refactor: more work.

bin/cli

@@ -27,8 +27,7 @@ CLI.prototype.log = function log(json) {
   console.log(JSON.stringify(json, null, 2));
 };
 
-CLI.prototype.createWallet = function createWallet() {
+CLI.prototype.createWallet = co(function* createWallet() {
-  return spawn(function *() {
   var options = { id: this.argv[0] };
   var wallet;
 
@@ -55,65 +54,49 @@ CLI.prototype.createWallet = function createWallet() {
 
   wallet = yield this.client.createWallet(options);
   this.log(wallet);
-  }, this);
+});
-};
 
-CLI.prototype.addKey = function addKey() {
+CLI.prototype.addKey = co(function* addKey() {
-  return spawn(function *() {
   var key = this.argv[0];
   yield this.wallet.addKey(this.config.account, key);
   this.log('added');
-  }, this);
+});
-};
 
-CLI.prototype.removeKey = function removeKey() {
+CLI.prototype.removeKey = co(function* removeKey() {
-  return spawn(function *() {
   var key = this.argv[0];
   yield this.wallet.removeKey(this.config.account, key);
   this.log('removed');
-  }, this);
+});
-};
 
-CLI.prototype.getAccount = function getAccount() {
+CLI.prototype.getAccount = co(function* getAccount() {
-  return spawn(function *() {
   var account = this.argv[0] || this.config.account;
   yield this.wallet.getAccount(account);
   this.log(account);
-  }, this);
+});
-};
 
-CLI.prototype.createAccount = function createAccount() {
+CLI.prototype.createAccount = co(function* createAccount() {
-  return spawn(function *() {
   var name = this.argv[0];
   var account = yield this.wallet.createAccount(name);
   this.log(account);
-  }, this);
+});
-};
 
-CLI.prototype.createAddress = function createAddress() {
+CLI.prototype.createAddress = co(function* createAddress() {
-  return spawn(function *() {
   var account = this.argv[0];
   var addr = yield this.wallet.createAddress(account);
   this.log(addr);
-  }, this);
+});
-};
 
-CLI.prototype.getAccounts = function getAccounts() {
+CLI.prototype.getAccounts = co(function* getAccounts() {
-  return spawn(function *() {
   var accounts = yield this.wallet.getAccounts();
   this.log(accounts);
-  }, this);
+});
-};
 
-CLI.prototype.getWallet = function getWallet() {
+CLI.prototype.getWallet = co(function* getWallet() {
-  return spawn(function *() {
   var info = yield this.wallet.getInfo();
   this.log(wallet);
-  }, this);
+});
-};
 
-CLI.prototype.getTX = function getTX() {
+CLI.prototype.getTX = co(function* getTX() {
-  return spawn(function *() {
   var hash = this.argv[0];
   var txs, tx;
 
@@ -131,11 +114,9 @@ CLI.prototype.getTX = function getTX() {
   }
 
   this.log(tx);
-  }, this);
+});
-};
 
-CLI.prototype.getBlock = function getBlock() {
+CLI.prototype.getBlock = co(function* getBlock() {
-  return spawn(function *() {
   var hash = this.argv[0];
   if (hash.length !== 64)
     hash = +hash;
@@ -148,11 +129,9 @@ CLI.prototype.getBlock = function getBlock() {
   }
 
   this.log(block);
-  }, this);
+});
-};
 
-CLI.prototype.getCoin = function getCoin() {
+CLI.prototype.getCoin = co(function* getCoin() {
-  return spawn(function *() {
   var hash = this.argv[0];
   var index = this.argv[1];
   var coins, coin;
@@ -171,15 +150,12 @@ CLI.prototype.getCoin = function getCoin() {
   }
 
   this.log(coin);
-  }, this);
+});
-};
 
-CLI.prototype.getWalletHistory = function getWalletHistory() {
+CLI.prototype.getWalletHistory = co(function* getWalletHistory() {
-  return spawn(function *() {
   var txs = yield this.wallet.getHistory(this.config.account);
   this.log(txs);
-  }, this);
+});
-};
 
 CLI.prototype.listenWallet = function listenWallet() {
   var self = this;
@@ -210,22 +186,17 @@ CLI.prototype.listenWallet = function listenWallet() {
   return new Promise(function() {});
 };
 
-CLI.prototype.getBalance = function getBalance() {
+CLI.prototype.getBalance = co(function* getBalance() {
-  return spawn(function *() {
   var balance = yield this.wallet.getBalance(this.config.account);
   this.log(balance);
-  }, this);
+});
-};
 
