[#1619] logger: Filter entries by tags provided in config

Change-Id: Ia2a79d6cb2a5eb263fb2e6db3f9cf9f2a7d57118
Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

pkg/util/logger/logger.go

@@ -13,8 +13,10 @@ import (
 // Logger represents a component
 // for writing messages to log.
 type Logger struct {
-	z   *zap.Logger
-	lvl zap.AtomicLevel
+	z *zap.Logger
+	c zapcore.Core
+	t Tag
+	w bool
 }
 
 // Prm groups Logger's parameters.
@@ -39,6 +41,9 @@ type Prm struct {
 
 	// Options for zap.Logger
 	Options []zap.Option
+
+	// map of tag's bit masks to log level, overrides lvl
+	tl map[Tag]zapcore.Level
 }
 
 const (
@@ -68,6 +73,12 @@ func (p *Prm) SetDestination(d string) error {
 	return nil
 }
 
+// SetTags parses list of tags with log level.
+func (p *Prm) SetTags(tags [][]string) (err error) {
+	p.tl, err = parseTags(tags)
+	return err
+}
+
 // NewLogger constructs a new zap logger instance. Constructing with nil
 // parameters is safe: default values will be used then.
 // Passing non-nil parameters after a successful creation (non-error) allows
@@ -91,10 +102,8 @@ func NewLogger(prm Prm) (*Logger, error) {
 }
 
 func newConsoleLogger(prm Prm) (*Logger, error) {
-	lvl := zap.NewAtomicLevelAt(prm.level)
-
 	c := zap.NewProductionConfig()
-	c.Level = lvl
+	c.Level = zap.NewAtomicLevelAt(zap.DebugLevel)
 	c.Encoding = "console"
 	if prm.SamplingHook != nil {
 		c.Sampling.Hook = prm.SamplingHook
@@ -115,15 +124,13 @@ func newConsoleLogger(prm Prm) (*Logger, error) {
 	if err != nil {
 		return nil, err
 	}
-
-	l := &Logger{z: lZap, lvl: lvl}
+	l := &Logger{z: lZap, c: lZap.Core()}
+	l = l.WithTag(TagMain)
 
 	return l, nil
 }
 
 func newJournaldLogger(prm Prm) (*Logger, error) {
-	lvl := zap.NewAtomicLevelAt(prm.level)
-
 	c := zap.NewProductionConfig()
 	if prm.SamplingHook != nil {
 		c.Sampling.Hook = prm.SamplingHook
@@ -137,7 +144,7 @@ func newJournaldLogger(prm Prm) (*Logger, error) {
 
 	encoder := zapjournald.NewPartialEncoder(zapcore.NewConsoleEncoder(c.EncoderConfig), zapjournald.SyslogFields)
 
-	core := zapjournald.NewCore(lvl, encoder, &journald.Journal{}, zapjournald.SyslogFields)
+	core := zapjournald.NewCore(zap.NewAtomicLevelAt(zap.DebugLevel), encoder, &journald.Journal{}, zapjournald.SyslogFields)
 	coreWithContext := core.With([]zapcore.Field{
 		zapjournald.SyslogFacility(zapjournald.LogDaemon),
 		zapjournald.SyslogIdentifier(),
@@ -161,22 +168,75 @@ func newJournaldLogger(prm Prm) (*Logger, error) {
 	}
 	opts = append(opts, prm.Options...)
 	lZap := zap.New(samplingCore, opts...)
-
-	l := &Logger{z: lZap, lvl: lvl}
+	l := &Logger{z: lZap, c: lZap.Core()}
+	l = l.WithTag(TagMain)
 
 	return l, nil
 }
 
-func (l *Logger) Reload(prm Prm) {
-	l.lvl.SetLevel(prm.level)
+// With create a child logger with new fields, don't affect the parent.
+// Throws panic if tag is unset.
+func (l *Logger) With(fields ...zap.Field) *Logger {
+	if l.t == 0 {
+		panic("tag is unset")
+	}
+	c := *l
+	c.z = l.z.With(fields...)
+	// With called under the logger
+	c.w = true
+	return &c
 }
 
-func (l *Logger) With(fields ...zap.Field) *Logger {
-	return &Logger{z: l.z.With(fields...)}
+type core struct {
+	c zapcore.Core
+	l zap.AtomicLevel
+}
+
+func (c *core) Enabled(lvl zapcore.Level) bool {
+	return c.l.Enabled(lvl)
+}
+
+func (c *core) With(fields []zapcore.Field) zapcore.Core {
+	clone := *c
+	clone.c = clone.c.With(fields)
+	return &clone
+}
+
+func (c *core) Check(e zapcore.Entry, ce *zapcore.CheckedEntry) *zapcore.CheckedEntry {
+	return c.c.Check(e, ce)
+}
+
+func (c *core) Write(e zapcore.Entry, fields []zapcore.Field) error {
+	return c.c.Write(e, fields)
+}
+
+func (c *core) Sync() error {
+	return c.c.Sync()
+}
+
+// WithTag is an equivalent of calling [NewLogger] with the same parameters for the current logger.
+// Throws panic if provided unsupported tag.
+func (l *Logger) WithTag(tag Tag) *Logger {
+	if tag == 0 || tag > Tag(len(_Tag_index)-1) {
+		panic("unsupported tag " + tag.String())
+	}
+	if l.w {
+		panic("unsupported operation for the logger's state")
+	}
+	c := *l
+	c.t = tag
+	c.z = l.z.WithOptions(zap.WrapCore(func(zapcore.Core) zapcore.Core {
+		return &core{
+			c: l.c.With([]zap.Field{zap.String("tag", tag.String())}),
+			l: tagToLogLevel[tag],
+		}
+	}))
+	return &c
 }
 
 func NewLoggerWrapper(z *zap.Logger) *Logger {
 	return &Logger{
 		z: z.WithOptions(zap.AddCallerSkip(1)),
+		t: TagMain,
 	}
 }