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POIncreasing performance of loops
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  1. POIncreasing performance of loops
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    copied!<p>I'm currently working on a script that helps to manage connections to phone numbers with different things like contacts, text messages, etc. The big problem with phone numbers in our data is that a phone number can be something like..</p> <pre><code>13334445555 3334445555 013334445555 444555 </code></pre> <p>All of these would probably be the same number. So, I've got a 'lookupNumber' method on an object that contains all sorts of references (none of which are important for this question), and a hasVariant method on each 'cloud' - a name that I gave to an object that represents one or more variations of a phone number. The 'cloud' could start off with a shorter number than the ones given to it, so it has to be able to vary which number it is trying to place.</p> <p>The object with all the 'clouds' has a relevant data structure of:</p> <pre><code>{ clouds: [], //0-n clouds phoneNumberCache: {} //i.e. 333444555: {//ref to cloud} } </code></pre> <p>The 'clouds' have the relevant data structure of:</p> <pre><code>{ numbers: [] //1-n numbers } </code></pre> <p>lookupNumber method:</p> <pre><code>lookupNumber: function (number) { if(this.phoneNumberCache[number] === undefined) { var i, l, cloud; for (i = 0, l = this.clouds.length; i &lt; l; i++) { cloud = this.clouds[i]; if(cloud.hasVariant(number)) { this.phoneNumberCache[number] = cloud; return cloud; } } return false; } else { return this.phoneNumberCache[number]; } } </code></pre> <p>hasVariant method:</p> <pre><code>hasVariant: function (testNumber) { for(var i = 0, l = this.numbers.length; i &lt; l; i++) { var number = this.numbers[i], needle, haystack, index, needleLength, haystackLength; if(testNumber.length &lt; number.length) { needle = testNumber; haystack = number; } else { needle = number; haystack = testNumber; } needleLength = needle.length; haystackLength = haystack.length; if(needleLength &lt;= this.minimumLength &amp;&amp; haystackLength != needleLength) { continue; } index = haystack.indexOf(needle); if(index != -1 &amp;&amp; (index + needleLength) == haystackLength &amp;&amp; (needleLength / haystackLength) &gt; this.minimumMatch) { return true; } } return false; } </code></pre> <p>On my testing account, the performance is 'meh' on firefox and terrible on IE8 (the minimum IE browser we support). Firebug is reporting the following times for the two methods:</p> <pre><code>Function Calls Percent Own Time Time Avg Min Max hasVariant 1355484 32.1% 1653.577ms 1653.577ms 0.001ms 0.001ms 0.205ms lookupNumber 2120 31.17% 1605.947ms 3259.524ms 1.538ms 0.001ms 4.736ms </code></pre> <p>The test data has 1674 unique phone numbers in it - about 450 of the 'lookupNumber' calls are going to return an already cached number. </p> <p>Maybe I've been staring at the data too long, but it seems the number of times the 'hasVariant' gets called is way too high and they're both such simple methods.. I can't think of any way to make them faster. Because it's still very slow on IE, I'm still looking for a way to squeeze some more performance out of it. Any ideas on how to make this more efficient? Or do I have a bug in here that might be causing this to not cache a number?</p>
 

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