-CLI.prototype.getMempool = function getMempool() {
+CLI.prototype.getMempool = co(function* getMempool() {
-  return spawn(function *() {
   var txs = yield this.client.getMempool();
   this.log(txs);
-  }, this);
+});
-};
 
-CLI.prototype.sendTX = function sendTX() {
+CLI.prototype.sendTX = co(function* sendTX() {
-  return spawn(function *() {
   var output = {};
   var options, tx;
 
@@ -246,11 +217,9 @@ CLI.prototype.sendTX = function sendTX() {
   tx = yield this.wallet.send(options);
 
   this.log(tx);
-  }, this);
+});
-};
 
-CLI.prototype.createTX = function createTX() {
+CLI.prototype.createTX = co(function* createTX() {
-  return spawn(function *() {
   var output = {};
   var options, tx;
 
@@ -271,61 +240,47 @@ CLI.prototype.createTX = function createTX() {
   tx = yield this.wallet.createTX(options);
 
   this.log(tx);
-  }, this);
+});
-};
 
-CLI.prototype.signTX = function signTX() {
+CLI.prototype.signTX = co(function* signTX() {
-  return spawn(function *() {
   var options = { passphrase: this.config.passphrase };
   var raw = options.tx || this.argv[0];
   var tx = yield this.wallet.sign(raw, options);
   this.log(tx);
-  }, this);
+});
-};
 
-CLI.prototype.zap = function zap() {
+CLI.prototype.zap = co(function* zap() {
-  return spawn(function *() {
   var age = (this.config.age >>> 0) || 72 * 60 * 60;
   yield this.wallet.zap(this.config.account, age);
   this.log('Zapped!');
-  }, this);
+});
-};
 
-CLI.prototype.broadcast = function broadcast() {
+CLI.prototype.broadcast = co(function* broadcast() {
-  return spawn(function *() {
   var self = this;
   var raw = this.argv[0] || this.config.tx;
   var tx = yield this.client.broadcast(raw);
   this.log('Broadcasted:');
   this.log(tx);
-  }, this);
+});
-};
 
-CLI.prototype.viewTX = function viewTX() {
+CLI.prototype.viewTX = co(function* viewTX() {
-  return spawn(function *() {
   var raw = this.argv[0] || this.config.tx;
   var tx = yield this.wallet.fill(raw);
   this.log(tx);
-  }, this);
+});
-};
 
-CLI.prototype.getDetails = function getDetails() {
+CLI.prototype.getDetails = co(function* getDetails() {
-  return spawn(function *() {
   var hash = this.argv[0];
   var details = yield this.wallet.getTX(hash);
   this.log(details);
-  }, this);
+});
-};
 
-CLI.prototype.retoken = function retoken() {
+CLI.prototype.retoken = co(function* retoken() {
-  return spawn(function *() {
   var result = yield this.wallet.retoken();
   this.log(result);
-  }, this);
+});
-};
 
-CLI.prototype.rpc = function rpc() {
+CLI.prototype.rpc = co(function* rpc() {
-  return spawn(function *() {
   var method = this.argv.shift();
   var params = [];
   var i, arg, param, result;
@@ -343,11 +298,9 @@ CLI.prototype.rpc = function rpc() {
   result = yield this.client.rpc.call(method, params);
 
   this.log(result);
-  }, this);
+});
-};
 
-CLI.prototype.handleWallet = function handleWallet() {
+CLI.prototype.handleWallet = co(function* handleWallet() {
-  return spawn(function *() {
   var options = {
     id: this.config.id || 'primary',
     token: this.config.token
@@ -427,11 +380,9 @@ CLI.prototype.handleWallet = function handleWallet() {
       this.log('  --account [account-name]: Account name.');
       return;
   }
-  }, this);
+});
-};
 
-CLI.prototype.handleNode = function handleNode() {
+CLI.prototype.handleNode = co(function* handleNode() {
-  return spawn(function *() {
   var info;
 
   this.client = new Client({
@@ -468,11 +419,9 @@ CLI.prototype.handleNode = function handleNode() {
       this.log('  $ block [hash/height]: View block.');
       return;
   }
-  }, this);
+});
-};
 
-CLI.prototype.open = function open() {
+CLI.prototype.open = co(function* open() {
-  return spawn(function *() {
   switch (this.argv[0]) {
     case 'w':
     case 'wallet':
@@ -485,8 +434,7 @@ CLI.prototype.open = function open() {
     default:
       return yield this.handleNode();
   }
-  }, this);
+});
-};
 
 CLI.prototype.destroy = function destroy() {
   if (this.wallet && !this.wallet.client.loading)

lib/chain/chain.js

@@ -1223,7 +1223,7 @@ Chain.prototype.add = co(function* add(block) {
   if (this.orphan.size > this.orphanLimit)
     this.pruneOrphans();
 
