go_study/fabric-main/internal/peer/channel/fetch.go

114 lines
2.6 KiB
Go

/*
Copyright IBM Corp. All Rights Reserved.
SPDX-License-Identifier: Apache-2.0
*/
package channel
import (
"fmt"
"io/ioutil"
"strconv"
"strings"
"github.com/golang/protobuf/proto"
cb "github.com/hyperledger/fabric-protos-go/common"
"github.com/hyperledger/fabric/internal/peer/common"
"github.com/hyperledger/fabric/protoutil"
"github.com/spf13/cobra"
)
func fetchCmd(cf *ChannelCmdFactory) *cobra.Command {
fetchCmd := &cobra.Command{
Use: "fetch <newest|oldest|config|(number)> [outputfile]",
Short: "Fetch a block",
Long: "Fetch a specified block, writing it to a file.",
RunE: func(cmd *cobra.Command, args []string) error {
return fetch(cmd, args, cf)
},
}
flagList := []string{
"channelID",
"bestEffort",
}
attachFlags(fetchCmd, flagList)
return fetchCmd
}
func fetch(cmd *cobra.Command, args []string, cf *ChannelCmdFactory) error {
if len(args) == 0 {
return fmt.Errorf("fetch target required, oldest, newest, config, or a number")
}
if len(args) > 2 {
return fmt.Errorf("trailing args detected")
}
// Parsing of the command line is done so silence cmd usage
cmd.SilenceUsage = true
// default to fetching from orderer
ordererRequired := OrdererRequired
peerDeliverRequired := PeerDeliverNotRequired
if len(strings.Split(common.OrderingEndpoint, ":")) != 2 {
// if no orderer endpoint supplied, connect to peer's deliver service
ordererRequired = OrdererNotRequired
peerDeliverRequired = PeerDeliverRequired
}
var err error
if cf == nil {
cf, err = InitCmdFactory(EndorserNotRequired, peerDeliverRequired, ordererRequired)
if err != nil {
return err
}
}
var block *cb.Block
switch args[0] {
case "oldest":
block, err = cf.DeliverClient.GetOldestBlock()
case "newest":
block, err = cf.DeliverClient.GetNewestBlock()
case "config":
iBlock, err2 := cf.DeliverClient.GetNewestBlock()
if err2 != nil {
return err2
}
lc, err2 := protoutil.GetLastConfigIndexFromBlock(iBlock)
if err2 != nil {
return err2
}
logger.Infof("Retrieving last config block: %d", lc)
block, err = cf.DeliverClient.GetSpecifiedBlock(lc)
default:
num, err2 := strconv.Atoi(args[0])
if err2 != nil {
return fmt.Errorf("fetch target illegal: %s", args[0])
}
block, err = cf.DeliverClient.GetSpecifiedBlock(uint64(num))
}
if err != nil {
return err
}
b, err := proto.Marshal(block)
if err != nil {
return err
}
var file string
if len(args) == 1 {
file = channelID + "_" + args[0] + ".block"
} else {
file = args[1]
}
if err = ioutil.WriteFile(file, b, 0o644); err != nil {
return err
}
return nil
}