cocos2d frame rate lag on dictionary creation and search - objective-c

Question

I am trying to create a create a simple iPhone game that would throughout the course of running be doing multiple checks to see if user input was a real word. I have a 1.7mb text file (is this a reasonable size?) with each word on its own line containing all of the words in the english language. This is the code that runs in the init method of the game scene. correctWords is an array that will contain all of the users verified word guesses. This code parses through the text file and puts all of the words into an array called currentDict:
correctWords = [[NSMutableArray alloc] init];
//set where to get the dictionary from
NSString *filePath = [[NSBundle mainBundle] pathForResource: [NSString stringWithFormat: #"dictionary"] ofType:#"txt"];
//pull the content from the file into memory
NSData* data = [NSData dataWithContentsOfFile:filePath];
//convert the bytes from the file into a string
NSString* string = [[[NSString alloc] initWithBytes:[data bytes]
length:[data length]
encoding:NSUTF8StringEncoding] autorelease];
//split the string around newline characters to create an array
NSString* delimiter = #"\n";
currentDict = [string componentsSeparatedByString:delimiter];
[currentDict retain];
and then to verify if the word the user inputs is in fact a word I have this check
if([currentDict containsObject: userInput]){
Whenever the game scene loads, there is a very noticeable delay (3-4 seconds) on the device itself, although there it happens almost instantly in the simulator, and then also I have animations running throughout most of the game, but whenever it tries to verify a word, there is a slight but noticeable lag in the animations. I am just wondering if there is a better way to get the dictionary loaded into memory, or if there is some kind of standard practice for verifying words. Also why would checking if it is a word cause a lag in the animation? I had assumed the animation was part of its own thread (and thus would theoretically not be affected)

Answer 1

I would recommend an alternative approach. I don't know how your game works, but it might make sense to give the player a limited set of possible word choices, for example something like Draw Something where there are only so many words you could type; then you would test against far fewer. Before the scene loads, you can have the set of possible words selected from your dictionary then provide letters or options (whatever your game is going) that only allows the user to come up with words that are in that set. Then you can test against a small set.
Another option is to repeat what I've said above frequently throughout your level, so the amount of available words are constantly changing, but load that set periodically when you're not in the middle of an animation or whatever. If there is a brief pause in the game play as the level gets harder, then load new words, or something similar.
That way the real-time game play is not affected by a large dictionary but you can still offer many options throughout the gameplay.

Answer 2

Nothing surprising that comparing thousands of string takes some time and causes lag in animation. You should something read about binary search, hashing, etc. Also loading entire file into NSString and then splitting it is very slow. Your code is just awful, sorry.