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Compare the date parsing performance of NSDateFormatter against SQLite's date parser for parsing an iOS 8601 date.
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#import <Foundation/Foundation.h> | |
#import "sqlite3.h" | |
typedef int64_t timestamp; | |
NSUInteger randomNumberInRange(NSUInteger start, NSUInteger end); | |
// Create a sample date using the ISO-8601 format. | |
// 2013-04-23T16:29:05Z | |
NSString* generateSampleDate(); | |
// Create an array of <count> dates in the ISO-8601 format. | |
NSArray* generateSampleDates(NSUInteger count); | |
// Parse all given dates using SQLite's strftime function | |
void parseDatesUsingSQLite(NSArray *dates); | |
// Parse all given dates using NSDateFormatter | |
void parseDatesUsingNSDateFormatter(NSArray *dates); | |
static NSDateFormatter *dateFormatter = nil; | |
int main() | |
{ | |
@autoreleasepool | |
{ | |
const NSUInteger count = 1000000; | |
NSArray *dates = generateSampleDates(count); | |
NSDate *start = nil; | |
NSDate *end = nil; | |
start = [NSDate date]; | |
parseDatesUsingNSDateFormatter(dates); | |
end = [NSDate date]; | |
printf("NSDateFormatter took %4.3f seconds\n", [end timeIntervalSinceDate:start]); | |
start = [NSDate date]; | |
parseDatesUsingSQLite(dates); | |
end = [NSDate date]; | |
printf("sqlite3 took %4.3f seconds\n", [end timeIntervalSinceDate:start]); | |
} | |
return 0; | |
} | |
NSArray* generateSampleDates(NSUInteger count) | |
{ | |
NSMutableArray *dates = [NSMutableArray array]; | |
for (int i = 0; i < count; i++) | |
{ | |
[dates addObject:generateSampleDate()]; | |
} | |
return dates; | |
} | |
NSString* generateSampleDate() | |
{ | |
NSUInteger year = randomNumberInRange(1980, 2013); | |
NSUInteger month = randomNumberInRange(1, 12); | |
NSUInteger date = randomNumberInRange(1, 28); | |
NSUInteger hour = randomNumberInRange(0, 23); | |
NSUInteger minute = randomNumberInRange(0, 59); | |
NSUInteger second = randomNumberInRange(0, 59); | |
NSString *dateString = [NSString stringWithFormat:@"%lu-%02lu-%02luT%02lu:%02lu:%02luZ", | |
year, | |
month, | |
date, | |
hour, | |
minute, | |
second | |
]; | |
return dateString; | |
} | |
void parseDatesUsingSQLite(NSArray *dates) | |
{ | |
sqlite3 *db = NULL; | |
sqlite3_open(":memory:", &db); | |
sqlite3_stmt *statement = NULL; | |
sqlite3_prepare_v2(db, "SELECT strftime('%s', ?);", -1, &statement, NULL); | |
for (NSString *dateString in dates) | |
{ | |
sqlite3_bind_text(statement, 1, [dateString UTF8String], -1, SQLITE_STATIC); | |
sqlite3_step(statement); | |
timestamp value = sqlite3_column_int64(statement, 0); | |
NSDate *date = [NSDate dateWithTimeIntervalSince1970:value]; | |
sqlite3_clear_bindings(statement); | |
sqlite3_reset(statement); | |
} | |
} | |
void parseDatesUsingNSDateFormatter(NSArray *dates) | |
{ | |
if (dateFormatter == nil) | |
{ | |
dateFormatter = [[NSDateFormatter alloc] init]; | |
[dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"]; | |
[dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]]; | |
} | |
for (NSString *dateString in dates) | |
{ | |
NSDate *date = [dateFormatter dateFromString:dateString]; | |
} | |
} | |
NSUInteger randomNumberInRange(NSUInteger start, NSUInteger end) | |
{ | |
NSUInteger span = end - start; | |
return start + arc4random_uniform(span); | |
} |
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Hi Anurag,
I have gone through your demo example code,
With few veriation i have made changes but it now working some how this return "SQL Date:1970-01-01 00:00:00 +0000"
Problem1
date:2015-06-26 06:43:41 +0000 dateFormat:MMM dd, yyyy hh:mm a
Result date:Jun 26, 2015 12:13 PM
i have made changes in the code
Problem2
timeZone:GMT date:2015-06-26 06:45:19 +0000 dateFormat:yyyy-MM-dd HH:mm:ss
Result date:2015-06-26 06:45:19
How to pass timezone to SQLite API and convert input time string to resultant date?
Please help