Async server to serve request for calculation infix expressions

Server serves requests, replies asynchroniously using boost asio on tcp port. https://www.boost.org/doc/libs/1_66_0/doc/html/boost_asio.html Requests processing is done using pool of workers. Data transmitted by chunks and connection isn't closed after getting reply. So client can stay online and send experssions interactively. Experssions are splitted by new line character ('\n') and are processed sequently for client. In the meantime sending results to clients is done as soon as result calculated by workers. Results are separated using '\n' character. Infix expression is processed using shunting yard algorithm by Edsgner Dijkstra to reverse polish notation https://en.wikipedia.org/wiki/Shunting-yard_algorithm https://en.wikipedia.org/wiki/Polish_notation There are also function for calculation expression using standart linux calc tool bc for debug and testing purposes.

Building

$ mkdir build .
$ cd build
$ cmake ..
$ make
$ make test
$ ls
libnet_calc_lib.a net-calc calculator_gtest generate-expression

linux thirdparties

sudo apt-get install libgtest-dev libboost-dev libboost-system-dev cmake g++
#sudo apt-get install netcat 

Build gtest >= 1.8

$ sudo apt-get install gtest-dev cmake
$ cd /usr/src/gtest
$ sudo cmake CMakeLists.txt
$ sudo make
$ sudo make install

mac thirdparties

brew install --HEAD https://gist.githubusercontent.com/Kronuz/96ac10fbd8472eb1e7566d740c4034f8/raw/gtest.rb
brew install boost

Running

$ ./net-calc 127.0.0.1 9090 2

Using

$ echo "(3+ 2*4) * 7" | nc 127.0.0.1 9090

Benchmarking

$ ./generate-expression 1000000000 > expression_bench.txt
#some versions of nc doesn't send EOF
$ nc 127.0.0.1 9090 < expression_bench.txt

Profiling

HotSpots

Using valgrind callgrind, valgrind generates report,

$ sudo apt-get install valgrind
$ valgrind --tool=callgrind  --dump-instr=yes --dump-line=yes --collect-jumps=yes build/net-calc 127.0.0.1 9090
# sudo apt-get install qcachegrind
$ qcachegrind 

Memory

Using valgrind massif

$ sudo apt-get install valgrind
$ valgrind --tool=massif build/net-calc 127.0.0.1 9090
# sudo apt-get install massif-visualizer
# sudo add-apt-repository ppa:kubuntu-ppa/backports 
# sudo apt-get update
# sudo apt-get install massif-visualizer
$ massif-visualizer

TODO

• Check overflow values
• support brackets in generate test expression tool
• check devision by zero
• extend errors descriptions
• fix using memory