// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// +build linux darwin freebsd
package fuse
import (
"bazil.org/fuse"
"bazil.org/fuse/fs"
"errors"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/swarm/storage"
"golang.org/x/net/context"
"io"
"os"
"sync"
)
const (
MaxAppendFileSize = 10485760 // 10Mb
)
var (
errInvalidOffset = errors.New("Invalid offset during write")
errFileSizeMaxLimixReached = errors.New("File size exceeded max limit")
)
var (
_ fs.Node = (*SwarmFile)(nil)
_ fs.HandleReader = (*SwarmFile)(nil)
_ fs.HandleWriter = (*SwarmFile)(nil)
)
type SwarmFile struct {
inode uint64
name string
path string
key storage.Key
fileSize int64
reader storage.LazySectionReader
mountInfo *MountInfo
lock *sync.RWMutex
}
func NewSwarmFile(path, fname string, minfo *MountInfo) *SwarmFile {
newFile := &SwarmFile{
inode: NewInode(),
name: fname,
path: path,
key: nil,
fileSize: -1, // -1 means , file already exists in swarm and you need to just get the size from swarm
reader: nil,
mountInfo: minfo,
lock: &sync.RWMutex{},
}
return newFile
}
func (file *SwarmFile) Attr(ctx context.Context, a *fuse.Attr) error {
a.Inode = file.inode
//TODO: need to get permission as argument
a.Mode = 0700
a.Uid = uint32(os.Getuid())
a.Gid = uint32(os.Getegid())
if file.fileSize == -1 {
reader := file.mountInfo.swarmApi.Retrieve(file.key)
quitC := make(chan bool)
size, err := reader.Size(quitC)
if err != nil {
log.Warn("Couldnt get size of file %s : %v", file.path, err)
}
file.fileSize = int64(size)
}
a.Size = uint64(file.fileSize)
return nil
}
func (sf *SwarmFile) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error {
sf.lock.RLock()
defer sf.lock.RUnlock()
if sf.reader == nil {
sf.reader = sf.mountInfo.swarmApi.Retrieve(sf.key)
}
buf := make([]byte, req.Size)
n, err := sf.reader.ReadAt(buf, req.Offset)
if err == io.ErrUnexpectedEOF || err == io.EOF {
err = nil
}
resp.Data = buf[:n]
sf.reader = nil
return err
}
func (sf *SwarmFile) Write(ctx context.Context, req *fuse.WriteRequest, resp *fuse.WriteResponse) error {
if sf.fileSize == 0 && req.Offset == 0 {
// A new file is created
err := addFileToSwarm(sf, req.Data, len(req.Data))
if err != nil {
return err
}
resp.Size = len(req.Data)
} else if req.Offset <= sf.fileSize {
totalSize := sf.fileSize + int64(len(req.Data))
if totalSize > MaxAppendFileSize {
log.Warn("Append file size reached (%v) : (%v)", sf.fileSize, len(req.Data))
return errFileSizeMaxLimixReached
}
err := appendToExistingFileInSwarm(sf, req.Data, req.Offset, int64(len(req.Data)))
if err != nil {
return err
}
resp.Size = int(sf.fileSize)
} else {
log.Warn("Invalid write request size(%v) : off(%v)", sf.fileSize, req.Offset)
return errInvalidOffset
}
return nil
}
