###Main goal

Speed up the program. Test condition: 4 threads, 512M file.

###Program description

Input file contains constant-size (4096B including null-termitation character) lines of letters add digits. The program swap case for letters and add one to each digit except 9 which turns into 0. Output lines are saved in output file.

##Repo Content

###generate_file.py

Creates input file: input.data (512M by default) ###process_file.py

Does required job. Can be used for consistency check and for comparison c++ and python code performance. ###main.cpp

Source code of c++ soluton ###CMakeLists.txt

File for project building

##Build the project

###Windows

Option 1: Google: how to build cmake project on windows;

Option 2: Create a project in your beloved IDE. Add main.cpp in the project;

Option3: [Download and install Clion IDE] Open CMateLists.txt as a project in Clion.

###Linux

Go to console, cd to project directory, run commands:

mkdir build

cd build

cmake ../

make

You may probably need pthread library to be included

##Tips and tricks

• Get rid of unnecessary data copying including implicit (vector.push_bak, string constructor, copy while passing var s in functions)

• Improve process_line algorithm. Get rid of if-statements, for example.

• Make data distribution per thread more cache-friendly. Data for each thread should lay down in memory in one continuous peace to minimise cache misses.

• Try to map file in memory (linux: mmap() windows: https://docs.microsoft.com/en-us/windows/win32/memory/file-mapping)