diff --git a/docs/modules/ROOT/pages/pallets/pallet_transaction_payment.adoc b/docs/modules/ROOT/pages/pallets/pallet_transaction_payment.adoc index e1f973c..3d3fa64 100644 --- a/docs/modules/ROOT/pages/pallets/pallet_transaction_payment.adoc +++ b/docs/modules/ROOT/pages/pallets/pallet_transaction_payment.adoc @@ -2,48 +2,44 @@ :highlightjs-languages: rust :github-icon: pass:[] -= Transaction Payment link:https://github.com/paritytech/polkadot-sdk/tree/master/substrate/frame/transaction-payment[{github-icon},role=heading-link] += Transaction Payment link:https://github.com/paritytech/polkadot-sdk/blob/release-polkadot-v1.3.0/substrate/frame/transaction-payment[{github-icon},role=heading-link] == Purpose `pallet-transaction-payment` implements transaction fee logic. -In substrate, every transaction has an associated `pallet::call`, and each `pallet::call` has a weight function. The weight function estimates the time it takes to execute the call. +In substrate, every transaction has an associated `call`, and each `call` has its own weight function. The weight function estimates the time it takes to execute the `call`. -[`Config::WeightToFee`] is set to a mapping between the smallest unit of compute (*Weight*) and smallest unit of fee. +`Config::WeightToFee` is a mapping between the smallest unit of compute (*Weight*) and smallest unit of fee. -The pallet also exposes -- how to update fees for the next block based on past fees ([`Config::FeeMultiplierUpdate`]). -- how fees are paid ([`Config::OnChargeTransaction`]). +This pallet also exposes +- how to update fees for the next block based on past fees (`Config::FeeMultiplierUpdate`) +- how fees are paid (`Config::OnChargeTransaction`) -The base fee and adjusted weight and length fees constitute the _inclusion fee_, which is -the minimum fee for a transaction to be included in a block. -The formula of final fee: -```rust,ignore -inclusion_fee = base_fee + length_fee + [targeted_fee_adjustment * weight_fee]; +The base fee and adjusted weight and length fees constitute the _inclusion fee_, which is the minimum fee for a transaction to be included in a block. The formula of final fee: +```rust, ignore +inclusion_fee = base_fee + length_fee + [fee_multiplier_update * weight_fee]; final_fee = inclusion_fee + tip; ``` -- `targeted_fee_adjustment`: This is a multiplier that can tune the final fee based on -the congestion of the network. -- `weight_fee`: A fee proportional to amount of weight a transaction consumes. -- `length_fee`: A fee proportional to the encoded length of the transaction. -- `tip`: An optional tip. Tip increases the priority of the transaction, giving it a higher -chance to be included by the transaction queue. +The inputs are defined below in the glossary and config sections. == Glossary -- _weight_: time it takes to execute a transaction in the body of a block. By controlling the execution time that a block can consume, weight bounds the storage changes and computation per block. -- _weight fee_: A fee proportional to amount of weight a transaction consumes. -- _length fee_: A fee proportional to the encoded length of the transaction. -- _tip_: An optional tip. Tip increases the priority of the transaction, giving it a higher chance to be included by the transaction queue. +** `Weight` -- The time it takes to execute runtime logic. By controlling the execution time that a block can consume, weight bounds the storage changes and computation per block. +** `WeightFee` -- A fee proportional to amount of weight a transaction consumes. +** `LengthFee` -- A fee proportional to the encoded length of the transaction. +** `Tip` -- An optional tip. Tip increases the priority of the transaction, giving it a higher chance to be included by the transaction queue. == Config link:https://github.com/paritytech/polkadot-sdk/blob/release-polkadot-v1.3.0/substrate/frame/pallet-transaction-payment/src/lib.rs#L445[{github-icon},role=heading-link] -* Pallet-specific configs: -** `WeightToFee` -- mapping between the smallest unit of weight and smallest unit of fee -** `Config::FeeMultiplierUpdate` -- A means of updating the fee for the next block, via defining a multiplier, based on the -final state of the chain at the end of the previous block. Possible values include `ConstantFee`, SlowAdjustingFee`, FastAdjustingFee`, etc. -** `Config::OnChargeTransaction` -- A means of defining the storage and state changes associated with paying transaction fees. +* Pallet-specific handlers: +** `OnChargeTransaction` -- Handler for withdrawing, refunding and depositing the transaction fee. Type must implement the trait `OnChargeTransaction`. +** `FeeMultiplierUpdate` -- Handler to define how base fees change over time (over blocks). Type must implement the trait `MultiplierUpdate`. Possible assignments include `ConstantFee`, SlowAdjustingFee`, and `FastAdjustingFee`. +* Pallet-specific converters: +** `WeightToFee` -- Mapping between the smallest unit of weight and smallest unit of fee. Type must implement the trait `WeightToFee>`. +** `LengthToFee` -- Convert a length value into a deductible fee based on the currency type. Type must implement the trait `WeightToFee>`. +* Pallet-specific constants: +** `OperationalFeeMultiplier` -- A fee mulitiplier for `Operational` extrinsics to compute "virtual tip" to boost their `priority`. Type must implement the trait `Get`. * Common configs: ** `RuntimeEvent` ** `Currency` @@ -51,39 +47,11 @@ final state of the chain at the end of the previous block. Possible values inclu == Dispatchables -[.contract-item] -[[dispatchable_name]] -==== `[.contract-item-name]#++dispatchable_name++#` -[source,rust] ----- -pub fn dispatchable_name( - param1: Type1, - param2: Type2 -) -> DispatchResult ----- -Freeform description of the dispatchable. It is good to include the important things that should be included there. - -// four following blocks show how to make a higlight of some information. It will become a styled block - -NOTE: This is how you state important information that should be acknowledged - -IMPORTANT: This is how you put some information that should not be missed - -WARNING: This thing is for important information missing which may lead to dangerous consequences - -TIP: This is how you should give some useful advice - -**Params:** - -* `param1: Type1` -- description of the parameter - -**Errors:** - -* `ErrorName` -- description of conditions, when this error happens +There are no dispatchables (and no errors) in this pallet. This pallet is only intended to configure the transaction fee logic for a chain. **Events:** -* `EventName(param1, param2)` -- description of event, if needed (they are often self-explanatory) +* `TransactionFeePaid(who, actual_fee, tip)` -- a transaction fee was paid by account `who` with total amount of `actual_fee + tip`. == More Reading