From 795b63e68673d1f770233604d62108517e171005 Mon Sep 17 00:00:00 2001 From: 4meta5 Date: Sun, 10 Dec 2023 21:13:47 -0500 Subject: [PATCH] init transaction payment doc --- docs/modules/ROOT/nav.adoc | 3 +- .../pages/pallet_transaction_payment.adoc | 86 +++++++++++++++++++ 2 files changed, 88 insertions(+), 1 deletion(-) create mode 100644 docs/modules/ROOT/pages/pallet_transaction_payment.adoc diff --git a/docs/modules/ROOT/nav.adoc b/docs/modules/ROOT/nav.adoc index 80121a4..6489733 100644 --- a/docs/modules/ROOT/nav.adoc +++ b/docs/modules/ROOT/nav.adoc @@ -1,3 +1,4 @@ * General Guides * Runtime Descriptions -* Pallet Specifications \ No newline at end of file +* Pallet Specifications +* [Pallet Transaction Payment](./pages/pallet_transaction_payment.adoc) \ No newline at end of file diff --git a/docs/modules/ROOT/pages/pallet_transaction_payment.adoc b/docs/modules/ROOT/pages/pallet_transaction_payment.adoc new file mode 100644 index 0000000..d979d15 --- /dev/null +++ b/docs/modules/ROOT/pages/pallet_transaction_payment.adoc @@ -0,0 +1,86 @@ +:source-highlighter: highlight.js +: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] + +== Purpose + +`pallet-transaction-payment` implements transaction fee logic. + +To implement this pallet, the runtime configures a mapping between the minimum unit of computation/block space (*Weight*) and the minimum unit of fees ([`Config::WeightToFee`]). + +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: +```ignore +inclusion_fee = base_fee + length_fee + [targeted_fee_adjustment * 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. + +== 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. + +== config + +- [`Config::WeightToFee`]: The mapping between one unit of weight to one 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. + +== 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 + +**Events:** + +* `EventName(param1, param2)` -- description of event, if needed (they are often self-explanatory) + +== More Reading + +- [Substrate Weight & Fees](https://www.shawntabrizi.com/blog/substrate/substrate-weight-and-fees/) by Shawn Tabrizi +* [Substrate Docs: Transaction Weight & Fees]https://docs.substrate.io/build/tx-weights-fees/ +* [Substrate Docs: How to Calculate Fees](https://docs.substrate.io/reference/how-to-guides/weights/calculate-fees/#:~:text=Weight%20fee%20%2D%20A%20fee%20calculated,change%20as%20the%20chain%20progresses) +