// Copyright 2016 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
// Command feed allows the user to create and update signed Swarm feeds
package main
import (
"fmt"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/cmd/utils"
swarm "github.com/ethereum/go-ethereum/swarm/api/client"
"github.com/ethereum/go-ethereum/swarm/storage/feed"
"gopkg.in/urfave/cli.v1"
)
var feedCommand = cli.Command{
CustomHelpTemplate: helpTemplate,
Name: "feed",
Usage: "(Advanced) Create and update Swarm Feeds",
ArgsUsage: "<create|update|info>",
Description: "Works with Swarm Feeds",
Subcommands: []cli.Command{
{
Action: feedCreateManifest,
CustomHelpTemplate: helpTemplate,
Name: "create",
Usage: "creates and publishes a new feed manifest",
Description: `creates and publishes a new feed manifest pointing to a specified user's updates about a particular topic.
The feed topic can be built in the following ways:
* use --topic to set the topic to an arbitrary binary hex string.
* use --name to set the topic to a human-readable name.
For example --name could be set to "profile-picture", meaning this feed allows to get this user's current profile picture.
* use both --topic and --name to create named subtopics.
For example, --topic could be set to an Ethereum contract address and --name could be set to "comments", meaning
this feed tracks a discussion about that contract.
The --user flag allows to have this manifest refer to a user other than yourself. If not specified,
it will then default to your local account (--bzzaccount)`,
Flags: []cli.Flag{SwarmFeedNameFlag, SwarmFeedTopicFlag, SwarmFeedUserFlag},
},
{
Action: feedUpdate,
CustomHelpTemplate: helpTemplate,
Name: "update",
Usage: "updates the content of an existing Swarm Feed",
ArgsUsage: "<0x Hex data>",
Description: `publishes a new update on the specified topic
The feed topic can be built in the following ways:
* use --topic to set the topic to an arbitrary binary hex string.
* use --name to set the topic to a human-readable name.
For example --name could be set to "profile-picture", meaning this feed allows to get this user's current profile picture.
* use both --topic and --name to create named subtopics.
For example, --topic could be set to an Ethereum contract address and --name could be set to "comments", meaning
this feed tracks a discussion about that contract.
If you have a manifest, you can specify it with --manifest to refer to the feed,
instead of using --topic / --name
`,
Flags: []cli.Flag{SwarmFeedManifestFlag, SwarmFeedNameFlag, SwarmFeedTopicFlag},
},
{
Action: feedInfo,
CustomHelpTemplate: helpTemplate,
Name: "info",
Usage: "obtains information about an existing Swarm feed",
Description: `obtains information about an existing Swarm feed
The topic can be specified directly with the --topic flag as an hex string
If no topic is specified, the default topic (zero) will be used
The --name flag can be used to specify subtopics with a specific name.
The --user flag allows to refer to a user other than yourself. If not specified,
it will then default to your local account (--bzzaccount)
If you have a manifest, you can specify it with --manifest instead of --topic / --name / ---user
to refer to the feed`,
Flags: []cli.Flag{SwarmFeedManifestFlag, SwarmFeedNameFlag, SwarmFeedTopicFlag, SwarmFeedUserFlag},
},
},
}
func NewGenericSigner(ctx *cli.Context) feed.Signer {
return feed.NewGenericSigner(getPrivKey(ctx))
}
func getTopic(ctx *cli.Context) (topic feed.Topic) {
var name = ctx.String(SwarmFeedNameFlag.Name)
var relatedTopic = ctx.String(SwarmFeedTopicFlag.Name)
var relatedTopicBytes []byte
var err error
if relatedTopic != "" {
relatedTopicBytes, err = hexutil.Decode(relatedTopic)
if err != nil {
utils.Fatalf("Error parsing topic: %s", err)
}
}
topic, err = feed.NewTopic(name, relatedTopicBytes)
if err != nil {
utils.Fatalf("Error parsing topic: %s", err)
}
return topic
}
// swarm feed create <frequency> [--name <name>] [--data <0x Hexdata> [--multihash=false]]
// swarm feed update <Manifest Address or ENS domain> <0x Hexdata> [--multihash=false]
// swarm feed info <Manifest Address or ENS domain>
func feedCreateManifest(ctx *cli.Context) {
var (
bzzapi = strings.TrimRight(ctx.GlobalString(SwarmApiFlag.Name), "/")
client = swarm.NewClient(bzzapi)
)
newFeedUpdateRequest := feed.NewFirstRequest(getTopic(ctx))
newFeedUpdateRequest.Feed.User = feedGetUser(ctx)
manifestAddress, err := client.CreateFeedWithManifest(newFeedUpdateRequest)
if err != nil {
utils.Fatalf("Error creating feed manifest: %s", err.Error())
return
}
fmt.Println(manifestAddress) // output manifest address to the user in a single line (useful for other commands to pick up)
}
func feedUpdate(ctx *cli.Context) {
args := ctx.Args()
var (
bzzapi = strings.TrimRight(ctx.GlobalString(SwarmApiFlag.Name), "/")
client = swarm.NewClient(bzzapi)
manifestAddressOrDomain = ctx.String(SwarmFeedManifestFlag.Name)
)
if len(args) < 1 {
fmt.Println("Incorrect number of arguments")
cli.ShowCommandHelpAndExit(ctx, "update", 1)
return
}
signer := NewGenericSigner(ctx)
data, err := hexutil.Decode(args[0])
if err != nil {
utils.Fatalf("Error parsing data: %s", err.Error())
return
}
var updateRequest *feed.Request
var query *feed.Query
if manifestAddressOrDomain == "" {
query = new(feed.Query)
query.User = signer.Address()
query.Topic = getTopic(ctx)
}
// Retrieve a feed update request
updateRequest, err = client.GetFeedRequest(query, manifestAddressOrDomain)
if err != nil {
utils.Fatalf("Error retrieving feed status: %s", err.Error())
}
// Check that the provided signer matches the request to sign
if updateRequest.User != signer.Address() {
utils.Fatalf("Signer address does not match the update request")
}
// set the new data
updateRequest.SetData(data)
// sign update
if err = updateRequest.Sign(signer); err != nil {
utils.Fatalf("Error signing feed update: %s", err.Error())
}
// post update
err = client.UpdateFeed(updateRequest)
if err != nil {
utils.Fatalf("Error updating feed: %s", err.Error())
return
}
}
func feedInfo(ctx *cli.Context) {
var (
bzzapi = strings.TrimRight(ctx.GlobalString(SwarmApiFlag.Name), "/")
client = swarm.NewClient(bzzapi)
manifestAddressOrDomain = ctx.String(SwarmFeedManifestFlag.Name)
)
var query *feed.Query
if manifestAddressOrDomain == "" {
query = new(feed.Query)
query.Topic = getTopic(ctx)
query.User = feedGetUser(ctx)
}
metadata, err := client.GetFeedRequest(query, manifestAddressOrDomain)
if err != nil {
utils.Fatalf("Error retrieving feed metadata: %s", err.Error())
return
}
encodedMetadata, err := metadata.MarshalJSON()
if err != nil {
utils.Fatalf("Error encoding metadata to JSON for display:%s", err)
}
fmt.Println(string(encodedMetadata))
}
func feedGetUser(ctx *cli.Context) common.Address {
var user = ctx.String(SwarmFeedUserFlag.Name)
if user != "" {
return common.HexToAddress(user)
}
pk := getPrivKey(ctx)
if pk == nil {
utils.Fatalf("Cannot read private key. Must specify --user or --bzzaccount")
}
return crypto.PubkeyToAddress(pk.PublicKey)
}
