bagage/s3_fs.go
2021-09-03 10:49:05 +02:00

148 lines
3.6 KiB
Go

package main
import (
"context"
"errors"
"io"
"log"
"os"
"path"
"strings"
"time"
"github.com/minio/minio-go/v7"
"golang.org/x/net/webdav"
)
/*
* S3FS lifetime is limited to a single request
* Conversely, Golang's abstraction has been thought to be shared between users
* Sharing an instance between users would be very dangerous (as we would need many checks between shared values)
*/
type S3FS struct {
cache map[string]*S3Stat
mc *minio.Client
ctx context.Context
}
func NewS3FS(mc *minio.Client) S3FS {
return S3FS{
cache: make(map[string]*S3Stat),
mc: mc,
}
}
func (s S3FS) Mkdir(ctx context.Context, name string, perm os.FileMode) error {
s.ctx = ctx
p := NewS3Path(name)
if p.class == ROOT {
return errors.New("Unable to create another root folder")
} else if p.class == BUCKET {
log.Println("Creating bucket is not implemented yet")
return nil
}
f, err := NewS3File(&s, path.Join(name, ".bagage"))
if err != nil {
return err
}
defer f.Close()
_, err = io.Copy(f, strings.NewReader("This is a placeholder"))
return nil
}
func (s S3FS) OpenFile(ctx context.Context, name string, flag int, perm os.FileMode) (webdav.File, error) {
s.ctx = ctx
// If the file does not exist when opening it, we create a stub
if _, ok := s.cache[name]; !ok {
st := new(S3Stat)
st.fs = &s
st.path = NewS3Path(name)
st.path.class = OBJECT
st.obj.Key = st.path.key
st.obj.LastModified = time.Now()
s.cache[name] = st
}
return NewS3File(&s, name)
}
func (s S3FS) RemoveAll(ctx context.Context, name string) error {
//@FIXME nautilus deletes files one by one, at the end, it does not find its folder as it is "already deleted"
s.ctx = ctx
p := NewS3Path(name)
if p.class == ROOT {
return errors.New("Unable to create another root folder")
} else if p.class == BUCKET {
log.Println("Deleting bucket is not implemented yet")
return nil
}
objCh := s.mc.ListObjects(s.ctx, p.bucket, minio.ListObjectsOptions{Prefix: p.key, Recursive: true})
rmCh := s.mc.RemoveObjects(s.ctx, p.bucket, objCh, minio.RemoveObjectsOptions{})
for rErr := range rmCh {
return rErr.Err
}
return nil
}
func (s S3FS) Rename(ctx context.Context, oldName, newName string) error {
s.ctx = ctx
po := NewS3Path(oldName)
pn := NewS3Path(newName)
if po.class == ROOT || pn.class == ROOT {
return errors.New("Unable to rename root folder")
} else if po.class == BUCKET || pn.class == BUCKET {
log.Println("Moving a bucket is not implemented yet")
return nil
}
//Check that newName is not inside oldName
if len(newName) > len(oldName) && newName[:len(oldName)] == oldName {
return errors.New("Cannot move an entity inside itself (eg. moving /data in /data/test is impossible)")
}
//Gather all keys, copy the object, delete the original
objCh := s.mc.ListObjects(s.ctx, po.bucket, minio.ListObjectsOptions{Prefix: po.key, Recursive: true})
for obj := range objCh {
src := minio.CopySrcOptions{
Bucket: po.bucket,
Object: obj.Key,
}
dst := minio.CopyDestOptions{
Bucket: pn.bucket,
Object: path.Join(pn.key, obj.Key[len(po.key):]),
}
_, err := s.mc.CopyObject(s.ctx, dst, src)
if err != nil {
return err
}
err = s.mc.RemoveObject(s.ctx, po.bucket, obj.Key, minio.RemoveObjectOptions{})
var e minio.ErrorResponse
log.Println(errors.As(err, &e))
log.Println(e)
if errors.As(err, &e) && e.StatusCode == 200 {
/* @FIXME workaround for garage's bug #98 */
} else if err != nil {
return err
}
}
return nil
}
func (s S3FS) Stat(ctx context.Context, name string) (os.FileInfo, error) {
s.ctx = ctx
return NewS3Stat(&s, name)
}