I have a function that calculates the next frame in an animation of various objects moving in both X and Y axis [ I call it frameRender() ] and a function that applies that resulting frame to the objects [ I call that frameDisplay() ]. The objects don't just move from point A to B, they move constantly, always receiving new target coords...
Hi, Initially I would like to ask you to forget about hashing passwords or w/e related to passwords, this question is not related to securing passwords, etc and I do know/understand how this should be done. What is the best approach to store the data in question, considering performance on read/write - to build one or more tables? Sin...
hello. I have ran into curious problem. Algorithm I working on consist of lots of computations like this q = x(0)*y(0)*z(0) + x(1)*y(1)*z(1) + ... where the length of summation is between 4 and 7 The original computations are all done using 64-bit precision. For experimentation, I try using 32-bit precision for x,y,z input values (...
I'm doing some load testing on a web app deployed in JBoss. It starts up fine, but as the test ramps up and more simulated users start hitting JBoss, performance degrades severely: Connecting VisualVM to it, I can see the threads were all fine, then suddenly started spending most of their time waiting for a monitor (green is running, ...
Hi, I have a pretty big web site (asp.net web) and I have used JavaScript intensively (jquery,custom javascipt, etc) and also The theme and CSS. Right now I have a huge amount of js and css files in my system and I am thinking about minifying and smashing the js and css to improve the performance. So, please advice me the suitable too...
Hello All, My Clients are Complaining for slow speed of my osCommerce Website.. I dont have the basic idea to check out for the speed down of my website.. What could be the issue in this matter? Could Anybody guide me regarding this... ...
I've started doing my own "struct of arrays" coding, but wondered if anyone knew of libs or templates that were already out there for doing intense data transform stuff on memory constrained hardware. I suppose what I'm looking for is a sort of "in memory" container that allows me to queue up insertions until a sync point, and mid itera...
Many sites appear to only download images or generate parts of the document (eg for reviews) when the user scrolls far enough down the page to actually see them. This obviously will give you faster loading pages and save on bandwidth for anyone that does not bother scrolling down. How is this done, ideally with jquery? Or to ask it ano...
Hello, I'm having hard time to decide between the following two implementations. I want to cache the javax.xml.parsers.DocumentBuilder object, per thread. My main concern is runtime performance - Hench I would be happy to avoid as much GC as possible. Memory is not an issue. I've written two POC implementations, and would be happy to ...
I set up a (perhaps very unscientific) small test to determine the overhead of virtual functions in a one-level single inheritance and the results I got were, well, exactly the same when accessing the derived class polymorphically or when accessing it directly. What was a bit surprising was the order of magnitude of computation time that...
What kind of ideas or tips and tricks do you have in order to boost PHP performance. Something like, I use: $str = 'my string'; if(isset($str[3]) Instead of: if(strlen($str) > 3) Which is a bit faster. Or storing values as keys instead of vars in array, makes searching if key exists much faster. Hence using isset($arr[$key]...
I want to use http streaming (ie. partial download) to serve some videos (medium to HD quality) to public. Idea is to have videos on server and offer some web page with embedded video player for user to watch selected video. Planned capacity is about 250 to 1000 daily views, with low concurrency requirement (ie. not many users in para...
We're developing a Java web app that utilizes JSF (Richfaces through Seam) for its UI. I've read several articles that indicate that using the "rendered=" attribute on UI components results in a pretty substantial performance hit. We have several components that we'd like to enable or disable based on whether or not their values are se...
In an effort to better understand the JavaScript and DOM performance of Mobile Safari, I was trying to run the Dromaeo JavaScript performance tests on an iPad. However, part way through the tests, Safari will crash and I am sent back to the home screen. I first tried to run all the Performance Tests and crashed either toward the end of...
I have a request to install a Linux server (preferably Ubuntu 64bit server), and Java (64 bit) on the following machine: Intel Core2Quad Q8200 - 2.33 GHz 8gb DDR2 ram 2x 320GB SATA HDD in soft RAID1 mirror (mirror) The problem is how to configure system and Java because I need JVM to use more than 4gb of memory. It cannot be di...
I have a curious little problem. I have a service that needs to create 2000 records in the database, minimum on various tables. While it would be nice to have them run in the same transaction, the performance gets to be really bad around 400-600 inserts. For some reason, the inserts go slower and slower. I suppose that Hibernate needs t...
hello. My problem is, I have block matrix updated by multiple threads. Multiple threads may be updating disjoint block at a time but in general there may be race conditions. right now matrix is locked using single lock. The question is, is it possible (and if it is, how?) to implement an efficient array of locks, so that only portions...
The reason I am asking this question is because we are planning to read A LOT (several GB's) of data from a SQL Server database to a .Net app for processing. I would like to know how much space overhead to calculate for each record for estimating the impact on our network traffic. E.g. a record consists of 5 integers (which makes 4 * 5...
Hi, Currently I'm building an application that is an image filter that should run in real-time. It's filter that transforms image captured from the camera and displays a transformed image just like the camera preview does. The problem that I'm having with this is that, the performance is critical to this app, as every captured pixel sh...
My demo is here. Basically, I have a HUGE image (19160px × 512px to be exact, just under 2MB) that I transition the backgroundx using javascript to make it appear as if a transformation was happening. I cannot compress the image much more without ruining its quality dramatically. Is there another way that I can achieve this with the sa...