PHP string concatenation speed
Something I have always wondered is the speed difference between concatenation strings with in-string variables verses the . operator. I've always assumed . would be much faster, and today I found out.
$amount = 0x1FFFF; $start = microtime(true); while ($amount--) $throwAway = "this is a test at the $amount point!"; //$throwAway = "this is a test at the ". $amount ." point!"; echo "Time: ". (microtime(true) - $start);
Exactly as expected, leaving it up to in-string parsing of variables ended up with a bench mark time of 0.1574 and manually concatenating in the variable was 0.1384, which is not a huge difference, but I wanted to see how this would scale when doing multiple concatenations. The string was changed to $throwAway = "this is ". $amount ." a test ". $amount ." at the ". $amount ." point!"; and it's respective in-string.
What I found is that it actually scales to in-string far better! In-string averaged to 0.3235 and manual to 0.3597. After some research it turns out this is because it does a single large concatenation while manually doing it could perform the operation 3 separate times.
PHP Array Performance
Index Checking
The functional difference between array_key_exists($key, $array) and isset($array[$key]) is that isset returns false when the key exists but contains null. Functionality aside, there is a demonstrable performance difference.
$dataSet = array(); $size = 0x1FFFF; $i = $size; while ($i--) $dataSet[$i] = $i+1; $start = microtime(true); $i = $size; while ($i--) array_key_exists($i, $dataSet); //isset($dataSet[$i]); echo "Time: ". (microtime(true) - $start);
Sure enough, after averaging a few benchmarks together the outcome was clear.
- isset
- 0.0248870849609
- array_key_exists
- 0.604112148285
When performance is important target isset() when applicable. It's even possible to use a fall through to increase performance, here's an example from my Options class: if (!isset($this->_options[$resolvedName]) && !array_key_exists($resolvedName, $this->_options))
Append Performance
In the following test case there was no performance difference between usage of append or directly addressing an index.
$dataSet = array(); $size = 0x1FFFF; $i = $size; $start = microtime(true); while ($i--) $dataSet[] = $i+1; //$dataSet[$i] = $i+1; echo "Time: ". (microtime(true) - $start);
Remodeling PHP’s compact()/extract() into an OO Pattern
A common usage, at least for extract(), has been to allow an associative array to be passed to a function for use as named optional parameters, however, there is a lot wrong with dumping an array into the symbol table and then checking if what you want exists or not.
I have designed a pattern that allows an object to accept and address public level optional named arguments without the problems that could be associated with the compact()/extract() pattern. This pattern does require at least PHP 5.3 (uses late static binding) and overloads __get/__set preventing the child class from doing so.
Queryable Food Nutrition Database
The USDA releases data for food nutritional information. I've taken this data and loaded it into my local database, and created a front end to allow it to be queryable.
Database Schema
Message Hasher
A small web-based message hasher, good for generating hashes of small amounts of text. No binary support yet, but it's planned via file uploads!
GraphicsPath Front – Vector drawing software
GraphicsPath Front is vector drawing software based upon the GraphicsPath .net class.
Download (source and binaries) — Execute \bin\debug\GraphicsPathFront.exe or compile from source.
Some of the notable features include:
- Save/load vectorized graphics, or save in numerous rasterized formats.
- Configurable and snap-to'able grid.
- Live preview of what's being drawn, including rendering in real-time.
- The ability to render as mouse input. (Need to see the videos to understand!)
There are several limitations in this program due to the limits of the underlying GraphicsPath class. Though the code is in place to do so, nodes can not be directly edited once created, for example. Nor can different paths be drawn using different pens.
Boggle.exe
Boggle.exe is a computerized version of the Hasbro dice game. It's intended to be played by multiple people infront of the computer using pens and paper, no internet play is supported as it's ridiculously easy to cheat. The main neat feature of Boggle.exe over it's physical counterpart is a board solver. Once the game is over, all of the valid words inside of the board are shown and can be highlighted (see picture).
Download (source and executable) — Extract to it's own directory and run \bin\debug\Boggle.exe. words.txt must be in the same directory as the executable.
Installing Windows 7 from and to the same hard drive
The reason why is pretty simple, DVDs are not remotely as fast as any other media, and in 2009, it's starting to show. Flash drives are larger, faster, and more versatile than DVDs, and they're costing less and less. But what about an older system that can not boot from USB storage? Well, there is an option, and that's to use the destination drive as the source. Install the drive into a separate computer (via a usb dongle is fine) and follow these steps. Note that these directions work if you're trying to make a bootable USB flash drive, too.
Replacing an Inspiron 1525 LCD video
Simple step by step guide to replacing the LCD on a Dell Inspiron 1525 laptop.
Hacking Windows XP PowerToy Calculator to run in Vista/Windows 7
This was more of a project than I was originally expecting, Microsoft prevents the Windows XP Powertoy Calculator from running in Vista or Windows 7 in 2 separate places, but in the end, it runs perfectly in Vista, all the limitations are false.
Don't feel like doing this yourself? No need! 