My other works

http://leverdeterre.github.io

PermissiveResearch

An iOS search engine that allows mistakes in the searched element in huge data. Many developpers would have executed a fectch request on a CoreData database or a predicate to filter on a NSArray.

PermissiveResearch is a alternative to simplify the search step. Advantages : - No more problems with CoreData (context/thread), - Performances, - 100% resusable for each projects that need to perform analysis in huge data, - Search algorithm are easy customizable, - 3 algorithms already implemented,

Performances (on iphone4, searchig in 5000 objects 4 properties)

| Type of search | time (ms) | data structure | | ------------- |:-------------:| -------------| | Exact search | 200 | Using predicates | | Exact search | 2800 | Using PermissiveResearch (ExactScoringOperation) | | Exact search | 100 | Using PermissiveResearch (HeuristicScoringOperation) | | Exact search | 700 | Using PermissiveResearch (HeurexactScoringOperation) | | Tolerated search | impossible.. | Using predicates | | Tolerated search | 2800 | Using PermissiveResearch (ExactScoringOperation) | | Tolerated search | 100 | Using PermissiveResearch (HeuristicScoringOperation) | | Tolerated search | 700 | Using PermissiveResearch (HeurexactScoringOperation) |

• ExactScoringOperation : Make a complex and total analysis,
• HeuristicScoringOperation : Scan using fragments (default size 3),
• HeurexactScoringOperation : Scan using fragments (default size 3), then make a complex and total analysis of the best pre-selected objects.

Algorithms

It's a custom implementation of the Smith-Waterman algorithm. The purpose of the algorithm is to obtain the optimum local alignment. A similarity matrix is use to tolerate errors.

Shared instance

[[PermissiveResearchDatabase sharedDatabase] setDatasource:self];

Datasource methods to fill your search database

-(void)rebuildDatabase

- (void)addObject:(id)obj forKey:(NSString *)key;
- (void)addObjects:(NSArray *)obj forKey:(NSString *)key;
- (void)addObjects:(NSArray *)objs forKeys:(NSArray *)keys;
- (void)addObjects:(NSArray *)objs forKeyPaths:(NSArray *)KeyPaths;


(void)addManagedObject:(NSManagedObject *)obj forKey:(NSString *)key;

(void)addManagedObjects:(NSArray *)objs forKey:(NSString *)key;

(void)addManagedObjects:(NSArray *)objs forKeys:(NSArray *)keys;

(void)addManagedObjects:(NSArray *)objs forKeyPaths:(NSArray *)KeyPaths;

Example :

///PermissiveResearchDatabase datasource
(void)rebuildDatabase
{
   NSString *jsonPath = [[NSBundle mainBundle] pathForResource:@"data5000"
                                                    ofType:@"json"];
   NSData *data = [NSData dataWithContentsOfFile:jsonPath];
   NSError *error = nil;
   id json = [NSJSONSerialization JSONObjectWithData:data
                                         options:kNilOptions
                                           error:&error];
   [[PermissiveResearchDatabase sharedDatabase] addObjects:json forKeyPaths:@[@"name",@"gender",@"company",@"email"]];
   self.searchedList = json;
}

Datasource method to customize scoring methods

-(NSInteger)customCostForEvent:(ScoringEvent)event

Example (default values) : ```objective-c

   case ScoringEventPerfectMatch:
       return 2;
       break;</p>

    case ScoringEventNotPerfectMatchKeyboardAnalyseHelp:
       return 1;
       break;

   case ScoringEventNotPerfectBecauseOfAccents:
       return 2;
       break;

   case ScoringEventLetterAddition:
       return -1;
       break;

   default:
       break;
}

return NSNotFound;

} ```

Easy search operation using PermissiveResearch delegate

[[PermissiveResearchDatabase sharedDatabase] setDelegate:self];
[[PermissiveResearchDatabase sharedDatabase] searchString:searchedString withOperation:ScoringOperationTypeExact];

#pragma mark PermissiveResearchDelegate
-(void)searchCompletedWithResults:(NSArray *)results
{
    dispatch_async(dispatch_get_main_queue(), ^{
        self.findedElements = results;
        [self.tableView reloadData];
    });
}

Create your first search operation

    [[ScoringOperationQueue mainQueue] cancelAllOperations]
    HeuristicScoringOperation *ope = [[HeuristicScoringOperation alloc] init];
    ope.searchedString = searchedString;

SearchCompletionBlock block = ^(NSArray *results) {
    dispatch_async(dispatch_get_main_queue(), ^{
        self.findedElements = results;
        NSLog(@"finded elements %@", results);
    });
};

[ope setCustomCompletionBlock:block];
[[ScoringOperationQueue mainQueue] addOperation:ope];

Actualy 3 operations are available, usage depends on the performance you need.

Algorithms complexities are very differents. HeuristicScoringOperation < HeurexactScoringOperation << ExactScoringOperation

ExactScoringOperation
HeuristicScoringOperation
HeurexactScoringOperation

TODO

• Tolerate keyboard errors, very proximal letters can be tolerate.