Skip to content

osamahammad21/Distributed

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

90 Commits
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Repository files navigation

What is this?

This is an Image sharing system based on a low level implmentation of UDP protocol that handles fragmentation and fault tollerance.

Archticture

The project is Object Oriented through these classes:

  • Message: class that represents the message entity that is used in message passing in the communication
  • UDPSocket: the lowest level of the system that handles communcation on the UDP protocol level and that does fragmentation of messages. as a blackbox, it is a socket that sends a message passed to it and receives a message in the received messages queue.
  • Peer: a higher level that represents the communicating entity which is the peer. it handles the RPC implmentation for the peer's operations.
  • directoryServer: which represents another communicating entity that handles the directoryServer's operation.
  • Image: represents the Image that is to be used on the system. it handles the steganogrophy of images, access management, formulation of all files related to the image.

How to use

UDPSocket

  • initializing socket:
    UDPSocket sock;
    sock.initializeSocket({PORT_NUMBER});
    replace {PORT_NUMBER} with an int representing the port number
  • sending message
    Message *msg = new Message();
    //initialize msg and fill it
    if(sock.sendMessage(msg)){
        //message added to the send queue successfully
        cout<<"Yaay";
    }
  • receiving message
    Message *msg = sock.receiveMsg();//blocks until a message is ready to be received
  • get socket info
    string ip = sock.getMyIP();
    int port = sock.getMyPort();

Image

for using this class you need to know which actor are you:

  • creator of a new image
  • owner of an existing image(using it for editing)
  • viewer of an image that is not owner by you

I am going to define code snippets for all test cases that may be required

  • Creator

    Image image;//create an object
    //you have to set the username and imageId in the beginning because it is needed for naming schemes
    image.setownerUsername("user1");//required in order
    image.setImageId("image123");//required in order
    //you supply the object with the path of the image
    image.chooseImage(string(IMAGE_DIR)+"small.jpg");//required in order
    struct userProperty prop;//this struct represent the setting for each user for the image
    prop.user_name="osama";
    prop.views=5;
    //access the properties of the image and edit as much as you want
    image.properties.push_back(prop);
    //write the properties to the properties file
    image.writeProperties();//required in order
    //steganize the image
    image.steg();//required in order
    //whenever you need to remove all other files except the steganized image file, call removeMiddleFiles
    image.removeMiddleFiles();
  • Owner

    Image image;
    //check if the image exists
    //findImage takes the username and imageId that are used for searching in the ImageDir
    if(!image.findImage("user1","image123"))
        //no Image Found
  • viewer

    string imagestr;//string that holds the image
    Image image;
    //check if the image exists
    //writeImage takes the string of the image and the owner(not the user's) username and imageId that are used for searching in the ImageDir
    image.writeImage(imagestr,"user1","image123");
  • Common Operations

    1 read and edit properties

    // readTheProperties and fill the propertiesVector
    image.readProperties();
    for(int i = 0;i<image.properties.size();i++)
    {
        if(image.properties[i].user_name=="osama"&&image.properties[i].views>0)
            image.properties[i].views+=10;
    }
    //updates the properties file but does not steganize
    image.updateProperties(); 

    2 get Image Paths

    string path1 = image.getAuthorizedImagePath();
    string path2 = image.getUnAuthorizedImagePath();

    3 remove middle files

    image.removeMiddleFiles();

    4 steganize && desteganize

    image.steg();
    image.desteg();

    5 get stegImage in a string for sharing

    string imageExtract = image.extractImage();

    6 get the actual image's thumbnail in a string

    image.desteg();//required in order
    string image64Extract = image.getSmallScaleImage();

    it is base64_enoded twice so you need to decode it twice before writing to a file

Peer

  • Initialization
    Peer peer(1);//port number
    peer.setDS("127.0.0.1",50);//the directoryService IP and port
  • Powering the Status update thread
    peer.startStatusUpdates("QisuAsSDAWeq126UhJS");//the token retreived after authentication
  • Sample Functions
    string token = peer.login("osama","123");//the username and password
    if(token=="not a user")
        cout<<"wrong username or password"<<endl;
    
    string token = peer.signup("osama","123");//the username and password
    if(token=="user already exists")
        cout<<"used username"<<endl;
    
    peer.addImageLocally("image123");//imageid
    peer.removeImageLocally("image123");
    
    string response = getAllImagesFromPeer("myUsername","theTargetPeerUsername","127.0.0.1",23);//the ip and port of the other peer
    if(response=="no photos")
        cout<<"no photos with that peer";
    else{
        vector<string> args;
        split(response,args,',');//you can copy the split function from the Peer.cpp class
        args[0];//the first encoded image received from the other peer
    }

directoryServer

Initialization in main

    directoryServer ds(1);//directory server's port number
    while(1);//keeps the ds running

login

remotley called by a peer. the DS validates the peer's credentials, returning a positive (token) or negative("not a user") reply based on the credentials sent. The permanent file containing the status of all users is updated.

logout

remotley called by a peer. The DS logs the user with the token sent, updating the permanent file. Replys with either "ok" or "not a user".

signup

Remotley called by a peer. Username is checked for duplication, reply is either "username already exists" or a new user is added and a token reply is sent back.

uploadImage

remotley called by a peer. Uploads a sample image and it's name. User is identified by a token. If successful, "ok" is the reply sent back.

getPortnIP

Remotley called by a peer. The desired username is looked up, sending back the port and ip of the peer, allowing peers to communicate directly. If username does not exist "not a user" is the reply sent back.

getAllImages

Remotley called by a peer. Returns all the images, imagenames, and their corresponding usernames to the peer.

updateStatus

Processes the status of the peer. If a peer does not send a status update for "TIMEOUT" seconds, they are considered offline, updating the permaenent file.

About

No description, website, or topics provided.

Resources

Stars

Watchers

Forks

Releases

No releases published

Packages

No packages published

Contributors 4

  •  
  •  
  •  
  •