databricks-cli/libs/cmdio/logger.go

148 lines
2.9 KiB
Go

package cmdio
import (
"bufio"
"context"
"encoding/json"
"fmt"
"io"
"os"
"github.com/databricks/bricks/libs/flags"
)
// This is the interface for all io interactions with a user
type Logger struct {
// Mode for the logger. One of (append, inplace, json).
Mode flags.ProgressLogFormat
// Input stream (eg. stdin). Answers to questions prompted using the Ask() method
// are read from here
Reader bufio.Reader
// Output stream where the logger writes to
Writer io.Writer
// If true, indicates no events have been printed by the logger yet. Used
// by inplace logging for formatting
isFirstEvent bool
}
func NewLogger(mode flags.ProgressLogFormat) *Logger {
return &Logger{
Mode: mode,
Writer: os.Stderr,
Reader: *bufio.NewReader(os.Stdin),
isFirstEvent: true,
}
}
func Default() *Logger {
return &Logger{
Mode: flags.ModeAppend,
Writer: os.Stderr,
Reader: *bufio.NewReader(os.Stdin),
isFirstEvent: true,
}
}
func Log(ctx context.Context, event Event) {
logger, ok := FromContext(ctx)
if !ok {
logger = Default()
}
logger.Log(event)
}
func LogString(ctx context.Context, message string) {
logger, ok := FromContext(ctx)
if !ok {
logger = Default()
}
logger.Log(&MessageEvent{
Message: message,
})
}
func Ask(ctx context.Context, question string) (bool, error) {
logger, ok := FromContext(ctx)
if !ok {
logger = Default()
}
return logger.Ask(question)
}
func (l *Logger) Ask(question string) (bool, error) {
if l.Mode == flags.ModeJson {
return false, fmt.Errorf("question prompts are not supported in json mode")
}
l.Writer.Write([]byte(question))
ans, err := l.Reader.ReadString('\n')
if err != nil {
return false, err
}
if ans == "y\n" {
return true, nil
} else {
return false, nil
}
}
func (l *Logger) writeJson(event Event) {
b, err := json.MarshalIndent(event, "", " ")
if err != nil {
// we panic because there we cannot catch this in jobs.RunNowAndWait
panic(err)
}
l.Writer.Write([]byte(b))
l.Writer.Write([]byte("\n"))
}
func (l *Logger) writeAppend(event Event) {
l.Writer.Write([]byte(event.String()))
l.Writer.Write([]byte("\n"))
}
func (l *Logger) writeInplace(event Event) {
if l.isFirstEvent {
// save cursor location
l.Writer.Write([]byte("\033[s"))
}
// move cursor to saved location
l.Writer.Write([]byte("\033[u"))
// clear from cursor to end of screen
l.Writer.Write([]byte("\033[0J"))
l.Writer.Write([]byte(event.String()))
l.Writer.Write([]byte("\n"))
l.isFirstEvent = false
}
func (l *Logger) Log(event Event) {
switch l.Mode {
case flags.ModeInplace:
if event.IsInplaceSupported() {
l.writeInplace(event)
} else {
l.writeAppend(event)
}
case flags.ModeJson:
l.writeJson(event)
case flags.ModeAppend:
l.writeAppend(event)
default:
// we panic because errors are not captured in some log sides like
// jobs.RunNowAndWait
panic("unknown progress logger mode: " + l.Mode.String())
}
}