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// 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 (
"fmt"
"io"
"net/http"
"regexp"
"strings"
"sync"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/swarm/storage"
)
var (
hashMatcher = regexp.MustCompile("^[0-9A-Fa-f]{64}")
slashes = regexp.MustCompile("/+")
domainAndVersion = regexp.MustCompile("[@:;,]+")
)
type Resolver interface {
Resolve(string) (common.Hash, error)
}
/*
Api implements webserver/file system related content storage and retrieval
on top of the dpa
it is the public interface of the dpa which is included in the ethereum stack
*/
type Api struct {
dpa *storage.DPA
dns Resolver
}
//the api constructor initialises
func NewApi(dpa *storage.DPA, dns Resolver) (self *Api) {
self = &Api{
dpa: dpa,
dns: dns,
}
return
}
// DPA reader API
func (self *Api) Retrieve(key storage.Key) storage.LazySectionReader {
return self.dpa.Retrieve(key)
}
func (self *Api) Store(data io.Reader, size int64, wg *sync.WaitGroup) (key storage.Key, err error) {
return self.dpa.Store(data, size, wg, nil)
}
type ErrResolve error
// DNS Resolver
func (self *Api) Resolve(hostPort string, nameresolver bool) (storage.Key, error) {
glog.V(logger.Detail).Infof("Resolving : %v", hostPort)
if hashMatcher.MatchString(hostPort) || self.dns == nil {
glog.V(logger.Detail).Infof("host is a contentHash: '%v'", hostPort)
return storage.Key(common.Hex2Bytes(hostPort)), nil
}
if !nameresolver {
return nil, fmt.Errorf("'%s' is not a content hash value.", hostPort)
}
contentHash, err := self.dns.Resolve(hostPort)
if err != nil {
err = ErrResolve(err)
glog.V(logger.Warn).Infof("DNS error : %v", err)
}
glog.V(logger.Detail).Infof("host lookup: %v -> %v", err)
return contentHash[:], err
}
func Parse(uri string) (hostPort, path string) {
if uri == "" {
return
}
parts := slashes.Split(uri, 3)
var i int
if len(parts) == 0 {
return
}
// beginning with slash is now optional
for len(parts[i]) == 0 {
i++
}
hostPort = parts[i]
for i < len(parts)-1 {
i++
if len(path) > 0 {
path = path + "/" + parts[i]
} else {
path = parts[i]
}
}
glog.V(logger.Debug).Infof("host: '%s', path '%s' requested.", hostPort, path)
return
}
func (self *Api) parseAndResolve(uri string, nameresolver bool) (key storage.Key, hostPort, path string, err error) {
hostPort, path = Parse(uri)
//resolving host and port
contentHash, err := self.Resolve(hostPort, nameresolver)
glog.V(logger.Debug).Infof("Resolved '%s' to contentHash: '%s', path: '%s'", uri, contentHash, path)
return contentHash[:], hostPort, path, err
}
// Put provides singleton manifest creation on top of dpa store
func (self *Api) Put(content, contentType string) (string, error) {
r := strings.NewReader(content)
wg := &sync.WaitGroup{}
key, err := self.dpa.Store(r, int64(len(content)), wg, nil)
if err != nil {
return "", err
}
manifest := fmt.Sprintf(`{"entries":[{"hash":"%v","contentType":"%s"}]}`, key, contentType)
r = strings.NewReader(manifest)
key, err = self.dpa.Store(r, int64(len(manifest)), wg, nil)
if err != nil {
return "", err
}
wg.Wait()
return key.String(), nil
}
// Get uses iterative manifest retrieval and prefix matching
// to resolve path to content using dpa retrieve
// it returns a section reader, mimeType, status and an error
func (self *Api) Get(uri string, nameresolver bool) (reader storage.LazySectionReader, mimeType string, status int, err error) {
key, _, path, err := self.parseAndResolve(uri, nameresolver)
if err != nil {
return nil, "", 500, fmt.Errorf("can't resolve: %v", err)
}
quitC := make(chan bool)
trie, err := loadManifest(self.dpa, key, quitC)
if err != nil {
glog.V(logger.Warn).Infof("loadManifestTrie error: %v", err)
return
}
glog.V(logger.Detail).Infof("getEntry(%s)", path)
entry, _ := trie.getEntry(path)
if entry != nil {
key = common.Hex2Bytes(entry.Hash)
status = entry.Status
mimeType = entry.ContentType
glog.V(logger.Detail).Infof("content lookup key: '%v' (%v)", key, mimeType)
reader = self.dpa.Retrieve(key)
} else {
status = http.StatusNotFound
err = fmt.Errorf("manifest entry for '%s' not found", path)
glog.V(logger.Warn).Infof("%v", err)
}
return
}
func (self *Api) Modify(uri, contentHash, contentType string, nameresolver bool) (newRootHash string, err error) {
root, _, path, err := self.parseAndResolve(uri, nameresolver)
if err != nil {
return "", fmt.Errorf("can't resolve: %v", err)
}
quitC := make(chan bool)
trie, err := loadManifest(self.dpa, root, quitC)
if err != nil {
return
}
if contentHash != "" {
entry := &manifestTrieEntry{
Path: path,
Hash: contentHash,
ContentType: contentType,
}
trie.addEntry(entry, quitC)
} else {
trie.deleteEntry(path, quitC)
}
err = trie.recalcAndStore()
if err != nil {
return
}
return trie.hash.String(), nil
}
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