test-triam-base-contract/src/contract_base/storage.js

Low level triam smart cotnract support library

export class Storage {
  
  constructor (_storage) {
    if (_storage) {
      this.storage = Object.assign ({}, _storage);
    } else {
      this.storage = {};
    }
  }
  
  set (_name, _data) {
    if (this.storage.hasOwnProperty (_name)) {
      throw new Error ('storage has property' + _name);
    }
    this.storage[_name] = _data;
  }
  
  get (_name) {
    return this.storage[_name];
  }
  
  remove (_name) {
    delete this.storage[_name];
  }
  
  update (_name, _data) {
    if (!this.storage.hasOwnProperty (_name)) {
      throw new Error ('storage can not find property' + _name);
    }
    this.storage[_name] = _data;
  }
  
  save () {
    let stringData = JSON.stringify (this.storage);
    let ab = str2ab (stringData);
    let buf = toBuffer (ab);
    return buf.toString ('hex');
  }
  
  recover (_data) {
    let _buf = Buffer.from (_data, 'hex');
    let _ab = toArrayBuffer (_buf);
    let _state = ab2str (_ab);
    let loadState = JSON.parse (_state);
    this.storage = Object.assign ({}, this.storage, loadState);
    return this.storage;
  }
  
  has (_name) {
    return this.storage.hasOwnProperty (_name);
  }
  
  show () {
    return this.storage
  }
}

const ab2str = function (buf) {
  return String.fromCharCode.apply (null, new Uint16Array (buf));
};

const str2ab = function (str) {
  let buf = new ArrayBuffer (str.length * 2); // 2 bytes for each char
  let bufView = new Uint16Array (buf);
  for (let i = 0, strLen = str.length; i < strLen; i++) {
    bufView[i] = str.charCodeAt (i);
  }
  return buf;
};


const toArrayBuffer = function (buf) {
  let ab = new ArrayBuffer (buf.length);
  let view = new Uint8Array (ab);
  for (let i = 0; i < buf.length; ++i) {
    view[i] = buf[i];
  }
  return ab;
};
const toBuffer = function (ab) {
  let buf = new Buffer (ab.byteLength);
  let view = new Uint8Array (ab);
  for (let i = 0; i < buf.length; ++i) {
    buf[i] = view[i];
  }
  return buf;
};