plugeth/swarm/api/api.go
Lewis Marshall 71fdaa4238 swarm/api: refactor and improve HTTP API (#3773)
This PR deprecates the file related RPC calls in favour of an improved HTTP API.

The main aim is to expose a simple to use API which can be consumed by thin
clients (e.g. curl and HTML forms) without the need for complex logic (e.g.
manipulating prefix trie manifests).
2017-04-07 00:22:22 +02:00

163 lines
4.5 KiB
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 (
"errors"
"fmt"
"io"
"net/http"
"regexp"
"strings"
"sync"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/log"
"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(uri *URI) (storage.Key, error) {
log.Trace(fmt.Sprintf("Resolving : %v", uri.Addr))
if hashMatcher.MatchString(uri.Addr) {
log.Trace(fmt.Sprintf("addr is a hash: %q", uri.Addr))
return storage.Key(common.Hex2Bytes(uri.Addr)), nil
}
if uri.Immutable() {
return nil, errors.New("refusing to resolve immutable address")
}
if self.dns == nil {
return nil, fmt.Errorf("unable to resolve addr %q, resolver not configured", uri.Addr)
}
hash, err := self.dns.Resolve(uri.Addr)
if err != nil {
log.Warn(fmt.Sprintf("DNS error resolving addr %q: %s", uri.Addr, err))
return nil, ErrResolve(err)
}
log.Trace(fmt.Sprintf("addr lookup: %v -> %v", uri.Addr, hash))
return hash[:], nil
}
// Put provides singleton manifest creation on top of dpa store
func (self *Api) Put(content, contentType string) (storage.Key, error) {
r := strings.NewReader(content)
wg := &sync.WaitGroup{}
key, err := self.dpa.Store(r, int64(len(content)), wg, nil)
if err != nil {
return nil, 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 nil, err
}
wg.Wait()
return key, 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(key storage.Key, path string) (reader storage.LazySectionReader, mimeType string, status int, err error) {
trie, err := loadManifest(self.dpa, key, nil)
if err != nil {
log.Warn(fmt.Sprintf("loadManifestTrie error: %v", err))
return
}
log.Trace(fmt.Sprintf("getEntry(%s)", path))
entry, _ := trie.getEntry(path)
if entry != nil {
key = common.Hex2Bytes(entry.Hash)
status = entry.Status
mimeType = entry.ContentType
log.Trace(fmt.Sprintf("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)
log.Warn(fmt.Sprintf("%v", err))
}
return
}
func (self *Api) Modify(key storage.Key, path, contentHash, contentType string) (storage.Key, error) {
quitC := make(chan bool)
trie, err := loadManifest(self.dpa, key, quitC)
if err != nil {
return nil, err
}
if contentHash != "" {
entry := newManifestTrieEntry(&ManifestEntry{
Path: path,
ContentType: contentType,
}, nil)
entry.Hash = contentHash
trie.addEntry(entry, quitC)
} else {
trie.deleteEntry(path, quitC)
}
if err := trie.recalcAndStore(); err != nil {
return nil, err
}
return trie.hash, nil
}