开发指南

合约调用(Solidity)

最近更新时间:2022-04-15 15:12:16

长安链证书转换 EVM 地址

ChainMake Solidity 语言版本智能合约完全兼容 EVM,更多长安链证书与 EVM 地址的转换详情可参见 EVM 地址说明

在“证书管理”界面申请证书后,可根据获得的用户证书文件 user_sign.crt 获取该用户的 EVM 地址,代码示例如下:

import (
    "encoding/hex"
    "encoding/pem"
    "fmt"
    "io/ioutil"

    "chainmaker.org/chainmaker-go/common/crypto/x509"
    "chainmaker.org/chainmaker-go/common/evmutils"
    "github.com/ethereum/go-ethereum/accounts/abi"
)

func MakeAddrAndSkiFromCrtFilePath() {
    crtFilePath := "./user_sign.crt"

    crtBytes, err := ioutil.ReadFile(crtFilePath)
    if err != nil {
        fmt.Printf("fail to read the crt file:%v", err)
    }

    blockCrt, _ := pem.Decode(crtBytes)
    crt, err := x509.ParseCertificate(blockCrt.Bytes)
    if err != nil {
        fmt.Printf("fail to parse certificate:%v", err)
    }

    ski := hex.EncodeToString(crt.SubjectKeyId)
    addrInt, err := evmutils.MakeAddressFromHex(ski)
    if err != nil {
    fmt.Printf("fail to make address from hex:%v", err)
    }

    // 证书 SKI
    fmt.Printf("clientAddrSki: %s\n", ski)
    // EVM 地址(十进制)
    fmt.Printf("clientAddrInt: %s\n", addrInt.String())
    // EVM 地址
    fmt.Printf("clientEthAddr: 0x%x\n", addrInt.AsStringKey())
}

成功运行可以查看到如下图输出:

ABI 编码示例

ChainMake Solidity 语言版本智能合约完全兼容 EVM,更多 ABI 编码的详情可参见 Solidity 官方文档

合约初始化

以 Token 合约为例,对合约初始化参数进行 ABI 编码。代码示例如下:

import (
    "encoding/hex"
    "fmt"
    "io/ioutil"
    "math/big"
    "strings"

    "chainmaker.org/chainmaker-go/common/evmutils"
    "github.com/ethereum/go-ethereum/accounts/abi"
)

const (
    // 编译合约后获取的 abi 文件的路径
    tokenABIPath = "./testdata/token-evm-demo/token.abi"
    // 合约安装时调用 constructor ,调用方法设为空字符串
    function = ""
    // 入参 1:发行 EVM 地址,可根据用户证书转换取得
    clientAddr = "0x89f4090e315621696d6936453661ec4b9795ad27"
)

func testUserContractTokenEVMConstructor () {
    abiJson, err := ioutil.ReadFile (tokenABIPath)
    if err != nil {
        fmt.Printf ("fail to read the abi file:%v", err)
    }

    myAbi, err := abi.JSON (strings.NewReader (string (abiJson)))
    if err != nil {
        fmt.Printf ("fail to get abi object:%v", err)
    }

    addr := evmutils.BigToAddress (evmutils.FromHexString (clientAddr [2:]))

    dataByte, err := myAbi.Pack (function, addr)
    if err != nil {
        fmt.Printf ("fail to pack contract input:%v", err)
    }

    data := hex.EncodeToString (dataByte)

    pairs := map [string] string {
        "data": data,
    }

    // 编码后的参数
    fmt.Printf ("FuncParam %v\n", pairs)
}

输出结果如下:

FuncParam map [data:00000000000000000000000089f4090e315621696d6936453661ec4b9795ad27]

通过 TBaaS 控制台安装合约并填写对应初始化参数:

  • key 取值:data
  • value 取值:00000000000000000000000089f4090e315621696d6936453661ec4b9795ad27

合约调用

以 Token 合约为例,对 transfer 函数的函数名及调用参数进行 ABI 编码。代码示例如下:

import (
    "encoding/hex"
    "fmt"
    "io/ioutil"
    "math/big"
    "strings"

    "chainmaker.org/chainmaker-go/common/evmutils"
    "github.com/ethereum/go-ethereum/accounts/abi"
)

const (
    // 编译合约后获取的 abi 文件的路径
    tokenABIPath = "./testdata/token-evm-demo/token.abi"
    // 调用方法
    function = "transfer"
    // 入参 1:转账 EVM 地址,可根据用户证书转换取得
    clientAddr = "0xa55f1e0cb68b0cc589906078237094bdb9715bfd"
    // 入参 2:转账金额
    amount = 200
)

func testUserContractTokenEVMTransfer () {
    abiJson, err := ioutil.ReadFile (tokenABIPath)
    if err != nil {
        fmt.Printf ("fail to read the abi file:%v", err)
    }

    myAbi, err := abi.JSON (strings.NewReader (string (abiJson)))
    if err != nil {
        fmt.Printf ("fail to get abi object:%v", err)
    }

    addr := evmutils.BigToAddress (evmutils.FromHexString (clientAddr [2:]))

    dataByte, err := myAbi.Pack (function, addr, big.NewInt (amount))
    if err != nil {
        fmt.Printf ("fail to pack contract input:%v", err)
    }

    data := hex.EncodeToString (dataByte)
    method := data [0:8]

    pairs := map [string] string {
        "data": data,
    }

    // 编码后的函数名
    fmt.Printf ("FuncName: %s\n", method)
    // 编码后的参数
    fmt.Printf ("FuncParam %v\n", pairs)
}

输出结果如下:

FuncName: a9059cbb
FuncParam map [data:a9059cbb000000000000000000000000a55f1e0cb68b0cc589906078237094bdb9715bfd00000000000000000000000000000000000000000000000000000000000000c8]

长安链 SDK 调用示例

将 ABI 编码后的函数名及调用参数分别作为 method 与 params,代码示例如下:

    method := "a9059cbb"
    params := map [string] string {
        "data": "a9059cbb000000000000000000000000a55f1e0cb68b0cc589906078237094bdb9715bfd00000000000000000000000000000000000000000000000000000000000000c8",
    }
    resp, err := client.InvokeContract ("fact", method, "", params, -1, true)
    if err != nil {
        fmt.Printf ("fail to invoke contract:%v", err)
    }

云 API 调用示例

将 ABI 编码后的函数名及调用参数分别填入 FuncName 与 FuncParam 字段,代码示例如下:

    action_params = {
        "ClusterId": "chainmaker-txtxtxtxtx",
        "ChainId": "chain_txtxt",
        "ContractName": "fact",
        "FuncName": "a9059cbb",
        "FuncParam": "{\"data\":\"a9059cbb000000000000000000000000a55f1e0cb68b0cc589906078237094bdb9715bfd00000000000000000000000000000000000000000000000000000000000000c8\"}",
        "AsyncFlag": 0,
        "Action": "InvokeChainMakerContract",
        "Version": "2018-04-16",
        "Region": "ap-beijing"
    }
    # 实例化一个请求对象,根据调用的接口和实际情况,可以进一步设置请求参数
    params = json.dumps (action_params)
    req = models.InvokeChainMakerContractRequest ()
    # 调用 InvokeChainMakerContractRequest 的 from_json_string 方法,使用 params 初始化 req 对象
    req.from_json_string (params)

    # 通过 client 对象调用想要访问的接口,需要传入请求对象
    resp = client.InvokeChainMakerContract (req)
    # 输出 json 格式的字符串回包
    print (resp.to_json_string ())

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