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fix(docs): Fix formatting in protocol specs (#5882)
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- Fixes and improperly formatted admonition
- Adds text to mermaid diagrams so that they render properly
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critesjosh authored Apr 22, 2024
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54 changes: 25 additions & 29 deletions docs/docs/protocol-specs/gas-and-fees/fee-payments-and-metering.md
Original file line number Diff line number Diff line change
Expand Up @@ -57,7 +57,7 @@ All of these phases occur **within the same transaction**, ultimately resulting

![Transaction Components](/img/protocol-specs/gas-and-fees/Transaction.png)

The fee preparation and fee distribution phases respectively are responsible for ensuring that sufficient quantity of the fee payment asset is made available for the transaction and that it is correctly distributed to the sequencer with any refund being returned to the transaction sender. The sequencer will have have agency over which contract methods they are willing to accept for execution in these phases and will have visibility over the arguments passed to them. This is important as these functions must be successfully executed in order for the sequencer to be paid. It is assumed that the network will settle on a number of universally recognised fee payment contracts implementing fee preparation and distribution.
The fee preparation and fee distribution phases respectively are responsible for ensuring that sufficient quantity of the fee payment asset is made available for the transaction and that it is correctly distributed to the sequencer with any refund being returned to the transaction sender. The sequencer will have have agency over which contract methods they are willing to accept for execution in these phases and will have visibility over the arguments passed to them. This is important as these functions must be successfully executed in order for the sequencer to be paid. It is assumed that the network will settle on a number of universally recognized fee payment contracts implementing fee preparation and distribution.

## Gas Metering

Expand All @@ -80,15 +80,15 @@ A comprehensive table of gas consuming operations can be found in the [fee sched

## Paying Transaction Fees

Transactions will need to be provided with sufficient fees to cover their gas consumption. The [private kernel circuits](../circuits/high-level-topology.md) understand a transaction's private execution as having 2 phases. The first phase is for the payment of fees. It is during this phase that the private execution must generate side-effects and enqueued function calls for the fee preparation and fee distribution phases of the transaction. These side-effects are deemed non-revertible. Typically, only contracts designed to be written as transaction entrypoints will need to be concerned with these phases and once the fee payment execution is complete, the transaction is moved to the second phase where all execution is considered the appication logic. The [private kernel circuits](../circuits/high-level-topology.md) maintain a 'high water mark' of side effects below which those side effects are deemed non-revertible.
Transactions will need to be provided with sufficient fees to cover their gas consumption. The [private kernel circuits](../circuits/high-level-topology.md) understand a transaction's private execution as having 2 phases. The first phase is for the payment of fees. It is during this phase that the private execution must generate side-effects and enqueued function calls for the fee preparation and fee distribution phases of the transaction. These side-effects are deemed non-revertible. Typically, only contracts designed to be written as transaction entrypoints will need to be concerned with these phases and once the fee payment execution is complete, the transaction is moved to the second phase where all execution is considered the application logic. The [private kernel circuits](../circuits/high-level-topology.md) maintain a 'high water mark' of side effects below which those side effects are deemed non-revertible.

Transaction senders will need to compute a sufficient fee for the transaction considering both the transaction specific and amortized gas consumption. Transaction specific L1, L2, and DA gas can be calculated via simulation whereas amortized gas will need to be calculated by using a transaction sender specified minimum amortization. This minimum amortization is simply the minimum sized rollup that the transaction sender is willing to be included in. From this value, the amortized L1, L2 and DA gas values can be determined. Finally, a fixed amount of gas for the execution of fee distribution will need to be specified.

