The Level type represents a logging priority. Higher levels indicate more severe conditions. The Logger discards messages with a level lower than its configured minimum.
Level type
Represents a logging priority with values ranging from DebugLevel to FatalLevel.
Level constants
DebugLevel
Designates fine grained informational events that are most useful to debug an application.
const DebugLevel Level = -1
logger.SetLevel(velo.DebugLevel)
logger.Debug("entering function", "name", "processRequest")
InfoLevel
Designates informational messages that highlight the progress of the application at coarse grained level. This is the default level.
const InfoLevel Level = 0
logger.Info("server started", "port", 8080)
WarnLevel
Designates potentially harmful situations.
const WarnLevel Level = 1
logger.Warn("high memory usage", "percent", 85)
ErrorLevel
Designates error events that might still allow the application to continue running.
const ErrorLevel Level = 2
logger.Error("failed to connect to database", "error", err)
DPanicLevel
Designates critical errors. In development, the Logger panics after writing the message.
const DPanicLevel Level = 3
logger.Log(velo.DPanicLevel, "critical state detected")
PanicLevel
Designates severe errors. The Logger panics after writing the message.
const PanicLevel Level = 4
logger.Panic("unrecoverable error", "component", "auth")
FatalLevel
Designates very severe error events. The Logger calls os.Exit(1) after writing the message.
const FatalLevel Level = 5
logger.Fatal("cannot start application", "error", err)
Level methods
String
Returns the lowercase ASCII representation of the level.
func (l Level) String() string
level := velo.InfoLevel
fmt.Println(level.String()) // Output: info
JSONField
Returns the formatted JSON key-value pair for the level.
func (l Level) JSONField() string
"level":"info") for the JSONEncoder to use during serialization.
Example
level := velo.InfoLevel
fmt.Println(level.JSONField()) // Output: "level":"info"
MarshalText
Serializes the Level to text.
func (l Level) MarshalText() ([]byte, error)
level := velo.WarnLevel
data, _ := level.MarshalText()
fmt.Println(string(data)) // Output: warn
UnmarshalText
Deserializes text into a Level.
func (l *Level) UnmarshalText(text []byte) error
The text representation of the level
var level velo.Level
err := level.UnmarshalText([]byte("error"))
if err != nil {
panic(err)
}
fmt.Println(level) // Output: error
Parsing functions
ParseLevel
Converts a string into a Level.
func ParseLevel(text string) (Level, error)
The string representation of the level
level, err := velo.ParseLevel("warn")
if err != nil {
panic(err)
}
logger.SetLevel(level)
AtomicLevel
Represents a dynamically adjustable logging level.
type AtomicLevel struct {
// contains filtered or unexported fields
}
NewAtomicLevel or NewAtomicLevelAt constructors.
NewAtomicLevel
Initializes an AtomicLevel set to InfoLevel.
func NewAtomicLevel() AtomicLevel
atomicLevel := velo.NewAtomicLevel()
fmt.Println(atomicLevel.Level()) // Output: info
NewAtomicLevelAt
Initializes an AtomicLevel set to the specified Level.
func NewAtomicLevelAt(l Level) AtomicLevel
atomicLevel := velo.NewAtomicLevelAt(velo.WarnLevel)
fmt.Println(atomicLevel.Level()) // Output: warn
ParseAtomicLevel
Converts a string into an AtomicLevel.
func ParseAtomicLevel(text string) (AtomicLevel, error)
The string representation of the level
atomicLevel, err := velo.ParseAtomicLevel("debug")
if err != nil {
panic(err)
}
AtomicLevel methods
Level
Retrieves the current minimum logging level.
func (lvl AtomicLevel) Level() Level
atomicLevel := velo.NewAtomicLevel()
fmt.Println(atomicLevel.Level()) // Output: info
SetLevel
Updates the minimum logging level safely across all goroutines.
func (lvl AtomicLevel) SetLevel(l Level)
atomicLevel := velo.NewAtomicLevel()
atomicLevel.SetLevel(velo.ErrorLevel)
Enabled
Determines if the specified level meets or exceeds the current minimum.
func (lvl AtomicLevel) Enabled(l Level) bool
atomicLevel := velo.NewAtomicLevelAt(velo.WarnLevel)
if atomicLevel.Enabled(velo.ErrorLevel) {
fmt.Println("Error logging is enabled")
}
String
Returns the string representation of the current minimum level.
func (lvl AtomicLevel) String() string
atomicLevel := velo.NewAtomicLevelAt(velo.DebugLevel)
fmt.Println(atomicLevel.String()) // Output: debug
MarshalText
Serializes the AtomicLevel to a byte slice.
func (lvl AtomicLevel) MarshalText() (text []byte, err error)
atomicLevel := velo.NewAtomicLevelAt(velo.InfoLevel)
data, _ := atomicLevel.MarshalText()
fmt.Println(string(data)) // Output: info
UnmarshalText
Deserializes text into the AtomicLevel.
func (lvl *AtomicLevel) UnmarshalText(text []byte) error
The text representation of the level
var atomicLevel velo.AtomicLevel
err := atomicLevel.UnmarshalText([]byte("warn"))
if err != nil {
panic(err)
}
fmt.Println(atomicLevel.Level()) // Output: warn