From 72b7adc800f1768e49eb40efc2b4000f6ee5a962 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 8 Feb 2016 18:06:39 -0800
Subject: [PATCH] get bcoin working in the browser again.

---
 lib/bcoin.js         | 37 ++++++++++++++++++++++--------
 lib/bcoin/chain.js   | 38 +++++++++++++++++++++++++++----
 lib/bcoin/hd.js      | 24 ++++----------------
 lib/bcoin/miner.js   |  2 --
 lib/bcoin/pool.js    | 42 ++++++++++++++++++++++------------
 lib/bcoin/ramdisk.js | 54 ++++++++++++++++++++++++++++++++++++++++++++
 lib/bcoin/utils.js   | 54 +++++++++++++++++++++++++++++++++-----------
 7 files changed, 188 insertions(+), 63 deletions(-)
 create mode 100644 lib/bcoin/ramdisk.js

diff --git a/lib/bcoin.js b/lib/bcoin.js
index 9ead06b7..f4941502 100644
--- a/lib/bcoin.js
+++ b/lib/bcoin.js
@@ -10,16 +10,41 @@ var bn = require('bn.js');
 var hash = require('hash.js');
 var async = require('async');
 
+bcoin.isBrowser =
+  (typeof process !== 'undefined' && process.browser)
+  || typeof window !== 'undefined';
+
 if (process.env.BCOIN_DEBUG) {
   bcoin.debug = process.env.BCOIN_DEBUG;
   if (bcoin.debug === '0' || bcoin.debug === '1')
     bcoin.debug = +bcoin.debug === 1;
 }
 
+if (!bcoin.isBrowser) {
+  bcoin.fs = require('f' + 's');
+  bcoin.crypto = require('cry' + 'pto');
+  bcoin.net = require('n' + 'et');
+}
+
+bcoin.elliptic = elliptic;
+bcoin.bn = bn;
+bcoin.hash = hash;
+bcoin.async = async;
+
 bcoin.ecdsa = elliptic.ec('secp256k1');
+
+if (bcoin.ecdsa.signature)
+  throw new Error;
+
+if (bcoin.ecdsa.keypair)
+  throw new Error;
+
+bcoin.ecdsa.signature = require('elliptic/lib/elliptic/ec/signature');
+bcoin.ecdsa.keypair = require('elliptic/lib/elliptic/ec/key');
+
 bcoin.utils = require('./bcoin/utils');
-bcoin.bloom = require('./bcoin/bloom');
 bcoin.protocol = require('./bcoin/protocol');
+bcoin.bloom = require('./bcoin/bloom');
 bcoin.script = require('./bcoin/script');
 bcoin.input = require('./bcoin/input');
 bcoin.output = require('./bcoin/output');
@@ -27,6 +52,7 @@ bcoin.coin = require('./bcoin/coin');
 bcoin.tx = require('./bcoin/tx');
 bcoin.txPool = require('./bcoin/tx-pool');
 bcoin.block = require('./bcoin/block');
+bcoin.ramdisk = require('./bcoin/ramdisk');
 bcoin.chain = require('./bcoin/chain');
 bcoin.keypair = require('./bcoin/keypair');
 bcoin.address = require('./bcoin/address');
@@ -37,12 +63,3 @@ bcoin.hd = require('./bcoin/hd');
 bcoin.miner = require('./bcoin/miner');
 
 bcoin.protocol.network.set(process.env.BCOIN_NETWORK || 'main');
-
-bcoin.bn = bn;
-bcoin.elliptic = elliptic;
-bcoin.utils.assert(!bcoin.ecdsa.signature);
-bcoin.ecdsa.signature = require('elliptic/lib/elliptic/ec/signature');
-bcoin.utils.assert(!bcoin.ecdsa.keypair);
-bcoin.ecdsa.keypair = require('elliptic/lib/elliptic/ec/key');
-bcoin.hash = hash;
-bcoin.async = async;
diff --git a/lib/bcoin/chain.js b/lib/bcoin/chain.js
index 1c90793e..4f1a6d6a 100644
--- a/lib/bcoin/chain.js
+++ b/lib/bcoin/chain.js
@@ -9,11 +9,11 @@ var EventEmitter = require('events').EventEmitter;
 
 var bcoin = require('../bcoin');
 var bn = require('bn.js');
-var fs = require('fs');
 var constants = bcoin.protocol.constants;
 var network = bcoin.protocol.network;
 var utils = bcoin.utils;
 var assert = utils.assert;
+var fs = bcoin.fs;
 