-  yield utils.wait();
+  yield spawn.wait();
 
   if (!this.synced && this.isFull()) {
     this.synced = true;

lib/chain/chainentry.js

@@ -235,7 +235,7 @@ ChainEntry.prototype.getAncestorByHeight = co(function* getAncestorByHeight(heig
   var main, entry;
 
   if (height < 0)
-    return yield utils.wait();
+    return yield spawn.wait();
 
   assert(height >= 0);
   assert(height <= this.height);

lib/crypto/crypto.js

@@ -14,15 +14,16 @@ var scryptAsync = require('./scrypt-async');
 var utils = require('../utils/utils');
 var spawn = require('../utils/spawn');
 var co = spawn.co;
+var wrap = spawn.wrap;
 var native = require('../utils/native');
-var nativeCrypto, hash, aes;
+var nodeCrypto, hash, aes;
 
 var isBrowser =
   (typeof process !== 'undefined' && process.browser)
   || typeof window !== 'undefined';
 
 if (!isBrowser) {
-  nativeCrypto = require('crypto');
+  nodeCrypto = require('crypto');
 } else {
   hash = require('hash.js');
   aes = require('./aes');
@@ -42,10 +43,10 @@ var crypto = exports;
  */
 
 crypto.hash = function _hash(alg, data) {
-  if (!nativeCrypto)
+  if (!nodeCrypto)
     return new Buffer(hash[alg]().update(data).digest());
 
-  return nativeCrypto.createHash(alg).update(data).digest();
+  return nodeCrypto.createHash(alg).update(data).digest();
 };
 
 if (native)
@@ -131,12 +132,12 @@ crypto.checksum = function checksum(data) {
 crypto.hmac = function hmac(alg, data, salt) {
   var hmac;
 
-  if (!nativeCrypto) {
+  if (!nodeCrypto) {
     hmac = hash.hmac(hash[alg], salt);
     return new Buffer(hmac.update(data).digest());
   }
 
-  hmac = nativeCrypto.createHmac(alg, salt);
+  hmac = nodeCrypto.createHmac(alg, salt);
   return hmac.update(data).digest();
 };
 
@@ -160,8 +161,8 @@ crypto.pbkdf2 = function pbkdf2(key, salt, iter, len, alg) {
   if (typeof salt === 'string')
     salt = new Buffer(salt, 'utf8');
 
-  if (nativeCrypto && nativeCrypto.pbkdf2Sync)
+  if (nodeCrypto && nodeCrypto.pbkdf2Sync)
-    return nativeCrypto.pbkdf2Sync(key, salt, iter, len, alg);
+    return nodeCrypto.pbkdf2Sync(key, salt, iter, len, alg);
 
   return crypto._pbkdf2(key, salt, iter, len, alg);
 };
@@ -185,13 +186,9 @@ crypto.pbkdf2Async = function pbkdf2Async(key, salt, iter, len, alg) {
   if (typeof salt === 'string')
     salt = new Buffer(salt, 'utf8');
 
-  if (nativeCrypto && nativeCrypto.pbkdf2) {
+  if (nodeCrypto && nodeCrypto.pbkdf2) {
     return new Promise(function(resolve, reject) {
-      nativeCrypto.pbkdf2(key, salt, iter, len, alg, function(err, key) {
+      nodeCrypto.pbkdf2(key, salt, iter, len, alg, wrap(resolve, reject));
-        if (err)
-          return reject(err);
-        resolve(key);
-      });
     });
   }
 
@@ -244,11 +241,7 @@ crypto.scryptAsync = function _scrypt(passwd, salt, N, r, p, len) {
     salt = new Buffer(salt, 'utf8');
 
   return new Promise(function(resolve, reject) {
-    scryptAsync(passwd, salt, N, r, p, len, function(err, key) {
+    scryptAsync(passwd, salt, N, r, p, len, wrap(resolve, reject));
-      if (err)
-        return reject(err);
-      resolve(key);
-    });
   });
 };
 
@@ -270,8 +263,7 @@ crypto.derive = function derive(passphrase) {
  * @param {Function} callback
  */
 
-crypto.encrypt = function encrypt(data, passphrase, iv) {
+crypto.encrypt = co(function* encrypt(data, passphrase, iv) {
-  return spawn(function *() {
   var key;
 
   assert(Buffer.isBuffer(data));
@@ -290,8 +282,7 @@ crypto.encrypt = function encrypt(data, passphrase, iv) {
   key.fill(0);
 
   return data;
-  });
+});
-};
 
