text: 'use strict';
  
  var util = require('util');
  var chainlib = require('chainlib');
  var log = chainlib.log;
  var BaseChain = require('../chain');
  var async = require('async');
  
  function Chain(options) {
    BaseChain.call(this, options);
  }
  
  util.inherits(Chain, BaseChain);
  
  Chain.prototype._writeBlock = function(block, callback) {
    // Update hashes
    this.cache.hashes[block.hash] = block.prevHash;
    // call db.putBlock to update prevHash index, but it won't write the block to disk
    this.db.putBlock(block, callback);
  };
  
  Chain.prototype._validateBlock = function(block, callback) {
    // All validation is done by bitcoind
    return callback();
  };
  
  module.exports = Chain;
  