go-vise

vanilla.go (5301B)

---

 package logging
 
 import (
 	"context"
 	"fmt"
 	"io"
 	"os"
 	"path"
 	"runtime"
 )
 
 var (
 	// LogWriter is used as io.Writer the Vanilla Logger implementation.
 	LogWriter io.Writer = os.Stderr
 )
 
 // Vanilla is a basic single-line structured output logger for terminal output.
 type Vanilla struct {
 	domain      string
 	levelFilter int
 	ctxkey      []string
 }
 
 // NewVanilla creates a new Vanilla logger.
 func NewVanilla() Vanilla {
 	return Vanilla{
 		domain:      "main",
 		levelFilter: LogLevel,
 	}
 }
 
 // WithDomain sets the logging domain. It is prepended to the caller file/line information.
 func (v Vanilla) WithDomain(domain string) Vanilla {
 	v.domain = domain
 	return v
 }
 
 // WithLevel overrides the globally set loglevel for the logger instance.
 func (v Vanilla) WithLevel(level int) Vanilla {
 	v.levelFilter = level
 	return v
 }
 
 func (v Vanilla) WithContextKey(k string) Vanilla {
 	v.ctxkey = append(v.ctxkey, k)
 	return v
 }
 
 // Printf logs to the global writer.
 func (v Vanilla) Printf(level int, msg string, args ...any) {
 	v.Writef(LogWriter, level, msg, args...)
 }
 
 // compile log line from inputs and send to given writer.
 func (v Vanilla) writef(ctx context.Context, w io.Writer, file string, line int, level int, msg string, args ...any) {
 	var argsStr string
 	if level > v.levelFilter {
 		return
 	}
 	if ctx == nil {
 		argsStr = v.argsToString(nil, args)
 	} else {
 		argsStr = v.argsToString(ctx, args)
 	}
 
 	if len(msg) > 0 {
 		fmt.Fprintf(w, "[%s] %s:%s:%v %s\t%s\n", AsString(level), v.domain, file, line, msg, argsStr)
 	} else {
 		fmt.Fprintf(w, "[%s] %s:%s:%v %s\n", AsString(level), v.domain, file, line, argsStr)
 	}
 }
 
 // Writef logs to the given writer.
 func (v Vanilla) Writef(w io.Writer, level int, msg string, args ...any) {
 	file, line := getCaller(2)
 	v.writef(nil, w, file, line, level, msg, args)
 }
 
 // WriteCtxf logs with context to the given writer.
 func (v Vanilla) WriteCtxf(ctx context.Context, w io.Writer, level int, msg string, args ...any) {
 	file, line := getCaller(2)
 	v.writef(ctx, w, file, line, level, msg, args...)
 }
 
 // get caller information and pass on to writef
 func (v Vanilla) printf(level int, msg string, args ...any) {
 	file, line := getCaller(3)
 	v.writef(nil, LogWriter, file, line, level, msg, args...)
 }
 
 // get caller information and pass on to writef
 func (v Vanilla) printCtxf(ctx context.Context, level int, msg string, args ...any) {
 	file, line := getCaller(3)
 	v.writef(ctx, LogWriter, file, line, level, msg, args...)
 }
 
 // PrintCtxf logs with context to the global writer.
 func (v Vanilla) PrintCtxf(ctx context.Context, level int, msg string, args ...any) {
 	v.printf(level, msg, args...)
 }
 
 // Tracef logs a line with level TRACE to the global writer.
 func (v Vanilla) Tracef(msg string, args ...any) {
 	v.printf(LVL_TRACE, msg, args...)
 }
 
 // Debugf logs a line with level DEBUG to the global writer.
 func (v Vanilla) Debugf(msg string, args ...any) {
 	v.printf(LVL_DEBUG, msg, args...)
 }
 
 // Infof logs a line with level INFO to the global writer.
 func (v Vanilla) Infof(msg string, args ...any) {
 	v.printf(LVL_INFO, msg, args...)
 }
 
 // Warnf logs a line with level WARN to the global writer.
 func (v Vanilla) Warnf(msg string, args ...any) {
 	v.printf(LVL_WARN, msg, args...)
 }
 
 // Errorf logs a line with level ERROR to the global writer.
 func (v Vanilla) Errorf(msg string, args ...any) {
 	v.printf(LVL_ERROR, msg, args...)
 }
 
 // TraceCtxf logs a line with context with level TRACE to the global writer.
 func (v Vanilla) TraceCtxf(ctx context.Context, msg string, args ...any) {
 	v.printCtxf(ctx, LVL_TRACE, msg, args...)
 }
 
 // DebugCtxf logs a line with context with level DEBUG to the global writer.
 func (v Vanilla) DebugCtxf(ctx context.Context, msg string, args ...any) {
 	v.printCtxf(ctx, LVL_DEBUG, msg, args...)
 }
 
 // InfoCtxf logs a line with context with level INFO to the global writer.
 func (v Vanilla) InfoCtxf(ctx context.Context, msg string, args ...any) {
 	v.printCtxf(ctx, LVL_INFO, msg, args...)
 }
 
 // WarnCtxf logs a line with context with level WARN to the global writer.
 func (v Vanilla) WarnCtxf(ctx context.Context, msg string, args ...any) {
 	v.printCtxf(ctx, LVL_WARN, msg, args...)
 }
 
 // ErrorCtxf logs a line with context with level ERROR to the global writer.
 func (v Vanilla) ErrorCtxf(ctx context.Context, msg string, args ...any) {
 	v.printCtxf(ctx, LVL_ERROR, msg, args...)
 }
 
 // return file basename and line for caller information.
 func getCaller(depth int) (string, int) {
 	var file string
 	var line int
 	_, file, line, _ = runtime.Caller(depth)
 	baseFile := path.Base(file)
 	return baseFile, line
 }
 
 // string representation of the given structured log args.
 func (v Vanilla) argsToString(ctx context.Context, args []any) string {
 	var s string
 
 	if ctx != nil {
 		for _, k := range v.ctxkey {
 			v := ctx.Value(k)
 			if v != nil {
 				v, ok := v.(string)
 				if ok {
 					args = append(args, "x-"+k, v)
 				}
 			}
 		}
 	}
 	c := len(args)
 	var i int
 	for i = 0; i < c; i += 2 {
 		if len(s) > 0 {
 			s += ", "
 		}
 
 		if i+1 < c {
 			var argByte []byte
 			var ok bool
 			argByte, ok = args[i+1].([]byte)
 			if ok {
 				s += fmt.Sprintf("%s=%x", args[i], argByte)
 			} else {
 				s += fmt.Sprintf("%s=%v", args[i], args[i+1])
 			}
 		} else {
 			s += fmt.Sprintf("%s=??", args[i])
 		}
 	}
 	return s
 }