werf/trdl

package util

import (
    "os"
    "path/filepath"
    "time"

    "github.com/werf/lockgate"
)

var metafileLockTimeout = 30 * time.Second

type Metafile struct {
    filePath string
}

func NewMetafile(filePath string) Metafile {
    return Metafile{filePath: filePath}
}

func (f Metafile) HasBeenModifiedWithinPeriod(locker lockgate.Locker, period time.Duration) (s bool, err error) {
    err = lockgate.WithAcquire(locker, f.filePath, lockgate.AcquireOptions{Shared: true, Timeout: metafileLockTimeout}, func(_ bool) error {
        s, err = f.hasBeenModifiedWithinPeriod(period)
        return err
    })

    return
}

func (f Metafile) hasBeenModifiedWithinPeriod(period time.Duration) (bool, error) {
    info, err := os.Stat(f.filePath)
    if err != nil {
        return false, nil
    }

    fTime := info.ModTime()
    if fTime.Add(period).After(time.Now()) {
        return true, nil
    }

    return false, nil
}

func (f Metafile) Reset(locker lockgate.Locker) error {
    return lockgate.WithAcquire(locker, f.filePath, lockgate.AcquireOptions{Shared: false, Timeout: metafileLockTimeout}, func(_ bool) error {
        return f.reset()
    })
}

func (f Metafile) reset() error {
    if err := f.delete(); err != nil {
        return err
    }

    if err := os.MkdirAll(filepath.Dir(f.filePath), os.ModePerm); err != nil {
        return err
    }

    file, err := os.Create(f.filePath)
    if err != nil {
        return err
    }

    if err := file.Close(); err != nil {
        return err
    }

    return nil
}

func (f Metafile) Delete(locker lockgate.Locker) error {
    return lockgate.WithAcquire(locker, f.filePath, lockgate.AcquireOptions{Shared: false, Timeout: metafileLockTimeout}, func(_ bool) error {
        return f.delete()
    })
}

func (f Metafile) delete() error {
    exist, err := IsRegularFileExist(f.filePath)
    if err != nil {
        return err
    }

    if exist {
        if err := os.Remove(f.filePath); err != nil {
            return err
        }
    }

    return nil
}