From caad4ff1fd4085b2fea16f63a4c5f052f37b3284 Mon Sep 17 00:00:00 2001
From: just-mitch <68168980+just-mitch@users.noreply.github.com>
Date: Thu, 19 Sep 2024 20:19:18 -0400
Subject: [PATCH] feat: proofClaim in Rollup (#8636)

Fix #8608

Add the proofClaim to the rollup.

Update the `canPrune` logic to account for it.
---
 l1-contracts/src/core/Rollup.sol | 38 ++++++++++++++++++++++++++++----
 1 file changed, 34 insertions(+), 4 deletions(-)

diff --git a/l1-contracts/src/core/Rollup.sol b/l1-contracts/src/core/Rollup.sol
index 782a3910bce..b92f04cbdd2 100644
--- a/l1-contracts/src/core/Rollup.sol
+++ b/l1-contracts/src/core/Rollup.sol
@@ -55,6 +55,9 @@ contract Rollup is Leonidas, IRollup, ITestRollup {
   uint256 public constant CLAIM_DURATION_IN_L2_SLOTS = 13;
   uint256 public constant PROOF_COMMITMENT_MIN_BOND_AMOUNT_IN_TST = 1000;
 
+  uint256 public constant CLAIM_DURATION_IN_L2_SLOTS = 13;
+  uint256 public constant PROOF_COMMITMENT_MIN_BOND_AMOUNT_IN_TST = 1000;
+
   uint256 public immutable L1_BLOCK_AT_GENESIS;
   IRegistry public immutable REGISTRY;
   IInbox public immutable INBOX;
@@ -720,7 +723,26 @@ contract Rollup is Leonidas, IRollup, ITestRollup {
     return tips.pendingBlockNumber;
   }
 
+  /**
+   * @notice  Get the epoch that should be proven
+   *
+   * @dev    This is the epoch that should be proven. It does so by getting the epoch of the block
+   *        following the last proven block. If there is no such block (i.e. the pending chain is
+   *        the same as the proven chain), then revert.
+   *
+   * @return uint256 - The epoch to prove
+   */
+  function getEpochToProve() public view override(IRollup) returns (uint256) {
+    if (tips.provenBlockNumber == tips.pendingBlockNumber) {
+      revert Errors.Rollup__NoEpochToProve();
+    } else {
+      return getEpochAt(blocks[getProvenBlockNumber() + 1].slotNumber);
+    }
+  }
+
   function _prune() internal {
+    delete proofClaim;
+
     uint256 pending = tips.pendingBlockNumber;
 
     // @note  We are not deleting the blocks, but we are "winding back" the pendingTip to the last block that was proven.
@@ -741,12 +763,20 @@ contract Rollup is Leonidas, IRollup, ITestRollup {
     uint256 oldestPendingEpoch = getEpochAt(blocks[tips.provenBlockNumber + 1].slotNumber);
     uint256 startSlotOfPendingEpoch = oldestPendingEpoch * Constants.AZTEC_EPOCH_DURATION;
 
-    // TODO: #8608 adds a proof claim, which will allow us to prune the chain more aggressively.
-    //       That is what will add a `CLAIM_DURATION` to the pruning logic.
-    if (currentSlot < startSlotOfPendingEpoch + 2 * Constants.AZTEC_EPOCH_DURATION) {
+    // suppose epoch 1 is proven, epoch 2 is pending, epoch 3 is the current epoch.
+    // we prune the pending chain back to the end of epoch 1 if:
+    // - the proof claim phase of epoch 3 has ended without a claim to prove epoch 2 (or proof of epoch 2)
+    // - we reach epoch 4 without a proof of epoch 2 (regardless of whether a proof claim was submitted)
+    bool inClaimPhase = currentSlot
+      < startSlotOfPendingEpoch + Constants.AZTEC_EPOCH_DURATION + CLAIM_DURATION_IN_L2_SLOTS;
+
+    bool claimExists = currentSlot < startSlotOfPendingEpoch + 2 * Constants.AZTEC_EPOCH_DURATION
+      && proofClaim.epochToProve == oldestPendingEpoch && proofClaim.proposerClaimant != address(0);
+
+    if (inClaimPhase || claimExists) {
+      // If we are in the claim phase, do not prune
       return false;
     }
-
     return true;
   }