An example of L2 gas amortization could be the transaction sender specifying a minimum amortization of 1024 transactions. The transaction sender would then compute the amount of amortized gas required for a rollup of that size:

```
TotalGasToBeAmortised = (1024 - 2) * GMerge + GRoot
L2AmortizedGasLimit = TotalGasToBeAmortised / 1024
TotalGasToBeAmortized = (1024 - 2) * GMerge + GRoot
L2AmortizedGasLimit = TotalGasToBeAmortized / 1024
Where
GMerge = The gas cost of proving the merge rollup circuit.
Expand Down Expand Up @@ -197,18 +197,16 @@ sequenceDiagram
Alice->>AccountContract: run entrypoint
AccountContract->>FPA: enqueue FPA.pay_fee(max_fee) msg_sender == Alice as fee distribution function
AccountContract->>App: app logic
App->>AccountContract:
App->>AccountContract: response
AccountContract->>Alice: finished private execution
Alice->>Sequencer: tx object
Sequencer->>Sequencer: Recognise whitelisted function FPA.pay_fee(max_fee) and msg.sender == Alice
Sequencer->>Sequencer: Recognize whitelisted function FPA.pay_fee(max_fee) and msg.sender == Alice
Sequencer->>FPA: verify that Alice has >= funds required from tx object
FPA->>Sequencer: Alice has >= funds required from tx object
Sequencer->>App: app logic
App->>Sequencer:
App->>Sequencer: response
Sequencer->>FPA: FPA.pay_fee(max_fee)
FPA->>FPA: calculate fee based on inputs to VM circuit
FPA->>Alice: Alice's balance is reduced by fee amount
Expand Down Expand Up @@ -241,19 +239,19 @@ sequenceDiagram
FPC->>AST: AST.transfer(FPC, max_fee + commission, nonce)
AST->>AccountContract: check auth witness
FPC->>FPC: enqueue FPA.private_fee_payment(max_fee) msg_sender == FPC as fee distribution function
FPC->>AccountContract:
FPC->>AccountContract: response
AccountContract->>App: app logic
App->>AccountContract:
App->>AccountContract: response
AccountContract->>Alice: finished private execution
Alice->>Sequencer: tx object
Sequencer->>Sequencer: Recognise whitelisted function FPA.private_fee_payment(max_fee) and msg.sender == FPC
Sequencer->>Sequencer: Recognize whitelisted function FPA.private_fee_payment(max_fee) and msg.sender == FPC
Sequencer->>FPA: verify that FPC has >= funds required from tx object
FPA->>Sequencer: FPC has >= funds required from tx object
Sequencer->>App: app logic
App->>Sequencer:
App->>Sequencer: response
Sequencer->>FPA: FPA.private_fee_payment(max_fee)
FPA->>FPA: calculate fee based on inputs to VM circuit
Expand Down Expand Up @@ -282,50 +280,49 @@ sequenceDiagram
end
Alice->>AccountContract: run entrypoint
AccountContract->>AccountContract: pulic auth witness for AST transfer
AccountContract->>AccountContract: public auth witness for AST transfer
AccountContract->>FPC: public_fee_entrypoint(AST, max_fee, nonce)
activate FPC
FPC->>FPC: enqueue FPC.public_fee_preparation(Alice, AST, max_fee, nonce) as fee preparation with msg_sender == FPC
FPC->>FPC: enqueue FPC.public_fee_payment(Alice, AST, max_fee) as fee distribution with msg_sender == FPC
FPC->>AccountContract:
deactivate FPC
FPC->>AccountContract: deactivate FPC
AccountContract->>App: app logic
App->>AccountContract:
App->>AccountContract: response
AccountContract->>Alice: finished private execution
Alice->>Sequencer: tx object
Sequencer->>Sequencer: Recognise whitelisted function FPC.public_fee_preparation(Alice, AST, max_fee, nonce) and msg.sender == FPC
Sequencer->>Sequencer: Recognize whitelisted function FPC.public_fee_preparation(Alice, AST, max_fee, nonce) and msg.sender == FPC
Sequencer->>FPC: FPC.public_fee_preparation(Alice, AST, max_fee, nonce)
activate FPC
FPC->>AST: AST.transfer_public(Alice, FPC, max_fee + commission, nonce)
AST->>AccountContract: check auth witness
AccountContract->>AST:
AST->>FPC:
AccountContract->>AST: response
AST->>FPC: response
FPC->>FPA: FPA.check_balance(max_fee)
FPA->>FPC:
FPA->>FPC: response
FPC->>Sequencer: FPC has the funds
deactivate FPC
Sequencer->>App: app logic
App->>Sequencer:
App->>Sequencer: response
Sequencer->>Sequencer: Recognise whitelisted function FPC.public_fee_payment(Alice, AST, max_fee) and msg.sender == FPC
Sequencer->>Sequencer: Recognize whitelisted function FPC.public_fee_payment(Alice, AST, max_fee) and msg.sender == FPC
Sequencer->>FPC: FPC.public_fee_payment(Alice, AST, max_fee)
activate FPC
FPC->>FPA: FPA.pay_fee(max_fee)
FPA->>FPA: calculate fee based on inputs to VM circuit
FPA->>Sequencer: Sequencer's balance is increased by fee amount
FPA->>FPC: rebate value
FPC->>AST: AST.transfer_public(FPC, Alice, rebate, 0)
AST->>FPC:
AST->>FPC: response
FPC->>Alice: Alice's balance is increased by rebate value
deactivate FPC
```