 /**
  * Chain
@@ -764,6 +764,12 @@ function ChainDB(chain, options) {
 }
 
 ChainDB.prototype._init = function _init() {
+  if (!bcoin.fs) {
+    utils.debug('`fs` module not available. Falling back to ramdisk.');
+    this.ramdisk = bcoin.ramdisk(new Buffer([]), 40 * 1024 * 1024);
+    return;
+  }
+
   if (+process.env.BCOIN_FRESH === 1) {
     try {
       fs.unlinkSync(this.file);
@@ -1054,6 +1060,9 @@ ChainDB.prototype._readSync = function _readSync(size, offset) {
   if (offset < 0 || offset == null)
     return;
 
+  if (!bcoin.fs)
+    return this.ramdisk.read(size, offset);
+
   data = this._malloc(size);
 
   try {
@@ -1081,8 +1090,13 @@ ChainDB.prototype._readAsync = function _readAsync(size, offset, callback) {
   var index = 0;
   var data, bytes;
 
+  callback = utils.asyncify(callback);
+
   if (offset < 0 || offset == null)
-    return false;
+    return callback();
+
+  if (!bcoin.fs)
+    return callback(null, this.ramdisk.read(size, offset));
 
   data = this._malloc(size);
 
@@ -1116,6 +1130,12 @@ ChainDB.prototype._writeSync = function _writeSync(data, offset) {
   if (offset < 0 || offset == null)
     return false;
 
+  if (!bcoin.fs) {
+    this.size += added;
+    this.ramdisk.write(data, offset);
+    return;
+  }
+
   try {
     while (bytes = fs.writeSync(this.fd, data, index, size, offset)) {
       index += bytes;
@@ -1139,10 +1159,18 @@ ChainDB.prototype._writeAsync = function _writeAsync(data, offset, callback) {
   var size = data.length;
   var index = 0;
 
-  if (offset < 0 || offset == null)
-    return false;
+  callback = utils.asyncify(callback);
 
-  self.size += added;
+  if (offset < 0 || offset == null)
+    return callback(null, false);
+
+  if (!bcoin.fs) {
+    this.size += added;
+    this.ramdisk.write(data, offset);
+    return callback(null, true);
+  }
+
+  this.size += added;
 
   (function next() {
     fs.write(self.fd, data, index, size, offset, function(err, bytes) {
diff --git a/lib/bcoin/hd.js b/lib/bcoin/hd.js
index 4a464a53..71c1ede9 100644
--- a/lib/bcoin/hd.js
+++ b/lib/bcoin/hd.js
@@ -558,7 +558,7 @@ HDPrivateKey.prototype._seed = function _seed(seed) {
     throw new Error('entropy not in range');
   }
 
-  var hash = sha512hmac(seed, 'Bitcoin seed');
+  var hash = utils.sha512hmac(seed, 'Bitcoin seed');
 
   return {
     version: null,
@@ -671,7 +671,7 @@ HDPrivateKey.prototype.derive = function derive(index, hardened) {
     ? [0].concat(this.privateKey).concat(array32(index))
     : data = [].concat(this.publicKey).concat(array32(index));
 
-  hash = sha512hmac(data, this.chainCode);
+  hash = utils.sha512hmac(data, this.chainCode);
   leftPart = new bn(hash.slice(0, 32));
   chainCode = hash.slice(32, 64);
 
@@ -973,7 +973,7 @@ HDPublicKey.prototype.derive = function derive(index, hardened) {
     throw new Error('invalid path');
 
   data = [].concat(this.publicKey).concat(array32(index));
-  hash = sha512hmac(data, this.chainCode);
+  hash = utils.sha512hmac(data, this.chainCode);
   leftPart = new bn(hash.slice(0, 32));
   chainCode = hash.slice(32, 64);
 
@@ -1077,20 +1077,6 @@ HDPrivateKey.fromSecret = function fromSecret(privateKey) {
  * Helpers
  */
 
