From d690c9ea5abc8632b882383dc9ce4f7bd9d511d3 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Fri, 18 Mar 2016 20:12:34 -0700
Subject: [PATCH] ldb.

---
 lib/bcoin/chaindb.js  |  2 +-
 lib/bcoin/ldb.js      | 12 ++++++++----
 lib/bcoin/txdb.js     |  2 +-
 lib/bcoin/utils.js    |  8 ++++++++
 lib/bcoin/walletdb.js |  2 +-
 5 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/lib/bcoin/chaindb.js b/lib/bcoin/chaindb.js
index 5df19e20..a1df36bb 100644
--- a/lib/bcoin/chaindb.js
+++ b/lib/bcoin/chaindb.js
@@ -11,7 +11,7 @@ var network = bcoin.protocol.network;
 var utils = require('./utils');
 var assert = utils.assert;
 var pad32 = utils.pad32;
-var DUMMY = new Buffer([]);
+var DUMMY = new Buffer([0]);
 
 /**
  * ChainDB
diff --git a/lib/bcoin/ldb.js b/lib/bcoin/ldb.js
index 25af3787..f03c8a42 100644
--- a/lib/bcoin/ldb.js
+++ b/lib/bcoin/ldb.js
@@ -11,8 +11,6 @@ var db = {};
 module.exports = function ldb(name, options) {
   var levelup = require('levelup');
   var file = bcoin.prefix + '/' + name + '-' + network.type + '.db';
-  var cacheSize = options.cacheSize || 8 * 1024 * 1024;
-  var writeBufferSize = options.writeBufferSize || (cacheSize / 2 | 0);
 
   bcoin.ensurePrefix();
 
@@ -23,9 +21,15 @@ module.exports = function ldb(name, options) {
       createIfMissing: true,
       errorIfExists: false,
       compression: options.compression !== false,
-      cacheSize: cacheSize,
-      writeBufferSize: writeBufferSize,
+      cacheSize: options.cacheSize || (8 << 20),
+      writeBufferSize: options.writeBufferSize || (4 << 20),
       maxOpenFiles: options.maxOpenFiles || 8192,
+
+      // For LMDB if we decide to use it:
+      sync: options.sync || false,
+      mapSize: options.mapSize || 150 * (1024 << 20),
+      writeMap: options.writeMap || false,
+
       db: bcoin.isBrowser
         ? require('level-js')
         : require('level' + 'down')
diff --git a/lib/bcoin/txdb.js b/lib/bcoin/txdb.js
index 450c38b2..f0fbaa77 100644
--- a/lib/bcoin/txdb.js
+++ b/lib/bcoin/txdb.js
@@ -9,7 +9,7 @@ var bcoin = require('../bcoin');
 var utils = require('./utils');
 var assert = bcoin.utils.assert;
 var EventEmitter = require('events').EventEmitter;
-var DUMMY = new Buffer([]);
+var DUMMY = new Buffer([0]);
 var pad32 = utils.pad32;
 
 /**
diff --git a/lib/bcoin/utils.js b/lib/bcoin/utils.js
index d892edbf..d34ebfa0 100644
--- a/lib/bcoin/utils.js
+++ b/lib/bcoin/utils.js
@@ -1038,6 +1038,14 @@ utils.read32 = function read32(arr, off) {
     | (arr[off + 1] << 8)
     | (arr[off + 2] << 16)
     | (arr[off + 3] << 24);
+
+  // arr = (arr[off])
+  //   | (arr[off + 1] << 8)
+  //   | (arr[off + 2] << 16)
+  //   | (arr[off + 3] << 24);
+  // if (arr & 0x80000000)
+  //   arr = ~arr + 1;
+  // return arr;
 };
 
 utils.read32BE = function read32BE(arr, off) {
diff --git a/lib/bcoin/walletdb.js b/lib/bcoin/walletdb.js
index 6fc367c6..2080d6c1 100644
--- a/lib/bcoin/walletdb.js
+++ b/lib/bcoin/walletdb.js
@@ -9,7 +9,7 @@ var EventEmitter = require('events').EventEmitter;
 var bcoin = require('../bcoin');
 var utils = require('./utils');
 var assert = utils.assert;
-var DUMMY = new Buffer([]);
+var DUMMY = new Buffer([0]);
 
 /**
  * WalletDB