Streams Smart Contract

Roloi is a payment customization platform that provides money streams, recurring and conditional payments. Roloi converts money into a fluid asset that can flow through a blockchain network. In a dynamic financial world, dynamic payments are necessary.

Environment setup

To compile the smart contract, Rust and Cargo are required. Here is an installation guide.

cargo-contract is required too. Install it using this command:

cargo install cargo-contract --force

Run tests off-chain

To run the tests off-chain, execute this command:

cargo +nightly contract test

Generate technical documentation

To generate the technical documentation, execute this command:

cargo doc

Build smart contract

To compile the smart contract and generates the optimized WebAssembly bytecode, the metadata and bundles, execute this command:

cargo +nightly contract build

Upload & Instantiate

Open the Substrate Contracts-UI.

Choose a chain in the dropdown placed in the top section of the left menu.

Follow the ink! guide to upload and instantiate the smart contract.

Data Model

Stream

pub struct Stream {
    pub payer: AccountId,
    pub recipient: AccountId,
    pub original_balance: u128,
    pub current_balance: u128,
    pub start_date: u64,
    pub end_date: u64
}

Storage

#[ink(storage)]
#[derive(SpreadAllocate)]
pub struct StreamsContract {
    owner: AccountId,
    next_stream_id: u64,
    streams: Mapping<u64, Stream>
}

Messages

Create Stream

Creates a token stream from the sender to the specified recipient setting the end date or the duration.

create_stream(
    recipient: AccountId,
    end_date: Option<u64>,
    duration: Option<u64>,
) -> Result<u64, ContractError>

Parameters:

• recipient: The recipient wallet address of the stream.
• end_date: The end date of the stream measured in seconds. If not specified, the stream will be created with the duration.
• duration: The duration of the stream measured in seconds. If not specified, the stream will be created with the end date.
• Transaction funds: The amount of funds to be transferred to the recipient through the stream.

Returns:

• The created stream ID.

Examples:

• Using end_date: 01/01/2024 01:00:00 GMT

    create_stream(
        "5FPE9bPa2yx8dhREN6iZ3PhAJqhbY87Gfg4ELJiRt8P5xUqN",
        Some(1704070800),
        None
    );

• Using duration: 5 minutes

    create_stream(
        "5FPE9bPa2yx8dhREN6iZ3PhAJqhbY87Gfg4ELJiRt8P5xUqN",
        None,
        Some(300)
    );

Recipient Withdraw

Withdraws tokens from a stream. The recipient can specify the expected amount of tokens or withdraw all the available balance.

recipient_withdraw(
    stream_id: u64,
    withdrawal_amount: Option<u128>,
) -> Result<u128, ContractError>

Parameters:

• stream_id: The stream ID.
• withdrawal_amount: The amount of tokens to be withdrawn. If not specified, all the available balance will be withdrawn.

Returns:

• The amount of tokens withdrawn.

Examples:

• Specifying withdrawal_amount: 1000

recipient_withdraw(1, Some(1000));

• Without specifying withdrawal_amount

recipient_withdraw(1, None);

Get Stream by ID

Returns a stream by its ID.

get_stream_by_id(
    stream_id: u64
) -> Result<Stream, ContractError>

Parameters:

• stream_id: The expected stream ID.

Returns:

• The expected stream.

Example:

get_stream_by_id(1);