ios - Saving and reading objects from plist cause huge memory of 2G -

i have system save lots of images plist , works good, except 2 main problems.

first, when start process ,memory on xcode goes 2g ! (and down when done) second, takes long(10+ seconds 100 images)compared nsuserdefaults, told slower .

i archiving data first.

what doing wrong having memory , slow saving ?

-(void)savetofilewithdata:(nsmutabledictionary*)dic {     nserror *error;     nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);     nsstring *documentsdirectory = [paths objectatindex:0];     nsstring *path = [documentsdirectory stringbyappendingpathcomponent:@"data.plist"];      nsfilemanager *filemanager = [nsfilemanager defaultmanager];      if (![filemanager fileexistsatpath: path])     {          nsstring *bundle = [[nsbundle mainbundle] pathforresource:@"data" oftype:@"plist"];         [filemanager copyitematpath:bundle topath: path error:&error];     }     nsdata *mydata = [nskeyedarchiver archiveddatawithrootobject:dic];     bool sucess=[mydata writetofile:path atomically:yes];     if(sucess)         nslog(@"saved:%lu",(unsigned long)[mydata length]);     else         nslog(@"failed:%lu",[mydata length]);       mydata=nil;  } 

the reading :

-(nsmutabledictionary*)readfromfile {     nserror *error;     nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes); //1     nsstring *documentsdirectory = [paths objectatindex:0]; //2     nsstring *path = [documentsdirectory stringbyappendingpathcomponent:@"data.plist"]; //3      nsfilemanager *filemanager = [nsfilemanager defaultmanager];      if (![filemanager fileexistsatpath: path]) //4     {         nsstring *bundle = [[nsbundle mainbundle] pathforresource:@"data" oftype:@"plist"]; //5         [filemanager copyitematpath:bundle topath: path error:&error]; //6     }     nsmutabledictionary *dic = [[ nsmutabledictionary alloc] init];     nsdata *serialized = [nsdata datawithcontentsoffile:path];       //check first if file exist, if has content(empty file had 42 bytes-and crashes archiver)     if ([[nsfilemanager defaultmanager] fileexistsatpath:path] && [serialized length]>1000000)        dic = (nsmutabledictionary*) [nskeyedunarchiver unarchiveobjectwithdata:serialized];       serialized=nil;     return dic;   } 

use them :

nsmutabledictionary *dic =   [[nsmutabledictionary alloc] init];     dic = [self readfromfile];    //change dic [self savetofilewithdata:dic]; 

there no reason copy plist app bundle documents directory read it.

a plist not solution, in case huge put images individual files , image file names in plist. read small plist , rest images 1 one. reading each file individually uses smaller amount of memory.

but, want 500mb of images in memory @ once? after having read plist of image information read images needed, perhaps cache purges images based on usage.