CODEWITHSUNDEEP
iphoneiosfile-ionsfilemanagerfseek
Nikita P
Nikita P

Reputation: 4246

Is there any way in NSFileManager to get contents of a file only for some range of bytes

I have some files that are of size 6.7GB, and more (these are video files). I want to get chunks of file data to send to my server, so what I currently do is :

contents = [fileManager contentsAtPath:path];
if (mFileOffset<[contents length]) {
NSRange range = NSMakeRange(mFileOffset, (allowedSize>[contents length]?[contents length]:allowedSize);
contents =[contents subdataWithRange:range];

However, this produces a memory issue:

malloc: *** mmap(size=616927232) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug
APP(2700,0x4136000) malloc: *** mmap(size=616927232) failed (error code=12)
*** error: can't allocate region

Is there a way like fseek in c++ so that I read bytes of the file that come in the specified range only?

Upvotes: 0

Views: 486

Answers (2)

Anoop Vaidya
Anoop Vaidya

Reputation: 46543

There is a method in NSFileHandle which synchronously reads data up to the specified number of bytes.

-[NSFileHandle readDataOfLength:]

For seeking :

– offsetInFile
– seekToEndOfFile
– seekToFileOffset:

Upvotes: 3

Sulthan
Sulthan

Reputation: 130102

fseek is not C++, it's a C function. The same function is available in Obj-C.

Note that Obj-C is only a layer over C and every valid C code is also a valid Obj-C code.

The file functions are also abstracted into an Obj-C class NSFileHandle. However, this class has exactly the same functionality as fopen, fseek, fclose etc.

Upvotes: 2

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