diff options
Diffstat (limited to 'vendor/github.com/go-kit/kit/log/level/level.go')
-rw-r--r-- | vendor/github.com/go-kit/kit/log/level/level.go | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/vendor/github.com/go-kit/kit/log/level/level.go b/vendor/github.com/go-kit/kit/log/level/level.go new file mode 100644 index 0000000..dd4ef60 --- /dev/null +++ b/vendor/github.com/go-kit/kit/log/level/level.go @@ -0,0 +1,205 @@ +package level + +import "github.com/go-kit/kit/log" + +// Error returns a logger that includes a Key/ErrorValue pair. +func Error(logger log.Logger) log.Logger { + return log.WithPrefix(logger, Key(), ErrorValue()) +} + +// Warn returns a logger that includes a Key/WarnValue pair. +func Warn(logger log.Logger) log.Logger { + return log.WithPrefix(logger, Key(), WarnValue()) +} + +// Info returns a logger that includes a Key/InfoValue pair. +func Info(logger log.Logger) log.Logger { + return log.WithPrefix(logger, Key(), InfoValue()) +} + +// Debug returns a logger that includes a Key/DebugValue pair. +func Debug(logger log.Logger) log.Logger { + return log.WithPrefix(logger, Key(), DebugValue()) +} + +// NewFilter wraps next and implements level filtering. See the commentary on +// the Option functions for a detailed description of how to configure levels. +// If no options are provided, all leveled log events created with Debug, +// Info, Warn or Error helper methods are squelched and non-leveled log +// events are passed to next unmodified. +func NewFilter(next log.Logger, options ...Option) log.Logger { + l := &logger{ + next: next, + } + for _, option := range options { + option(l) + } + return l +} + +type logger struct { + next log.Logger + allowed level + squelchNoLevel bool + errNotAllowed error + errNoLevel error +} + +func (l *logger) Log(keyvals ...interface{}) error { + var hasLevel, levelAllowed bool + for i := 1; i < len(keyvals); i += 2 { + if v, ok := keyvals[i].(*levelValue); ok { + hasLevel = true + levelAllowed = l.allowed&v.level != 0 + break + } + } + if !hasLevel && l.squelchNoLevel { + return l.errNoLevel + } + if hasLevel && !levelAllowed { + return l.errNotAllowed + } + return l.next.Log(keyvals...) +} + +// Option sets a parameter for the leveled logger. +type Option func(*logger) + +// AllowAll is an alias for AllowDebug. +func AllowAll() Option { + return AllowDebug() +} + +// AllowDebug allows error, warn, info and debug level log events to pass. +func AllowDebug() Option { + return allowed(levelError | levelWarn | levelInfo | levelDebug) +} + +// AllowInfo allows error, warn and info level log events to pass. +func AllowInfo() Option { + return allowed(levelError | levelWarn | levelInfo) +} + +// AllowWarn allows error and warn level log events to pass. +func AllowWarn() Option { + return allowed(levelError | levelWarn) +} + +// AllowError allows only error level log events to pass. +func AllowError() Option { + return allowed(levelError) +} + +// AllowNone allows no leveled log events to pass. +func AllowNone() Option { + return allowed(0) +} + +func allowed(allowed level) Option { + return func(l *logger) { l.allowed = allowed } +} + +// ErrNotAllowed sets the error to return from Log when it squelches a log +// event disallowed by the configured Allow[Level] option. By default, +// ErrNotAllowed is nil; in this case the log event is squelched with no +// error. +func ErrNotAllowed(err error) Option { + return func(l *logger) { l.errNotAllowed = err } +} + +// SquelchNoLevel instructs Log to squelch log events with no level, so that +// they don't proceed through to the wrapped logger. If SquelchNoLevel is set +// to true and a log event is squelched in this way, the error value +// configured with ErrNoLevel is returned to the caller. +func SquelchNoLevel(squelch bool) Option { + return func(l *logger) { l.squelchNoLevel = squelch } +} + +// ErrNoLevel sets the error to return from Log when it squelches a log event +// with no level. By default, ErrNoLevel is nil; in this case the log event is +// squelched with no error. +func ErrNoLevel(err error) Option { + return func(l *logger) { l.errNoLevel = err } +} + +// NewInjector wraps next and returns a logger that adds a Key/level pair to +// the beginning of log events that don't already contain a level. In effect, +// this gives a default level to logs without a level. +func NewInjector(next log.Logger, level Value) log.Logger { + return &injector{ + next: next, + level: level, + } +} + +type injector struct { + next log.Logger + level interface{} +} + +func (l *injector) Log(keyvals ...interface{}) error { + for i := 1; i < len(keyvals); i += 2 { + if _, ok := keyvals[i].(*levelValue); ok { + return l.next.Log(keyvals...) + } + } + kvs := make([]interface{}, len(keyvals)+2) + kvs[0], kvs[1] = key, l.level + copy(kvs[2:], keyvals) + return l.next.Log(kvs...) +} + +// Value is the interface that each of the canonical level values implement. +// It contains unexported methods that prevent types from other packages from +// implementing it and guaranteeing that NewFilter can distinguish the levels +// defined in this package from all other values. +type Value interface { + String() string + levelVal() +} + +// Key returns the unique key added to log events by the loggers in this +// package. +func Key() interface{} { return key } + +// ErrorValue returns the unique value added to log events by Error. +func ErrorValue() Value { return errorValue } + +// WarnValue returns the unique value added to log events by Warn. +func WarnValue() Value { return warnValue } + +// InfoValue returns the unique value added to log events by Info. +func InfoValue() Value { return infoValue } + +// DebugValue returns the unique value added to log events by Warn. +func DebugValue() Value { return debugValue } + +var ( + // key is of type interfae{} so that it allocates once during package + // initialization and avoids allocating every time the value is added to a + // []interface{} later. + key interface{} = "level" + + errorValue = &levelValue{level: levelError, name: "error"} + warnValue = &levelValue{level: levelWarn, name: "warn"} + infoValue = &levelValue{level: levelInfo, name: "info"} + debugValue = &levelValue{level: levelDebug, name: "debug"} +) + +type level byte + +const ( + levelDebug level = 1 << iota + levelInfo + levelWarn + levelError +) + +type levelValue struct { + name string + level +} + +func (v *levelValue) String() string { return v.name } +func (v *levelValue) levelVal() {} |