portal/api/s5/file.go

235 lines
3.9 KiB
Go

package s5
import (
"context"
"encoding/hex"
"errors"
"io"
"time"
"git.lumeweb.com/LumeWeb/portal/protocols/s5"
"git.lumeweb.com/LumeWeb/portal/metadata"
"git.lumeweb.com/LumeWeb/portal/storage"
"git.lumeweb.com/LumeWeb/libs5-go/encoding"
"git.lumeweb.com/LumeWeb/libs5-go/types"
)
var _ io.ReadSeekCloser = (*S5File)(nil)
type S5File struct {
reader io.ReadCloser
hash []byte
storage storage.StorageService
metadata metadata.MetadataService
record *metadata.UploadMetadata
protocol *s5.S5Protocol
cid *encoding.CID
read bool
tus *s5.TusHandler
}
type FileParams struct {
Storage storage.StorageService
Metadata metadata.MetadataService
Hash []byte
Protocol *s5.S5Protocol
Tus *s5.TusHandler
}
func NewFile(params FileParams) *S5File {
return &S5File{
storage: params.Storage,
metadata: params.Metadata,
hash: params.Hash,
protocol: params.Protocol,
tus: params.Tus,
}
}
func (f *S5File) Exists() bool {
_, err := f.metadata.GetUpload(context.Background(), f.hash)
if err != nil {
return false
}
return true
}
func (f *S5File) Read(p []byte) (n int, err error) {
err = f.init(0)
if err != nil {
return 0, err
}
f.read = true
return f.reader.Read(p)
}
func (f *S5File) Seek(offset int64, whence int) (int64, error) {
switch whence {
case io.SeekStart:
if !f.read {
return 0, nil
}
if f.reader != nil {
err := f.reader.Close()
if err != nil {
return 0, err
}
f.reader = nil
}
err := f.init(offset)
if err != nil {
return 0, err
}
case io.SeekCurrent:
return 0, errors.New("not supported")
case io.SeekEnd:
return int64(f.Size()), nil
default:
return 0, errors.New("invalid whence")
}
return 0, nil
}
func (f *S5File) Close() error {
if f.reader != nil {
r := f.reader
f.reader = nil
return r.Close()
}
return nil
}
func (f *S5File) init(offset int64) error {
if f.reader == nil {
reader, err := f.tus.GetUploadReader(f.hash, offset)
if err == nil {
f.reader = reader
f.read = false
return nil
}
reader, err = f.storage.DownloadObject(context.Background(), f.StorageProtocol(), f.hash, offset)
if err != nil {
return err
}
f.reader = reader
f.read = false
}
return nil
}
func (f *S5File) Record() (*metadata.UploadMetadata, error) {
if f.record == nil {
record, err := f.metadata.GetUpload(context.Background(), f.Hash())
if err != nil {
return nil, errors.New("file does not exist")
}
f.record = &record
}
return f.record, nil
}
func (f *S5File) Hash() []byte {
hashStr := f.HashString()
if hashStr == "" {
return nil
}
str, err := hex.DecodeString(hashStr)
if err != nil {
return nil
}
return str
}
func (f *S5File) HashString() string {
record, err := f.Record()
if err != nil {
return ""
}
return hex.EncodeToString(record.Hash)
}
func (f *S5File) Name() string {
cid, _ := f.CID().ToString()
return cid
}
func (f *S5File) Modtime() time.Time {
record, err := f.Record()
if err != nil {
return time.Unix(0, 0)
}
return record.Created
}
func (f *S5File) Size() uint64 {
record, err := f.Record()
if err != nil {
return 0
}
return record.Size
}
func (f *S5File) CID() *encoding.CID {
if f.cid == nil {
multihash := encoding.MultihashFromBytes(f.Hash(), types.HashTypeBlake3)
cid := encoding.NewCID(types.CIDTypeRaw, *multihash, f.Size())
f.cid = cid
}
return f.cid
}
func (f *S5File) Mime() string {
record, err := f.Record()
if err != nil {
return ""
}
return record.MimeType
}
func (f *S5File) StorageProtocol() storage.StorageProtocol {
return s5.GetStorageProtocol(f.protocol)
}
func (f *S5File) Proof() ([]byte, error) {
object, err := f.storage.DownloadObjectProof(context.Background(), f.StorageProtocol(), f.hash)
if err != nil {
return nil, err
}
proof, err := io.ReadAll(object)
if err != nil {
return nil, err
}
err = object.Close()
if err != nil {
return nil, err
}
return proof, nil
}