 /**
  * Encrypt with aes-256-cbc.
@@ -304,10 +295,10 @@ crypto.encrypt = function encrypt(data, passphrase, iv) {
 crypto.encipher = function encipher(data, key, iv) {
   var cipher;
 
-  if (!nativeCrypto)
+  if (!nodeCrypto)
     return aes.cbc.encrypt(data, key, iv);
 
-  cipher = nativeCrypto.createCipheriv('aes-256-cbc', key, iv);
+  cipher = nodeCrypto.createCipheriv('aes-256-cbc', key, iv);
 
   return Buffer.concat([
     cipher.update(data),
@@ -323,8 +314,7 @@ crypto.encipher = function encipher(data, key, iv) {
  * @param {Function} callback
  */
 
-crypto.decrypt = function decrypt(data, passphrase, iv) {
+crypto.decrypt = co(function* decrypt(data, passphrase, iv) {
-  return spawn(function *() {
   var key;
 
   assert(Buffer.isBuffer(data));
@@ -343,8 +333,7 @@ crypto.decrypt = function decrypt(data, passphrase, iv) {
   key.fill(0);
 
   return data;
-  });
+});
-};
 
 /**
  * Decrypt with aes-256-cbc.
@@ -357,10 +346,10 @@ crypto.decrypt = function decrypt(data, passphrase, iv) {
 crypto.decipher = function decipher(data, key, iv) {
   var decipher;
 
-  if (!nativeCrypto)
+  if (!nodeCrypto)
     return aes.cbc.decrypt(data, key, iv);
 
-  decipher = nativeCrypto.createDecipheriv('aes-256-cbc', key, iv);
+  decipher = nodeCrypto.createDecipheriv('aes-256-cbc', key, iv);
 
   return Buffer.concat([
     decipher.update(data),

lib/db/lowlevelup.js

@@ -12,7 +12,7 @@ var assert = utils.assert;
 var AsyncObject = require('../utils/async');
 var spawn = require('../utils/spawn');
 var co = spawn.co;
-var P = utils.P;
+var wrap = spawn.wrap;
 var VERSION_ERROR;
 
 /**
@@ -66,7 +66,7 @@ utils.inherits(LowlevelUp, AsyncObject);
 LowlevelUp.prototype._open = function open() {
   var self = this;
   return new Promise(function(resolve, reject) {
-    self.binding.open(self.options, P(resolve, reject));
+    self.binding.open(self.options, wrap(resolve, reject));
   });
 };
 
@@ -79,7 +79,7 @@ LowlevelUp.prototype._open = function open() {
 LowlevelUp.prototype._close = function close() {
   var self = this;
   return new Promise(function(resolve, reject) {
-    self.binding.close(P(resolve, reject));
+    self.binding.close(wrap(resolve, reject));
   });
 };
 
@@ -98,7 +98,7 @@ LowlevelUp.prototype.destroy = function destroy() {
   return new Promise(function(resolve, reject) {
     if (!self.backend.destroy)
       return utils.asyncify(reject)(new Error('Cannot destroy.'));
-    self.backend.destroy(self.location, P(resolve, reject));
+    self.backend.destroy(self.location, wrap(resolve, reject));
   });
 };
 
@@ -117,7 +117,7 @@ LowlevelUp.prototype.repair = function repair() {
   return new Promise(function(resolve, reject) {
     if (!self.backend.repair)
       return utils.asyncify(reject)(new Error('Cannot repair.'));
-    self.backend.repair(self.location, P(resolve, reject));
+    self.backend.repair(self.location, wrap(resolve, reject));
   });
 };
 
@@ -138,7 +138,7 @@ LowlevelUp.prototype.backup = function backup(path) {
     return this.clone(path);
 
   return new Promise(function(resolve, reject) {
-    self.binding.backup(path, P(resolve, reject));
+    self.binding.backup(path, wrap(resolve, reject));
   });
 };
 
@@ -178,7 +178,7 @@ LowlevelUp.prototype.put = function put(key, value, options) {
   var self = this;
   assert(this.loaded, 'Cannot use database before it is loaded.');
   return new Promise(function(resolve, reject) {
-    self.binding.put(key, value, options || {}, P(resolve, reject));
+    self.binding.put(key, value, options || {}, wrap(resolve, reject));
   });
 };
 
@@ -193,7 +193,7 @@ LowlevelUp.prototype.del = function del(key, options) {
   var self = this;
   assert(this.loaded, 'Cannot use database before it is loaded.');
   return new Promise(function(resolve, reject) {
-    self.binding.del(key, options || {}, P(resolve, reject));
+    self.binding.del(key, options || {}, wrap(resolve, reject));
   });
 };
 
