Brother Lian Blockchain technical Training Fabric 1.0 Source Code Analysis (a) Peer #peer Channel Command and Sub-command implementation

Brother Lian Blockchain technical training Fabric 1.0 Source Code Analysis (a) Peer #peer Channel Command and Sub-command implementation

# Fabric 1.0 Source Code notes Peer #peer Channel command and subcommand implementation

# 1, peer channel Create sub-command implementation (create channel)

# # # 1.1, initialize the Orderer client

"Go

Const (

endorserrequired Endorserrequirement = True

Endorsernotrequired Endorserrequirement = False

ordererrequired Ordererrequirement = True

Orderernotrequired Ordererrequirement = False

)

CF, err = initcmdfactory (endorsernotrequired, ordererrequired)

Code in Peer/channel/create.go

```

CF, err = initcmdfactory (endorsernotrequired, ordererrequired) code is as follows:

"Go

Type channelcmdfactory struct {

Endorserclient PB. Endorserclient//endorserclient

Signer MSP. Signingidentity//signer

Broadcastclient Common. Broadcastclient//broadcastclient

Deliverclient deliverclientintf//deliverclient

Broadcastfactory broadcastclientfactory//broadcastclientfactory,type broadcastclientfactory func (Common). Broadcastclient, error)

}

Func initcmdfactory (isendorserrequired endorserrequirement, isordererrequired ordererrequirement) (* Channelcmdfactory, error) {

var err error

Cmdfact: = &channelcmdfactory{}

Cmdfact.signer, err = common. GETDEFAULTSIGNERFNC ()//GETDEFAULTSIGNERFNC = Getdefaultsigner

Cmdfact.broadcastfactory = func () (Common. Broadcastclient, error) {

Return common. GETBROADCASTCLIENTFNC (Orderingendpoint, TLS, cafile)//GETBROADCASTCLIENTFNC = getbroadcastclient

}

Peer channel join or list needs to be endorser and is not currently used

If isendorserrequired {

Cmdfact.endorserclient, err = common. GETENDORSERCLIENTFNC ()

}

Peer channel create or fetch requires orderer

If isordererrequired {

var opts []grpc. Dialoption

If TLS {

If cafile! = "" {

Creds, err: = credentials. Newclienttlsfromfile (Cafile, "")

opts = append (opts, Grpc. Withtransportcredentials (creds))

}

} else {

opts = append (opts, Grpc. Withinsecure ())

}

Conn, err: = Grpc. Dial (Orderingendpoint, opts ...)

Client, err: = AB. Newatomicbroadcastclient (conn). Deliver (context. TODO ())

Cmdfact.deliverclient = newdeliverclient (conn, client, Chainid)//Construction Deliverclient

}

Return cmdfact, Nil

}

Code in Peer/channel/channel.go

```

# # 1.2, send a transaction to create a blockchain

"Go

Err = sendcreatechaintransaction (CF)

Code in Peer/channel/create.go

```

The sendcreatechaintransaction (CF) code is as follows:

"Go

Func sendcreatechaintransaction (cf *channelcmdfactory) error {

var err error

var chcrtenv *cb. Envelope

If channeltxfile! = "" "{//peer channel create-f specified channels trading profile

Chcrtenv, err = CREATECHANNELFROMCONFIGTX (channeltxfile)//Get Genesis block

} else {

Chcrtenv, err = createchannelfromdefaults (CF)//No channel trade profile specified

}

Chcrtenv, err = SANITYCHECKANDSIGNCONFIGTX (chcrtenv)//check and sign trading configuration

var broadcastclient common. Broadcastclient

Broadcastclient, err = cf. Broadcastfactory ()

Defer Broadcastclient.close ()

Err = Broadcastclient.send (chcrtenv)

return err

}

Code in Peer/channel/create.go

```

# # 1.3, get the Genesis Chunk and write the file

"Go

var block *CB. Block

block, err = getgenesisblock (CF)//Get Genesis block

B, err: = Proto. Marshal (block)//blocks serialization

Err = Ioutil. WriteFile (file, B, 0644)//write files

Code in Peer/channel/create.go

```

# 2, Peer channel join Sub-command implementation (join channels)

# # # 2.1, initialize the endorser client

"Go

CF, err = initcmdfactory (endorserrequired, orderernotrequired)

Code in Peer/channel/join.go

```

# # # 2.2, construct Chaincodeinvocationspec message (Cscc.joinchain)

"Go

Spec, err: = Getjoinccspec ()

