幣幣合約執行解析(包含部分原始碼)
阿新 • • 發佈：2018-12-10
比原專案倉庫：
本文解析的為比原提供的幣幣合約 模板如下：
contract TradeOffer(assetRequested: Asset, amountRequested: Amount, seller: Program, cancelKey: PublicKey) locks offered { clause trade() requires payment: amountRequested of assetRequested { lock payment with seller unlock offered } clause cancel(sellerSig: Signature) { verify checkTxSig(cancelKey, sellerSig) unlock offered } }
導讀：
初次接觸比原只能合約的請點選[比原智慧合約入門](https://bbs.bbug.org.cn/thread-26.htm) 和 [鎖定合約
第一步：呼叫create-account-receiver 生成 control_program
以下是相關程式碼片段：
sendHttpPost("{\"account_id\":\"0IJVD7MNG0A02\"}","create-account-receiver","http://127.0.0.1:9888","");第二步呼叫list-pubkeys 獲取 pubkey
以下是相關程式碼片段：
sendHttpPost("{\"account_id\":\"0IJVD7MNG0A02\"}","list-pubkeys","http://127.0.0.1:9888","");
第三步： 將1 2步獲取的值呼叫compile介面編譯合約獲得program 合約程式
以下是相關程式碼片段：
JSONObject param=new JSONObject(); JSONArray agrs=new JSONArray(); //合約的四個引數值 JSONObject assetParam=new JSONObject(); assetParam.put("string","81d097312645696daea84b761d2898d950d8fba0de06c9267d8513b16663dd3a"); agrs.put(assetParam); JSONObject amountParam=new JSONObject(); amountParam.put("integer",200000000l); agrs.put(amountParam); JSONObject programParam=new JSONObject(); programParam.put("string",control_program); agrs.put(programParam); JSONObject publicKeyParam=new JSONObject(); publicKeyParam.put("string",pubkey); agrs.put(publicKeyParam); param.put("agrs",agrs); param.put("contract","contract TradeOffer(assetRequested: Asset, amountRequested: Amount, seller: Program, cancelKey: PublicKey) locks offered { clause trade() requires payment: amountRequested of assetRequested { lock payment with seller unlock offered } clause cancel(sellerSig: Signature) { verify checkTxSig(cancelKey, sellerSig) unlock offered } }"); //呼叫編譯合約 sendHttpPost(param.toString(),"list-pubkeys","http://127.0.0.1:9888","");
第四步：將program 傳入build-transaction介面去build一個交易的到data
以下是相關程式碼片段：
param=new JSONObject();
agrs=new JSONArray();
JSONObject spendAccount=new JSONObject();
spendAccount.put("account_id","0H757LPD00A02");
spendAccount.put("amount",9909099090000l);
spendAccount.put("asset_id","161b9767b664df907fa926a31f9e835236e57f3e9ccc5f80c12bd97723322652");
spendAccount.put("type","spend_account");
agrs.put(spendAccount);
JSONObject controlAccount=new JSONObject();
controlAccount.put("control_program",program);
controlAccount.put("amount",9909099090000l);
controlAccount.put("asset_id","161b9767b664df907fa926a31f9e835236e57f3e9ccc5f80c12bd97723322652");
controlAccount.put("type","control_program");
agrs.put(controlAccount);
JSONObject spendAccount2=new JSONObject();
spendAccount2.put("account_id","0H757LPD00A02");
spendAccount2.put("amount",6000000l);
spendAccount2.put("asset_id","ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
spendAccount2.put("type","spend_account");
agrs.put(spendAccount2);
param.put("actions",agrs);
param.put("ttl",0);
sendHttpPost(param.toString(),"build-transaction","http://127.0.0.1:9888","");第五步：輸入密碼呼叫sign-transaction簽名第四步build的data 得到raw_transaction
以下是相關程式碼片段：
param=new JSONObject();
param.put("password","xxx");
param.put("transaction",data);