@@ -214,7 +214,7 @@ LowlevelUp.prototype.batch = function batch(ops, options) {
     return new Batch(this);
 
   return new Promise(function(resolve, reject) {
-    self.binding.batch(ops, options || {}, P(resolve, reject));
+    self.binding.batch(ops, options || {}, wrap(resolve, reject));
   });
 };
 
@@ -281,7 +281,7 @@ LowlevelUp.prototype.approximateSize = function approximateSize(start, end) {
     if (!self.binding.approximateSize)
       return utils.asyncify(reject)(new Error('Cannot get size.'));
 
-    self.binding.approximateSize(start, end, P(resolve, reject));
+    self.binding.approximateSize(start, end, wrap(resolve, reject));
   });
 };
 
@@ -439,7 +439,7 @@ Batch.prototype.del = function del(key) {
 Batch.prototype.write = function write() {
   var self = this;
   return new Promise(function(resolve, reject) {
-    self.batch.write(P(resolve, reject));
+    self.batch.write(wrap(resolve, reject));
   });
 };
 
@@ -465,7 +465,7 @@ Iterator.prototype.next = function() {
       }
 
       if (key === undefined && value === undefined) {
-        self.iter.end(P(resolve, reject));
+        self.iter.end(wrap(resolve, reject));
         return;
       }
 
@@ -481,7 +481,7 @@ Iterator.prototype.seek = function seek(key) {
 Iterator.prototype.end = function end() {
   var self = this;
   return new Promise(function(resolve, reject) {
-    self.iter.end(P(resolve, reject));
+    self.iter.end(wrap(resolve, reject));
   });
 };
 

lib/http/rpc.js

@@ -4145,13 +4145,13 @@ function reverseEndian(data) {
 
 function writeFile(file, data) {
   return new Promise(function(resolve, reject) {
-    fs.writeFile(file, data, utils.P(resolve, reject));
+    fs.writeFile(file, data, spawn.wrap(resolve, reject));
   });
 }
 
 function readFile(file, enc) {
   return new Promise(function(resolve, reject) {
-    fs.readFile(file, enc, utils.P(resolve, reject));
+    fs.readFile(file, enc, spawn.wrap(resolve, reject));
   });
 }
 

lib/mempool/mempool.js

@@ -189,7 +189,7 @@ Mempool.prototype.addBlock = co(function* addBlock(block) {
   // There may be a locktime in a TX that is now valid.
   this.rejects.reset();
 
-  yield utils.wait();
+  yield spawn.wait();
   unlock();
 });
 

lib/miner/miner.js

@@ -160,9 +160,8 @@ Miner.prototype._close = function close() {
  * @param {Number?} version - Custom block version.
  */
 
-Miner.prototype.start = function start() {
+Miner.prototype.start = co(function* start() {
   var self = this;
-  spawn(function *() {
   var attempt, block;
 
   this.stop();
@@ -211,10 +210,7 @@ Miner.prototype.start = function start() {
 
   // `tip` will now be emitted by chain
   // and the whole process starts over.
-  }, this).catch(function(err) {
+});
-    self.emit('error', err);
-  });
-};
 
 /**
  * Stop mining.

lib/net/peer.js

@@ -1119,9 +1119,7 @@ Peer.prototype._handleUTXOs = function _handleUTXOs(utxos) {
  * @private
  */
 
-Peer.prototype._handleGetUTXOs = function _handleGetUTXOs(packet) {
+Peer.prototype._handleGetUTXOs = co(function* _handleGetUTXOs(packet) {
-  var self = this;
-  spawn(function *() {
   var unlock = yield this._lock();
   var i, utxos, prevout, hash, index, coin;
 
@@ -1145,7 +1143,12 @@ Peer.prototype._handleGetUTXOs = function _handleGetUTXOs(packet) {
     index = prevout.index;
 
     if (this.mempool && packet.mempool) {
+      try {
         coin = this.mempool.getCoin(hash, index);
+      } catch (e) {
+        this.emit('error', e);
+        return;
+      }
 
       if (coin) {
         utxos.hits.push(1);
@@ -1159,7 +1162,12 @@ Peer.prototype._handleGetUTXOs = function _handleGetUTXOs(packet) {
       }
     }
 
+    try {
       coin = yield this.chain.db.getCoin(hash, index);
+    } catch (e) {
+      this.emit('error', e);
+      return;
+    }
 
     if (!coin) {
       utxos.hits.push(0);
@@ -1175,10 +1183,7 @@ Peer.prototype._handleGetUTXOs = function _handleGetUTXOs(packet) {
 
   this.send(utxos);
   unlock();
-  }, this).catch(function(err) {
+});
-    self.emit('error', err);
-  });
-};
 
