1.联盟链

联盟链仅限于联盟成员，因其只针对成员开放全部或部分功能，所以联盟规则就是联盟链的权限机制。联盟链上的共识过程由预先选好的节点控制，目前普遍适用于机构间的信息共享，如交易、结算、或清算等B2B场景。联盟链几乎不采用工作量证明共识机制而是采用权益证明或PBTF等共识算法。联盟链由参与成员机构共同维护，并提供了对参与成员的管理、认证、授权、监控、审计等全套安全管理功能。

2015年成立的R3联盟，就是银行业的一个联盟链，目前已加入的成员多达40多个，包括世界著名的银行摩根大通、汇丰、高盛等。联盟链建立在各个节点本身之间已经存在信任，一般用于行业协会、高级别机构组织、大型连锁企业对下属单位和分管机构的交易和监管。

最近商业落地比较多的应该就是超级积分。

• 超级积分demo

  
  image.png

抽象出来，合约主要的功能：有创建组织对象（oneitfarm）、创建app、创建用户、增加积分、减少积分；

我贴一段自己写「超级积分」智能合约逻辑部分代码（js）：

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Sample transaction processor function.
 * @param {org.acme.model.createInitialData} trade The sample transaction instance.
 * @transaction
 */
function createInitialData(tx){
  //创建一个对象叫oneitfarm，给他初始值 100w 
    var factory = getFactory();
    var oneitfarm = factory.newResource( 'org.acme.model', 'OneItFarm','1' );
    oneitfarm.value = "1000000";
    oneitfarm.isSet = true;
    return getParticipantRegistry('org.acme.model.OneItFarm')
        .then(function (registry) {
            // update the grower's balance
            return registry.add(oneitfarm);
        })
}

function createApp(tx){
    //获取oneitfarm 对象
    // 创建 App 对象，赋值1w
    // oneitfarm 内value 减少1w
    var NS = 'org.acme.model'
    var oneitfarm = null;
    var oneitfarmRegist = null;
  var coin = 10000  
    return getParticipantRegistry( NS + '.OneItFarm' )
      .then(function (oneitfarmRegistry) {
          oneitfarmRegist = oneitfarmRegistry
            return oneitfarmRegist.get('1');
        })
      .then(function(oneitfarmDriver){
        oneitfarm = oneitfarmDriver
        if (oneitfarm.value < coin) {
          throw new Error ("Insufficient funds");
        }
        var factory = getFactory();
        var app = factory.newResource( NS, 'App', tx.appkey); 
        app.value = coin;
        return getParticipantRegistry('org.acme.model.App')
          .then(function(appRegistry){
            return appRegistry.add(app);
          })
          .then(function(){
            oneitfarm.value = oneitfarm.value - coin;
            return oneitfarmRegist.update(oneitfarm);
          })
           .catch(function (error) {
          // Add optional error handling here.
        });
      })
      .catch(function (error) {
    // Add optional error handling here.
  });
}

 
function createMember(tx){
    //获取App 对象
    // 创建 Member 对象，赋值10
    // accountId所属的App 内value 减少10
    var NS = 'org.acme.model'
    var appkey = tx.app.appkey
    var coin = 10  
    var app = null;
    var appRegist = null;
    return getParticipantRegistry( NS + '.App')
     .then(function (appRegistry) {
            appRegist = appRegistry;
            return appRegist.get(appkey);
        })
      .then(function(appDriver){
      console.log("111111")
        app = appDriver;
        if (app.value < coin) {
          throw new Error ("Insufficient funds");
        }
        var factory = getFactory();
        var member = factory.newResource( NS, 'Member', tx.accountId); 
        member.value = coin;
        member.app = tx.app
        return getParticipantRegistry('org.acme.model.Member')
          .then(function(memberRegistry){
            return memberRegistry.add(member);
          })
          .then(function(){
          console.log("333333")
            app.value = app.value - coin;
            return appRegist.update(app);
          })
           .catch(function (error) {
          // Add optional error handling here.
        });
      })
      .catch(function (error) {
    // Add optional error handling here.
      });
}
/**
 * Sample transaction processor function.
 * @param {org.acme.model.addMemberValue} trade The sample transaction instance.
 * @transaction
 */
function addMemberValue(tx) {
  //用户买东西- 商家给用户积分
  //用户增加积分
  //商家加减少积分
  var NS = 'org.acme.model'
  var coin = tx.coin
  var appkey = tx.app.appkey
  var app = null
  var appRegist = null
  var accountId = tx.member.accountId
  var member = null
  var memberRegist = null
  return getParticipantRegistry( NS + '.App')
   .then(function (appRegistry) {
      appRegist = appRegistry;
      return appRegist.get(appkey);
      })
  .then(function(appDriver){
      app = appDriver;
      if (app.value < coin) {
        throw new Error ("Insufficient funds");
      }
      return getParticipantRegistry( NS + '.Member')
      .then(function(memberRegistry){
        memberRegist = memberRegistry
        return memberRegist.get(accountId);
      })
      .then(function(memberDriver){
        member = memberDriver;
        member.value += coin;
        return memberRegist.update(member);
      })
      .then(function(){
        app.value -=coin;
      return appRegist.update(app);
      })  
      .catch(function (error) {
          // Add optional error handling here.
      });
   })
  .catch(function (error) {
          // Add optional error handling here.
  });
}

/**
 * Sample transaction processor function.
 * @param {org.acme.model.reduceMemberValue} trade The sample transaction instance.
 * @transaction
 */
function reduceMemberValue(tx) {
  //兑换
  //用户减少积分
  //商家增加积分
  var NS = 'org.acme.model'
  var coin = tx.coin
  var appkey = tx.app.appkey
  var app = null
  var appRegist = null
  var accountId = tx.member.accountId
  var member = null
  var memberRegist = null
  return getParticipantRegistry( NS + '.Member')
    .then(function(memberRegistry){
      memberRegist = memberRegistry
      return memberRegist.get(accountId);
      })
    .then(function(memberDriver){
      member = memberDriver;
      if (member.value < coin) {
        throw new Error ("Insufficient funds");
      }
      return getParticipantRegistry( NS + '.App')
        .then(function (appRegistry) {
          appRegist = appRegistry;
          return appRegist.get(appkey);
        })
        .then(function(appDriver){
          app = appDriver;
          app.value +=coin;
          return appRegist.update(app);
        })
        .then(function(){
        member.value -=coin;
        return memberRegist.update(member);
        })
        .catch(function (error) {
          // Add optional error handling here.
        });
   })
    .catch(function (error) {
     // Add optional error handling here.
  });
}