texas-without-memcpy

<!DOCTYPE html> <html> <head> <title>texas.js</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <link rel="stylesheet" media="all" href="docco.css" /> </head> <body> <div id="container"> <div id="background"></div> <table cellpadding="0" cellspacing="0"> <thead> <tr> <th class="docs"> <h1> texas.js </h1> </th> <th class="code"> </th> </tr> </thead> <tbody> <tr id="section-1"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-1">¶</a> </div> Texas Hold'em hand evaluator for <a href="http://nodejs.org/">node.js</a>. </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-2"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-2">¶</a> </div> Dependencies: <a href="http://documentcloud.github.com/underscore/">underscore.js</a>, <a href="http://github.com/egorFiNE/node-compress-buffer/">compress-buffer</a>. </td> <td class="code"> <div class="highlight"><pre>var _ = require('underscore'); var fs = require('fs'); var crypto = require('crypto'); var gzip = require('compress-buffer');</pre></div> </td> </tr> <tr id="section-3"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-3">¶</a> </div> <h2>Definitions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-4"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-4">¶</a> </div> Standard deck size. </td> <td class="code"> <div class="highlight"><pre>var deckSize = 52;</pre></div> </td> </tr> <tr id="section-5"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-5">¶</a> </div> Card abbreviations. </td> <td class="code"> <div class="highlight"><pre>var chars = '23456789TJQKAc♣d♦h♥s♠'; var abbr = _.object(chars, _.range(chars.length));</pre></div> </td> </tr> <tr id="section-6"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-6">¶</a> </div> Card ranks. </td> <td class="code"> <div class="highlight"><pre>var ranks = ['Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine', 'Ten', 'Jack', 'Queen', 'King', 'Ace'];</pre></div> </td> </tr> <tr id="section-7"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-7">¶</a> </div> Card suits. </td> <td class="code"> <div class="highlight"><pre>var suits = ['Clubs', 'Diamonds', 'Hearts', 'Spades'];</pre></div> </td> </tr> <tr id="section-8"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-8">¶</a> </div> Types of hand. </td> <td class="code"> <div class="highlight"><pre>var hands = ['Invalid', 'High Card', 'One Pair', 'Two Pairs', 'Three of a Kind', 'Straight', 'Flush', 'Full House', 'Four of a Kind', 'Straight Flush'];</pre></div> </td> </tr> <tr id="section-9"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-9">¶</a> </div> Loads the look-up table. </td> <td class="code"> <div class="highlight"><pre>var buffer = fs.readFileSync(__dirname + '/HandRanks.dat.gz'); var evaluator = new Int32Array(gzip.uncompress(buffer));</pre></div> </td> </tr> <tr id="section-10"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-10">¶</a> </div> <h2>Internal Functions</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-11"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-11">¶</a> </div> Parses the formatted card to get its numeric code. </td> <td class="code"> <div class="highlight"><pre>var getCode = function (card) { if (typeof card == 'number') return card >= 1 && card <= deckSize ? card : undefined; // Already codified if (typeof card != 'string' || card.length != 2) return undefined; // Invalid input var posRank = abbr[card[0]]; var posSuit = (abbr[card[1]] - ranks.length) >> 1; if (typeof posRank != 'number' || posRank >= ranks.length || posSuit < 0) return undefined; // Invalid characters return posRank * suits.length + posSuit + 1; };</pre></div> </td> </tr> <tr id="section-12"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-12">¶</a> </div> Helper function to create card formatters. </td> <td class="code"> <div class="highlight"><pre>var filter = function (format) { return function (card) { card = getCode(card); if (!card) return undefined; card--; return format({rank: card >> 2, suit: card & 3}); }; };</pre></div> </td> </tr> <tr id="section-13"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-13">¶</a> </div> <h2>Main Functions</h2> </td> <td class="code"> <div class="highlight"><pre>module.exports = {</pre></div> </td> </tr> <tr id="section-14"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-14">¶</a> </div> Creates a new shuffled deck. </td> <td class="code"> <div class="highlight"><pre> deck: function (format) { var res = _.range(1, deckSize + 1); var buffer = crypto.randomBytes(deckSize << 2); for (var pos = res.length - 1; pos > 0; pos--) { var rand = buffer.readUInt32LE(pos << 2) % (pos + 1); var temp = res[pos]; res[pos] = res[rand]; res[rand] = temp; }; return format ? _.map(res, format) : res; }, </pre></div> </td> </tr> <tr id="section-15"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-15">¶</a> </div> Evaluates the 5 to 7 card hands. </td> <td class="code"> <div class="highlight"><pre> evaluate: function (cards) { var res = deckSize + 1; for (var c = 0; c < cards.length; c++) res = evaluator[res + getCode(cards[c])]; if (cards.length < 7) res = evaluator[res]; return {name: hands[res >> 12], value: res}; }, </pre></div> </td> </tr> <tr id="section-16"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-16">¶</a> </div> Sorts the set of cards. </td> <td class="code"> <div class="highlight"><pre> sort: function (cards) { return _.sortBy(cards, getCode); }, </pre></div> </td> </tr> <tr id="section-17"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-17">¶</a> </div> Calculates the exact odds. </td> <td class="code"> <div class="highlight"><pre> odds: function (hands, table, dead) {</pre></div> </td> </tr> <tr id="section-18"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-18">¶</a> </div> Preprocesses the input data. </td> <td class="code"> <div class="highlight"><pre> table = table ? _.map(table, getCode) : []; dead = dead ? _.map(dead, getCode) : []; hands = _.map(hands, function (hand) { return _.map(hand, getCode); }); var res = deckSize + 1; for (var c = 0; c < table.length; c++) res = evaluator[res + table[c]]; var deck = _.chain(_.range(1, deckSize + 1)).difference(table) .difference(_.flatten(hands)).difference(dead).value(); var player = _.map(hands, function (hand) { return evaluator[evaluator[res + hand[0]] + hand[1]]; }); var combinations = function (n, k, res, callback) { if (k <= 0) { callback(res); } else { while (n < deck.length) { var parcial = evaluator[res + deck[n++]]; combinations(n, k - 1, parcial, callback); } } }; </pre></div> </td> </tr> <tr id="section-19"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-19">¶</a> </div> Calculates the outcome of each play. </td> <td class="code"> <div class="highlight"><pre> var remaining = 5 - table.length; var plays = deck.length / remaining; for (var c = 1; c < remaining; c++) plays *= (deck.length - c) / c; var values = new Array(hands.length); for (var p = 0; p < hands.length; p++) { var s = 0; values[p] = new Int32Array(plays); combinations(0, remaining, player[p], function (res) { values[p][s++] = res; }); } </pre></div> </td> </tr> <tr id="section-20"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-20">¶</a> </div> Determines the results. </td> <td class="code"> <div class="highlight"><pre> var wins = new Int32Array(hands.length); var splits = new Int32Array(hands.length); for (var s = 0; s < plays; s++) { var winner = [0]; for (var p = 1; p < hands.length; p++) { if (values[p][s] > values[winner[0]][s]) winner = [p]; else if (values[p][s] == values[winner[0]][s]) winner.push(p); } if (winner.length == 1) { wins[winner[0]]++; } else { for (var p = 0; p < winner.length; p++) splits[winner[p]]++; } } </pre></div> </td> </tr> <tr id="section-21"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-21">¶</a> </div> Formats odds output. </td> <td class="code"> <div class="highlight"><pre> var odds = []; for (var p = 0; p < hands.length; p++) odds[p] = {win: wins[p] / plays, split: splits[p] / plays}; return odds; }, </pre></div> </td> </tr> <tr id="section-22"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-22">¶</a> </div> Formats the card to extended text. </td> <td class="code"> <div class="highlight"><pre> extended: filter(function (card) { return ranks[card.rank] + ' of ' + suits[card.suit]; }), </pre></div> </td> </tr> <tr id="section-23"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-23">¶</a> </div> Formats the card to abbreviated text. </td> <td class="code"> <div class="highlight"><pre> abbr: filter(function (card) { return chars[card.rank] + chars[(card.suit << 1) + ranks.length]; }), </pre></div> </td> </tr> <tr id="section-24"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-24">¶</a> </div> Formats the card to unicode text. </td> <td class="code"> <div class="highlight"><pre> unicode: filter(function (card) { return chars[card.rank] + chars[(card.suit << 1) + ranks.length + 1]; }), </pre></div> </td> </tr> <tr id="section-25"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-25">¶</a> </div> Parses the formatted card to get its numeric code. </td> <td class="code"> <div class="highlight"><pre> code: getCode, </pre></div> </td> </tr> <tr id="section-26"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-26">¶</a> </div> Benchmarks the evaluator within all possible 7 card hands. </td> <td class="code"> <div class="highlight"><pre> benchmark: function () { var freq = new Int32Array(hands.length); var start = Date.now(); for (var c1 = 1; c1 <= deckSize; c1++) { var r1 = evaluator[deckSize + c1 + 1]; for (var c2 = c1 + 1; c2 <= deckSize; c2++) { var r2 = evaluator[r1 + c2]; for (var c3 = c2 + 1; c3 <= deckSize; c3++) { var r3 = evaluator[r2 + c3]; for (var c4 = c3 + 1; c4 <= deckSize; c4++) { var r4 = evaluator[r3 + c4]; for (var c5 = c4 + 1; c5 <= deckSize; c5++) { var r5 = evaluator[r4 + c5]; for (var c6 = c5 + 1; c6 <= deckSize; c6++) { var r6 = evaluator[r5 + c6]; for (var c7 = c6 + 1; c7 <= deckSize; c7++) { var r7 = evaluator[r6 + c7]; freq[r7 >> 12]++; } } } } } } } var finish = Date.now(); var total = 0; for (var key = 0; key < hands.length; key++) { total += freq[key]; console.log(hands[key] + ': ' + freq[key]); } console.log('Total: ' + total); console.log((finish - start) + 'ms'); }