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Module sui::accumulator

use std::ascii;
use std::bcs;
use std::option;
use std::string;
use std::vector;
use sui::address;
use sui::dynamic_field;
use sui::hex;
use sui::object;
use sui::party;
use sui::transfer;
use sui::tx_context;
use sui::vec_map;

Struct AccumulatorRoot​

public struct AccumulatorRoot has key
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Fields

Struct Key​

Key is used only for computing the field id of accumulator objects. T is the type of the accumulated value, e.g. Balance<SUI>

public struct Key<phantom T> has copy, drop, store
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Fields
address: address

Struct U128​

Storage for 128-bit accumulator values.

Currently only used to represent the sum of 64 bit values (such as Balance<T>). The additional bits are necessary to prevent overflow, as it would take 2^64 deposits of U64_MAX to cause an overflow.

public struct U128 has store
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Fields
value: u128

Constants​

const ENotSystemAddress: u64 = 0;


const EInvalidSplitAmount: u64 = 1;

Function create​

fun create(ctx: &sui::tx_context::TxContext)
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Implementation
fun create(ctx: &TxContext) {
    assert!(ctx.sender() == @0x0, ENotSystemAddress);
    transfer::share_object(AccumulatorRoot {
        id: object::sui_accumulator_root_object_id(),
    })
}

Function accumulator_address​

public(package) fun accumulator_address<T>(address: address): address
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Implementation
public(package) fun accumulator_address<T>(address: address): address {
    let key = Key<T> { address };
    dynamic_field::hash_type_and_key(sui_accumulator_root_address(), key)
}

Function root_has_accumulator​

Balance object methods

fun root_has_accumulator<K, V: store>(accumulator_root: &sui::accumulator::AccumulatorRoot, name: sui::accumulator::Key<K>): bool
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Implementation
fun root_has_accumulator<K, V: store>(accumulator_root: &AccumulatorRoot, name: Key<K>): bool {
    dynamic_field::exists_with_type<Key<K>, V>(&accumulator_root.id, name)
}

Function root_add_accumulator​

fun root_add_accumulator<K, V: store>(accumulator_root: &mut sui::accumulator::AccumulatorRoot, name: sui::accumulator::Key<K>, value: V)
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Implementation
fun root_add_accumulator<K, V: store>(
    accumulator_root: &mut AccumulatorRoot,
    name: Key<K>,
    value: V,
) {
    dynamic_field::add(&mut accumulator_root.id, name, value);
}

Function root_borrow_accumulator_mut​

fun root_borrow_accumulator_mut<K, V: store>(accumulator_root: &mut sui::accumulator::AccumulatorRoot, name: sui::accumulator::Key<K>): &mut V
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Implementation
fun root_borrow_accumulator_mut<K, V: store>(
    accumulator_root: &mut AccumulatorRoot,
    name: Key<K>,
): &mut V {
    dynamic_field::borrow_mut<Key<K>, V>(&mut accumulator_root.id, name)
}

Function root_remove_accumulator​

fun root_remove_accumulator<K, V: store>(accumulator_root: &mut sui::accumulator::AccumulatorRoot, name: sui::accumulator::Key<K>): V
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Implementation
fun root_remove_accumulator<K, V: store>(accumulator_root: &mut AccumulatorRoot, name: Key<K>): V {
    dynamic_field::remove<Key<K>, V>(&mut accumulator_root.id, name)
}

Function settlement_prologue​

Called by settlement transactions to ensure that the settlement transaction has a unique digest.

fun settlement_prologue(_epoch: u64, _checkpoint_height: u64, _idx: u64, ctx: &sui::tx_context::TxContext)
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Implementation
fun settlement_prologue(_epoch: u64, _checkpoint_height: u64, _idx: u64, ctx: &TxContext) {
    assert!(ctx.sender() == @0x0, ENotSystemAddress);
}

Function settle_u128​

fun settle_u128<T>(accumulator_root: &mut sui::accumulator::AccumulatorRoot, owner: address, merge: u128, split: u128, ctx: &sui::tx_context::TxContext)
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Implementation
fun settle_u128<T>(
    accumulator_root: &mut AccumulatorRoot,
    owner: address,
    merge: u128,
    split: u128,
    ctx: &TxContext,
) {
    assert!(ctx.sender() == @0x0, ENotSystemAddress);
    // Merge and split should be netted out prior to calling this function.
    assert!((merge == 0 ) != (split == 0), EInvalidSplitAmount);
    let name = Key<T> { address: owner };
    if (accumulator_root.has_accumulator<T, U128>(name)) {
        let is_zero = {
            let value: &mut U128 = accumulator_root.borrow_accumulator_mut(name);
            value.value = value.value + merge - split;
            value.value == 0
        };
        if (is_zero) {
            let U128 { value: _ } = accumulator_root.remove_accumulator<T, U128>(
                name,
            );
        }
    } else {
        // cannot split if the field does not yet exist
        assert!(split == 0, EInvalidSplitAmount);
        let value = U128 {
            value: merge,
        };
        accumulator_root.add_accumulator(name, value);
    };
}

Function emit_deposit_event​

public(package) fun emit_deposit_event<T>(accumulator: address, recipient: address, amount: u64)
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Implementation
public(package) native fun emit_deposit_event<T>(
    accumulator: address,
    recipient: address,
    amount: u64,
);

Function emit_withdraw_event​

public(package) fun emit_withdraw_event<T>(accumulator: address, owner: address, amount: u64)
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Implementation
public(package) native fun emit_withdraw_event<T>(
    accumulator: address,
    owner: address,
    amount: u64,
);