log.go

package main

import (
	"fmt"
	"os"

	"github.com/btcsuite/btclog"
	"github.com/btcsuite/seelog"

	"github.com/decred/gominer/stratum"
)

var (
	backendLog = seelog.Disabled
	mainLog    = btclog.Disabled
	minrLog    = btclog.Disabled
	poolLog    = btclog.Disabled
)

var subsystemLoggers = map[string]btclog.Logger{
	"MAIN": mainLog,
	"MINR": minrLog,
	"POOL": poolLog,
}

// useLogger updates the logger references for subsystemID to logger.  Invalid
// subsystems are ignored.
func useLogger(subsystemID string, logger btclog.Logger) {
	if _, ok := subsystemLoggers[subsystemID]; !ok {
		return
	}
	subsystemLoggers[subsystemID] = logger

	switch subsystemID {
	case "MAIN":
		mainLog = logger
	case "MINR":
		minrLog = logger
	case "POOL":
		poolLog = logger
		stratum.UseLogger(logger)
	}
}

// initSeelogLogger initializes a new seelog logger that is used as the backend
// for all logging subsytems.
func initSeelogLogger(logFile string) {
	config := `
	<seelog type="adaptive" mininterval="2000000" maxinterval="100000000"
		critmsgcount="500" minlevel="trace">
		<outputs formatid="all">
			<console />
			<rollingfile type="size" filename="%s" maxsize="10485760" maxrolls="3" />
		</outputs>
		<formats>
			<format id="all" format="%%Time %%Date [%%LEV] %%Msg%%n" />
		</formats>
	</seelog>`
	config = fmt.Sprintf(config, logFile)

	logger, err := seelog.LoggerFromConfigAsString(config)
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to create logger: %v", err)
		os.Exit(1)
	}

	backendLog = logger
}

// setLogLevel sets the logging level for provided subsystem.  Invalid
// subsystems are ignored.  Uninitialized subsystems are dynamically created as
// needed.
func setLogLevel(subsystemID string, logLevel string) {
	// Ignore invalid subsystems.
	logger, ok := subsystemLoggers[subsystemID]
	if !ok {
		return
	}

	// Default to info if the log level is invalid.
	level, ok := btclog.LogLevelFromString(logLevel)
	if !ok {
		level = btclog.InfoLvl
	}

	// Create new logger for the subsystem if needed.
	if logger == btclog.Disabled {
		logger = btclog.NewSubsystemLogger(backendLog, subsystemID+": ")
		useLogger(subsystemID, logger)
	}
	logger.SetLevel(level)
}

// setLogLevels sets the log level for all subsystem loggers to the passed
// level.  It also dynamically creates the subsystem loggers as needed, so it
// can be used to initialize the logging system.
func setLogLevels(logLevel string) {
	// Configure all sub-systems with the new logging level.  Dynamically
	// create loggers as needed.
	for subsystemID := range subsystemLoggers {
		setLogLevel(subsystemID, logLevel)
	}
}