path: root/swarm/api/filesystem.go

// Copyright 2016 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/>.

package api

import (
    "bufio"
    "context"
    "fmt"
    "io"
    "os"
    "path"
    "path/filepath"
    "sync"

    "github.com/dexon-foundation/dexon/common"
    "github.com/dexon-foundation/dexon/swarm/log"
    "github.com/dexon-foundation/dexon/swarm/storage"
)

const maxParallelFiles = 5

type FileSystem struct {
    api *API
}

func NewFileSystem(api *API) *FileSystem {
    return &FileSystem{api}
}

// Upload replicates a local directory as a manifest file and uploads it
// using FileStore store
// This function waits the chunks to be stored.
// TODO: localpath should point to a manifest
//
// DEPRECATED: Use the HTTP API instead
func (fs *FileSystem) Upload(lpath, index string, toEncrypt bool) (string, error) {
    var list []*manifestTrieEntry
    localpath, err := filepath.Abs(filepath.Clean(lpath))
    if err != nil {
        return "", err
    }

    f, err := os.Open(localpath)
    if err != nil {
        return "", err
    }
    stat, err := f.Stat()
    if err != nil {
        return "", err
    }

    var start int
    if stat.IsDir() {
        start = len(localpath)
        log.Debug(fmt.Sprintf("uploading '%s'", localpath))
        err = filepath.Walk(localpath, func(path string, info os.FileInfo, err error) error {
            if (err == nil) && !info.IsDir() {
                if len(path) <= start {
                    return fmt.Errorf("Path is too short")
                }
                if path[:start] != localpath {
                    return fmt.Errorf("Path prefix of '%s' does not match localpath '%s'", path, localpath)
                }
                entry := newManifestTrieEntry(&ManifestEntry{Path: filepath.ToSlash(path)}, nil)
                list = append(list, entry)
            }
            return err
        })
        if err != nil {
            return "", err
        }
    } else {
        dir := filepath.Dir(localpath)
        start = len(dir)
        if len(localpath) <= start {
            return "", fmt.Errorf("Path is too short")
        }
        if localpath[:start] != dir {
            return "", fmt.Errorf("Path prefix of '%s' does not match dir '%s'", localpath, dir)
        }
        entry := newManifestTrieEntry(&ManifestEntry{Path: filepath.ToSlash(localpath)}, nil)
        list = append(list, entry)
    }

    errors := make([]error, len(list))
    sem := make(chan bool, maxParallelFiles)
    defer close(sem)

    for i, entry := range list {
        sem <- true
        go func(i int, entry *manifestTrieEntry) {
            defer func() { <-sem }()

            f, err := os.Open(entry.Path)
            if err != nil {
                errors[i] = err
                return
            }
            defer f.Close()

            stat, err := f.Stat()
            if err != nil {
                errors[i] = err
                return
            }

            var hash storage.Address
            var wait func(context.Context) error
            ctx := context.TODO()
            hash, wait, err = fs.api.fileStore.Store(ctx, f, stat.Size(), toEncrypt)
            if err != nil {
                errors[i] = err
                return
            }
            if hash != nil {
                list[i].Hash = hash.Hex()
            }
            if err := wait(ctx); err != nil {
                errors[i] = err
                return
            }

            list[i].ContentType, err = DetectContentType(f.Name(), f)
            if err != nil {
                errors[i] = err
                return
            }

        }(i, entry)
    }
    for i := 0; i < cap(sem); i++ {
        sem <- true
    }

    trie := &manifestTrie{
        fileStore: fs.api.fileStore,
    }
    quitC := make(chan bool)
    for i, entry := range list {
        if errors[i] != nil {
            return "", errors[i]
        }
        entry.Path = RegularSlashes(entry.Path[start:])
        if entry.Path == index {
            ientry := newManifestTrieEntry(&ManifestEntry{
                ContentType: entry.ContentType,
            }, nil)
            ientry.Hash = entry.Hash
            trie.addEntry(ientry, quitC)
        }
        trie.addEntry(entry, quitC)
    }

    err2 := trie.recalcAndStore()
    var hs string
    if err2 == nil {
        hs = trie.ref.Hex()
    }
    return hs, err2
}

// Download replicates the manifest basePath structure on the local filesystem
// under localpath
//
// DEPRECATED: Use the HTTP API instead
func (fs *FileSystem) Download(bzzpath, localpath string) error {
    lpath, err := filepath.Abs(filepath.Clean(localpath))
    if err != nil {
        return err
    }
    err = os.MkdirAll(lpath, os.ModePerm)
    if err != nil {
        return err
    }

    //resolving host and port
    uri, err := Parse(path.Join("bzz:/", bzzpath))
    if err != nil {
        return err
    }
    addr, err := fs.api.Resolve(context.TODO(), uri.Addr)
    if err != nil {
        return err
    }
    path := uri.Path

    if len(path) > 0 {
        path += "/"
    }

    quitC := make(chan bool)
    trie, err := loadManifest(context.TODO(), fs.api.fileStore, addr, quitC, NOOPDecrypt)
    if err != nil {
        log.Warn(fmt.Sprintf("fs.Download: loadManifestTrie error: %v", err))
        return err
    }

    type downloadListEntry struct {
        addr storage.Address
        path string
    }

    var list []*downloadListEntry
    var mde error

    prevPath := lpath
    err = trie.listWithPrefix(path, quitC, func(entry *manifestTrieEntry, suffix string) {
        log.Trace(fmt.Sprintf("fs.Download: %#v", entry))

        addr = common.Hex2Bytes(entry.Hash)
        path := lpath + "/" + suffix
        dir := filepath.Dir(path)
        if dir != prevPath {
            mde = os.MkdirAll(dir, os.ModePerm)
            prevPath = dir
        }
        if (mde == nil) && (path != dir+"/") {
            list = append(list, &downloadListEntry{addr: addr, path: path})
        }
    })
    if err != nil {
        return err
    }

    wg := sync.WaitGroup{}
    errC := make(chan error)
    done := make(chan bool, maxParallelFiles)
    for i, entry := range list {
        select {
        case done <- true:
            wg.Add(1)
        case <-quitC:
            return fmt.Errorf("aborted")
        }
        go func(i int, entry *downloadListEntry) {
            defer wg.Done()
            err := retrieveToFile(quitC, fs.api.fileStore, entry.addr, entry.path)
            if err != nil {
                select {
                case errC <- err:
                case <-quitC:
                }
                return
            }
            <-done
        }(i, entry)
    }
    go func() {
        wg.Wait()
        close(errC)
    }()
    select {
    case err = <-errC:
        return err
    case <-quitC:
        return fmt.Errorf("aborted")
    }
}

func retrieveToFile(quitC chan bool, fileStore *storage.FileStore, addr storage.Address, path string) error {
    f, err := os.Create(path) // TODO: basePath separators
    if err != nil {
        return err
    }
    reader, _ := fileStore.Retrieve(context.TODO(), addr)
    writer := bufio.NewWriter(f)
    size, err := reader.Size(context.TODO(), quitC)
    if err != nil {
        return err
    }
    if _, err = io.CopyN(writer, reader, size); err != nil {
        return err
    }
    if err := writer.Flush(); err != nil {
        return err
    }
    return f.Close()
}