filter

log/filter.go

@@ -0,0 +1,97 @@
+package log
+
+// NewFilter wraps next and implements 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 or
+// Error helper methods are squelched.
+func NewFilter(next Logger, options ...Option) Logger {
+	l := &filter{
+		next: next,
+	}
+	for _, option := range options {
+		option(l)
+	}
+	return l
+}
+
+type filter struct {
+	next          Logger
+	allowed       level
+	errNotAllowed error
+}
+
+func (l *filter) Info(msg string, keyvals ...interface{}) error {
+	levelAllowed := l.allowed&levelInfo != 0
+	if !levelAllowed {
+		return l.errNotAllowed
+	}
+	return l.next.Info(msg, keyvals...)
+}
+
+func (l *filter) Debug(msg string, keyvals ...interface{}) error {
+	levelAllowed := l.allowed&levelDebug != 0
+	if !levelAllowed {
+		return l.errNotAllowed
+	}
+	return l.next.Debug(msg, keyvals...)
+}
+
+func (l *filter) Error(msg string, keyvals ...interface{}) error {
+	levelAllowed := l.allowed&levelError != 0
+	if !levelAllowed {
+		return l.errNotAllowed
+	}
+	return l.next.Error(msg, keyvals...)
+}
+
+func (l *filter) With(keyvals ...interface{}) Logger {
+	return l.next.With(keyvals...)
+}
+
+// Option sets a parameter for the filter.
+type Option func(*filter)
+
+// 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 | levelInfo | levelDebug)
+}
+
+// AllowInfo allows error, warn and info level log events to pass.
+func AllowInfo() Option {
+	return allowed(levelError | levelInfo)
+}
+
+// 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 *filter) { 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 *filter) { l.errNotAllowed = err }
+}
+
+type level byte
+
+const (
+	levelDebug level = 1 << iota
+	levelInfo
+	levelError
+)

log/filter_test.go

@@ -0,0 +1,103 @@
+package log_test
+
+import (
+	"bytes"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/tendermint/tmlibs/log"
+)
+
+func TestVariousLevels(t *testing.T) {
+	testCases := []struct {
+		name    string
+		allowed log.Option
+		want    string
+	}{
+		{
+			"AllowAll",
+			log.AllowAll(),
+			strings.Join([]string{
+				`{"_msg":"here","level":"debug","this is":"debug log"}`,
+				`{"_msg":"here","level":"info","this is":"info log"}`,
+				`{"_msg":"here","level":"error","this is":"error log"}`,
+			}, "\n"),
+		},
+		{
+			"AllowDebug",
+			log.AllowDebug(),
+			strings.Join([]string{
+				`{"_msg":"here","level":"debug","this is":"debug log"}`,
+				`{"_msg":"here","level":"info","this is":"info log"}`,
+				`{"_msg":"here","level":"error","this is":"error log"}`,
+			}, "\n"),
+		},
+		{
+			"AllowInfo",
+			log.AllowInfo(),
+			strings.Join([]string{
+				`{"_msg":"here","level":"info","this is":"info log"}`,
+				`{"_msg":"here","level":"error","this is":"error log"}`,
+			}, "\n"),
+		},
+		{
+			"AllowError",
+			log.AllowError(),
+			strings.Join([]string{
+				`{"_msg":"here","level":"error","this is":"error log"}`,
+			}, "\n"),
+		},
+		{
+			"AllowNone",
+			log.AllowNone(),
+			``,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			logger := log.NewFilter(log.NewTMJSONLogger(&buf), tc.allowed)
+
+			logger.Debug("here", "this is", "debug log")
+			logger.Info("here", "this is", "info log")
+			logger.Error("here", "this is", "error log")
+
+			if want, have := tc.want, strings.TrimSpace(buf.String()); want != have {
+				t.Errorf("\nwant:\n%s\nhave:\n%s", want, have)
+			}
+		})
+	}
+}
+
+func TestErrNotAllowed(t *testing.T) {
+	myError := errors.New("squelched!")
+	opts := []log.Option{
+		log.AllowError(),
+		log.ErrNotAllowed(myError),
+	}
+	logger := log.NewFilter(log.NewNopLogger(), opts...)
+
+	if want, have := myError, logger.Info("foo", "bar", "baz"); want != have {
+		t.Errorf("want %#+v, have %#+v", want, have)
+	}
+
+	if want, have := error(nil), logger.Error("foo", "bar", "baz"); want != have {
+		t.Errorf("want %#+v, have %#+v", want, have)
+	}
+}
+
+func TestLevelContext(t *testing.T) {
+	var buf bytes.Buffer
+
+	var logger log.Logger
+	logger = log.NewTMJSONLogger(&buf)
+	logger = log.NewFilter(logger, log.AllowAll())
+	logger = logger.With("context", "value")
+
+	logger.Info("foo", "bar", "baz")
+	if want, have := `{"_msg":"foo","bar":"baz","context":"value","level":"info"}`, strings.TrimSpace(buf.String()); want != have {
+		t.Errorf("\nwant '%s'\nhave '%s'", want, have)
+	}
+}

log/logger.go

@@ -13,7 +13,6 @@ type Logger interface {
 	Error(msg string, keyvals ...interface{}) error
 
