From 46fbaf951472be6bc76ab62a8586ee7b90aae7d4 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sun, 12 Jun 2016 11:16:36 -0700
Subject: [PATCH] optimize keys.

---
 lib/bcoin/chaindb.js | 116 +++++++++++++++++++++++--------------------
 1 file changed, 63 insertions(+), 53 deletions(-)

diff --git a/lib/bcoin/chaindb.js b/lib/bcoin/chaindb.js
index f604bce0..4acf4377 100644
--- a/lib/bcoin/chaindb.js
+++ b/lib/bcoin/chaindb.js
@@ -39,109 +39,109 @@ var layout = {
     ? new Buffer([0x52]) // R
     : '52',
   e: function e(hash) {
-    var key = new BufferWriter();
-    key.writeU8(0x65); // e
-    key.writeHash(hash);
-    key = key.render();
+    var key = new Buffer(33);
+    key[0] = 0x65; // e
+    write(key, hash, 1);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   h: function h(hash) {
-    var key = new BufferWriter();
-    key.writeU8(0x68); // h
-    key.writeHash(hash);
-    key = key.render();
+    var key = new Buffer(33);
+    key[0] = 0x68; // h
+    write(key, hash, 1);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   H: function H(height) {
-    var key = new BufferWriter();
-    key.writeU8(0x48); // H
-    key.writeU32(height);
-    key = key.render();
+    var key = new Buffer(5);
+    key[0] = 0x48; // H
+    key.writeUInt32LE(height, 1, true);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   n: function n(hash) {
-    var key = new BufferWriter();
-    key.writeU8(0x6e); // n
-    key.writeHash(hash);
-    key = key.render();
+    var key = new Buffer(33);
+    key[0] = 0x6e; // n
+    write(key, hash, 1);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   b: function b(hash) {
-    var key = new BufferWriter();
-    key.writeU8(0x62); // b
-    key.writeHash(hash);
-    key = key.render();
+    var key = new Buffer(33);
+    key[0] = 0x62; // b
+    write(key, hash, 1);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   t: function t(hash) {
-    var key = new BufferWriter();
-    key.writeU8(0x74); // t
-    key.writeHash(hash);
-    key = key.render();
+    var key = new Buffer(33);
+    key[0] = 0x74; // t
+    write(key, hash, 1);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   c: function c(hash) {
-    var key = new BufferWriter();
-    key.writeU8(0x63); // c
-    key.writeHash(hash);
-    key = key.render();
+    var key = new Buffer(33);
+    key[0] = 0x63; // c
+    write(key, hash, 1);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   u: function u(hash) {
-    var key = new BufferWriter();
-    key.writeU8(0x75); // u
-    key.writeHash(hash);
-    key = key.render();
+    var key = new Buffer(33);
+    key[0] = 0x75; // u
+    write(key, hash, 1);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   q: function q(height) {
-    var key = new BufferWriter();
-    key.writeU8(0x71); // q
-    key.writeU32(height);
-    key = key.render();
+    var key = new Buffer(5);
+    key[0] = 0x71; // q
+    key.writeUInt32LE(height, 1, true);
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   T: function T(address, hash) {
-    var key = new BufferWriter();
-    if (address.length === 32 || address.length === 64)
-      key.writeU8(0xab); // W + T
-    else
-      key.writeU8(0x54); // T
-    key.writeHash(address);
-    key.writeHash(hash);
-    key = key.render();
+    var key;
+    if (address.length === 32 || address.length === 64) {
+      key = new Buffer(65);
+      key[0] = 0xab; // W + T
+      write(key, address, 1);
+      write(key, hash, 33);
+    } else {
+      key = new Buffer(53);
+      key[0] = 0x54; // T
+      write(key, address, 1);
+      write(key, hash, 21);
+    }
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
   },
   C: function C(address, hash, index) {
-    var key = new BufferWriter();
-    if (address.length === 32 || address.length === 64)
-      key.writeU8(0x9a); // W + C
-    else
-      key.writeU8(0x43); // C
-    key.writeHash(address);
-    key.writeHash(hash);
-    key.writeU32(index);
-    key = key.render();
+    var key;
+    if (address.length === 32 || address.length === 64) {
+      key = new Buffer(69);
+      key[0] = 0x9a; // W + C
+      write(key, address, 1);
+      write(key, hash, 33);
+      key.writeUInt32LE(index, 65, true);
+    } else {
+      key = new Buffer(57);
+      key[0] = 0x43; // C
+      write(key, address, 1);
+      write(key, hash, 21);
+      key.writeUInt32LE(index, 53, true);
+    }
     if (utils.isBrowser)
       key = key.toString('hex');
     return key;
@@ -1529,6 +1529,16 @@ NullCache.prototype.get = function get(key) {};
 NullCache.prototype.has = function has(key) {};
 NullCache.prototype.reset = function reset() {};
 
+/*
+ * Helpers
+ */
+
+function write(data, str, off) {
+  if (Buffer.isBuffer(str))
+    return str.copy(data, off);
+  data.write(str, off, 'hex');
+}
+
 /*
  * Expose
  */