ios - Getting photos via PHFetchResult extremely slow with lots of photos -


i'm using yangmingshan photo picker, , it's need, i'm running problems when user has lots of photos.

i've been testing on phone 25,000+ photos , 250 albums, , when present view controller, app freezes 30 seconds before collectionview loads.

here's problematic bit of code, , i'm trying figure out if there's more optimal way fetch results. 

- (void)fetchcollections {  nsmutablearray *allablums = [nsmutablearray array];      phfetchresult *smartalbums = [phassetcollection fetchassetcollectionswithtype:phassetcollectiontypesmartalbum subtype:phassetcollectionsubtypealbumregular options:nil];      __block __weak void (^weakfetchalbums)(phfetchresult *collections);     void (^fetchalbums)(phfetchresult *collections);     weakfetchalbums = fetchalbums = ^void(phfetchresult *collections) {         // create fecth options         phfetchoptions *options = [phfetchoptions new];         options.predicate = [nspredicate predicatewithformat:@"mediatype = %d",phassetmediatypeimage];         options.sortdescriptors = @[[nssortdescriptor sortdescriptorwithkey:@"creationdate" ascending:no]];          (phcollection *collection in collections) {             if ([collection iskindofclass:[phassetcollection class]]) {                 phassetcollection *assetcollection = (phassetcollection *)collection;                 phfetchresult *assetsfetchresult = [phasset fetchassetsinassetcollection:assetcollection options:options];                 if (assetsfetchresult.count > 0) {                     [allablums addobject:@{@"collection": assetcollection                                            , @"assets": assetsfetchresult}];                 }             }             else if ([collection iskindofclass:[phcollectionlist class]]) {                 // if there more sub-folders, dig collection fetch albums                 phcollectionlist *collectionlist = (phcollectionlist *)collection;                 phfetchresult *fetchresult = [phcollectionlist fetchcollectionsincollectionlist:(phcollectionlist *)collectionlist options:nil];                 weakfetchalbums(fetchresult);             }         }     };      phfetchresult *toplevelusercollections = [phcollectionlist fetchtoplevelusercollectionswithoptions:nil];     fetchalbums(toplevelusercollections);      (phassetcollection *collection in smartalbums) {         phfetchoptions *options = [phfetchoptions new];         options.predicate = [nspredicate predicatewithformat:@"mediatype = %d",phassetmediatypeimage];         options.sortdescriptors = @[[nssortdescriptor sortdescriptorwithkey:@"creationdate" ascending:no]];         phfetchresult *assetsfetchresult = [phasset fetchassetsinassetcollection:collection options:options];         if (assetsfetchresult.count > 0) {              // put "all photos" in first index             if (collection.assetcollectionsubtype == phassetcollectionsubtypesmartalbumuserlibrary) {                 [allablums insertobject:@{@"collection": collection                                               , @"assets": assetsfetchresult} atindex:0];             }             else {                 [allablums addobject:@{@"collection": collection                                            , @"assets": assetsfetchresult}];             }         }     }     self.collectionitems = [allablums copy]; }


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