 	With(keyvals ...interface{}) Logger
-	WithLevel(lvl string) Logger
 }
 
 // NewSyncWriter returns a new writer that is safe for concurrent use by

log/nop_logger.go

@@ -23,7 +23,3 @@ func (nopLogger) Error(string, ...interface{}) error {
 func (l *nopLogger) With(...interface{}) Logger {
 	return l
 }
-
-func (l *nopLogger) WithLevel(lvl string) Logger {
-	return l
-}

log/tm_json_logger.go

@@ -0,0 +1,15 @@
+package log
+
+import (
+	"io"
+
+	kitlog "github.com/go-kit/kit/log"
+)
+
+// NewTMJSONLogger returns a Logger that encodes keyvals to the Writer as a
+// single JSON object. Each log event produces no more than one call to
+// w.Write. The passed Writer must be safe for concurrent use by multiple
+// goroutines if the returned Logger will be used concurrently.
+func NewTMJSONLogger(w io.Writer) Logger {
+	return &tmLogger{kitlog.NewJSONLogger(w)}
+}

log/tm_logger.go

@@ -5,7 +5,7 @@ import (
 	"io"
 
 	kitlog "github.com/go-kit/kit/log"
-	"github.com/go-kit/kit/log/level"
+	kitlevel "github.com/go-kit/kit/log/level"
 	"github.com/go-kit/kit/log/term"
 )
 
@@ -23,15 +23,13 @@ var _ Logger = (*tmLogger)(nil)
 // NewTMTermLogger returns a logger that encodes msg and keyvals to the Writer
 // using go-kit's log as an underlying logger and our custom formatter. Note
 // that underlying logger could be swapped with something else.
-//
-// Default logging level is info. You can change it using SetLevel().
 func NewTMLogger(w io.Writer) Logger {
 	// Color by level value
 	colorFn := func(keyvals ...interface{}) term.FgBgColor {
-		if keyvals[0] != level.Key() {
+		if keyvals[0] != kitlevel.Key() {
 			panic(fmt.Sprintf("expected level key to be first, got %v", keyvals[0]))
 		}
-		switch keyvals[1].(level.Value).String() {
+		switch keyvals[1].(kitlevel.Value).String() {
 		case "debug":
 			return term.FgBgColor{Fg: term.DarkGray}
 		case "error":
@@ -41,26 +39,24 @@ func NewTMLogger(w io.Writer) Logger {
 		}
 	}
 
-	srcLogger := term.NewLogger(w, NewTMFmtLogger, colorFn)
-	srcLogger = level.NewFilter(srcLogger, level.AllowInfo())
-	return &tmLogger{srcLogger}
+	return &tmLogger{term.NewLogger(w, NewTMFmtLogger, colorFn)}
 }
 
 // Info logs a message at level Info.
 func (l *tmLogger) Info(msg string, keyvals ...interface{}) error {
-	lWithLevel := level.Info(l.srcLogger)
+	lWithLevel := kitlevel.Info(l.srcLogger)
 	return kitlog.With(lWithLevel, msgKey, msg).Log(keyvals...)
 }
 
 // Debug logs a message at level Debug.
 func (l *tmLogger) Debug(msg string, keyvals ...interface{}) error {
-	lWithLevel := level.Debug(l.srcLogger)
+	lWithLevel := kitlevel.Debug(l.srcLogger)
 	return kitlog.With(lWithLevel, msgKey, msg).Log(keyvals...)
 }
 
 // Error logs a message at level Error.
 func (l *tmLogger) Error(msg string, keyvals ...interface{}) error {
-	lWithLevel := level.Error(l.srcLogger)
+	lWithLevel := kitlevel.Error(l.srcLogger)
 	return kitlog.With(lWithLevel, msgKey, msg).Log(keyvals...)
 }
 
@@ -69,17 +65,3 @@ func (l *tmLogger) Error(msg string, keyvals ...interface{}) error {
 func (l *tmLogger) With(keyvals ...interface{}) Logger {
 	return &tmLogger{kitlog.With(l.srcLogger, keyvals...)}
 }
-
-// WithLevel returns a new logger with the level set to lvl.
-func (l *tmLogger) WithLevel(lvl string) Logger {
-	switch lvl {
-	case "info":
-		return &tmLogger{level.NewFilter(l.srcLogger, level.AllowInfo())}
-	case "debug":
-		return &tmLogger{level.NewFilter(l.srcLogger, level.AllowDebug())}
-	case "error":
-		return &tmLogger{level.NewFilter(l.srcLogger, level.AllowError())}
-	default:
-		panic(fmt.Sprintf("Unexpected level %v, expect either \"info\" or \"debug\" or \"error\"", lvl))
-	}
-}

log/tmfmt_logger.go

@@ -8,7 +8,7 @@ import (
 	"time"
 
 	kitlog "github.com/go-kit/kit/log"
-	"github.com/go-kit/kit/log/level"
+	kitlevel "github.com/go-kit/kit/log/level"
 	"github.com/go-logfmt/logfmt"
 )
 
@@ -56,13 +56,13 @@ func (l tmfmtLogger) Log(keyvals ...interface{}) error {
 
 	for i := 0; i < len(keyvals)-1; i += 2 {
 		// Extract level
-		if keyvals[i] == level.Key() {
+		if keyvals[i] == kitlevel.Key() {
 			lvlIndex = i
 			switch keyvals[i+1].(type) {
 			case string:
 				lvl = keyvals[i+1].(string)
-			case level.Value:
-				lvl = keyvals[i+1].(level.Value).String()
+			case kitlevel.Value:
+				lvl = keyvals[i+1].(kitlevel.Value).String()
 			default:
 				panic(fmt.Sprintf("level value of unknown type %T", keyvals[i+1]))
 			}