github.com/leonlxy/hyperledger@v1.0.0-alpha.0.20170427033203-34922035d248/peer/channel/deliverclient.go (about)

     1  /*
     2  Copyright IBM Corp. 2017 All Rights Reserved.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8                   http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package channel
    18  
    19  import (
    20  	"fmt"
    21  	"math"
    22  
    23  	"github.com/hyperledger/fabric/common/localmsp"
    24  	"github.com/hyperledger/fabric/protos/common"
    25  	ab "github.com/hyperledger/fabric/protos/orderer"
    26  	"github.com/hyperledger/fabric/protos/utils"
    27  )
    28  
    29  type deliverClientIntf interface {
    30  	getBlock() (*common.Block, error)
    31  }
    32  
    33  type deliverClient struct {
    34  	client  ab.AtomicBroadcast_DeliverClient
    35  	chainID string
    36  }
    37  
    38  func newDeliverClient(client ab.AtomicBroadcast_DeliverClient, chainID string) *deliverClient {
    39  	return &deliverClient{client: client, chainID: chainID}
    40  }
    41  
    42  func seekHelper(chainID string, start *ab.SeekPosition) *common.Envelope {
    43  	seekInfo := &ab.SeekInfo{
    44  		Start:    &ab.SeekPosition{Type: &ab.SeekPosition_Oldest{Oldest: &ab.SeekOldest{}}},
    45  		Stop:     &ab.SeekPosition{Type: &ab.SeekPosition_Specified{Specified: &ab.SeekSpecified{Number: math.MaxUint64}}},
    46  		Behavior: ab.SeekInfo_BLOCK_UNTIL_READY,
    47  	}
    48  
    49  	//TODO- epoch and msgVersion may need to be obtained for nowfollowing usage in orderer/configupdate/configupdate.go
    50  	msgVersion := int32(0)
    51  	epoch := uint64(0)
    52  	env, err := utils.CreateSignedEnvelope(common.HeaderType_CONFIG_UPDATE, chainID, localmsp.NewSigner(), seekInfo, msgVersion, epoch)
    53  	if err != nil {
    54  		fmt.Printf("Error signing envelope %s\n", err)
    55  		return nil
    56  	}
    57  	return env
    58  }
    59  
    60  func (r *deliverClient) seekOldest() error {
    61  	return r.client.Send(seekHelper(r.chainID, &ab.SeekPosition{Type: &ab.SeekPosition_Oldest{Oldest: &ab.SeekOldest{}}}))
    62  }
    63  
    64  func (r *deliverClient) seekNewest() error {
    65  	return r.client.Send(seekHelper(r.chainID, &ab.SeekPosition{Type: &ab.SeekPosition_Newest{Newest: &ab.SeekNewest{}}}))
    66  }
    67  
    68  func (r *deliverClient) seek(blockNumber uint64) error {
    69  	return r.client.Send(seekHelper(r.chainID, &ab.SeekPosition{Type: &ab.SeekPosition_Specified{Specified: &ab.SeekSpecified{Number: blockNumber}}}))
    70  }
    71  
    72  func (r *deliverClient) readBlock() (*common.Block, error) {
    73  	for {
    74  		msg, err := r.client.Recv()
    75  		if err != nil {
    76  			fmt.Println("Error receiving:", err)
    77  			return nil, err
    78  		}
    79  
    80  		switch t := msg.Type.(type) {
    81  		case *ab.DeliverResponse_Status:
    82  			fmt.Println("Got status ", t)
    83  			continue
    84  		case *ab.DeliverResponse_Block:
    85  			fmt.Println("Received block: ", t.Block)
    86  			return t.Block, nil
    87  		}
    88  	}
    89  }
    90  
    91  func (r *deliverClient) getBlock() (*common.Block, error) {
    92  	err := r.seek(0)
    93  	if err != nil {
    94  		fmt.Println("Received error:", err)
    95  		return nil, err
    96  	}
    97  
    98  	b, err := r.readBlock()
    99  	if err != nil {
   100  		return nil, err
   101  	}
   102  
   103  	return b, nil
   104  }