Igraph network building

This exercise is about using igraph (a graph module) for building network of a (sub-)folder/files structure of the local drive with storing extra file informations with the vertices.

For the implementation the following libraries and tools were used with Python 3.6.4:

igraph (http://igraph.org/)
sqlite (https://docs.python.org/2/library/sqlite3.html)
redis (https://redis.io/)
flask (http://flask.pocoo.org/)
pycaire (https://github.com/pygobject/pycairo)
for testing: locust (https://locust.io/)
for deploying: docker (https://www.docker.com/)

Storage concept

For storing the created igraph model, two approaching were used:

SQLite as an SQL relational database
Redis as a NoSQL database (with key-value management)

To access SQLite we are using usual SQL queries, but with the use of Redis, another concept needs to be use. Key-values are really useful and fast for storing strings and numbers, but we have verteces and edges. The main contept is to use JSON objects for storing them in Redis and parsing them when reading from the database. The core Redis server not support JSON storing, but with the ReJSON Redis module, the ECMA-404 JSON Data Interchange Standard is implemented as a native data type.

Now the JSON encoding can be used like this:

redis.execute_command('JSON.SET','edges','.',json.dumps(self.graph.get_edgelist()))

And the JSON decoding can be used like this:

json.loads(cache.execute_command('JSON.GET', 'edges'))

Installation

The project using Docker-compose to set up the required environment. Docker could be download from here or for Debian based Linux, use:

$ sudo apt-get install docker docker-compose

Running docker-conpose

To start the system, run the following command (with a running Docker server at the background):

$ docker-compose up

This will use the docker-compose.yml and Dockerfile files to set up the required parts of the project and run the servers.

Endpoints

Specifications are next to the implementation

GET /graph/create
GET /graph/redis
GET /graph/sqlite
GET /search/sqlite/?key={part of the file path}
GET /search/igraph/?key={full file path}

Testing

The endpoints are available on the host machine's port of 5000. For example:

 http://localhost:5000/graph/create

Performance testing

Locust, a well designed testing tool available on the host mashine's port of 8089:

 http://localhost:8089