From 578ff8f68443051b51fc0184fe79d4f95bea5b37 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Thu, 18 Aug 2016 00:11:40 -0700
Subject: [PATCH] lru: refactor.

---
 lib/bcoin/chaindb.js  | 10 ++++---
 lib/bcoin/lru.js      | 62 ++++++++++++-------------------------------
 lib/bcoin/txdb.js     |  2 +-
 lib/bcoin/walletdb.js |  6 ++---
 4 files changed, 28 insertions(+), 52 deletions(-)

diff --git a/lib/bcoin/chaindb.js b/lib/bcoin/chaindb.js
index 41835c13..09c03a7f 100644
--- a/lib/bcoin/chaindb.js
+++ b/lib/bcoin/chaindb.js
@@ -263,11 +263,11 @@ function ChainDB(chain, options) {
   this.coinWindow = 25 << 20;
 
   this.coinCache = new bcoin.lru.nil();
-  this.cacheHash = new bcoin.lru(this.cacheWindow, 1);
-  this.cacheHeight = new bcoin.lru(this.cacheWindow, 1);
+  this.cacheHash = new bcoin.lru(this.cacheWindow);
+  this.cacheHeight = new bcoin.lru(this.cacheWindow);
 
   if (this.options.coinCache)
-    this.coinCache = new bcoin.lru(this.coinWindow);
+    this.coinCache = new bcoin.lru(this.coinWindow, getSize);
 }
 
 utils.inherits(ChainDB, AsyncObject);
@@ -1864,6 +1864,10 @@ function ipair(prefix, num) {
   return key;
 }
 
+function getSize(value) {
+  return 80 + value.length;
+}
+
 /*
  * Expose
  */
diff --git a/lib/bcoin/lru.js b/lib/bcoin/lru.js
index f4bcdcac..b699d10b 100644
--- a/lib/bcoin/lru.js
+++ b/lib/bcoin/lru.js
@@ -22,34 +22,16 @@ function LRU(maxSize, getSize) {
     return new LRU(maxSize, getSize);
 
   this.maxSize = maxSize;
-  this.getSize = this._createGetSize(getSize);
+  this.getSize = getSize;
 
-  this.data = {};
+  assert(!getSize || typeof getSize === 'function', 'Bad size callback.');
+
+  this.map = {};
   this.size = 0;
   this.head = null;
   this.tail = null;
 }
 
-/**
- * Create a getSize callback.
- * @private
- * @param {Number} size
- * @returns {Function}
- */
-
-LRU.prototype._createGetSize = function _createGetSize(size) {
-  if (!size)
-    return;
-
-  if (typeof size === 'number')
-    return function() { return size; };
-
-  if (typeof size === 'function')
-    return size;
-
-  assert(false, 'Bad getSize callback.');
-};
-
 /**
  * Calculate size of an item.
  * @private
@@ -58,22 +40,12 @@ LRU.prototype._createGetSize = function _createGetSize(size) {
  */
 
 LRU.prototype._getSize = function _getSize(item) {
-  var keySize = item.key.length * 2;
+  var keySize;
 
-  if (this.getSize)
-    return this.getSize(item.key, item.value);
-
-  if (item.value == null)
-    return keySize + 1;
-
-  if (typeof item.value === 'number')
-    return keySize + 4;
-
-  if (typeof item.value === 'string')
-    return keySize + item.value.length * 2;
-
-  if (typeof item.value.length === 'number')
-    return keySize + item.value.length;
+  if (this.getSize) {
+    keySize = Math.floor(item.key.length * 1.375);
+    return 120 + keySize + this.getSize(item.value);
+  }
 
   return 1;
 };
@@ -93,7 +65,7 @@ LRU.prototype._compact = function _compact() {
     if (this.size <= this.maxSize)
       break;
     this.size -= this._getSize(item);
-    delete this.data[item.key];
+    delete this.map[item.key];
     next = item.next;
     item.prev = null;
     item.next = null;
@@ -117,7 +89,7 @@ LRU.prototype.reset = function reset() {
   var item, next;
 
   for (item = this.head; item; item = next) {
-    delete this.data[item.key];
+    delete this.map[item.key];
     next = item.next;
     item.prev = null;
     item.next = null;
@@ -141,7 +113,7 @@ LRU.prototype.set = function set(key, value) {
 
   key = key + '';
 
-  item = this.data[key];
+  item = this.map[key];
 
   if (item) {
     this.size -= this._getSize(item);
@@ -155,7 +127,7 @@ LRU.prototype.set = function set(key, value) {
 
   item = new LRUItem(key, value);
 
-  this.data[key] = item;
+  this.map[key] = item;
 
   this._appendList(item);
 
@@ -175,7 +147,7 @@ LRU.prototype.get = function get(key) {
 
   key = key + '';
 
-  item = this.data[key];
+  item = this.map[key];
 
   if (!item)
     return;
@@ -193,7 +165,7 @@ LRU.prototype.get = function get(key) {
  */
 
 LRU.prototype.has = function get(key) {
-  return this.data[key] != null;
+  return this.map[key] != null;
 };
 
 /**
@@ -207,14 +179,14 @@ LRU.prototype.remove = function remove(key) {
 
   key = key + '';
 
-  item = this.data[key];
+  item = this.map[key];
 
   if (!item)
     return false;
 
   this.size -= this._getSize(item);
 
-  delete this.data[key];
+  delete this.map[key];
 
   this._removeList(item);
 
diff --git a/lib/bcoin/txdb.js b/lib/bcoin/txdb.js
index 4397381c..b3a38e42 100644
--- a/lib/bcoin/txdb.js
+++ b/lib/bcoin/txdb.js
@@ -258,7 +258,7 @@ function TXDB(wallet) {
   this.locked = {};
 
   this.locker = new bcoin.locker(this);
-  this.coinCache = new bcoin.lru(10000, 1);
+  this.coinCache = new bcoin.lru(10000);
 
   this.current = null;
   this.balance = null;
diff --git a/lib/bcoin/walletdb.js b/lib/bcoin/walletdb.js
index 7d9a9e14..d09e18c7 100644
--- a/lib/bcoin/walletdb.js
+++ b/lib/bcoin/walletdb.js
@@ -171,9 +171,9 @@ function WalletDB(options) {
   this.writeLock = new bcoin.locker.mapped(this);
   this.txLock = new bcoin.locker(this);
 
-  this.walletCache = new bcoin.lru(10000, 1);
-  this.accountCache = new bcoin.lru(10000, 1);
-  this.pathCache = new bcoin.lru(100000, 1);
+  this.walletCache = new bcoin.lru(10000);
+  this.accountCache = new bcoin.lru(10000);
+  this.pathCache = new bcoin.lru(100000);
 
   // Try to optimize for up to 1m addresses.
   // We use a regular bloom filter here