WIP: Logging

log/event.go

@@ -0,0 +1,150 @@
+package log
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"sort"
+	"strings"
+	"time"
+)
+
+const (
+	tagField   = "tag"
+	errorField = "error"
+)
+
+type Event struct {
+	Time    int64  `json:"time"`
+	Level   Level  `json:"level"`
+	Message string `json:"message"`
+	fields  map[string]any
+}
+
+func newEvent() *Event {
+	return &Event{
+		Time:   time.Now().UnixMilli(),
+		fields: make(map[string]any),
+	}
+}
+
+func (e *Event) Fatal(message string, v ...any) {
+	e.Log(FatalLevel, message, v...)
+	os.Exit(1)
+}
+
+func (e *Event) Error(message string, v ...any) {
+	e.Log(ErrorLevel, message, v...)
+}
+
+func (e *Event) Warn(message string, v ...any) {
+	e.Log(WarnLevel, message, v...)
+}
+
+func (e *Event) Info(message string, v ...any) {
+	e.Log(InfoLevel, message, v...)
+}
+
+func (e *Event) Debug(message string, v ...any) {
+	e.Log(DebugLevel, message, v...)
+}
+
+func (e *Event) Trace(message string, v ...any) {
+	e.Log(TraceLevel, message, v...)
+}
+
+func (e *Event) Tag(tag string) *Event {
+	e.fields[tagField] = tag
+	return e
+}
+
+func (e *Event) Err(err error) *Event {
+	e.fields[errorField] = err
+	return e
+}
+
+func (e *Event) Field(key string, value any) *Event {
+	e.fields[key] = value
+	return e
+}
+
+func (e *Event) Fields(fields map[string]any) *Event {
+	for k, v := range fields {
+		e.fields[k] = v
+	}
+	return e
+}
+
+func (e *Event) Context(contexts ...Ctx) *Event {
+	for _, c := range contexts {
+		e.Fields(c.Context())
+	}
+	return e
+}
+
+func (e *Event) Log(l Level, message string, v ...any) {
+	e.Message = fmt.Sprintf(message, v...)
+	e.Level = l
+	if e.shouldPrint() {
+		if CurrentFormat() == JSONFormat {
+			log.Println(e.JSON())
+		} else {
+			log.Println(e.String())
+		}
+	}
+}
+
+// Loggable returns true if the given log level is lower or equal to the current log level
+func (e *Event) Loggable(l Level) bool {
+	return e.globalLevelWithOverride() <= l
+}
+
+// IsTrace returns true if the current log level is TraceLevel
+func (e *Event) IsTrace() bool {
+	return e.Loggable(TraceLevel)
+}
+
+// IsDebug returns true if the current log level is DebugLevel or below
+func (e *Event) IsDebug() bool {
+	return e.Loggable(DebugLevel)
+}
+
+func (e *Event) JSON() string {
+	b, _ := json.Marshal(e)
+	s := string(b)
+	if len(e.fields) > 0 {
+		b, _ := json.Marshal(e.fields)
+		s = fmt.Sprintf("{%s,%s}", s[1:len(s)-1], string(b[1:len(b)-1]))
+	}
+	return s
+}
+
+func (e *Event) String() string {
+	if len(e.fields) == 0 {
+		return fmt.Sprintf("%s %s", e.Level.String(), e.Message)
+	}
+	fields := make([]string, 0)
+	for k, v := range e.fields {
+		fields = append(fields, fmt.Sprintf("%s=%v", k, v))
+	}
+	sort.Strings(fields)
+	return fmt.Sprintf("%s %s (%s)", e.Level.String(), e.Message, strings.Join(fields, ", "))
+}
+
+func (e *Event) shouldPrint() bool {
+	return e.globalLevelWithOverride() <= e.Level
+}
+
+func (e *Event) globalLevelWithOverride() Level {
+	mu.Lock()
+	l, ov := level, overrides
+	mu.Unlock()
+	for field, override := range ov {
+		value, exists := e.fields[field]
+		if exists && value == override.value {
+			return override.level
+		}
+	}
+	return l
+}

log/log.go

@@ -2,71 +2,60 @@ package log
 
 import (
 	"log"
-	"strings"
 	"sync"
 )
 
