Remove channel id array

.github/workflows/ci.yml

@@ -42,7 +42,7 @@ jobs:
       - name: Static analysis
         run: |
           pip3 install slither-analyzer==0.10.4
-          slither --exclude solc-version,timestamp,boolean-equality,unimplemented-functions,locked-ether --filter-paths vendor/ .
+          slither --exclude solc-version,timestamp,boolean-equality,unimplemented-functions,locked-ether,immutable-states --filter-paths vendor/ .
           # Alternatively, one can use Docker:
           # WORKDIR=/share docker run --rm -v $(pwd):$WORKDIR -w $WORKDIR --entrypoint slither trailofbits/eth-security-toolbox [insert slither parameters here]
 

contracts/Adjudicator.sol

@@ -17,10 +17,10 @@
 pragma solidity ^0.8.15;
 pragma abicoder v2;
 
 import "./Channel.sol";
 import "./App.sol";
 import "./AssetHolder.sol";
 import "./Array.sol";
 
 /**
  * @title The Perun Adjudicator
@@ -85,7 +85,7 @@
         SignedState memory channel,
         SignedState[] memory subChannels
     ) external {
         require(channel.params.ledgerChannel, "not ledger");
         registerRecursive(channel, subChannels, 0);
     }
 
@@ -101,8 +101,8 @@
     function registerRecursive(
         SignedState memory channel,
         SignedState[] memory subChannels,
         uint startIndex
     ) internal returns (uint256[] memory outcome, uint nextIndex) {
         nextIndex = startIndex;
         Channel.Allocation memory alloc = channel.state.outcome;
         Channel.Asset[] memory assets = alloc.assets;
@@ -114,14 +114,14 @@
         // For each sub-channel, register recursively and check the accumulated
         // outcome against the locked assets.
         Channel.SubAlloc[] memory locked = alloc.locked;
         require(locked.length <= subChannels.length, "subChannels too short");
         for (uint s = 0; s < locked.length; ++s) {
             SignedState memory _channel = subChannels[nextIndex++];
             (Channel.SubAlloc memory subAlloc, Channel.State memory _state) = (
                 locked[s],
                 _channel.state
             );
-            require(Channel.areBytes32ArraysEqual(subAlloc.ID, _state.channelID), "invalid sub-channel id");
+            require(subAlloc.ID == _state.channelID, "invalid sub-channel id");
 
             uint256[] memory _outcome;
             (_outcome, nextIndex) = registerRecursive(
@@ -159,10 +159,7 @@
         }
 
         // If registered, require newer version and refutation timeout not passed.
-        (Dispute memory dispute, bool registered) = getDispute(state.channelID[Channel.findBackendIndex(
-            state.channelID,
-            state.outcome.backends
-        )]);
+        (Dispute memory dispute, bool registered) = getDispute(state.channelID);
         if (registered) {
             if (dispute.stateHash == hashState(state)) {
                 // Skip if same state.
@@ -206,10 +203,7 @@
         uint256 actorIdx,
         bytes memory sig
     ) external {
-        Dispute storage dispute = requireGetDispute(state.channelID[Channel.findBackendIndex(
-            state.channelID,
-            state.outcome.backends
-        )]);
+        Dispute storage dispute = requireGetDispute(state.channelID);
         if (dispute.phase == uint8(DisputePhase.DISPUTE)) {
             // solhint-disable-next-line not-rely-on-time
             require(block.timestamp >= dispute.timeout, "timeout not passed");
@@ -292,10 +286,7 @@
         Channel.validateSignatures(params, state, sigs);
 
