My Windows 10 PC started to glitch a little bit and I scanned its disks with the following commands:
chkdsk C: /f /r /x
The type of the file system is NTFS.
Cannot lock current drive.
Chkdsk cannot run because the volume is in use by another
process. Would you like to schedule this volume to be
checked the next time the system restarts? (Y/N) y
This volume will be checked the next time the system restarts.
I did a quick Google search on “SQLite performance” and found the following:
Then to benchmark SQLite performance by myself I used the following C++ code that inserts 1000 batches of 1000 000 rows to a single table with an integer primary key:
(more…)I keep working on my Lines Game and probably I try to make it the best Lines Game in the world, but there is some disappointing incident that prevents it from being the best and makes it a usual game that glitches a bit. To see the glitch in action download the beta version of the game.
Adding Interstitial Ads to a QT application on Android platform is an interesting and relatively exciting job. I learned the following facts while doing it:
The code below demonstrates how to parse GUID in C++ using a regular expression:
#include <iostream>
#include <string>
#include <regex>
int main()
{
static const std::wregex regex(L"[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}");
std::wstring sample = L"850fe1da-0ea6-c1a8-9810-0c1cece30698";
std::match_results<std::wstring::const_iterator> match;
if (std::regex_match(sample, match, regex))
{
std::wcout << L"matches" << std::endl;
}
else
{
std::wcout << L"does not match" << std::endl;
}
return 0;
}
For example, std::forward comes to play if I implement a template container with two ‘insert‘ function overloads that take the parameters of type const T & and T && respectively. I implement all the private insertion logic with T&&, but when I need to know the original value type passed to ‘insert‘ method I use std::forward as shown in the example below:
#include <iostream>
#include <string>
class Value
{
public:
Value(const char * sz) : m_s(sz)
{
}
Value(const Value & other) : m_s(other.m_s)
{
std::cout << "copy constructor: " << m_s << std::endl;
}
Value(Value && other) : m_s(std::move(other.m_s))
{
std::cout << "move constructor: " << m_s << std::endl;
}
const std::string & ToString() const
{
return m_s;
}
private:
std::string m_s;
};
QT does not work with OpenSSL 1.0 anymore. Versions QT 5.12.4 and above require OpenSSL 1.1, but fortunately OpenSSL 1.1 can be easily compiled with MS2017 as follows:
set PATH=%PATH%;C:\Perl64\bin
set PATH=%PATH%;C:\PFiles\nasm-2.14.02-win64
perl Configure VC-WIN64A
nmake
The key to the success is using ‘VS2017 x64 Native Tools Command Prompt‘, but not ‘VS2017 Developer Command Prompt’.
To make QT use OpenSSL, two dlls
libcrypto-1_1-x64.dll
libssl-1_1-x64.dll
should be copied to QT binary directory, for example, C:\Qt\Qt5.13.0\5.13.0\msvc2017_64\bin
Below I provided the results of two following queries:
SELECT USERNAME, USER_ID FROM DBA_USERS ORDER BY USER_ID DESC;
SELECT ROLE, ROLE_ID FROM DBA_ROLES ORDER BY ROLE_ID DESC;
that display Oracle Database 18 users, roles and their IDs:
(more…)First, check MySQL version:
SHOW VARIABLES LIKE "%version%";
+-------------------------+-------------------------+
| Variable_name | Value |
+-------------------------+-------------------------+
| innodb_version | 5.7.25 |
| protocol_version | 10 |
| slave_type_conversions | |
| tls_version | TLSv1,TLSv1.1 |
| version | 5.7.25-0ubuntu0.16.04.2 |
| version_comment | (Ubuntu) |
| version_compile_machine | x86_64 |
| version_compile_os | Linux |
+-------------------------+-------------------------+
The string representation of a type is implementation defined in C++, for example the following code produce the different output with MSVC, GCC and CLang:
#include <string>
#include <iostream>
struct A {};
class B {};
namespace ns
{
struct X {};
}
int main()
{
std::cout << typeid(A).name() << ", " << typeid(B).name() << ", " << typeid(ns::X).name() << ", " << typeid(std::string).name() << std::endl;
return 0;
}