Invocation: = &PB. CHAINCODEINVOCATIONSPEC{CHAINCODESPEC:SPEC}

Code in Peer/channel/join.go

```

Spec, err: = Getjoinccspec () code is as follows:

"Go

Func Getjoinccspec () (*PB. Chaincodespec, error) {

GB, err: = Ioutil. ReadFile (Genesisblockpath)

Input: = &PB. Chaincodeinput{args: [][]byte{[]byte (CSCC. Joinchain), GB}}

Spec: = &PB. chaincodespec{

TYPE:PB. Chaincodespec_type (PB. chaincodespec_type_value["Golang"]),

Chaincodeid: &PB. Chaincodeid{name: "CSCC"},

Input:input,

}

Return spec, Nil

}

Code in Peer/channel/join.go

```

# # # 2.3, create CSCC proposal and sign

"Go

Creator, Err: = cf. Signer.serialize ()

Create Proposal,cis-Chaincodeinvocationspec from CIS

Call Createchaincodeproposal (Typ, Chainid, CIS, creator)

Then call Createchaincodeproposalwithtransient (Typ, Chainid, CIS, creator, nil)

Prop, _, err = Putils. Createproposalfromcis (Pcommon. Headertype_config, "", Invocation, creator)

var signedprop *pb. Signedproposal

Signedprop, err = putils. Getsignedproposal (prop, cf. Signer)

Code in Peer/channel/join.go

```

The code for Createchaincodeproposalwithtransient (Typ, Chainid, CIS, creator, nil) is as follows:

"Go

Func createchaincodeproposalwithtransient (Typ common. Headertype, Chainid string, cis *peer. Chaincodeinvocationspec, Creator []byte, Transientmap Map[string][]byte] (*peer. Proposal, str ing, error) {

Create Random Nonce

Nonce, err: = Crypto. Getrandomnonce ()

Calculate Transaction ID

Digest, Err: = Factory. Getdefault (). Hash (Append (nonce, creator ...), &BCCSP. sha256opts{})

Txid, err: = Computeproposaltxid (nonce, creator)

Return Createchaincodeproposalwithtxidnonceandtransient (Txid, Typ, Chainid, CIS, nonce, creator, Transientmap)

}

Code in Protos/utils/proputils.go

```

Createchaincodeproposalwithtxidnonceandtransient (Txid, Typ, Chainid, CIS, nonce, creator, Transientmap) codes are as follows:

"Go

Func createchaincodeproposalwithtxidnonceandtransient (Txid string, Typ common. Headertype, Chainid string, cis *peer. Chaincodeinvocationspec, Nonce, creator []byte, Transientmap Map[string][]byte] (*peer. Proposal, string, error) {

Cchdrext: = &peer. Chaincodeheaderextension{chaincodeid:cis. Chaincodespec.chaincodeid}

Cchdrextbytes, err: = Proto. Marshal (Cchdrext)

Cisbytes, err: = Proto. Marshal (CIS)

Ccproppayload: = &peer. Chaincodeproposalpayload{input:cisbytes, Transientmap:transientmap}

Ccproppayloadbytes, err: = Proto. Marshal (Ccproppayload)

var epoch uint64 = 0

Timestamp: = util. Createutctimestamp ()

HDR: = &common. Header{channelheader:marshalorpanic (&common. channelheader{

Type:int32 (Typ),

Txid:txid,

Timestamp:timestamp,

Channelid:chainid,

Extension:cchdrextbytes,

Epoch:epoch}),

Signatureheader:marshalorpanic (&common. Signatureheader{nonce:nonce, Creator:creator})}

Hdrbytes, err: = Proto. Marshal (HDR)

Return &peer. Proposal{header:hdrbytes, payload:ccproppayloadbytes}, Txid, nil

}

Code in Protos/utils/proputils.go

```

# # 2.4, Submit and process proposal

"Go

var proposalresp *pb. Proposalresponse

PROPOSALRESP, err = cf. Endorserclient.processproposal (context. Background (), Signedprop)

Code in Peer/channel/join.go

```

# 3, Peer Channel Update (update anchor node configuration)

"Go

CF, err = initcmdfactory (endorsernotrequired, ordererrequired)

FileData, err: = Ioutil. ReadFile (Channeltxfile)

Ctxenv, err: = Utils. Unmarshalenvelope (FileData)

Sctxenv, err: = SANITYCHECKANDSIGNCONFIGTX (ctxenv)

var broadcastclient common. Broadcastclient

Broadcastclient, err = cf. Broadcastfactory ()

Defer Broadcastclient.close ()

Return Broadcastclient.send (sctxenv)

Code in Peer/channel

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