### DApp Sponsorship

In this scenario a DApp wishes to pay the fee on behalf of a user for interactng with it. The DApp has a balance of FPA from which it wishes to pay for the transaction. It shares many similarities with the previous native asset fee payment scenario.
In this scenario a DApp wishes to pay the fee on behalf of a user for interacting with it. The DApp has a balance of FPA from which it wishes to pay for the transaction. It shares many similarities with the previous native asset fee payment scenario.

```mermaid
sequenceDiagram
Expand All @@ -342,21 +339,20 @@ sequenceDiagram
Alice->>DApp: run entrypoint
DApp->>AccountContract: check auth witness
AccountContract->>DApp:
AccountContract->>DApp: app logic
DApp->>DApp: check if will sponsor action
DApp->>FPA: enqueue FPA.pay_fee(max_fee) and msg_sender == DApp as fee distribution
DApp->>DApp: app logic
DApp->>Alice: finished private execution
Alice->>Sequencer: tx object
Sequencer->>Sequencer: Recognise whitelisted function FPA.pay_fee(max_fee) and msg.sender == DApp
Sequencer->>Sequencer: Recognize whitelisted function FPA.pay_fee(max_fee) and msg.sender == DApp
Sequencer->>FPA: verify that DApp has >= funds required from tx object
FPA->>Sequencer: DApp has >= funds required from tx object
Sequencer->>DApp: app logic
DApp->>Sequencer:
DApp->>Sequencer: response
Sequencer->>FPA: FPA.pay_fee(max_fee)
FPA->>FPA: calculate fee based on inputs to VM circuit
FPA->>DApp: DApp's balance is reduced by fee amount
Expand Down
5 changes: 4 additions & 1 deletion docs/docs/protocol-specs/l1-smart-contracts/index.md
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Expand Up @@ -12,7 +12,8 @@ The purpose of the L1 contracts are simple:

- Facilitate cross-chain communication such that L1 liquidity can be used on L2
- Act as a validating light node for L2 that every L1 node implicitly run
:::

:::

## Overview

Expand Down Expand Up @@ -41,10 +42,12 @@ def process(block: ProvenBlock, proof: Proof):
```

:::info Why `math.ceil(log2(MAX_NEW_L2_TO_L1_MSGS_PER_TX))`?

The argument to the `insert` function is the `outbox` is the heigh of the message tree.
Since every transaction can hold more than 1 message, it might add multiple layers to the tree.
For a binary tree, the number of extra layers to add is computed as `math.ceil(log2(MAX_NEW_L2_TO_L1_MSGS_PER_TX))`.
Currently, `MAX_NEW_L2_TO_L1_MSGS_PER_TX = 2` which means that we are simply adding 1 extra layer.

:::

While the `ProvenBlock` must be published and available for nodes to build the state of the rollup, we can build the validating light node (the contract) such that as long as the node can be _convinced_ that the data is available we can progress the state.
Expand Down

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