 /**
  * Handle `havewitness` packet.
@@ -1197,9 +1202,7 @@ Peer.prototype._handleHaveWitness = function _handleHaveWitness(packet) {
  * @param {GetHeadersPacket}
  */
 
-Peer.prototype._handleGetHeaders = function _handleGetHeaders(packet) {
+Peer.prototype._handleGetHeaders = co(function* _handleGetHeaders(packet) {
-  var self = this;
-  spawn(function *() {
   var unlock = yield this._lock();
   var headers = [];
   var hash, entry;
@@ -1242,10 +1245,7 @@ Peer.prototype._handleGetHeaders = function _handleGetHeaders(packet) {
   this.sendHeaders(headers);
 
   unlock();
-  }, this).catch(function(err) {
+});
-    self.emit('error', err);
-  });
-};
 
 /**
  * Handle `getblocks` packet.
@@ -1253,9 +1253,7 @@ Peer.prototype._handleGetHeaders = function _handleGetHeaders(packet) {
  * @param {GetBlocksPacket}
  */
 
-Peer.prototype._handleGetBlocks = function _handleGetBlocks(packet) {
+Peer.prototype._handleGetBlocks = co(function* _handleGetBlocks(packet) {
-  var self = this;
-  spawn(function *() {
   var unlock = yield this._lock();
   var blocks = [];
   var hash;
@@ -1293,10 +1291,7 @@ Peer.prototype._handleGetBlocks = function _handleGetBlocks(packet) {
 
   this.sendInv(blocks);
   unlock();
-  }, this).catch(function(err) {
+});
-    self.emit('error', err);
-  });
-};
 
 /**
  * Handle `version` packet.
@@ -1480,9 +1475,7 @@ Peer.prototype._getItem = co(function* _getItem(item) {
  * @param {GetDataPacket}
  */
 
-Peer.prototype._handleGetData = function _handleGetData(packet) {
+Peer.prototype._handleGetData = co(function* _handleGetData(packet) {
-  var self = this;
-  spawn(function *() {
   var unlock = yield this._lock();
   var notFound = [];
   var items = packet.items;
@@ -1589,10 +1582,7 @@ Peer.prototype._handleGetData = function _handleGetData(packet) {
     this.send(new packets.NotFoundPacket(notFound));
 
   unlock();
-  }, this).catch(function(err) {
+});
-    self.emit('error', err);
-  });
-};
 
 /**
  * Handle `notfound` packet.

lib/net/pool.js

@@ -431,7 +431,7 @@ Pool.prototype.listen = function listen() {
   });
 
   return new Promise(function(resolve, reject) {
-    self.server.listen(self.port, '0.0.0.0', utils.P(resolve, reject));
+    self.server.listen(self.port, '0.0.0.0', spawn.wrap(resolve, reject));
   });
 };
 
@@ -450,7 +450,7 @@ Pool.prototype.unlisten = function unlisten() {
     return;
 
   return new Promise(function(resolve, reject) {
-    self.server.close(utils.P(resolve, reject));
+    self.server.close(spawn.wrap(resolve, reject));
     self.server = null;
   });
 };
@@ -902,7 +902,7 @@ Pool.prototype._handleBlock = co(function* _handleBlock(block, peer) {
     this.logger.warning(
       'Received unrequested block: %s (%s).',
       block.rhash, peer.hostname);
-    return yield utils.wait();
+    return yield spawn.wait();
   }
 
   try {
@@ -1062,7 +1062,7 @@ Pool.prototype.createPeer = function createPeer(addr, socket) {
         self.startInterval();
         self.startTimeout();
       }
-    }).catch(function(err) {
+    }, function(err) {
       self.emit('error', err);
     });
   });
@@ -1081,7 +1081,7 @@ Pool.prototype.createPeer = function createPeer(addr, socket) {
         self.startInterval();
         self.startTimeout();
       }
-    }).catch(function(err) {;
+    }, function(err) {
       self.emit('error', err);
     });
   });

lib/utils/async.js

@@ -10,8 +10,8 @@ var utils = require('../utils/utils');
 var spawn = require('../utils/spawn');
 var co = spawn.co;
 var assert = utils.assert;
+var wait = spawn.wait;
 var EventEmitter = require('events').EventEmitter;
-var wait = utils.wait;
 
 /**
  * An abstract object that handles state and

lib/utils/spawn.js

@@ -1,5 +1,20 @@
+/*!
+ * spawn.js - promise and generator control flow for bcoin
+ * Originally based on yoursnetwork's "asink" module.
+ * Copyright (c) 2014-2016, Christopher Jeffrey (MIT License).
+ * https://github.com/bcoin-org/bcoin
+ */
+
 'use strict';
 
