fix(core): adjust gas heuristics to support large contracts on Scroll

.changeset/green-cups-train.md

@@ -0,0 +1,7 @@
+---
+'@sphinx-labs/contracts': patch
+'@sphinx-labs/plugins': patch
+'@sphinx-labs/core': patch
+---
+
+Adjust gas heuristics to support large contracts on Scroll

packages/contracts/contracts/foundry/Sphinx.sol

@@ -388,10 +388,14 @@ abstract contract Sphinx {
             //    more likely to be "warm" (i.e. cheaper) than the production environment, where
             //    transactions may be split between batches.
             //
-            // We chose to multiply the gas by 1.3 because multiplying it by a higher number could
-            // make a very large transaction unexecutable on-chain. Since the 1.3x multiplier
-            // doesn't impact small transactions very much, we add a constant amount of 20k too.
-            gasEstimates[i] = 20_000 + ((startGas - finalGas) * 13) / 10;
+            // Collecting the user's transactions in the same process as this function does not
+            // impact the Merkle leaf gas fields because we use `vm.snapshot`/`vm.revertTo`. Also,
+            // state changes on one fork do not impact the gas cost on other forks.
+            //
+            // We chose to multiply the gas by 1.1 because multiplying it by a higher number could
+            // make a very large transaction unexecutable on-chain. Since the 1.1x multiplier
+            // doesn't impact small transactions very much, we add a constant amount of 60k too.
+            gasEstimates[i] = 60_000 + ((startGas - finalGas) * 11) / 10;
         }
 
         vm.stopPrank();

packages/core/src/actions/execute.ts

@@ -207,7 +207,7 @@ export const executeBatchActions = async (
   const executionReceipts: ethers.TransactionReceipt[] = []
   const batches: SphinxLeafWithProof[][] = []
 
-  const maxGasLimit = getMaxGasLimit(blockGasLimit)
+  const maxGasLimit = getMaxGasLimit(blockGasLimit, chainId)
 
   // Pull the Merkle root state from the contract so we're guaranteed to be up to date.
   const activeRoot = await sphinxModule.activeMerkleRoot()
@@ -532,7 +532,7 @@ export const executeActionsViaSigner: ExecuteActions = async (
  * Here are the data points in the format (<CALLDATA_LENGTH>, <GAS_ESTIMATE>):
  * (0,10202),(1000,10592),(100000,67166),(500000,676492),(1000000,2296456).
  *
- * After summing these values, we multiply by 1.1 to ensure that the heuristic overestimates the
+ * After summing these values, we include a buffer to ensure that the heuristic overestimates the
  * amount of gas. This ensures we don't underestimate the gas, which would otherwise be a concern
  * because we don't incorporate the cost of executing the `DELEGATECALL` on the `SphinxModuleProxy`,
  * or the cost of potentially returning data from the `exec` function on the `ManagedService`. This
@@ -566,7 +566,7 @@ export const estimateGasViaManagedService: EstimateGas = (
   const estimate =
     21_000 + callDataGas + estimateModuleExecutionGas(batch) + managedServiceGas
 
-  return Math.round(estimate * 1.1)
+  return Math.round(estimate * 1.05 + 50_000) // Include a buffer
 }
 
 /**
@@ -580,7 +580,7 @@ export const estimateGasViaManagedService: EstimateGas = (
  * zero-byte of calldata.
  * 3. The estimated cost of executing the logic in the `SphinxModule`.
  *
- * After summing these values, we multiply by 1.1 to ensure that the heuristic overestimates the
+ * After summing these values, we include a buffer to ensure that the heuristic overestimates the
  * amount of gas. This ensures we don't underestimate the gas, which would otherwise be a concern
  * because we don't incorporate the cost of executing the `DELEGATECALL` on the `SphinxModuleProxy`.
  * This buffer also makes our estimate closer to the value that would be returned by the
@@ -597,7 +597,7 @@ export const estimateGasViaSigner: EstimateGas = (moduleAddress, batch) => {
 
   const estimate = 21_000 + callDataGas + estimateModuleExecutionGas(batch)
 
-  return Math.round(estimate * 1.1)
+  return Math.round(estimate * 1.05 + 50_000) // Include a buffer
 }
 
 /**

packages/core/src/utils.ts

@@ -1436,7 +1436,19 @@ export const getCreate3Salt = (
  * which transactions to include. As a result, we restrict our total gas usage to a fraction of the
  * block gas limit.
  */
-export const getMaxGasLimit = (blockGasLimit: bigint): bigint => {
+export const getMaxGasLimit = (
+  blockGasLimit: bigint,
+  chainId: bigint
+): bigint => {
+  // On Scroll and Scroll Sepolia, set the max gas limit to be 80% of the block gas limit. We set a
+  // higher value for these networks because their block gas limit is low (10 million), which means
+  // a lower max gas limit could cause large contract deployments to be unexecutable. Transactions
+  // that use ~8.5M gas were executed quickly on Scroll Sepolia, so an 80% limit shouldn't
+  // meaningfully impact execution speed.
+  if (chainId === BigInt(534351) || chainId === BigInt(534352)) {
+    return (blockGasLimit * BigInt(8)) / BigInt(10)
+  }
+
   return blockGasLimit / BigInt(2)
 }
 

packages/plugins/src/foundry/decode.ts

@@ -16,6 +16,7 @@ import {
   decodeDeterministicDeploymentProxyData,
   Create2ActionInput,
   ActionInputType,
+  getNetworkNameForChainId,
 } from '@sphinx-labs/core'
 import { AbiCoder, ConstructorFragment, ethers } from 'ethers'
 import {
@@ -158,8 +159,9 @@ export const makeParsedConfig = (
     const gas = gasEstimates[i].toString()
 
     if (BigInt(gas) > maxAllowedGasPerLeaf) {
+      const networkName = getNetworkNameForChainId(BigInt(chainId))
       throw new Error(
-        `Estimated gas for a transaction is too close to the block gas limit.`
+        `Estimated gas for a transaction is too close to the block gas limit on ${networkName}.`
       )
     }
 

packages/plugins/test/mocha/common.ts

@@ -410,7 +410,12 @@ export const makeDeployment = async (
         },
         arbitraryChain: false,
         accountAccesses,
-        gasEstimates: new Array(numActionInputs).fill(BigInt(5_000_000)),
+        // We set the Merkle leaf gas fields to 6 million to ensure that a very large contract
+        // deployment can fit in a batch. This is important to check on networks like Scroll which
+        // have low block gas limits. (Scroll's block gas limit is 10 million). A Merkle leaf gas
+        // field of 6 million corresponds to a contract at the max size limit with a couple dozen
+        // SSTOREs in its constructor.
+        gasEstimates: new Array(numActionInputs).fill(BigInt(6_000_000)),
         sphinxLibraryVersion: CONTRACTS_LIBRARY_VERSION,
       }