package main
import (
"context"
"errors"
"fmt"
"io"
"io/fs"
"log"
"mime"
"path"
"github.com/minio/minio-go/v7"
"golang.org/x/net/webdav"
)
type S3File struct {
fs *S3FS
obj *minio.Object
objw *io.PipeWriter
donew chan error
pos int64
path S3Path
}
func NewS3File(s *S3FS, path string) (webdav.File, error) {
f := new(S3File)
f.fs = s
f.pos = 0
f.path = NewS3Path(path)
return f, nil
}
func (f *S3File) Close() error {
err := make([]error, 0)
if f.obj != nil {
err = append(err, f.obj.Close())
f.obj = nil
}
if f.objw != nil {
// wait that minio completes its transfers in background
err = append(err, f.objw.Close())
err = append(err, <-f.donew)
f.donew = nil
f.objw = nil
}
count := 0
for _, e := range err {
if e != nil {
count++
log.Println(e)
}
}
if count > 0 {
return errors.New(fmt.Sprintf("%d errors when closing this WebDAV File. Read previous logs to know more.", count))
}
return nil
}
func (f *S3File) loadObject() error {
if f.obj == nil {
obj, err := f.fs.mc.GetObject(f.fs.ctx, f.path.bucket, f.path.key, minio.GetObjectOptions{})
if err != nil {
return err
}
f.obj = obj
}
return nil
}
func (f *S3File) Read(p []byte) (n int, err error) {
//if f.Stat() & OBJECT == 0 { /* @FIXME Ideally we would check against OBJECT but we need a non OPAQUE_KEY */
// return 0, os.ErrInvalid
//}
if err := f.loadObject(); err != nil {
return 0, err
}
return f.obj.Read(p)
}
func (f *S3File) Write(p []byte) (n int, err error) {
/*if f.path.class != OBJECT {
return 0, os.ErrInvalid
}*/
if f.objw == nil {
if f.pos != 0 {
return 0, errors.New("writing with an offset is not implemented")
}
r, w := io.Pipe()
f.donew = make(chan error, 1)
f.objw = w
contentType := mime.TypeByExtension(path.Ext(f.path.key))
go func() {
_, err := f.fs.mc.PutObject(context.Background(), f.path.bucket, f.path.key, r, -1, minio.PutObjectOptions{ContentType: contentType})
f.donew <- err
}()
}
return f.objw.Write(p)
}
func (f *S3File) Seek(offset int64, whence int) (int64, error) {
if err := f.loadObject(); err != nil {
return 0, err
}
pos, err := f.obj.Seek(offset, whence)
f.pos += pos
return pos, err
}
/*
ReadDir reads the contents of the directory associated with the file f and returns a slice of DirEntry values in directory order. Subsequent calls on the same file will yield later DirEntry records in the directory.
If n > 0, ReadDir returns at most n DirEntry records. In this case, if ReadDir returns an empty slice, it will return an error explaining why. At the end of a directory, the error is io.EOF.
If n <= 0, ReadDir returns all the DirEntry records remaining in the directory. When it succeeds, it returns a nil error (not io.EOF).
*/
func (f *S3File) Readdir(count int) ([]fs.FileInfo, error) {
if count > 0 {
return nil, errors.New("returning a limited number of directory entry is not supported in readdir")
}
if f.path.class == ROOT {
return f.readDirRoot(count)
} else {
return f.readDirChild(count)
}
}
func (f *S3File) readDirRoot(count int) ([]fs.FileInfo, error) {
buckets, err := f.fs.mc.ListBuckets(f.fs.ctx)
if err != nil {
return nil, err
}
entries := make([]fs.FileInfo, 0, len(buckets))
for _, bucket := range buckets {
//log.Println("Stat from GarageFile.readDirRoot()", "/"+bucket.Name)
nf, err := NewS3Stat(f.fs, "/"+bucket.Name)
if err != nil {
return nil, err
}
entries = append(entries, nf)
}
return entries, nil
}
func (f *S3File) readDirChild(count int) ([]fs.FileInfo, error) {
prefix := f.path.key
if len(prefix) > 0 && prefix[len(prefix)-1:] != "/" {
prefix = prefix + "/"
}
objs_info := f.fs.mc.ListObjects(f.fs.ctx, f.path.bucket, minio.ListObjectsOptions{
Prefix: prefix,
Recursive: false,
})
entries := make([]fs.FileInfo, 0)
for object := range objs_info {
if object.Err != nil {
return nil, object.Err
}
//log.Println("Stat from GarageFile.readDirChild()", path.Join("/", f.path.bucket, object.Key))
nf, err := NewS3StatFromObjectInfo(f.fs, f.path.bucket, object)
if err != nil {
return nil, err
}
entries = append(entries, nf)
}
return entries, nil
}
func (f *S3File) Stat() (fs.FileInfo, error) {
return NewS3Stat(f.fs, f.path.path)
}
