How to make memory use minimal and most efficient when iOS optimizes copying large files

I also struggle for a few days, I want to think of a way, but the data can not be copied up, I do not understand, if someone knows where I was wrong, please leave a message, if there is a better way, please share common progress.

________________________________________ copying files with an input stream

This is the path to my original picture.

NSString *path=[nshomedirectory () stringbyappendingpathcomponent:@ "2238-110h514215143.jpg"];

Nserror *error;

This is the path where I want to copy the picture.

NSString *path1=[nshomedirectory () stringbyappendingpathcomponent:@ "movies/2238-110h514215143oooo.jpg"];

NSLog (@ "%@", Path1);

Create a File object

Nsfilemanager *filemanager=[nsfilemanager Defaultmanager];

Create an empty file ready to write to the data

BOOL Success=[filemanager createfileatpath:path1 Contents:nil Attributes:nil];

if (success) {

NSLog (@ "Copy file succeeded");

}

Gets the properties of the copied file all

Nsdictionary *dictionary=[filemanager Attributesofitematpath:path error:&error];

Get the size of a file

NSNumber *number=[dictionary Objectforkey:nsfilesize];

Long long a=[number longlongvalue];

Preparing for reading and writing

Nsfilehandle *filehandle=[nsfilehandle Filehandleforreadingatpath:path];

Nsfilehandle *filehandle=[nsfilehandle Filehandleforwritingatpath:path1];

Nsmutabledata *data1;

How to implement Read 5000 byte write 5000 bytes

For (long long l=0; l<=a;) {

for (int i=0; i<=5000;i++) {

NSData *data2=[filehandle Readdataoflength:l]; That's what I'm thinking, but it's not working.

[Data1 APPENDDATA:DATA2];

l++;

//        }

[FileHandle writedata:data1];

//        }

while (a) {

NSData *data;

if (a<5000) {

If the file is less than 5000 bytes is copied directly

Data=[filehandle Readdatatoendoffile];

[FileHandle Writedata:data];

}else{

This is read from beginning to end 5000 bytes

Data=[filehandle readdataoflength:5000];

[FileHandle Writedata:data];

A minus is 5000 bytes from the beginning, which is exactly what's left when a is 0.

a-=5000;

}

}

[FileHandle CloseFile];

[FileHandle CloseFile];

return 0;

}

}

How to make memory use minimal and most efficient when iOS optimizes copying large files