sendHttpPost(param.toString(),"sign-transaction","http://127.0.0.1:9888","");第六步：呼叫submit-transactions提交交易
以下是相關程式碼片段：
param=new JSONObject();
param.put("raw_transaction",raw_transaction);
sendHttpPost(param.toString(),"submit-transactions","http://127.0.0.1:9888","");解鎖/取消合約
首先需要decode出生成合約時候的引數
呼叫list-unspent-outputs 獲取生成的合約資訊獲取program
以下是相關程式碼片段：
param=new JSONObject();
param.put("id",outputid);
param.put("smart_contract",true);
sendHttpPost(param.toString(),"list-unspent-outputs","http://127.0.0.1:9888","");呼叫decode-program 傳入獲取生成的合約引數資訊
以下是相關程式碼片段：
param=new JSONObject();
param.put("program",program);
sendHttpPost(param.toString(),"decode-program","http://127.0.0.1:9888","");需要注意的是decode出來的為值是逆序的(後續會有文章詳細介紹)
解鎖/取消其實就是把生成合約的步驟中的第三步去掉,替換呼叫生成合約第四步的引數即可
取消合約的構造引數如下：
spendAccountUnspentOutput = arguments: [{
type: 'raw_tx_signature',
// 生成合約第二步的pubkeylist 詳情
raw_data: {
derivation_path: pubkeylist.pubkey_infos[0].derivation_path,
xpub: pubkeylist.root_xpub
}
}, {
type: 'data',
raw_data: {
// 引數偏移量 在一個合約裡是固定的
value: '13000000'
}
}],
output_id: output_id,
type: 'spend_account_unspent_output'
}
const controlAction = {
type: 'control_program',
amount: 100000000,
asset_id: asset_id,
control_program:control_program
}
const gasAction = {
type: 'spend_account',
account_id:account_id,
asset_alias: 'BTM',
amount: 50000000
}執行合約的引數構造如下：
const spendAccountUnspentOutput = {
arguments: [{
type: 'data',
raw_data: {
// 執行合約輸入資產偏移量
value: '00000000'
}
}],
output_id: output_id,
type: 'spend_account_unspent_output'
}
// 合約執行提供的資產
const issueControlAction = {
control_program: control_program,
amount: 100000000,
asset_id: asset_id,
type: 'control_program'
}
// 合約執行提供的資產
const issueSpendAction = {
account_id: account_id,
amount: 100000000,
asset_id: asset_id,
type: 'spend_account'
}
// 曠工費
const gasAction = {
type: 'spend_account',
account_id: account_id,
asset_alias: 'BTM',
amount: 50000000
}
// 合約執行獲得資產物件
const controlAction = {
type: 'control_program',
amount: 100000000,
asset_id: asset_id,
control_program: compileData.control_program
}build 操作其實就是指定輸入輸出的過程,詳情請檢視 官方build文件 和 官方api文件
備註
呼叫比原基於okhttp介面javautil 如下：
public static String sendHttpPost(String bodyStr,String method,String bytomApiserverUrl,String bytomApiserverToken) throws IOException {
OkHttpClient client = new OkHttpClient();
MediaType mediaType = MediaType.parse("application/json");
RequestBody body = RequestBody.create(mediaType, bodyStr);
Request request = new Request.Builder()
.url(bytomApiserverUrl+"/"+method)
.post(body)
.addHeader("cache-control", "no-cache")
.addHeader("Connection", "close")
.build();
if (bytomApiserverUrl==null || bytomApiserverUrl.contains("127.0.0.1") || bytomApiserverUrl.contains("localhost")){
}else {
byte[] encodedAuth = Base64.encodeBase64(bytomApiserverToken.getBytes(Charset.forName("US-ASCII")));
String authHeader = "Basic " + new String(encodedAuth);
request = new Request.Builder()
.url(bytomApiserverUrl+"/"+method)
.post(body)
.addHeader("authorization", authHeader)
.addHeader("cache-control", "no-cache")
.addHeader("Connection", "close")
.build();
}
Response response = client.newCall(request).execute();
return response.body().string();
}