+var utils = require('./utils');
+
+/**
+ * Execute an instantiated generator.
+ * @param {Generator} gen
+ * @returns {Promise}
+ */
+
 function exec(gen) {
   return new Promise(function(resolve, reject) {
     function step(value, rejection) {
@@ -34,11 +49,27 @@ function exec(gen) {
   });
 }
 
+/**
+ * Execute generator function
+ * with a context and execute.
+ * @param {GeneratorFunction} generator
+ * @param {Object} self
+ * @returns {Promise}
+ */
+
 function spawn(generator, self) {
   var gen = generator.call(self);
   return exec(gen);
 }
 
+/**
+ * Wrap a generator function to be
+ * executed into a function that
+ * returns a promise.
+ * @param {GeneratorFunction}
+ * @returns {Function}
+ */
+
 function co(generator) {
   return function() {
     var gen = generator.apply(this, arguments);
@@ -46,6 +77,157 @@ function co(generator) {
   };
 }
 
-spawn.co = co;
+/**
+ * Wrap a generator function to be
+ * executed into a function that
+ * accepts a node.js style callback.
+ * @param {GeneratorFunction}
+ * @returns {Function}
+ */
+
+function cob(generator) {
+  return function() {
+    var i, args, callback, gen;
+
+    if (arguments.length === 0
+        || typeof arguments[arguments.length - 1] !== 'function') {
+      throw new Error('Function must accept a callback.');
+    }
+
+    args = new Array(arguments.length - 1);
+    callback = arguments[arguments.length - 1];
+
+    for (i = 0; i < args.length; i++)
+      args[i] = arguments[i];
+
+    gen = generator.apply(this, args);
+
+    return cb(exec(gen), callback);
+  };
+}
+
+/**
+ * Wait for promise to resolve and
+ * execute a node.js style callback.
+ * @param {Promise} promise
+ * @param {Function} callback
+ */
+
+function cb(promise, callback) {
+  promise.then(function(value) {
+    callback(null, value);
+  }, function(err) {
+    callback(err);
+  });
+}
+
+/**
+ * Wait for a nextTick with a promise.
+ * @returns {Promise}
+ */
+
+function wait() {
+  return new Promise(function(resolve, reject) {
+    utils.nextTick(resolve);
+  });
+};
+
+/**
+ * Wait for a timeout with a promise.
+ * @param {Number} time
+ * @returns {Promise}
+ */
+
+function timeout(time) {
+  return new Promise(function(resolve, reject) {
+    setTimeout(function() {
+      resolve();
+    }, time);
+  });
+}
+
+/**
+ * Wrap `resolve` and `reject` into
+ * a node.js style callback.
+ * @param {Function} resolve
+ * @param {Function} reject
+ * @returns {Function}
+ */
+
+function wrap(resolve, reject) {
+  return function(err, result) {
+    if (err)
+      return reject(err);
+    resolve(result);
+  };
+}
+
+/**
+ * Call a function that accepts node.js
+ * style callbacks, wrap with a promise.
+ * @param {Function} func
+ * @returns {Promise}
+ */
+
+function call(func) {
+  var args = new Array(Math.max(0, arguments.length - 1));
+  var i;
+
+  for (i = 1; i < arguments.length; i++)
+    args[i] = arguments[i];
+
+  return new Promise(function(resolve, reject) {
+    args.push(function(err, result) {
+      if (err)
+        return reject(err);
+      resolve(result);
+    });
+    func.apply(self, args);
+  });
+}
+
+/**
+ * Wrap a function that accepts node.js
+ * style callbacks into a function that
+ * returns a promise.
+ * @param {Function} func
+ * @param {Object?} self
+ * @returns {Function}
+ */
+
+function promisify(func, self) {
+  return function() {
+    var args = new Array(arguments.length);
+    var i;
+
+    for (i = 0; i < args.length; i++)
+      args[i] = arguments[i];
+
+    return new Promise(function(resolve, reject) {
+      args.push(function(err, result) {
+        if (err)
+          return reject(err);
+        resolve(result);
+      });
+      func.apply(self, args);
+    });
+  };
+}
+
+/*
+ * Expose
+ */
+
+exports = spawn;
+exports.exec = exec;
+exports.spawn = spawn;
+exports.co = co;
+exports.cob = cob;
+exports.cb = cb;
+exports.wait = wait;
+exports.timeout = timeout;
+exports.wrap = wrap;
+exports.call = call;
+exports.promisify = promisify;
 
 module.exports = spawn;

