From 83e1de2e9892c74b8f00a1a5b8097d6655f845ee Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Tue, 5 Dec 2017 02:32:54 -0800
Subject: [PATCH] db: stop relying on encoding.

---
 lib/blockchain/chaindb.js | 14 ++++++++++----
 lib/wallet/walletdb.js    | 26 +++++++++++++++++++-------
 test/wallet-test.js       | 13 +++++++++----
 3 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/lib/blockchain/chaindb.js b/lib/blockchain/chaindb.js
index f5fda9e8..fed78df6 100644
--- a/lib/blockchain/chaindb.js
+++ b/lib/blockchain/chaindb.js
@@ -24,8 +24,6 @@ const ChainEntry = require('./chainentry');
 const TXMeta = require('../primitives/txmeta');
 const CoinEntry = require('../coins/coinentry');
 const {encoding} = bio;
-const u8 = encoding.u8;
-const u32 = encoding.u32;
 
 /**
  * ChainDB
@@ -1386,7 +1384,7 @@ class ChainDB {
     const hash = block.hash();
 
     // Hash->height index.
-    this.put(layout.h.build(hash), u32(entry.height));
+    this.put(layout.h.build(hash), fromU32(entry.height));
 
     // Entry data.
     this.put(layout.e.build(hash), entry.toRaw());
@@ -2288,7 +2286,9 @@ class CacheUpdate {
   }
 
   toRaw() {
-    return u8(this.state);
+    const data = Buffer.allocUnsafe(1);
+    data[0] = this.state;
+    return data;
   }
 }
 
@@ -2300,6 +2300,12 @@ function getSize(value) {
   return value.length + 80;
 }
 
+function fromU32(num) {
+  const data = Buffer.allocUnsafe(4);
+  data.writeUInt32LE(num, 0, true);
+  return data;
+}
+
 /*
  * Expose
  */
diff --git a/lib/wallet/walletdb.js b/lib/wallet/walletdb.js
index 5c5eaaee..afd36073 100644
--- a/lib/wallet/walletdb.js
+++ b/lib/wallet/walletdb.js
@@ -27,8 +27,6 @@ const Outpoint = require('../primitives/outpoint');
 const layouts = require('./layout');
 const records = require('./records');
 const NullClient = require('./nullclient');
-const {encoding} = bio;
-const {u32} = encoding;
 const layout = layouts.wdb;
 const tlayout = layouts.txdb;
 
@@ -216,7 +214,7 @@ class WalletDB extends EventEmitter {
 
     if (!raw) {
       const b = this.db.batch();
-      b.put(layout.O.build(), u32(this.network.magic));
+      b.put(layout.O.build(), fromU32(this.network.magic));
       return b.write();
     }
 
@@ -750,7 +748,7 @@ class WalletDB extends EventEmitter {
     const id = wallet.id;
 
     b.put(layout.w.build(wid), wallet.toRaw());
-    b.put(layout.l.build(id), u32(wid));
+    b.put(layout.l.build(id), fromU32(wid));
   }
 
   /**
@@ -760,7 +758,7 @@ class WalletDB extends EventEmitter {
    */
 
   increment(b, wid) {
-    b.put(layout.D.build(), u32(wid + 1));
+    b.put(layout.D.build(), fromU32(wid + 1));
   }
 
   /**
@@ -1125,10 +1123,10 @@ class WalletDB extends EventEmitter {
     b.put(layout.a.build(wid, index), account.toRaw());
 
     // Name->Index lookups
-    b.put(layout.i.build(wid, name), u32(index));
+    b.put(layout.i.build(wid, name), fromU32(index));
 
     // Index->Name lookups
-    b.put(layout.n.build(wid, index), Buffer.from(name, 'ascii'));
+    b.put(layout.n.build(wid, index), fromString(name));
   }
 
   /**
@@ -2264,6 +2262,20 @@ class WalletOptions {
   }
 }
 
+/*
+ * Helpers
+ */
+
+function fromU32(num) {
+  const data = Buffer.allocUnsafe(4);
+  data.writeUInt32LE(num, 0, true);
+  return data;
+}
+
+function fromString(str) {
+  return Buffer.from(str, 'ascii');
+}
+
 /*
  * Expose
  */
diff --git a/test/wallet-test.js b/test/wallet-test.js
index de0f209a..f5d045b4 100644
--- a/test/wallet-test.js
+++ b/test/wallet-test.js
@@ -19,7 +19,6 @@ const Input = require('../lib/primitives/input');
 const Outpoint = require('../lib/primitives/outpoint');
 const Script = require('../lib/script/script');
 const HD = require('../lib/hd');
-const u32 = encoding.u32;
 
 const KEY1 = 'xprv9s21ZrQH143K3Aj6xQBymM31Zb4BVc7wxqfUhMZrzewdDVCt'
   + 'qUP9iWfcHgJofs25xbaUpCps9GDXj83NiWvQCAkWQhVj5J4CorfnpKX94AZ';
@@ -37,6 +36,12 @@ let importedKey = null;
 let doubleSpendWallet = null;
 let doubleSpendCoin = null;
 
+function fromU32(num) {
+  const data = Buffer.allocUnsafe(4);
+  data.writeUInt32LE(num, 0, true);
+  return data;
+}
+
 function curBlock(wdb) {
   return fakeBlock(wdb.state.height);
 };
@@ -46,9 +51,9 @@ function nextBlock(wdb) {
 }
 
 function fakeBlock(height) {
-  const prev = hash256.digest(u32((height - 1) >>> 0));
-  const hash = hash256.digest(u32(height >>> 0));
-  const root = hash256.digest(u32((height | 0x80000000) >>> 0));
+  const prev = hash256.digest(fromU32((height - 1) >>> 0));
+  const hash = hash256.digest(fromU32(height >>> 0));
+  const root = hash256.digest(fromU32((height | 0x80000000) >>> 0));
 
   return {
     hash: hash.toString('hex'),