build: move LevelSubLogger to own file

To make the upcoming commits easier to review and for general code
organisation.

build/log.go

@@ -1,9 +1,7 @@
 package build
 
 import (
-	"fmt"
 	"io"
-	"strings"
 
 	"github.com/btcsuite/btclog"
 )
@@ -121,114 +119,3 @@ func NewSubLogger(subsystem string,
 	// For any other configurations, we'll disable logging.
 	return btclog.Disabled
 }
-
-// SubLoggers is a type that holds a map of subsystem loggers keyed by their
-// subsystem name.
-type SubLoggers map[string]btclog.Logger
-
-// LeveledSubLogger provides the ability to retrieve the subsystem loggers of
-// a logger and set their log levels individually or all at once.
-type LeveledSubLogger interface {
-	// SubLoggers returns the map of all registered subsystem loggers.
-	SubLoggers() SubLoggers
-
-	// SupportedSubsystems returns a slice of strings containing the names
-	// of the supported subsystems. Should ideally correspond to the keys
-	// of the subsystem logger map and be sorted.
-	SupportedSubsystems() []string
-
-	// SetLogLevel assigns an individual subsystem logger a new log level.
-	SetLogLevel(subsystemID string, logLevel string)
-
-	// SetLogLevels assigns all subsystem loggers the same new log level.
-	SetLogLevels(logLevel string)
-}
-
-// ParseAndSetDebugLevels attempts to parse the specified debug level and set
-// the levels accordingly on the given logger. An appropriate error is returned
-// if anything is invalid.
-func ParseAndSetDebugLevels(level string, logger LeveledSubLogger) error {
-	// Split at the delimiter.
-	levels := strings.Split(level, ",")
-	if len(levels) == 0 {
-		return fmt.Errorf("invalid log level: %v", level)
-	}
-
-	// If the first entry has no =, treat is as the log level for all
-	// subsystems.
-	globalLevel := levels[0]
-	if !strings.Contains(globalLevel, "=") {
-		// Validate debug log level.
-		if !validLogLevel(globalLevel) {
-			str := "the specified debug level [%v] is invalid"
-			return fmt.Errorf(str, globalLevel)
-		}
-
-		// Change the logging level for all subsystems.
-		logger.SetLogLevels(globalLevel)
-
-		// The rest will target specific subsystems.
-		levels = levels[1:]
-	}
-
-	// Go through the subsystem/level pairs while detecting issues and
-	// update the log levels accordingly.
-	for _, logLevelPair := range levels {
-		if !strings.Contains(logLevelPair, "=") {
-			str := "the specified debug level contains an " +
-				"invalid subsystem/level pair [%v]"
-			return fmt.Errorf(str, logLevelPair)
-		}
-
-		// Extract the specified subsystem and log level.
-		fields := strings.Split(logLevelPair, "=")
-		if len(fields) != 2 {
-			str := "the specified debug level has an invalid " +
-				"format [%v] -- use format subsystem1=level1," +
-				"subsystem2=level2"
-			return fmt.Errorf(str, logLevelPair)
-		}
-		subsysID, logLevel := fields[0], fields[1]
-		subLoggers := logger.SubLoggers()
-
-		// Validate subsystem.
-		if _, exists := subLoggers[subsysID]; !exists {
-			str := "the specified subsystem [%v] is invalid -- " +
-				"supported subsystems are %v"
-			return fmt.Errorf(
-				str, subsysID, logger.SupportedSubsystems(),
-			)
-		}
-
-		// Validate log level.
-		if !validLogLevel(logLevel) {
-			str := "the specified debug level [%v] is invalid"
-			return fmt.Errorf(str, logLevel)
-		}
-
-		logger.SetLogLevel(subsysID, logLevel)
-	}
-
-	return nil
-}
-
-// validLogLevel returns whether or not logLevel is a valid debug log level.
-func validLogLevel(logLevel string) bool {
-	switch logLevel {
-	case "trace":
-		fallthrough
-	case "debug":
-		fallthrough
-	case "info":
-		fallthrough
-	case "warn":
-		fallthrough
-	case "error":
-		fallthrough
-	case "critical":
-		fallthrough
-	case "off":
-		return true
-	}
-	return false
-}

