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olog

• olog is a lightweight, high-performance, out-of-the-box logging library that relies solely on the Go standard library.
• Support outputting logs in JSON, plain text, and custom formats.
• Supports setting context handling functions to retrieve fields from the context for output.
• Supports seven log levels: TRACE, DEBUG, INFO, NOTICE, WARN, ERROR, and FATAL, corresponding to the "trace", "debug", "info", "notice", "warn", "error", and "fatal" tags. Users can also define their own semantic tags, such as "slow" and "stat".
• Provides output switch control for all log levels except FATAL.
• Enhances control over caller printing. Users can disable caller printing in global settings to improve performance, but can enable support for caller printing when printing certain critical logs.
• Provides a Logger interface for users to easily construct their own logger.

code example

    Trace("hello world")
    Tracew("hello", Field{Key: "name", Value: "bob"})
    Debug("hello world")
    Infow("hello", Field{Key: "name", Value: "linda"}, Field{Key: "age", Value: 18})
    Noticef("hello %s", "world")
    Warnf("hello %s", "world")
    Warnw("hello", Field{Key: "order_no", Value: "AWESDDF"})
    Errorw("hello world", Field{Key: "success", Value: true})
    Log(Record{Level: DEBUG, LevelTag: "print", Caller: Disable, Fields: []Field{{Key: "price", Value: 32.5}},
        Stack: Enable, StackSize: 1, MsgOrFormat: "hello world"})
    Fatal("fatal exit")

The json output is as follows:

{"@timestamp":"2023-04-20T18:33:42+08:00","level":"trace","caller":"olog/log_test.go:377","content":"hello world","stack":"\ngithub.com/welllog/olog.TestPlainOutput\n\t/olog/log_test.go:377\ntesting.tRunner\n\t/usr/local/opt/go/libexec/src/testing/testing.go:1576\nruntime.goexit\n\t/usr/local/opt/go/libexec/src/runtime/asm_amd64.s:1598"}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"trace","caller":"olog/log_test.go:378","content":"hello","name":"bob","stack":"\ngithub.com/welllog/olog.TestPlainOutput\n\t/olog/log_test.go:378\ntesting.tRunner\n\t/usr/local/opt/go/libexec/src/testing/testing.go:1576\nruntime.goexit\n\t/usr/local/opt/go/libexec/src/runtime/asm_amd64.s:1598"}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"debug","caller":"olog/log_test.go:379","content":"hello world"}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"info","caller":"olog/log_test.go:380","content":"hello","name":"linda","age":18}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"notice","caller":"olog/log_test.go:381","content":"hello world"}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"warn","caller":"olog/log_test.go:382","content":"hello world"}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"warn","caller":"olog/log_test.go:383","content":"hello","order_no":"AWESDDF"}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"error","caller":"olog/log_test.go:384","content":"hello world","success":true}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"print","content":"hello world","price":32.5,"stack":"\ngithub.com/welllog/olog.TestPlainOutput\n\t/olog/log_test.go:385"}
{"@timestamp":"2023-04-20T18:33:42+08:00","level":"fatal","caller":"olog/log_test.go:388","content":"fatal exit"}

The plain output is as follows:

2023-04-20T18:32:09+08:00	trace	olog/log_test.go:377	hello world	stack=
github.com/welllog/olog.TestPlainOutput
	/olog/log_test.go:377
testing.tRunner
	/usr/local/opt/go/libexec/src/testing/testing.go:1576
runtime.goexit
	/usr/local/opt/go/libexec/src/runtime/asm_amd64.s:1598
2023-04-20T18:32:09+08:00	trace	olog/log_test.go:378	hello	name=bob	stack=
github.com/welllog/olog.TestPlainOutput
	/olog/log_test.go:378
testing.tRunner
	/usr/local/opt/go/libexec/src/testing/testing.go:1576
runtime.goexit
	/usr/local/opt/go/libexec/src/runtime/asm_amd64.s:1598
2023-04-20T18:32:09+08:00	debug	olog/log_test.go:379	hello world
2023-04-20T18:32:09+08:00	info	olog/log_test.go:380	hello	name=linda	age=18
2023-04-20T18:32:09+08:00	notice	olog/log_test.go:381	hello world
2023-04-20T18:32:09+08:00	warn	olog/log_test.go:382	hello world
2023-04-20T18:32:09+08:00	warn	olog/log_test.go:383	hello	order_no=AWESDDF
2023-04-20T18:32:09+08:00	error	olog/log_test.go:384	hello world	success=true
2023-04-20T18:32:09+08:00	print	hello world	price=32.5	stack=
github.com/welllog/olog.TestPlainOutput
	/olog/log_test.go:385
2023-04-20T18:32:09+08:00	fatal	olog/log_test.go:388	fatal exit

contextLogger uses

        SetDefCtxHandle(func(ctx context.Context) []Field {
		var fs []Field
		uid, ok := ctx.Value("uid").(int)
		if ok {
			fs = append(fs, Field{Key: "uid", Value: uid})
		}

		name, ok := ctx.Value("name").(string)
		if ok {
			fs = append(fs, Field{Key: "name", Value: name})
		}
		return fs
	})

        logger := WithContext(GetLogger(), context.WithValue(context.Background(), "uid", 3))
	logger.Debug("test")
	
	logger = WithContext(logger, context.WithValue(context.Background(), "name", "bob"))
        logger = WithEntries(logger, map[string]any{"requestId": "ae32fec"})
	logger.Debug("test 2")

Implement your own logger

type CustomLogger struct {
	Logger
}

func (l *CustomLogger) Slow(a ...any) {
    l.Log(Record{Level: WARN, LevelTag: "slow", CallerSkip: 1, MsgArgs: a})
}

func (l *CustomLogger) Stat(a ...any) {
    l.Log(Record{Level: INFO, LevelTag: "stat", CallerSkip: 1, MsgArgs: a})
}

func (l *CustomLogger) Debug(a ...any) {
    l.Log(Record{Level: DEBUG, CallerSkip: 1, Caller: Enable, MsgArgs: a})
}

slog support

logger := slog.New(
    NewSlogHandler(NewLogger()),
)

logger.Info("hello world")

Log Content Output

Currently, log content is output to the console by default. To output content to a file, you need to set the log's Writer by constructing a Writer with the NewWriter function and passing a file pointer. If you want to implement more powerful output control, such as log file splitting, you can use github.com/lestrrat-go/file-rotatelogs to construct a Writer. When implementing the Write method on your own, it is important to note that the []byte parameter should not exceed the scope of the method, otherwise data concurrency issues may occur and result in confusion.

Performance

Log a message and 3 fields(disable caller output and RunParallel):

goos: darwin
goarch: arm64
pkg: github.com/welllog/olog
BenchmarkInfow
BenchmarkInfow/std.logger
BenchmarkInfow/std.logger-10         	 3760806	       287.4 ns/op	      48 B/op	       1 allocs/op
BenchmarkInfow/olog.json
BenchmarkInfow/olog.json-10          	14397530	        77.93 ns/op	      96 B/op	       1 allocs/op
BenchmarkInfow/olog.plain
BenchmarkInfow/olog.plain-10         	21455214	        56.19 ns/op	      96 B/op	       1 allocs/op
BenchmarkInfow/olog.ctx.json
BenchmarkInfow/olog.ctx.json-10      	14290038	        83.48 ns/op	      96 B/op	       1 allocs/op
BenchmarkInfow/olog.ctx.plain
BenchmarkInfow/olog.ctx.plain-10     	19133161	        59.64 ns/op	      96 B/op	       1 allocs/op
PASS