swarm/api: FUSE read-write support (#13872)

- Moved fuse related code in a new package, swarm/fuse
- Added write support
  - Create new files
  - Delete existing files
  - Append to files (with limitations)
- More test coverage

1 files changed, 144 insertions, 0 deletions

diff --git a/swarm/fuse/swarmfs_util.go b/swarm/fuse/swarmfs_util.go
new file mode 100644
index 000000000..d20ab258e
--- /dev/null
+++ b/swarm/fuse/swarmfs_util.go
@@ -0,0 +1,144 @@
+// 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 (
+	"fmt"
+	"github.com/ethereum/go-ethereum/log"
+	"os/exec"
+	"runtime"
+	"time"
+)
+
+func externalUnMount(mountPoint string) error {
+
+	var cmd *exec.Cmd
+
+	switch runtime.GOOS {
+
+	case "darwin":
+		cmd = exec.Command("/usr/bin/diskutil", "umount", "force", mountPoint)
+
+	case "linux":
+		cmd = exec.Command("fusermount", "-u", mountPoint)
+
+	default:
+		return fmt.Errorf("unmount: unimplemented")
+	}
+
+	errc := make(chan error, 1)
+	go func() {
+		defer close(errc)
+
+		if err := exec.Command("umount", mountPoint).Run(); err == nil {
+			return
+		}
+		errc <- cmd.Run()
+	}()
+
+	select {
+
+	case <-time.After(unmountTimeout):
+		return fmt.Errorf("umount timeout")
+
+	case err := <-errc:
+		return err
+	}
+}
+
+func addFileToSwarm(sf *SwarmFile, content []byte, size int) error {
+
+	fkey, mhash, err := sf.mountInfo.swarmApi.AddFile(sf.mountInfo.LatestManifest, sf.path, sf.name, content, true)
+	if err != nil {
+		return err
+	}
+
+	sf.lock.Lock()
+	defer sf.lock.Unlock()
+	sf.key = fkey
+	sf.fileSize = int64(size)
+
+	sf.mountInfo.lock.Lock()
+	defer sf.mountInfo.lock.Unlock()
+	sf.mountInfo.LatestManifest = mhash
+
+	log.Info("Added new file:", "fname", sf.name, "New Manifest hash", mhash)
+	return nil
+
+}
+
+func removeFileFromSwarm(sf *SwarmFile) error {
+
+	mkey, err := sf.mountInfo.swarmApi.RemoveFile(sf.mountInfo.LatestManifest, sf.path, sf.name, true)
+	if err != nil {
+		return err
+	}
+
+	sf.mountInfo.lock.Lock()
+	defer sf.mountInfo.lock.Unlock()
+	sf.mountInfo.LatestManifest = mkey
+
+	log.Info("Removed file:", "fname", sf.name, "New Manifest hash", mkey)
+	return nil
+}
+
+func removeDirectoryFromSwarm(sd *SwarmDir) error {
+
+	if len(sd.directories) == 0 && len(sd.files) == 0 {
+		return nil
+	}
+
+	for _, d := range sd.directories {
+		err := removeDirectoryFromSwarm(d)
+		if err != nil {
+			return err
+		}
+	}
+
+	for _, f := range sd.files {
+		err := removeFileFromSwarm(f)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+
+}
+
+func appendToExistingFileInSwarm(sf *SwarmFile, content []byte, offset int64, length int64) error {
+
+	fkey, mhash, err := sf.mountInfo.swarmApi.AppendFile(sf.mountInfo.LatestManifest, sf.path, sf.name, sf.fileSize, content, sf.key, offset, length, true)
+	if err != nil {
+		return err
+	}
+
+	sf.lock.Lock()
+	defer sf.lock.Unlock()
+	sf.key = fkey
+	sf.fileSize = sf.fileSize + int64(len(content))
+
+	sf.mountInfo.lock.Lock()
+	defer sf.mountInfo.lock.Unlock()
+	sf.mountInfo.LatestManifest = mhash
+
+	log.Info("Appended file:", "fname", sf.name, "New Manifest hash", mhash)
+	return nil
+
+}