build/sub_logger.go

@@ -0,0 +1,124 @@
+package build
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/btcsuite/btclog"
+)
+
+// SubLoggers is a type that holds a map of subsystem loggers keyed by their
+// subsystem name.
+type SubLoggers map[string]btclog.Logger
+
+// LeveledSubLogger provides the ability to retrieve the subsystem loggers of
+// a logger and set their log levels individually or all at once.
+type LeveledSubLogger interface {
+	// SubLoggers returns the map of all registered subsystem loggers.
+	SubLoggers() SubLoggers
+
+	// SupportedSubsystems returns a slice of strings containing the names
+	// of the supported subsystems. Should ideally correspond to the keys
+	// of the subsystem logger map and be sorted.
+	SupportedSubsystems() []string
+
+	// SetLogLevel assigns an individual subsystem logger a new log level.
+	SetLogLevel(subsystemID string, logLevel string)
+
+	// SetLogLevels assigns all subsystem loggers the same new log level.
+	SetLogLevels(logLevel string)
+}
+
+// ParseAndSetDebugLevels attempts to parse the specified debug level and set
+// the levels accordingly on the given logger. An appropriate error is returned
+// if anything is invalid.
+func ParseAndSetDebugLevels(level string, logger LeveledSubLogger) error {
+	// Split at the delimiter.
+	levels := strings.Split(level, ",")
+	if len(levels) == 0 {
+		return fmt.Errorf("invalid log level: %v", level)
+	}
+
+	// If the first entry has no =, treat is as the log level for all
+	// subsystems.
+	globalLevel := levels[0]
+	if !strings.Contains(globalLevel, "=") {
+		// Validate debug log level.
+		if !validLogLevel(globalLevel) {
+			str := "the specified debug level [%v] is invalid"
+
+			return fmt.Errorf(str, globalLevel)
+		}
+
+		// Change the logging level for all subsystems.
+		logger.SetLogLevels(globalLevel)
+
+		// The rest will target specific subsystems.
+		levels = levels[1:]
+	}
+
+	// Go through the subsystem/level pairs while detecting issues and
+	// update the log levels accordingly.
+	for _, logLevelPair := range levels {
+		if !strings.Contains(logLevelPair, "=") {
+			str := "the specified debug level contains an " +
+				"invalid subsystem/level pair [%v]"
+
+			return fmt.Errorf(str, logLevelPair)
+		}
+
+		// Extract the specified subsystem and log level.
+		fields := strings.Split(logLevelPair, "=")
+		if len(fields) != 2 {
+			str := "the specified debug level has an invalid " +
+				"format [%v] -- use format subsystem1=level1," +
+				"subsystem2=level2"
+
+			return fmt.Errorf(str, logLevelPair)
+		}
+		subsysID, logLevel := fields[0], fields[1]
+		subLoggers := logger.SubLoggers()
+
+		// Validate subsystem.
+		if _, exists := subLoggers[subsysID]; !exists {
+			str := "the specified subsystem [%v] is invalid -- " +
+				"supported subsystems are %v"
+
+			return fmt.Errorf(
+				str, subsysID, logger.SupportedSubsystems(),
+			)
+		}
+
+		// Validate log level.
+		if !validLogLevel(logLevel) {
+			str := "the specified debug level [%v] is invalid"
+			return fmt.Errorf(str, logLevel)
+		}
+
+		logger.SetLogLevel(subsysID, logLevel)
+	}
+
+	return nil
+}
+
+// validLogLevel returns whether or not logLevel is a valid debug log level.
+func validLogLevel(logLevel string) bool {
+	switch logLevel {
+	case "trace":
+		fallthrough
+	case "debug":
+		fallthrough
+	case "info":
+		fallthrough
+	case "warn":
+		fallthrough
+	case "error":
+		fallthrough
+	case "critical":
+		fallthrough
+	case "off":
+		return true
+	}
+
+	return false
+}