SimpleFTP

Canton Ledger Facilitated File Transfer

What it does

• Uses a Canton ledger to broker a WebRTC connection from one client to another
• Uses that connection to send a file

What it does not do

• Peer Discovery

  • TODO: Verify, this appears to be a limitation of either the DAML language or the Canton runtime

  • Why?

    ChatGPT Explains:

      Unfortunately, it is not possible to achieve dynamic discovery 
      of parties in DAML. The query function expects a specific party
      as an argument to determine the visibility of contracts. You 
      cannot dynamically retrieve contracts across all parties without 
      explicitly specifying them.
    
      If you need to discover parties dynamically, you may consider 
      an alternative approach such as maintaining a separate registry 
      or creating an additional contract that keeps track of the 
      parties participating in the network.
    

Participant Nodes Context Diagram

SimpleFTP.daml

• data TaskResult_ENUM
  • Data class enumerating possible SimpleFTP TransferTask outcomes
  • i.e.
    • Complete
    • NotComplete
    • Finalizing
    • Rejected
    • Cancelled
    • Error
• template Client
  • DAML Template containing choices necessary to create and accept file transfers
• template TaskProposal
  • DAML Template containing choices necessary to propose and allow the counterparty to either accept or reject the transfer
• template TransferTask
  • DAML Template containing choices necessary to complete a file transfer
• setup script
  • Demonstrates creation and brokering of the SimpleFTP TransferTask

On-Deck Tasks

• Send/Receive Text
• Make gRPC connectors

Version History

• (Version NEXT)

  • [2023-07-11]

    • Initial check-in
    • Setup script simulates happy path file transfer

  • [2023-07-14]

    • Implementing Rubrik Requirements

  • [Not Implemented] Test Reject a task proposal

  • [Not Implemented] Test Finalizing (i.e. NotifyReceivingComplete seen before NotifySendingComplete)

  • [Not Implemented] Test Interrupted

  • [Not Implemented] Test Cancelled

  • [Not Implemented] Test Error

  • [Not Implemented] Test Simultaneous Task Proposals are allowed

  • [Not Implemented] Test accepting more than one Task Proposals is not allowed

  • [Not Implemented] Test accepting Task Proposal is not allowed while TransferTask is active

  • [Not Implemented] Test accepting Task Proposal is not allowed while TransferTask is active

License

(c) Digital Asset 2023 - All Rights Reserved