Question

I developing an application, in which i working with database manipulation. The method i have written in database class as follows.

-(NSMutableArray *)getData: (NSString *)dbPath{
    NSMutableArray *dataArray = [[NSMutableArray alloc] init];

    if(sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK){
        NSString *sqlQuery = [NSString stringWithFormat:@"SELECT empID, addText FROM Employee WHERE nameID = %@", nameID];
        sqlite3_stmt *selectstmt;
        if(sqlite3_prepare_v2(database, [sqlQuery UTF8String], -1, &selectstmt, NULL) == SQLITE_OK){

           while (sqlite3_step(selectstmt) == SQLITE_ROW){
                [dataArray addObject:[[NSMutableDictionary alloc] init]];

                [[dataArray lastObject] setObject:[NSString 
                                 stringWithFormat:@"%d", sqlite3_column_int(selectstmt, 0)] forKey:@"empID"];

                [[dataArray lastObject] setObject:[NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt,1)] forKey:@"addText"];
            }
        }

        sqlite3_finalize(selectstmt);
    }
    sqlite3_close(database);
    return dataArray;
}

The above code work fine on the simulator but cannot on device.
I also was tracing the memory leaks , in which i founding that memory leak in above method code. But i not able to solve the that memory leak.

Now i also find out memory leak in following method.

• (id)initWithString:(NSString *)str attributes:(NSDictionary *)attributes

{
if ((self = [super init]))
{
_buffer = [str mutableCopy];
_attributes = [NSMutableArray arrayWithObjects:[ZAttributeRun attributeRunWithIndex:0 attributes:attributes], nil];
}
return self;
}

The leak near _buffer = [str mutableCopy];. And leak trace gives me in the output continuous increasing NSCFString string allocation. How i maintain it?

Thanks in advance.

Answer 1

Your inner loop leaks the NSMutableDictionary objects, as you should release them after adding to the array, i.e.

NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
[dict setObject:[NSString  stringWithFormat:@"%d", sqlite3_column_int(selectstmt, 0)] forKey:@"empID"];
[dict setObject:[NSString stringWithUTF8String:(char *)sqlite3_column_text(selectstmt,1)] forKey:@"addText"];
[dataArray addObject:dict];
[dict release];

Also, your whole method should most probably return an autoreleased object by naming convention. Not sure if this is a leak – depends on how you call that method and if you release the returned value.

So maybe use

return [dataArray autorelease];