-// Level is a well-known log level, as defined below
-type Level int
-
-// Well known log levels
-const (
-	TraceLevel Level = iota
-	DebugLevel
-	InfoLevel
-	WarnLevel
-	ErrorLevel
-)
-
-func (l Level) String() string {
-	switch l {
-	case TraceLevel:
-		return "TRACE"
-	case DebugLevel:
-		return "DEBUG"
-	case InfoLevel:
-		return "INFO"
-	case WarnLevel:
-		return "WARN"
-	case ErrorLevel:
-		return "ERROR"
-	}
-	return "unknown"
-}
-
 var (
-	level = InfoLevel
-	mu    = &sync.Mutex{}
+	level     = InfoLevel
+	format    = TextFormat
+	overrides = make(map[string]*levelOverride)
+	mu        = &sync.Mutex{}
 )
 
-// Trace prints the given message, if the current log level is TRACE
-func Trace(message string, v ...any) {
-	logIf(TraceLevel, message, v...)
-}
-
-// Debug prints the given message, if the current log level is DEBUG or lower
-func Debug(message string, v ...any) {
-	logIf(DebugLevel, message, v...)
-}
-
-// Info prints the given message, if the current log level is INFO or lower
-func Info(message string, v ...any) {
-	logIf(InfoLevel, message, v...)
-}
-
-// Warn prints the given message, if the current log level is WARN or lower
-func Warn(message string, v ...any) {
-	logIf(WarnLevel, message, v...)
+// Fatal prints the given message, and exits the program
+func Fatal(message string, v ...any) {
+	newEvent().Fatal(message, v...)
 }
 
 // Error prints the given message, if the current log level is ERROR or lower
 func Error(message string, v ...any) {
-	logIf(ErrorLevel, message, v...)
+	newEvent().Error(message, v...)
 }
 
-// Fatal prints the given message, and exits the program
-func Fatal(v ...any) {
-	log.Fatalln(v...)
+// Warn prints the given message, if the current log level is WARN or lower
+func Warn(message string, v ...any) {
+	newEvent().Warn(message, v...)
+}
+
+// Info prints the given message, if the current log level is INFO or lower
+func Info(message string, v ...any) {
+	newEvent().Info(message, v...)
+}
+
+// Debug prints the given message, if the current log level is DEBUG or lower
+func Debug(message string, v ...any) {
+	newEvent().Debug(message, v...)
+}
+
+// Trace prints the given message, if the current log level is TRACE
+func Trace(message string, v ...any) {
+	newEvent().Trace(message, v...)
+}
+
+func Context(contexts ...Ctx) *Event {
+	return newEvent().Context(contexts...)
+}
+
+func Field(key string, value any) *Event {
+	return newEvent().Field(key, value)
+}
+
+func Fields(fields map[string]any) *Event {
+	return newEvent().Fields(fields)
+}
+
+func Tag(tag string) *Event {
+	return newEvent().Tag(tag)
 }
 
 // CurrentLevel returns the current log level
@@ -83,30 +72,42 @@ func SetLevel(newLevel Level) {
 	level = newLevel
 }
 
+// SetLevelOverride adds a log override for the given field
+func SetLevelOverride(field string, value any, level Level) {
+	mu.Lock()
+	defer mu.Unlock()
+	overrides[field] = &levelOverride{value: value, level: level}
+}
+
+// ResetLevelOverride removes all log level overrides
+func ResetLevelOverride() {
+	mu.Lock()
+	defer mu.Unlock()
+	overrides = make(map[string]*levelOverride)
+}
+
+// CurrentFormat returns the current log formt
+func CurrentFormat() Format {
+	mu.Lock()
+	defer mu.Unlock()
+	return format
+}
+
+// SetFormat sets a new log format
+func SetFormat(newFormat Format) {
+	mu.Lock()
+	defer mu.Unlock()
+	format = newFormat
+	if newFormat == JSONFormat {
+		DisableDates()
+	}
+}
+
 // DisableDates disables the date/time prefix
 func DisableDates() {
 	log.SetFlags(0)
 }
 
