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ZipArchive memory issues on iPhone for large archive

I am trying to compress multiple files into one ZIP archive and I am running low memory warning. Since the full zip file is loaded into memory, I think that is the problem. Is there a way that I can better manage the compression / decompression with ZipArchive so that not all of the data is in memory at once?

Thanks!

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After doing some research on ZipArchive alternatives, I found another project called Objective-zip that seems to be slightly better than ZipArchive. Here's a link:

http://code.google.com/p/objective-zip/

The API is pretty simple. One thing I ran into was that in begging, I was reading data and never releasing it, so if you add large files to the zip file remember to release the data. Here's the little code I used:



ZipFile * zipFile = [[ZipFile alloc] initWithFileName: archivePath mode: ZipFileModeCreate];

for (NSString * path in subpaths) {
  NSData * data = [[NSData alloc] initWithContentsOfFile: longPath];
  ZipWriteStream * stream = [zipFile writeFileInZipWithName: path compressionLevel: ZipCompressionLevelNone];
  [stream writeData: data];
  [stream finishedWriting];
  [data release];
}

[zipFile close];
[zipFile release];

I hope this is helpful for anyone else who is facing the same problem.

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An easier way to deal with this is to simply change the ZipArchive method to read the file into NSData. Just change the following code

data = [ NSData dataWithContentsOfFile:file ];

to



data = [ NSData dataWithContentsOfMappedFile:file ];

This will force the OS to read the file as a card. Basically it just uses less memory as it reads from the file as it needs to rather than load it into memory right away.

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