Simple Robots Database

Simple one-table remote database that can store robots. Made during GlobalLogic C++ practice.

Installation

Dependencies: libjsoncpp, libzmq

On Ubuntu:

apt-get install libjsoncpp-dev libzmq3-dev

On Arch:

pacman -S jsoncpp zeromq

After installing dependencies, run:

git clone https://github.com/ly0va/GL-robots-db.git
cd GL-robots-db
mkdir build
cd build
cmake ..
cmake --build .

Usage

Server

To start, run ./server [port]. Default port is 31111.

Client

To use, run ./client [host] [port]. Default host is localhost, default port is 31111.

Using client, you can add/remove/update/find robots in the database. Robot is defined as:

struct Robot {
    int price;
    float weight;
    std::string name;
};

// Examples
Robot bumblebee = {100500, 3.1415, "Bumblebee"};
Robot bender = {18, 2.71828, "Bender"};

Efficiency

Let S be the size of the entry, and T be the total size of the database. Then, time efficiency of the operations can be expressed as

Add	Delete	Update	Find by id	Find by field
O(S)	O(1)	O(S)	O(S)	O(T)

As per space, whole database is stored in 2 files (instead of 1 file per entry), so there is practically no overhead due to file system block sizes.

Features

• Basic database operations
• Fully stored on the filesystem
• Time and space efficient
• LRU cache for faster retrieval
• Server can handle multiple clients at the same time
• Endianness-agnostic serialization
• Crossplatform