-var isBrowser = (typeof process !== 'undefined' && process.browser)
-  || typeof window !== 'undefined';
-
-function sha512hmac(data, salt) {
-  if (isBrowser) {
-    var hmac = hash.hmac(hash.sha512, utils.toArray(salt));
-    return hmac.update(utils.toArray(data)).digest();
-  }
-  var crypto = require('crypto');
-  var hmac = crypto.createHmac('sha512', new Buffer(salt));
-  var h = hmac.update(new Buffer(data)).digest();
-  return Array.prototype.slice.call(h);
-}
-
 function array32(data) {
   var b = [];
   utils.writeU32BE(b, data, 0);
@@ -1141,12 +1127,12 @@ function pbkdf2(key, salt, iterations, dkLen) {
     block1[salt.length + 2] = i >> 8 & 0xff;
     block1[salt.length + 3] = i >> 0 & 0xff;
 
-    U = sha512hmac(block1, key);
+    U = utils.sha512hmac(block1, key);
 
     utils.copy(U.slice(0, hLen), T, 0);
 
     for (j = 1; j < iterations; j++) {
-      U = sha512hmac(U, key);
+      U = utils.sha512hmac(U, key);
 
       for (k = 0; k < hLen; k++)
         T[k] ^= U[k];
diff --git a/lib/bcoin/miner.js b/lib/bcoin/miner.js
index 2794a92e..24db9ae2 100644
--- a/lib/bcoin/miner.js
+++ b/lib/bcoin/miner.js
@@ -13,8 +13,6 @@ var bn = require('bn.js');
 var inherits = require('inherits');
 var EventEmitter = require('events').EventEmitter;
 
-var crypto = require('crypto');
-
 /**
  * Miner
  */
diff --git a/lib/bcoin/pool.js b/lib/bcoin/pool.js
index e2c5ff7a..29d21c2b 100644
--- a/lib/bcoin/pool.js
+++ b/lib/bcoin/pool.js
@@ -236,6 +236,11 @@ Pool.prototype._init = function _init() {
   }
 };
 
+Pool.prototype.startServer = function startServer() {
+  bcoin.net.createServer(function(socket) {
+  });
+};
+
 Pool.prototype._startTimer = function _startTimer() {
   var self = this;
 
@@ -309,8 +314,9 @@ Pool.prototype.createConnection = function createConnection(peer, options) {
   if (this._createSocket) {
     socket = this._createSocket(addr.port, addr.host);
   } else {
-    net = require('net');
-    socket = net.connect(addr.port, addr.host);
+    if (!bcoin.net)
+      throw new Error('Please include a `createSocket` callback.');
+    socket = bcoin.net.connect(addr.port, addr.host);
   }
 
   utils.debug(
@@ -719,13 +725,14 @@ Pool.prototype.loadMempool = function loadMempool() {
   });
 };
 
-Pool.prototype._createPeer = function _createPeer(priority) {
+Pool.prototype._createPeer = function _createPeer(priority, socket) {
   var self = this;
 
   var peer = new bcoin.peer(this, this.createConnection, {
     startHeight: this.options.startHeight,
     relay: this.options.relay,
-    priority: priority
+    priority: priority,
+    socket: socket
   });
 
   peer.on('error', function(err) {
@@ -801,23 +808,30 @@ Pool.prototype._handleTX = function _handleTX(tx, peer) {
     this.emit('watched', tx, peer);
 };
 
-Pool.prototype._addPeer = function _addPeer() {
+Pool.prototype._addPeer = function _addPeer(socket) {
   var self = this;
   var peer;
 
-  if (this.destroyed)
-    return;
+  if (!socket) {
+    if (this.destroyed)
+      return;
 
-  if (this.peers.block.length + this.peers.pending.length >= this.size)
-    return;
+    if (this.peers.block.length + this.peers.pending.length >= this.size)
+      return;
 
-  if (!this.getSeed()) {
-    setTimeout(this._addPeer.bind(this), 5000);
-    return;
+    if (!this.getSeed()) {
+      setTimeout(this._addPeer.bind(this), 5000);
+      return;
+    }
+
+    peer = this._createPeer(false);
+  } else {
+    if (this.destroyed)
+      return socket.destroy();
+
+    peer = this._createPeer(false, socket);
   }
 
