iPad中大量数据出现崩溃问题

Question

I am working on the app in which large amount of data (eg 30K dictionary in array) is received through web service. I am using JSON kit for parsing this large amount of data. After getting response, i will store this data into plist file(because i want to run app in offline mode).

After that i am accessing this data using NSMutableArray(with 30K dictionary). Now for further calculation i am using this array and use this loop 7- 8 times for calculation to draw the Graph.

//path = path from which i access the plist

NSMutableArray *array = [[NSMutableDictionary alloc] initWithContentsOfFile: path];

//where array contains about 30K dictionaries.

for(int i=0; i<[array count]; i++) {

    // some calculation formula
}

same loop is called 7-8 times after executing the above loop.

My app is crashing after i read the data from plist due to memory issue. Please help me to solve the problem.

Answer 1

As your issue is memory related you have to free the memory asap. I assume that you are using ARC with iOS 6.0. Try using the loop inside the @autoreleasepool and see if that makes any difference. You can also use nested @autoreleasepool if you need.

for(int i=0; i<[array count]; i++) {
   @autoreleasepool {
       // calculation formula
    }
}

Old way;

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
for(int i=0; i<[array count]; i++) {
       // calculation formula
}
[pool drain];