lib/utils/utils.js

@@ -326,28 +326,6 @@ if (typeof setImmediate === 'function') {
   };
 }
 
-utils.wait = function wait() {
-  return new Promise(function(resolve, reject) {
-    utils.nextTick(resolve);
-  });
-};
-
-utils.timeout = function timeout(time) {
-  return new Promise(function(resolve, reject) {
-    setTimeout(function() {
-      resolve();
-    }, time);
-  });
-};
-
-utils.P = function P(resolve, reject) {
-  return function(err, result) {
-    if (err)
-      return reject(err);
-    resolve(result);
-  };
-};
-
 /**
  * Wrap a function in a `nextTick`.
  * @param {Function} callback

lib/workers/workers.js

@@ -576,7 +576,7 @@ Worker.prototype._execute = function _execute(method, args, timeout, callback) {
 Worker.prototype.execute = function execute(method, args, timeout) {
   var self = this;
   return new Promise(function(resolve, reject) {
-    self._execute(method, args, timeout, utils.P(resolve, reject));
+    self._execute(method, args, timeout, spawn.wrap(resolve, reject));
   });
 };
 

test/chain-test.js

@@ -7,6 +7,8 @@ var utils = bcoin.utils;
 var crypto = require('../lib/crypto/crypto');
 var assert = require('assert');
 var opcodes = constants.opcodes;
+var spawn = require('../lib/utils/spawn');
+var c = require('../lib/utils/spawn').cb;
 
 describe('Chain', function() {
   var chain, wallet, node, miner, walletdb;
@@ -14,22 +16,6 @@ describe('Chain', function() {
 
   this.timeout(5000);
 
-  function c(p, cb) {
-    var called = false;
-    p.then(function(result) {
-      called = true;
-      cb(null, result);
-    }).catch(function(err) {
-      if (called) {
-        utils.nextTick(function() {
-          throw err;
-        });
-        return;
-      }
-      cb(err);
-    });
-  }
-
   node = new bcoin.fullnode({ db: 'memory' });
   chain = node.chain;
   walletdb = node.walletdb;
@@ -250,7 +236,7 @@ describe('Chain', function() {
       assert.ifError(err);
       c(chain.db.scan(null, hashes, function *(block, txs) {
         total += txs.length;
-        yield utils.wait();
+        yield spawn.wait();
       }), function(err) {
         assert.ifError(err);
         assert.equal(total, 25);

test/http-test.js

@@ -8,6 +8,7 @@ var utils = bcoin.utils;
 var crypto = require('../lib/crypto/crypto');
 var assert = require('assert');
 var scriptTypes = constants.scriptTypes;
+var c = require('../lib/utils/spawn').cb;
 
 var dummyInput = {
   prevout: {
@@ -28,22 +29,6 @@ var dummyInput = {
   sequence: 0xffffffff
 };
 
-function c(p, cb) {
-  var called = false;
-  p.then(function(result) {
-    called = true;
-    cb(null, result);
-  }).catch(function(err) {
-    if (called) {
-      utils.nextTick(function() {
-        throw err;
-      });
-      return;
-    }
-    cb(err);
-  });
-}
-
 describe('HTTP', function() {
   var request = bcoin.http.request;
   var w, addr, hash;

test/mempool-test.js

@@ -7,22 +7,7 @@ var utils = bcoin.utils;
 var crypto = require('../lib/crypto/crypto');
 var assert = require('assert');
 var opcodes = constants.opcodes;
-
+var c = require('../lib/utils/spawn').cb;
-function c(p, cb) {
-  var called = false;
-  p.then(function(result) {
-    called = true;
-    cb(null, result);
-  }).catch(function(err) {
-    if (called) {
-      utils.nextTick(function() {
-        throw err;
-      });
-      return;
-    }
-    cb(err);
-  });
-}
 
 describe('Mempool', function() {
   this.timeout(5000);

test/wallet-test.js

@@ -9,6 +9,7 @@ var crypto = require('../lib/crypto/crypto');
 var spawn = require('../lib/utils/spawn');
 var assert = require('assert');
 var scriptTypes = constants.scriptTypes;
+var c = require('../lib/utils/spawn').cb;
 
 var FAKE_SIG = new Buffer([0,0,0,0,0,0,0,0,0]);
 
@@ -53,22 +54,6 @@ assert.range = function range(value, lo, hi, message) {
   }
 };
 
-function c(p, cb) {
-  var called = false;
-  p.then(function(result) {
-    called = true;
-    cb(null, result);
-  }).catch(function(err) {
-    if (called) {
-      utils.nextTick(function() {
-        throw err;
-      });
-      return;
-    }
-    cb(err);
-  });
-}
-
 describe('Wallet', function() {
   var walletdb = new bcoin.walletdb({
     name: 'wallet-test',