Airdrop

Sui Tears💧 Airdrop modules are "pulled" based. The modules store the root of a Merkle tree that consists of the address of the user and the airdrop amount. Users are required to submit a Merkle proof to claim their airdrops. The leafs are constructed by hashing (sha3256) the sender's address concatenated with the amount.

Please check here on how to construct the Merkle Tree.

Structs

Airdrop

struct Airdrop<phantom T> has key, store { 
    id: UID,
    balance: Balance<T>,
    root: vector<u8>,
    start: u64, 
    map: Bitmap
}

• balance - Coins to airdrop

• root - The root of the Merkle tree

• start - The timestamp in which users can claim the airdrop

• map - Bitmap keeps track of airdrop claims.

Interface

new

It creates the Airdrop object.

public fun new(airdrop_coin: Coin<T>, root: vector<u8>, start: u64, c: &Clock, ctx: &mut TxContext): Airdrop<T>

• @param airdrop_coin: The coin that will be distributed in the airdrop.

• @param root: The Merkle tree root that keeps track of all the airdrops.

• @param start: The start timestamp of the airdrop in milliseconds.

• @param c: The sui::clock::Clock shared object.

• @return Airdrop<T>

Aborts

• root is empty.

• start time of the airdrop is in the past.

balance

Returns the current amount of airdrop coins in the Airdrop object.

public fun balance<T>(self: &Airdrop<T>): u64

• @param: self The shared Airdrop object

• @return u64

root

Returns the root of the Merkle tree for the airdrop.

public fun root<T>(self: &Airdrop<T>): vector<u8>

• @param: self The shared Airdrop object.

• @return vector<u8>.

start

Returns the start timestamp of the airdrop. Users can claim after this date.

public fun start<T>(self: &Airdrop<T>): u64

• @param: self The shared Airdrop object.

• @return u64.

borrow_map

Returns an immutable reference of the Bitmap. It keeps track of the claimed airdrops.

public fun borrow_map<T>(self: &Airdrop<T>): &Bitmap

• @param: self The shared Airdrop object.

• @return &Bitmap.

has_account_claimed

Checks if a user has already claimed his airdrop.

public fun has_account_claimed<T>(
    self: &Airdrop<T>, 
    proof: vector<vector<u8>>, 
    amount: u64, 
    user: address
  ): bool

• @param self: The shared Airdrop object.

• @param proof: The proof that the sender can redeem the amount from the airdrop.

• @param amount: Number of coins the sender can redeem.

• @param address: A user address.

• @return bool. True if he has claimed the airdrop already.

Aborts

• If the proof is not valid.

get_airdrop

Allows a user to claim his airdrop by proving that his address and amount are in the Merkle tree.

public fun get_airdrop<T>(
    self: &mut Airdrop<T>, 
    proof: vector<vector<u8>>, 
    c: &Clock,
    amount: u64, 
    ctx: &mut TxContext
): Coin<T>

• @param self: The shared Airdrop object.

• @param proof: The proof that the sender can redeem the amount from the airdrop.

• @param c: The sui::clock::Clock shared object.

• @param amount: Number of coins the sender can redeem.

• @return Coin<T>. The airdrop Coin.

Aborts

• If the proof is not valid.

• The airdrop has not started yet.

• The user already claimed it

destroy_zero

Destroys an empty Airdrop object.

public fun destroy_zero<T>(self: Airdrop<T>)

• @param self: The shared {Airdrop} object.

Aborts

• The self has left over coins.