-  peer = this._createPeer(false);
-
   this.peers.pending.push(peer);
   this.peers.all.push(peer);
 
diff --git a/lib/bcoin/ramdisk.js b/lib/bcoin/ramdisk.js
new file mode 100644
index 00000000..9876837c
--- /dev/null
+++ b/lib/bcoin/ramdisk.js
@@ -0,0 +1,54 @@
+function Ramdisk(fileData, size) {
+  if (!(this instanceof Ramdisk))
+    return new Ramdisk(fileData, size);
+
+  if (size < fileData.length)
+    size = fileData.length + (fileData.length / 2 | 0);
+
+  this.size = fileData.length;
+  this.heap = new Buffer(size);
+
+  fileData.copy(this.heap, 0, 0, fileData.length);
+}
+
+Ramdisk.prototype.brk = function brk() {
+  var heap = new Buffer(this.heap.length + (this.heap.length / 2 | 0));
+  utils.debug('brk1(%d, %d)', this.heap.length, heap.length);
+  this.heap.copy(heap, 0, 0, this.heap.length);
+  utils.debug('brk2(%d, %d)', this.heap.length, heap.length);
+  this.heap = heap;
+};
+
+Ramdisk.prototype.write = function write(data, offset) {
+  var added = Math.max(0, (offset + data.length) - this.size);
+
+  while (offset + data.length > this.heap.length)
+    this.brk();
+
+  data.copy(this.heap, offset, 0, data.length);
+
+  this.size += added;
+
+  return data.length;
+};
+
+Ramdisk.prototype.truncate = function truncate(size) {
+  assert(size <= this.size);
+  this.size = size;
+};
+
+Ramdisk.prototype.read = function read(size, offset) {
+  var data, ret;
+
+  if (offset + size > this.size)
+    return;
+
+  data = this.heap.slice(offset, offset + size);
+  ret = new Buffer(size);
+
+  data.copy(ret, 0, 0, data.length);
+
+  return ret;
+};
+
+module.exports = Ramdisk;
diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index ede01f45..b9274113 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -10,7 +10,6 @@ var bcoin = require('../bcoin');
 var bn = require('bn.js');
 var hash = require('hash.js');
 var util = require('util');
-var crypto = require('crypto');
 
 /**
  * Utils
@@ -151,21 +150,31 @@ utils.isBase58 = function isBase58(msg) {
 };
 
 utils.ripemd160 = function ripemd160(data, enc) {
-  // return hash.ripemd160().update(data, enc).digest();
-  var hash;
+  var result;
+
+  if (!bcoin.crypto)
+    return hash.ripemd160().update(data, enc).digest();
+
   if (Array.isArray(data))
     data = new Buffer(data);
-  hash = crypto.createHash('ripemd160').update(data, enc).digest();
-  return utils.toArray(hash);
+
+  result = bcoin.crypto.createHash('ripemd160').update(data, enc).digest();
+
+  return utils.toArray(result);
 };
 
 utils.sha1 = function sha1(data, enc) {
-  // return hash.sha1().update(data, enc).digest();
-  var hash;
+  var result;
+
+  if (!bcoin.crypto)
+    return hash.sha1().update(data, enc).digest();
+
   if (Array.isArray(data))
     data = new Buffer(data);
-  hash = crypto.createHash('sha1').update(data, enc).digest();
-  return utils.toArray(hash);
+
+  result = bcoin.crypto.createHash('sha1').update(data, enc).digest();
+
+  return utils.toArray(result);
 };
 
 utils.ripesha = function ripesha(data, enc) {
@@ -177,18 +186,37 @@ utils.checksum = function checksum(data, enc) {
 };
 
 utils.sha256 = function sha256(data, enc) {
-  // return hash.sha256().update(data, enc).digest();
-  var hash;
+  var result;
+
+  if (!bcoin.crypto)
+    return hash.sha256().update(data, enc).digest();
+
   if (Array.isArray(data))
     data = new Buffer(data);
-  hash = crypto.createHash('sha256').update(data, enc).digest();
-  return utils.toArray(hash);
+
+  result = bcoin.crypto.createHash('sha256').update(data, enc).digest();
+
+  return utils.toArray(result);
 };
 
 utils.dsha256 = function dsha256(data, enc) {
   return utils.sha256(utils.sha256(data, enc));
 };
 
+utils.sha512hmac = function sha512hmac(data, salt) {
+  var hmac, result;
+
+  if (!bcoin.crypto) {
+    hmac = hash.hmac(hash.sha512, utils.toArray(salt));
+    return hmac.update(utils.toArray(data)).digest();
+  }
+
+  hmac = bcoin.crypto.createHmac('sha512', new Buffer(salt));
+  result = hmac.update(new Buffer(data)).digest();
+
+  return utils.toArray(result);
+};
+
 utils.writeAscii = function writeAscii(dst, str, off) {
   var i = 0;
   var c;