ARM-software/golang-utils

/*
 * Copyright (C) 2020-2022 Arm Limited or its affiliates and Contributors. All rights reserved.
 * SPDX-License-Identifier: Apache-2.0
 */
package subprocess

import (
    "context"
    "io"
    "strings"

    "github.com/ARM-software/golang-utils/utils/logs"
    "github.com/ARM-software/golang-utils/utils/platform"
    "github.com/ARM-software/golang-utils/utils/safeio"
)

var lineSep = platform.UnixLineSeparator()

// INTERNAL
// Way of redirecting process output to a logger.
type logStreamer struct {
    IsStdErr bool
    Loggers  logs.Loggers
}

func (l *logStreamer) Write(p []byte) (n int, err error) {
    lines := strings.Split(string(p), lineSep)
    for i := range lines { // https://stackoverflow.com/questions/62446118/implicit-memory-aliasing-in-for-loop
        line := lines[i]
        if line != "" {
            if l.IsStdErr {
                l.Loggers.LogError(line)
            } else {
                l.Loggers.Log(line)
            }
        }
    }
    return len(p), nil
}

func newLogStreamer(ctx context.Context, isStdErr bool, loggers logs.Loggers) io.Writer {
    return safeio.ContextualWriter(ctx, &logStreamer{
        IsStdErr: isStdErr,
        Loggers:  loggers,
    })
}

func newOutStreamer(ctx context.Context, loggers logs.Loggers) io.Writer {
    return newLogStreamer(ctx, false, loggers)
}

func newErrLogStreamer(ctx context.Context, loggers logs.Loggers) io.Writer {
    return newLogStreamer(ctx, true, loggers)
}