From 0b2023d62cfb0c92d5087fc3e1d97d8c914fdff5 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Tue, 16 Aug 2016 11:34:25 -0700
Subject: [PATCH] mempool: refactor.

---
 lib/bcoin/http/rpc.js |  1 -
 lib/bcoin/mempool.js  | 71 +++++++++++++++++--------------------------
 2 files changed, 28 insertions(+), 44 deletions(-)

diff --git a/lib/bcoin/http/rpc.js b/lib/bcoin/http/rpc.js
index dd026c0b..5a220b52 100644
--- a/lib/bcoin/http/rpc.js
+++ b/lib/bcoin/http/rpc.js
@@ -1563,7 +1563,6 @@ RPC.prototype.getnetworkhashps = function getnetworkhashps(args, callback) {
 };
 
 RPC.prototype.prioritisetransaction = function prioritisetransaction(args, callback) {
-  var self = this;
   var hash, pri, fee, entry;
 
   if (args.help || args.length !== 3) {
diff --git a/lib/bcoin/mempool.js b/lib/bcoin/mempool.js
index 994916e9..78c12c87 100644
--- a/lib/bcoin/mempool.js
+++ b/lib/bcoin/mempool.js
@@ -102,6 +102,7 @@ function Mempool(options) {
   this.prematureWitness = !!this.options.prematureWitness;
 
   this.maxSize = options.maxSize || constants.mempool.MAX_MEMPOOL_SIZE;
+  this.expiryTime = options.expiryTime || constants.mempool.MEMPOOL_EXPIRY;
   this.blockSinceBump = false;
   this.lastFeeUpdate = utils.now();
   this.minFeeRate = 0;
@@ -236,7 +237,7 @@ Mempool.prototype.limitMempoolSize = function limitMempoolSize(entryHash) {
     return trimmed;
 
   hashes = this.getSnapshot();
-  end = utils.now() - constants.mempool.MEMPOOL_EXPIRY;
+  end = utils.now() - this.expiryTime;
 
   for (i = 0; i < hashes.length; i++) {
     hash = hashes[i];
@@ -661,11 +662,8 @@ Mempool.prototype.addUnchecked = function addUnchecked(entry, callback, force) {
 
   callback = utils.wrap(callback, unlock);
 
-  this._addUnchecked(entry);
+  this.trackEntry(entry);
 
-  this.totalSpent += entry.tx.inputs.length;
-  this.size += this.memUsage(entry.tx);
-  this.totalTX++;
   this.emit('tx', entry.tx);
   this.emit('add tx', entry.tx);
 
@@ -714,11 +712,14 @@ Mempool.prototype.removeUnchecked = function removeUnchecked(entry, limit) {
 
   this.removeOrphan(entry.tx);
 
-  this._removeUnchecked(entry, limit);
+  // We do not remove spenders if this is
+  // being removed for a block. The spenders
+  // are still spending valid coins (which
+  // now exist on the blockchain).
+  if (limit)
+    this._removeSpenders(entry);
 
-  this.totalSpent -= entry.tx.inputs.length;
-  this.size -= this.memUsage(entry.tx);
-  this.totalTX--;
+  this.untrackEntry(entry);
 
   if (this.fees) {
     hash = entry.tx.hash('hex');
@@ -1353,12 +1354,12 @@ Mempool.prototype.getConfidence = function getConfidence(hash, callback) {
 };
 
 /**
- * Add a transaction to the mempool database.
+ * Map a transaction to the mempool.
  * @private
  * @param {MempoolEntry} entry
  */
 
-Mempool.prototype._addUnchecked = function _addUnchecked(entry) {
+Mempool.prototype.trackEntry = function trackEntry(entry) {
   var tx = entry.tx;
   var hash = tx.hash('hex');
   var i, input, output, key, coin;
@@ -1368,13 +1369,12 @@ Mempool.prototype._addUnchecked = function _addUnchecked(entry) {
   if (this.options.indexAddress)
     this.indexTX.addTX(tx);
 
+  assert(!tx.isCoinbase());
+
   for (i = 0; i < tx.inputs.length; i++) {
     input = tx.inputs[i];
     key = input.prevout.hash + input.prevout.index;
 
-    if (tx.isCoinbase())
-      break;
-
     assert(input.coin);
 
     if (this.options.indexAddress)
@@ -1394,55 +1394,34 @@ Mempool.prototype._addUnchecked = function _addUnchecked(entry) {
       this.coinIndex.addCoin(coin);
     }
   }
+
+  this.totalSpent += tx.inputs.length;
+  this.size += this.memUsage(tx);
+  this.totalTX++;
 };
 
 /**
- * Remove a transaction from the database. Note
- * that this _may_ not disconnect the inputs.
- * Transactions get removed for 2 reasons:
- * Either they are included in a block,
- * or they are limited.
- *
- * - If they are limited, we want to disconnect
- *   the inputs and also remove all spender
- *   transactions along with their outputs/coins.
- *
- * - If they are included in a block, we do not
- *   disconnect the inputs (the coins have already
- *   been used on the blockchain-layer). We also
- *   do not remove spenders, since they are still
- *   spending valid coins that exist on the blockchain.
- *
+ * Unmap a transaction from the mempool.
  * @private
  * @param {MempoolEntry} entry
- * @param {Boolean} limit
- * @param {Function} callback
  */
 
-Mempool.prototype._removeUnchecked = function _removeUnchecked(entry, limit) {
+Mempool.prototype.untrackEntry = function untrackEntry(entry) {
   var tx = entry.tx;
   var hash = tx.hash('hex');
   var i, input, output, key, coin;
 
-  // We do not remove spenders if this is
-  // being removed for a block. The spenders
-  // are still spending valid coins (which
-  // now exist on the blockchain).
-  if (limit)
-    this._removeSpenders(entry);
-
   delete this.tx[hash];
 
   if (this.options.indexAddress)
     this.txIndex.removeTX(tx);
 
+  assert(!tx.isCoinbase());
+
   for (i = 0; i < tx.inputs.length; i++) {
     input = tx.inputs[i];
     key = input.prevout.hash + input.prevout.index;
 
-    if (tx.isCoinbase())
-      break;
-
     delete this.spents[key];
 
     assert(input.coin);
@@ -1462,6 +1441,10 @@ Mempool.prototype._removeUnchecked = function _removeUnchecked(entry, limit) {
       this.coinIndex.removeCoin(coin);
     }
   }
+
+  this.totalSpent -= tx.inputs.length;
+  this.size -= this.memUsage(tx);
+  this.totalTX--;
 };
 
 /**
@@ -1497,6 +1480,8 @@ Mempool.prototype.memUsage = function memUsage(tx) {
   var mem = 0;
   var i, j, input, output;
 
+  mem += 8;
+  mem += 8;
   mem += 8;
 
   for (i = 0; i < tx.inputs.length; i++) {