Project for comp90015 2019 semester 1.
The TCP server uses a non-blocking IO to communicate with other peers. The main thread repeatedly check if a channel is ready to read, and if a channel is ready to read, the main thread will push the channel into a queue and lock this channel until it has been read by a worker.
The UDP server monitor a single port and push every data received from that port to the queue and let the workers process the data.
Several worker threads monitoring the queue and execute the jobs in the queue continuously.
There is also a synchronize thread which will generate synchronize jobs every syncInterval seconds.
About timeout detection, there is a thread monitoring a delay queue. If a job want to add timeout detection, it add a TimeoutJob to that delay queue. If a task (a job or a series of jobs) is finished within the given time, it will be removed from that queue. If the task is not finished at that time, the timeout detection thread will execute the corresponding method to whether execute some job again or just interrupt some thread. Currently we have three kinds of TimeoutJobs:
-
BlockingTimeoutJob: It shows how many times a thread can be blocked and will interrupt that thread if the time runs out. Used in TCP mode.
-
NoResponseTimeoutJob: It is used when a maximum response time is needed from other peers. The corresponding job will be sent to the queue again if maximum response time is reached.
-
Pulse: A pulse is to detect if a UDP peer is still alive. We assume every a UDP package is received from a peer, the peer pulses. If a peer does not pulse in a certain amount of time, the peer is treated as dead and the server will disconnect to it.
The File System Observer provided by Aaron is monitoring the file system and generate file event jobs when some modifications are made.
The client communicate with the server using AES128 Electronic Codebook (ECB) mode. The AES key is encrypted using client's public key stored in configuration file. A sample public key looks like:
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC+N1y1sovCtFw6X2XRWrAs5NfAhIV6UU/yDIyxuAwaWGxaJAeMJeiVv0Ax0imvpeN8pZsRqng6Wdo+mMd2gx8LrzDkjNHSZBDvhQ9VGejBbjMcTIt+UQqKU1QsyAd7oOLpeZrSnhRjN+HrDZc2k74ONMba21ufseiJD2dpl0+iu5u2o5xeR4sjuHxVVBJhJ0OeSzGSwIhYBk6VPfJLyZNX7COdKv4xrMts1Zg2TQ+VPHJAeODyyU2P1qd04dRouoQ6AihOxqqzI8Ye7H5+KRlS8GAw5HuLign8cnyLZ8CBHUPtehSix1ht928obEeafI8MOlwddBKmJiCp1SC+w3WB wcy@test
For the client side, the client private key is stored in a local file called "bitboxclient_rsa". A sample private key looks like:
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
The client support three commands:
-
listing peers
java -cp bitbox.jar unimelb.bitbox.Client -c list_peers -s [server address] -i [client id] -
connect to peer
java -cp bitbox.jar unimelb.bitbox.Client -c connect_peer -s [server address] -p [peer address] -i [client id] -
disconnect to peer
java -cp bitbox.jar unimelb.bitbox.Client -c disconnect_peer -s [server address] -p [peer address] -i [client id]
- Peer.java: the bitbox peer
- ServerMain.java: the main class for server
- PeerInfo.java: store informations of connected peer
- Protocol.java: store all of the protocols
- Worker.java: workers processing the jobs
- ProtocolParsingException.java: exception for parsing protocols
- TimeoutMonitor.java: a monitor for timeout detection
- ClientListenThread: thread listening to the client
- Client: the bitbox client
- jobs/ : jobs for workers to execute.
- Job.java: Inherited by all the other jobs
- JobStatus.java: the return status of a job
- RegisterTCPIn.java: when other peers want to connect to the server in TCP mode
- RegisterTCPOut.java: when connecting to other peers in TCP mode
- RegisterUDPIn.java: when other peers want to connect to the server in UDP mode
- RegisterUDPOut.java: when connecting to other peers in UDP mode
- ParseTCPRequest.java: parse TCP requests
- ParseUDPRequest.java: parse UDP requests
- InvalidRequest.java: when processing an invalid request
- FileEventRequest.java: send file events to connected peers
- FileBytesRequest.java: send request for file bytes
- Response.java: process request response
- TimeoutJob.java: Inherited by all the other timeout jobs
- BlockingTimeoutJob.java: thread block timeout
- NoResponseTimeoutJob.java: response timeout
- Pulse.java: pulse (peer alive) timeout (in UDP mode)
- util/ : utilities for this project. (provided by Aaron)
Since we have many new functions implemented, we some new values in configuration file. Here are the values types and meanings.
| value | type | meaning |
|---|---|---|
| path | string | path to the share folder |
| port | int | the port the server is listening |
| advertisedName | string | the name of the peer |
| peers | string | the peers that the server want to connect to, comma seperated |
| maximumIncommingConnections | int | maximum incomming connection for the server |
| blockSize | int | block size for file read. (minimum of 8192 and blockSize in UDP mode ) |
| syncInterval | int | time interval (second) for synchronize event. |
| maxTries | int | max tries for a job before it fails |
| maxResponseTime | int | max response time (second) for a request |
| maxBlockTime | int | max wait time (second) for a blocking operation |
| maxPulseInterval | int | max interval (second) for a peer pulse |
| mode | string | either "tcp" or "udp" |
| clientPort | int | the port listening for client |
| authorized_keys | string | authorized client public keys |