heap: minor refactor.

lib/mining/miner.js

@@ -409,11 +409,11 @@ Miner.prototype.build = function build(attempt) {
     if (item.depCount > 0)
       continue;
 
-    queue.push(item);
+    queue.insert(item);
   }
 
   while (queue.size() > 0) {
-    item = queue.pop();
+    item = queue.shift();
     tx = item.tx;
     hash = item.hash;
     weight = attempt.weight;
@@ -441,7 +441,7 @@ Miner.prototype.build = function build(attempt) {
         queue.set(cmpRate);
         queue.init();
         priority = false;
-        queue.push(item);
+        queue.insert(item);
         continue;
       }
     } else {
@@ -464,7 +464,7 @@ Miner.prototype.build = function build(attempt) {
     for (j = 0; j < deps.length; j++) {
       item = deps[j];
       if (--item.depCount === 0)
-        queue.push(item);
+        queue.insert(item);
     }
   }
 
@@ -621,11 +621,11 @@ MinerOptions.fromOptions = function fromOptions(options) {
  */
 
 function cmpPriority(a, b) {
-  return a.priority - b.priority;
+  return b.priority - a.priority;
 }
 
 function cmpRate(a, b) {
-  return a.descRate - b.descRate;
+  return b.descRate - a.descRate;
 }
 
 /*

lib/utils/heap.js

@@ -1,6 +1,6 @@
 /*!
  * heap.js - heap object for bcoin
- * Copyright (c) 2014-2017, Christopher Jeffrey (MIT License).
+ * Copyright (c) 2017, Christopher Jeffrey (MIT License).
  * https://github.com/bcoin-org/bcoin
  */
 
@@ -9,19 +9,21 @@
 var assert = require('assert');
 
 /**
- * Priority Queue
+ * Binary Heap
  * @alias module:utils.Heap
  * @constructor
- * @param {Function?} cmp
+ * @param {Function?} compare
  */
 
-function Heap(cmp) {
+function Heap(compare) {
   if (!(this instanceof Heap))
-    return new Heap(cmp);
+    return new Heap(compare);
 
-  this.cmp = null;
+  this.compare = comparator;
   this.items = [];
-  this.set(cmp);
+
+  if (compare)
+    this.set(compare);
 }
 
 /**
@@ -50,13 +52,13 @@ Heap.prototype.size = function size() {
 
 /**
  * Set comparator.
- * @param {Function} cmp
+ * @param {Function} compare
  */
 
-Heap.prototype.set = function set(cmp) {
+Heap.prototype.set = function set(compare) {
-  assert(cmp == null || typeof cmp === 'function',
+  assert(typeof compare === 'function',
     'Comparator must be a function.');
-  this.cmp = cmp || null;
+  this.compare = compare;
 };
 
 /**
@@ -65,7 +67,7 @@ Heap.prototype.set = function set(cmp) {
  * @returns {Number}
  */
 
-Heap.prototype.push = function push(item) {
+Heap.prototype.insert = function insert(item) {
   this.items.push(item);
   this.up(this.items.length - 1);
   return this.items.length;
@@ -77,7 +79,7 @@ Heap.prototype.push = function push(item) {
  * @returns {Object}
  */
 
-Heap.prototype.pop = function pop(item) {
+Heap.prototype.shift = function shift() {
   var n;
 
   if (this.items.length === 0)
@@ -105,6 +107,9 @@ Heap.prototype.remove = function remove(i) {
 
   n = this.items.length - 1;
 
+  if (i < 0 || i > n)
+    return;
+
   if (n !== i) {
     this.swap(i, n);
     this.down(i, n);
@@ -137,7 +142,7 @@ Heap.prototype.swap = function swap(a, b) {
  */
 
 Heap.prototype.less = function less(i, j) {
-  return this.cmp(this.items[i], this.items[j]) >= 0;
+  return this.compare(this.items[i], this.items[j]) < 0;
 };
 
 /**
@@ -203,31 +208,41 @@ Heap.prototype.up = function up(i) {
  */
 
 Heap.prototype.toArray = function toArray() {
-  var heap = new Heap(this.cmp);
+  var heap = new Heap();
   var result = [];
 
+  heap.compare = this.compare;
   heap.items = this.items.slice();
 
   while (heap.size() > 0)
-    result.push(heap.pop());
+    result.push(heap.shift());
 
-  return result.reverse();
+  return result;
 };
 
 /**
  * Instantiate heap from array and comparator.
- * @param {Function} cmp
+ * @param {Function} compare
  * @param {Object[]} items
  * @returns {Heap}
  */
 
-Heap.fromArray = function fromArray(cmp, items) {
+Heap.fromArray = function fromArray(compare, items) {
-  var heap = new Heap(cmp);
+  var heap = new Heap();
+  heap.set(compare);
   heap.items = items;
   heap.init();
   return heap;
 };
 
+/*
+ * Helpers
+ */
+
+function comparator(a, b) {
+  throw new Error('No heap comparator set.');
+}
+
 /*
  * Expose
  */

lib/utils/index.js

@@ -12,6 +12,7 @@ exports.Bloom = require('./bloom');
 exports.RollingFilter = exports.Bloom.Rolling;
 exports.co = require('./co');
 exports.encoding = require('./encoding');
+exports.Heap = require('./heap');
 exports.IP = require('./ip');
 exports.lazy = require('./lazy');
 exports.Lock = require('./lock');