Memory leak in Nested NSDictionary copy sqlite3

liligago · 12-12-2011, 09:03 AM

I have developed an application which used sqlit3 database. I have made a wrapper class, in this wrapper class I have an NSMutableDictionary and NSMutableArray.
Each time a query is run i used removeAllObjects from the dictonary and the array in the wrapper class (I don't release it). I then add the results from the query to the array and dictionary. The dictionary contains another subdictionaries.
I have 2 sub tableViewController, in these classs ,I get data from the database using my wrapper class and copy it to my tableviewcontroller variable,
but when i change the tableViewController, it is cause the leak in memory,

in the
**brandsRecords = [[FairPriceDB getBrandIDs_NSDictionary]copy];**
i marked as ** and bold the memory leak happends

I appreciate if somebody can guide me to improve these classes and solve the memory leak...
Thank you
CustomeViewController.h

Code:

  @interface BrandViewController : UIViewController
<UITableViewDataSource , UITableViewDelegate>
{
    FairPriceDatabaseView *FairPriceDB;
    NSArray *brandsIDs;
    NSMutableDictionary *brandsRecords;
    UITableView *tableView;  
}

CustomeViewController.m

Code:

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self loadBrandsIDs];
    [tableView reloadData];
}
- (void)dealloc {
    [super dealloc];
    if (brandsRecords) [brandsRecords release];
    if (brandsIDs) [brandsIDs release];
    if (FairPriceDB) [FairPriceDB release];
}
-(NSArray *) loadBrandsIDs
{
    if (!FairPriceDB) 
        [self loadBrandsDB];
    if(brandsIDs)
        [brandsIDs release];
    brandsIDs = [[FairPriceDB getBrandIDs]copy];
    if (brandsRecords) 
        [brandsRecords release];
    **brandsRecords = [[FairPriceDB getBrandIDs_NSDictionary]copy];**
    [FairPriceDB release];
    FairPriceDB = nil;
    return brandsIDs;
}
- (FairPriceDatabaseView *) loadBrandsDB {
    if (!FairPriceDB) 
        FairPriceDB = [[FairPriceDatabaseView alloc] initWithFairPriceDatabaseViewFilename:@"b.db"];
    return FairPriceDB;
}

FairPriceDataBaseViewController.h (wrapper class)

Code:

@interface FairPriceDatabaseView {
    NSMutableArray * idList;
    NSMutableDictionary * recordList;
}

FairPriceDataBaseViewController.m (wrapper class)

Code:

- (NSArray *) getBrandIDs {
            NSDictionary * row;
            [idList removeAllObjects];  // reset the array
            for (row in [self getQuery:@"SELECT productID,brandName FROM product GROUP BY brandName;"]) 
                [idList addObject:[row objectForKey:@"productID"]];
            return idList;
        }

        -(NSDictionary *) getBrandIDs_NSDictionary{
            [recordList removeAllObjects];
            [idList removeAllObjects];
            [self getBrandIDs];

            NSNumber * rowid;
            for(rowid in [self idList])
                [recordList setObject:[self getProductRow:rowid]  forKey:rowid];

            return recordList; 
        }
    - (NSDictionary *) getProductRow: (NSNumber *) rowid {
        self.tableName = @"select * from product where productID = ?";
        return [self getRow:rowid];
    }

BrianSlick · 12-12-2011, 09:13 AM

Code:

- (void)dealloc {
    [super dealloc];
    if (brandsRecords) [brandsRecords release];
    if (brandsIDs) [brandsIDs release];
    if (FairPriceDB) [FairPriceDB release];
}

Oh dear lord, learn memory management.

[super dealloc] should always - ALWAYS - be the last thing you do in this method.

And the mere existence of an object does NOT mean that it should be released, so "if (anything) release" is a ridiculous sequence to go through.

Use properties. Start with the link in my signature if you don't know how.

liligago · 12-12-2011, 09:23 AM

Quote:

Originally Posted by BrianSlick

Code:

- (void)dealloc {
    [super dealloc];
    if (brandsRecords) [brandsRecords release];
    if (brandsIDs) [brandsIDs release];
    if (FairPriceDB) [FairPriceDB release];
}

Oh dear lord, learn memory management.

[super dealloc] should always - ALWAYS - be the last thing you do in this method.

And the mere existence of an object does NOT mean that it should be released, so "if (anything) release" is a ridiculous sequence to go through.

Use properties. Start with the link in my signature if you don't know how.

this is my first application, and i have just finished Memory management around 1 hour ago. i admitted it, since after i read the memory management i realized this problem. This is my first program, do you think the other issues are correct or not? i have learnt iphone and objetive-c just through web... i appreciate to guide me if there is any other problem in this design.... Thank You