bitcore-node-zcash/lib/Sync.js

'use strict';

require('classtool');


function spec() {
  var sockets = require('../app/controllers/socket.js');
  var BlockDb = require('./BlockDb').class();

  var TransactionDb = require('./TransactionDb').class();
  var config = require('../config/config');
  var networks = require('bitcore/networks');
  var async = require('async');


  function Sync(opts) {
    this.opts = opts || {};
    this.bDb = new BlockDb(opts);
    this.txDb = new TransactionDb(opts);
    this.txDb.on('tx_for_address', this.handleTxForAddress.bind(this));
    this.txDb.on('new_tx', this.handleNewTx.bind(this));
    this.bDb.on('new_block', this.handleNewBlock.bind(this));
    this.network = config.network === 'testnet' ? networks.testnet : networks.livenet;
  }

  Sync.prototype.close = function(cb) {
    var self = this;
    self.txDb.close(function() {
      self.bDb.close(cb);
    });
  };


  Sync.prototype.destroy = function(next) {
    var self = this;
    async.series([

      function(b) {
        self.bDb.drop(b);
      },
      function(b) {
        self.txDb.drop(b);
      },
    ], next);
  };

  /*
   * Arrives a NEW block, which is the new TIP
   *
   * Case 0) Simple case
   *    A-B-C-D-E(TIP)-NEW
   *
   * Case 1)
   *    A-B-C-D-E(TIP)
   *        \
   *         NEW
   *
   *  1) Declare D-E orphans (and possible invalidate TXs on them)
   *
   * Case 2)
   *    A-B-C-D-E(TIP)
   *        \
   *         F-G-NEW
   *  1) Set F-G as connected (mark TXs as valid)
   *  2) Declare D-E orphans (and possible invalidate TXs on them)
   *
   *
   * Case 3)
   *
   *    A-B-C-D-E(TIP) ...  NEW
   *
   *    NEW is ignored (if allowReorgs is false)
   *
   *
   */

  Sync.prototype.storeTipBlock = function(b, allowReorgs, cb) {

    if (typeof allowReorgs === 'function') {
      cb = allowReorgs;
      allowReorgs = true;
    }
    if (!b) return cb();

    var self = this;
    var oldTip, oldNext, needReorg = false;
    var newPrev = b.previousblockhash;

    async.series([

        function(c) {
          self.bDb.has(b.hash, function(err, val) {
            return c(err ||
              (val ? new Error('WARN: Ignoring already existing block:' + b.hash) : null));
          });
        },
        function(c) {
          if (!allowReorgs) return c();
          self.bDb.has(newPrev, function(err, val) {
            if (!val && newPrev.match(/^0+$/)) return c();

            return c(err ||
              (!val ? new Error('NEED_SYNC Ignoring block with non existing prev:' + b.hash) : null));
          });
        },
        function(c) {
          self.txDb.createFromBlock(b, function(err) {
            return c(err);
          });
        },
        function(c) {
          if (!allowReorgs) return c();
          self.bDb.getTip(function(err, val) {
            oldTip = val;
            if (oldTip && newPrev !== oldTip) needReorg = true;
            return c();
          });
        },
        function(c) {
          if (!needReorg) return c();
          self.bDb.getNext(newPrev, function(err, val) {
            if (err) return c(err);
            oldNext = val;
            return c();
          });
        },
        function(c) {
          self.bDb.add(b, c);
        },
        function(c) {
          if (!needReorg) return c();
          console.log('NEW TIP: %s NEED REORG (old tip: %s)', b.hash, oldTip);
          self.processReorg(oldTip, oldNext, newPrev, c);
        },
        function(c) {
          if (!allowReorgs) return c();
          self.bDb.setTip(b.hash, function(err) {
            return c(err);
          });
        },
        function(c) {
          self.bDb.setNext(newPrev, b.hash, function(err) {
            return c(err);
          });
        }
 
      ],
      function(err) {
        if (err && err.toString().match(/WARN/)) {
          err = null;
        }
        return cb(err);
      });
  };



  Sync.prototype.processReorg = function(oldTip, oldNext, newPrev, cb) {
    var self = this;

    var orphanizeFrom;

    async.series([

        function(c) {
          self.bDb.isMain(newPrev, function(err, val) {
            if (!val) return c();

            console.log('# Reorg Case 1)');
            // case 1
            orphanizeFrom = oldNext;
            return c(err);
          });
        },
        function(c) {
          if (orphanizeFrom) return c();

          console.log('# Reorg Case 2)');
          self.setBranchConnectedBackwards(newPrev, function(err, yHash, newYHashNext) {
            if (err) return c(err);
            self.bDb.getNext(yHash, function(err, yHashNext) {
              orphanizeFrom = yHashNext;
              self.bDb.setNext(yHash, newYHashNext, function(err) {
                return c(err);
              });
            });
          });
        },
        function(c) {
          if (!orphanizeFrom) return c();
          self.setBranchOrphan(orphanizeFrom, function(err) {
            return c(err);
          });
        },
      ],
      function(err) {
        return cb(err);
      });
  };

  Sync.prototype.setBlockMain = function(hash, isMain, cb) {
    var self = this;
    self.bDb.setMain(hash, isMain, function(err) {
      if (err) return cb(err);
      return self.txDb.handleBlockChange(hash, isMain, cb);
    });
  };

  Sync.prototype.setBranchOrphan = function(fromHash, cb) {
    var self = this,
      hashInterator = fromHash;

    async.whilst(
      function() {
        return hashInterator;
      },
      function(c) {
        self.setBlockMain(hashInterator, false, function(err) {
          if (err) return cb(err);
          self.bDb.getNext(hashInterator, function(err, val) {
            hashInterator = val;
            return c(err);
          });
        });
      }, cb);
  };

  Sync.prototype.setBranchConnectedBackwards = function(fromHash, cb) {
    var self = this,
      hashInterator = fromHash,
      lastHash = fromHash,
      isMain;

    async.doWhilst(
      function(c) {
        self.setBlockMain(hashInterator, true, function(err) {
          if (err) return c(err);
          self.bDb.getPrev(hashInterator, function(err, val) {
            if (err) return c(err);
            lastHash = hashInterator;
            hashInterator = val;
            self.bDb.isMain(hashInterator, function(err, val) {
              isMain = val;
              return c();
            });
          });
        });
      },
      function() {
        return hashInterator && !isMain;
      },
      function(err) {
        console.log('\tFound yBlock:', hashInterator);
        return cb(err, hashInterator, lastHash);
      }
    );
  };


  Sync.prototype.handleTxForAddress = function(data) {
    if (this.opts.shouldBroadcast) {
      sockets.broadcastAddressTx(data.address, data.txid);
    }
  };

  Sync.prototype.handleNewTx = function(data) {
    if (this.opts.shouldBroadcast) {
      sockets.broadcastTx(data.tx);
    }
  };

  Sync.prototype.handleNewBlock = function(data) {
    if (this.opts.shouldBroadcast) {
      sockets.broadcastBlock(data.blockid);
    }
  };

  Sync.prototype.storeTxs = function(txs, cb) {
    var self = this;
    self.txDb.createFromArray(txs, null, function(err) {
      if (err) return cb(err);
      return cb(err);
    });
  };


  return Sync;
}
module.defineClass(spec);