sawtooth-sdk/processor/handler.js

An SDK for interacting with the Hyperledger Sawtooth distributed ledger.

/**
 * Copyright 2017 Intel Corporation
 *
 * 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.
 * ------------------------------------------------------------------------------
 */

'use strict'

/**
 * TransactionHandler is the interface that defines the business logic
 * for a new transaction family. This is the only interface that needs
 * to be implemented to create a new transaction family.
 *
 * The transactionFamilyName, versions, and namespaces properties are
 * used by the processor to route processing requests to the handler.
 */
class TransactionHandler {
  /**
   * @param {string} transactionFamilyName - the name of the
   * transaction family that this handler can process, e.g. "intkey"
   * @param {string[]} versions - the versions of the transaction
   * family that this handler can process, e.g. ["1.0", "1.5"]
   * @param {string[]} namespaces - a list containing all of the
   * handler's namespaces, e.g. ["abcdef"]
   */
  constructor (transactionFamilyName, versions, namespaces) {
    _readOnlyProperty(this, 'transactionFamilyName', transactionFamilyName)
    _readOnlyProperty(this, 'versions', versions)
    _readOnlyProperty(this, 'namespaces', namespaces)
  }

  /**
   * Apply is the single method where all the business logic for a
   * transaction family is defined. The method will be called by the
   * transaction processor upon receiving a TpProcessRequest that the
   * handler understands and will pass in the TpProcessRequest and an
   * initialized instance of the Context type.
   *
   * @param {TpProcessRequest} transactionProcessRequest - the
   * transaction to be processed
   * @param {Context} context - the context the handler can use to
   * access state
   */
  apply (transactionProcessRequest, context) {
    throw new Error('apply(TpProcessRequest, context) not implemented')
  }
}

const _readOnlyProperty = (instance, propertyName, value) =>
  Object.defineProperty(instance, propertyName, {
    writeable: false,
    enumerable: true,
    congigurable: true,
    value
  })

module.exports = {
  TransactionHandler
}