-// ToLevel converts a string to a Level. It returns InfoLevel if the string
-// does not match any known log levels.
-func ToLevel(s string) Level {
-	switch strings.ToUpper(s) {
-	case "TRACE":
-		return TraceLevel
-	case "DEBUG":
-		return DebugLevel
-	case "INFO":
-		return InfoLevel
-	case "WARN", "WARNING":
-		return WarnLevel
-	case "ERROR":
-		return ErrorLevel
-	default:
-		return InfoLevel
-	}
-}
-
 // Loggable returns true if the given log level is lower or equal to the current log level
 func Loggable(l Level) bool {
 	return CurrentLevel() <= l
@@ -121,9 +122,3 @@ func IsTrace() bool {
 func IsDebug() bool {
 	return Loggable(DebugLevel)
 }
-
-func logIf(l Level, message string, v ...any) {
-	if CurrentLevel() <= l {
-		log.Printf(l.String()+" "+message, v...)
-	}
-}

log/log_test.go

@@ -0,0 +1,57 @@
+package log_test
+
+import (
+	"heckel.io/ntfy/log"
+	"net/http"
+	"testing"
+)
+
+const tagPay = "PAY"
+
+type visitor struct {
+	UserID string
+	IP     string
+}
+
+func (v *visitor) Context() map[string]any {
+	return map[string]any{
+		"user_id": v.UserID,
+		"ip":      v.IP,
+	}
+}
+
+func TestEvent_Info(t *testing.T) {
+	/*
+		log-level: INFO, user_id:u_abc=DEBUG
+		log-level-overrides:
+			- user_id=u_abc: DEBUG
+		log-filter =
+
+	*/
+	v := &visitor{
+		UserID: "u_abc",
+		IP:     "1.2.3.4",
+	}
+	stripeCtx := log.NewCtx(map[string]any{
+		"tag": "pay",
+	})
+	log.SetLevel(log.InfoLevel)
+	//log.SetFormat(log.JSONFormat)
+	//log.SetLevelOverride("user_id", "u_abc", log.DebugLevel)
+	log.SetLevelOverride("tag", "pay", log.DebugLevel)
+	mlog := log.Field("tag", "manager")
+	mlog.Field("one", 1).Info("this is one")
+	mlog.Err(http.ErrHandlerTimeout).Field("two", 2).Info("this is two")
+	log.Info("somebody did something")
+	log.
+		Context(stripeCtx, v).
+		Fields(map[string]any{
+			"tier":    "ti_abc",
+			"user_id": "u_abc",
+		}).
+		Debug("Somebody paid something for $%d", 10)
+	log.
+		Field("tag", "account").
+		Field("user_id", "u_abc").
+		Debug("User logged in")
+}

log/types.go

@@ -0,0 +1,111 @@
+package log
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+// Level is a well-known log level, as defined below
+type Level int
+
+// Well known log levels
+const (
+	TraceLevel Level = iota
+	DebugLevel
+	InfoLevel
+	WarnLevel
+	ErrorLevel
+	FatalLevel
+)
+
+func (l Level) String() string {
+	switch l {
+	case TraceLevel:
+		return "TRACE"
+	case DebugLevel:
+		return "DEBUG"
+	case InfoLevel:
+		return "INFO"
+	case WarnLevel:
+		return "WARN"
+	case ErrorLevel:
+		return "ERROR"
+	case FatalLevel:
+		return "FATAL"
+	}
+	return "unknown"
+}
+
+func (l Level) MarshalJSON() ([]byte, error) {
+	return json.Marshal(l.String())
+}
+
+// ToLevel converts a string to a Level. It returns InfoLevel if the string
+// does not match any known log levels.
+func ToLevel(s string) Level {
+	switch strings.ToUpper(s) {
+	case "TRACE":
+		return TraceLevel
+	case "DEBUG":
+		return DebugLevel
+	case "INFO":
+		return InfoLevel
+	case "WARN", "WARNING":
+		return WarnLevel
+	case "ERROR":
+		return ErrorLevel
+	default:
+		return InfoLevel
+	}
+}
+
+// Format is a well-known log format
+type Format int
+
+// Log formats
+const (
+	TextFormat Format = iota
+	JSONFormat
+)
+
+func (f Format) String() string {
+	switch f {
+	case TextFormat:
+		return "text"
+	case JSONFormat:
+		return "json"
+	}
+	return "unknown"
+}
+
+// ToFormat converts a string to a Format. It returns TextFormat if the string
+// does not match any known log formats.
+func ToFormat(s string) Format {
+	switch strings.ToLower(s) {
+	case "text":
+		return TextFormat
+	case "json":
+		return JSONFormat
+	default:
+		return TextFormat
+	}
+}
+
+type Ctx interface {
+	Context() map[string]any
+}
+
+type fieldsCtx map[string]any
+
+func (f fieldsCtx) Context() map[string]any {
+	return f
+}
+
+func NewCtx(fields map[string]any) Ctx {
+	return fieldsCtx(fields)
+}
+
+type levelOverride struct {
+	value any
+	level Level
+}