Transaction.md

Transaction

Only a platform account can generate a transaction. The transaction generator pays the transaction fees. Transactions that cost less than the minimum fee are rejected. The minumum fee is different for each transaction type.

The seq must be identical with the payer’s account seq. The account seq will be increased by 1 after a transaction is added to the block. The amount of fee is deducted from the payer’s balance. A transaction will not be included if the seq of the account doesn’t match or the balance of the account is less than the fee.

struct Transaction {
    seq: u64,
    fee: u64,
    network_id: NetworkId,
    action: Action,
}

enum Action {
    MintAsset { ..., },
    TransferAsset { ..., },
    ChangeAssetScheme { ..., },
    Pay { ..., },
    SetRegularKey { ..., },
    WrapCCC { ..., },
    UnwrapCCC { ..., },
    Store { ..., },
    Remove { ..., },
    Custom { ..., },
}

MintAsset

MintAsset issues a new asset and an asset scheme that goes along with it. The output becomes the lock script hash and parameters of the new asset.

A permissioned asset is an asset that has an approver. This kind of asset needs permission to be transferred.

A regulated asset is an asset that has an registrar. The registrar can change the asset scheme and transfer the asset arbitrarily.

MintAsset {
    network_id: NetworkId,
    shard_id: ShardId,
    metadata: String,
    approver: Option<PlatformAddress>,
    registrar: Option<PlatformAddress>,

    output: AssetMintOutput,

    approvals: Vec<Signature>,
}

struct AssetMintOutput {
    lock_script_hash: H160,
    parameters: Vec<Bytes>,
    amount: u64,
}

TransferAsset

It transfers assets. The transfer must provide the valid lock_script and unlock_script.

TransferAsset {
    network_id: NetworkId,
    burns: Vec<AssetTransferInput>,
    inputs: Vec<AssetTransferInput>,
    outputs: Vec<AssetTransferOutput>,
    orders: Vec<OrderOnTransfer>,

    metadata: String,
    approvals: Vec<Signature>,
    expiration: Option<u64>,
}

struct AssetTransferInput {
    prev_out: AssetOutPoint,
    timelock: Option<Timelock>,
    lock_script: Script,
    unlock_script: Script,
}
struct AssetOutPoint {
    transaction_hash: H256,
    index: usize,
    asset_type: H256,
    amount: u64,
}
struct AssetTransferOutput {
    lock_script_hash: H160,
    parameters: Vec<Bytes>,
    asset_type: H256,
    amount: u64,
}

Timelock

A transaction fails if any timelock condition isn't met. There are 4 types of timelock. Basically, they keep the transaction from being executed until the specific point in time. Block and Time types indicate the absolute time. BlockAge and TimeAge types indicate relative time based on how long has the asset been created.

• Block(u64): The given value must be less than or equal to the current block's number.
• BlockAge(u64): The given value must be less than or equal to the value X, where X = current block number - the block number that the asset of the AssetOutPoint was created at.
• Time(u64): The given value must be less than or equal to the current block's timestamp.
• TimeAge(u64): The given value must be less than or equal to the value X, where X = current block timestamp - the block timestamp that the asset of the AssetOutPoint was created at.

enum Timelock {
    Block(u64),
    BlockAge(u64),
    Time(u64),
    TimeAge(u64),
}

Order

Order is used for the DEX. Please see this page for more information.

ChangeAssetScheme

It changes the asset scheme. Only the registrar of the asset can use it.

ChangeAssetScheme {
    network_id: NetworkId,
    asset_type: H256,
    metadata: String,
    approver: Option<PlatformAddress>,
    registrar: Option<PlatformAddress>,

    approvals: Vec<Signature>,
}

Pay

Pay sends value amount of CCC to the receiver.

Pay {
    receiver: Address,
    amount: u64,
}

SetRegularKey

SetRegularKey sets the regular key of the payer. It overwrites the existing one if a key already exists.

SetRegularKey {
    key: Public,
}

WrapCCC

WrapCCC converts CCC to WCCC. The payer must own enough CCC to convert.

WrapCCC {
    shard_id: ShardId,
    lock_script_hash: H160,
    parameters: Vec<Parameters>,
    amount: u64,
}

UnwrapCCC

UnwrapCCC converts WCCC to CCC. The payer has the converted CCC.

UnwrapCCC {
    network_id: NetworkId,
    burn: AssetTransferInput,
    receiver: PlatformAddress,
}

Custom {
    handler_id: u64,
    bytes: Bytes,
}

Store

This is a special kind of transaction that allows a user to upload text onto the blockchain.

Store {
    content: String,
    certifier: Address,
    signature: Signature,
}

Remove

It removes the content created by the Store transaction.

Remove {
    hash: H256,
    signature: Signature,
}

Custom

Custom is a special transaction. The types of transactions that may exist depends on the consensus engine.