Use the system.ScanReader function to replace this logic

This commit is contained in:
Dane Everitt 2020-12-25 17:07:57 -08:00
parent a4c68eed16
commit 94d41bc1f5
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@ -2,7 +2,6 @@ package docker
import (
"bufio"
"bytes"
"context"
"emperror.dev/errors"
"encoding/json"
@ -15,6 +14,7 @@ import (
"github.com/docker/docker/daemon/logger/jsonfilelog"
"github.com/pterodactyl/wings/config"
"github.com/pterodactyl/wings/environment"
"github.com/pterodactyl/wings/system"
"io"
"strconv"
"strings"
@ -295,60 +295,10 @@ func (e *Environment) followOutput() error {
go func(reader io.ReadCloser) {
defer reader.Close()
r := bufio.NewReader(reader)
// Micro-optimization to create these replacements one time when this routine
// fires up, rather than on every line that is executed.
cr := []byte(" \r")
crr := []byte("\r\n")
// Avoid constantly re-allocating memory when we're flooding lines through this
// function by using the same buffer for the duration of the call and just truncating
// the value back to 0 every loop.
var str strings.Builder
ParentLoop:
for {
str.Reset()
var line []byte
var isPrefix bool
for {
// Read the line and write it to the buffer.
line, isPrefix, err = r.ReadLine()
// Certain games like Minecraft output absolutely random carriage returns in the output seemingly
// in line with that it thinks is the terminal size. Those returns break a lot of output handling,
// so we'll just replace them with proper new-lines and then split it later and send each line as
// its own event in the response.
str.Write(bytes.Replace(line, cr, crr, -1))
// Finish this loop and begin outputting the line if there is no prefix (the line fit into
// the default buffer), or if we hit the end of the line.
if !isPrefix || err == io.EOF {
break
}
// If we encountered an error with something in ReadLine that was not an EOF just abort
// the entire process here.
if err != nil {
break ParentLoop
}
}
// Publish the line for this loop. Break on new-line characters so every line is sent as a single
// output event, otherwise you get funky handling in the browser console.
for _, line := range strings.Split(str.String(), "\r\n") {
e.Events().Publish(environment.ConsoleOutputEvent, line)
}
// If the error we got previously that lead to the line being output is an io.EOF we want to
// exit the entire looping process.
if err == io.EOF {
break
}
}
evts := e.Events()
err := system.ScanReader(reader, func(line string) {
evts.Publish(environment.ConsoleOutputEvent, line)
})
if err != nil && err != io.EOF {
log.WithField("error", err).WithField("container_id", e.Id).Warn("error processing scanner line in console output")
}