regardless of the current log level
+ setting. This allows for route table collection verbose levels to be taken
+ into consideration separately from the err/warn/debug messages. Component
+ verbosity would be better and should be implemented.
+*/
+
+extern void rmr_vlog_force( int write_level, char* fmt, ... ) {
+ va_list argp; // first arg in our parms which is variable
+ char msg[4096];
+ int hlen;
+ char* body; // pointer into msg, past header
+
+ if( ! log_initialised ) {
+ rmr_vlog_init();
+ }
+
+ if( write_level > RMR_VL_DEBUG || write_level < 0 ) {
+ write_level = RMR_VL_DEBUG;
+ }
+
+ hlen = snprintf( msg, sizeof( msg ), "%ld %d/RMR [%s] ", (long) time( NULL ), log_pid, log_situations[write_level] );
+ body = msg + hlen;
+
+ va_start( argp, fmt ); // suss out parm past fmt
+
+ vsnprintf( body, sizeof( msg ) - (hlen+2), fmt, argp ); // add in user message formatting it along the way
+ fprintf( stderr, "%s", msg ); // we grew from printfs so all existing msg have \n; assume there
+}
+
+// -------------------- public functions that are needed -----------------
+
+/*
+ Allow user control to logging level control. Accepts a new log level
+ from the user programme. Messages which have a write level setting
+ which is >= to the new level will be written. Setting the new value
+ to RMR_VL_OFF disables all logging (not advised).
+*/
+extern void rmr_set_vlevel( int new_level ) {
+ if( new_level >= 0 ) {
+ log_vlevel = new_level;
+ }
+}
+
+#endif
Code Review / ric-plt / lib / rmr.git / commitdiff