(1) allow the logger backend to be implemented externally, (2) making logger.Backend.Write more generic (#52)

Author: nnthnn

logger/filelogger.go

@@ -32,7 +32,11 @@ package logger
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-import "os"
+import (
+	"fmt"
+	"os"
+	"time"
+)
 
 type FileLogger struct {
 	fp *os.File
@@ -48,11 +52,13 @@ func NewFileLogger(filename string) (*FileLogger, error) {
 	return &FileLogger{fp: file}, nil
 }
 
-func (l *FileLogger) write(logStr string) {
-	l.fp.Write([]byte(logStr))
+func (l *FileLogger) Write(prefix string, name string, msg string) {
+	l.fp.Write([]byte(time.Now().Format(time.StampMicro)))
+	l.fp.Write([]byte(fmt.Sprintf(" %s %s: ", prefix, name)))
+	l.fp.Write([]byte(msg + "\n"))
 }
 
-func (l *FileLogger) close() {
+func (l *FileLogger) Close() {
 	if l.fp != nil {
 		l.fp.Close()
 	}

logger/logger.go

@@ -36,7 +36,6 @@ import (
 	"fmt"
 	"os"
 	"runtime"
-	"time"
 )
 
 // LogLevel is the enum type for the log levels.
@@ -54,12 +53,12 @@ const (
 
 // Backend defines the public interface that must be implemented by all logger backends
 type Backend interface {
-	write(logStr string)
-	close()
+	Write(prefix string, name string, msg string)
+	Close()
 }
 
 var (
-	prefixes         = []string{"TRACE", "DEBUG", "INFO ", "WARN ", "ERROR", "FATAL"}
+	prefixes         = []string{"TRACE", "DEBUG", "INFO", "WARN", "ERROR", "FATAL"}
 	level            = WARN
 	logger   Backend = &STDIOLogger{}
 )
@@ -69,9 +68,7 @@ type Logger struct {
 }
 
 func (l *Logger) print(level LogLevel, format string, args ...interface{}) {
-	logger.write(time.Now().Format(time.StampMicro))
-	logger.write(fmt.Sprintf(" %s %s: ", prefixes[level], l.name))
-	logger.write(fmt.Sprintf(format+"\n", args...))
+	logger.Write(prefixes[level], l.name, fmt.Sprintf(format, args...))
 }
 
 func New(name string) *Logger {
@@ -133,7 +130,7 @@ func SetLogLevel(newLevel LogLevel) {
 
 func SetLogger(newLogger Backend) {
 	if logger != newLogger {
-		logger.close()
+		logger.Close()
 		logger = newLogger
 	}
 }

logger/stdiologger.go

@@ -32,14 +32,20 @@ package logger
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-import "os"
+import (
+	"fmt"
+	"os"
+	"time"
+)
 
 type STDIOLogger struct {
 }
 
-func (l *STDIOLogger) write(logStr string) {
-	os.Stdout.Write([]byte(logStr))
+func (l *STDIOLogger) Write(prefix string, name string, msg string) {
+	os.Stdout.Write([]byte(time.Now().Format(time.StampMicro)))
+	os.Stdout.Write([]byte(fmt.Sprintf(" %s %s: ", prefix, name)))
+	os.Stdout.Write([]byte(msg + "\n"))
 }
 
-func (l *STDIOLogger) close() {
+func (l *STDIOLogger) Close() {
 }

logger_test.go

@@ -0,0 +1,80 @@
+package vertigo
+
+// Copyright (c) 2019 Micro Focus or one of its affiliates.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+import (
+	"testing"
+
+	"github.com/vertica/vertica-sql-go/logger"
+)
+
+type LogMessage struct {
+	Prefix string
+	Name string
+	Msg string
+}
+type MyLogger struct {
+	LastMessage *LogMessage
+}
+func (l *MyLogger) Write(prefix string, name string, msg string) {
+	l.LastMessage = &LogMessage{Prefix: prefix, Name: name, Msg: msg}
+}
+func (l MyLogger) Close() {}
+
+func TestExternalLogging(t *testing.T) {
+	ml := &MyLogger{}
+
+	logger.SetLogger(ml)
+	logger.SetLogLevel(logger.TRACE)
+
+	log := logger.New("TestExternalLogging")
+
+	log.Debug("Basic logging message here")
+	assertEqual(t, ml.LastMessage.Prefix, "DEBUG")
+	assertEqual(t, ml.LastMessage.Name, "TestExternalLogging")
+	assertEqual(t, ml.LastMessage.Msg, "Basic logging message here")
+
+	log.Info("Basic logging message here with number %v", 1234)
+	assertEqual(t, ml.LastMessage.Prefix, "INFO")
+	assertEqual(t, ml.LastMessage.Name, "TestExternalLogging")
+	assertEqual(t, ml.LastMessage.Msg, "Basic logging message here with number 1234")
+
+	log.Warn("With a string and a number: %s, %d", "a string", 5678)
+	assertEqual(t, ml.LastMessage.Prefix, "WARN")
+	assertEqual(t, ml.LastMessage.Name, "TestExternalLogging")
+	assertEqual(t, ml.LastMessage.Msg, "With a string and a number: a string, 5678")
+
+	log.LineTrace()
+	assertEqual(t, ml.LastMessage.Prefix, "TRACE")
+	assertEqual(t, ml.LastMessage.Name, "TestExternalLogging")
+}