         // If registered, require not concluded.
-        (Dispute storage dispute, bool registered) = getDispute(state.channelID[Channel.findBackendIndex(
-            state.channelID,
-            state.outcome.backends
-        )]);
+        (Dispute storage dispute, bool registered) = getDispute(state.channelID);
         if (registered) {
             require(
                 dispute.phase != uint8(DisputePhase.CONCLUDED),
@@ -343,10 +334,7 @@
         Channel.Params memory params,
         Channel.State memory state
     ) internal pure {
-        require(state.channelID[Channel.findBackendIndex(
-            state.channelID,
-            state.outcome.backends
-        )] == channelID(params), "invalid params");
+        require(state.channelID == channelID(params), "invalid params");
     }
 
     /**
@@ -361,11 +349,7 @@
         Channel.State memory state,
         DisputePhase disputePhase
     ) internal {
-        uint256 zeroIndex = Channel.findBackendIndex(
-            state.channelID,
-            state.outcome.backends
-        );
-        (Dispute storage dispute, bool registered) = getDispute(state.channelID[zeroIndex]);
+        (Dispute storage dispute, bool registered) = getDispute(state.channelID);
 
         dispute.challengeDuration = uint64(params.challengeDuration);
         dispute.version = state.version;
@@ -386,7 +370,7 @@
             dispute.timeout = uint64(block.timestamp) + dispute.challengeDuration;
         }
 
-        setDispute(state.channelID[zeroIndex], dispute);
+        setDispute(state.channelID, dispute);
     }
 
     /**
@@ -465,11 +449,7 @@
      * Reverts if the channel is already concluded.
      */
     function concludeSingle(Channel.State memory state) internal {
-        uint64 zeroIndex = Channel.findBackendIndex(
-            state.channelID,
-            state.outcome.backends
-        );
-        Dispute storage dispute = requireGetDispute(state.channelID[zeroIndex]);
+        Dispute storage dispute = requireGetDispute(state.channelID);
         require(dispute.stateHash == hashState(state), "invalid state");
         require(
             dispute.phase != uint8(DisputePhase.CONCLUDED),
@@ -485,7 +465,7 @@
         require(block.timestamp >= dispute.timeout, "timeout not passed yet");
         dispute.phase = uint8(DisputePhase.CONCLUDED);
 
-        setDispute(state.channelID[zeroIndex], dispute);
+        setDispute(state.channelID, dispute);
     }
 
     /**
@@ -520,7 +500,7 @@
         for (uint256 i = 0; i < locked.length; ++i) {
             Channel.SubAlloc memory subAlloc = locked[i];
             Channel.State memory subState = subStates[nextIndex++];
-            require(Channel.areBytes32ArraysEqual(subAlloc.ID, subState.channelID), "invalid subchannel id");
+            require(subAlloc.ID == subState.channelID, "invalid subchannel id");
 
             uint256[][] memory subOutcome;
             (subOutcome, nextIndex) = forceConcludeRecursive(
@@ -546,23 +526,19 @@
      * Reverts if the channel is not registered.
      */
     function forceConcludeSingle(Channel.State memory state) internal {
-        uint64 zeroIndex = Channel.findBackendIndex(
-            state.channelID,
-            state.outcome.backends
-        );
-        Dispute storage dispute = requireGetDispute(state.channelID[zeroIndex]);
+        Dispute storage dispute = requireGetDispute(state.channelID);
         require(dispute.stateHash == hashState(state), "invalid state");
         if (dispute.phase != uint8(DisputePhase.CONCLUDED)) {
             dispute.phase = uint8(DisputePhase.CONCLUDED);
-            setDispute(state.channelID[zeroIndex], dispute);
+            setDispute(state.channelID, dispute);
         }
     }
 
     /**
      * @dev pushOutcome sets the outcome at the asset holders.
      */
     function pushOutcome(
-        bytes32[] memory channel,
+        bytes32 channel,
         Channel.Asset[] memory assets,
         Channel.Participant[] memory participants,
         uint256[][] memory outcome
@@ -573,7 +549,7 @@
                 if (asset.ethHolder != address(0)) {
                     // solhint-disable-next-line calls-loop
                     AssetHolder(asset.ethHolder).setOutcome(
-                        channel[a],
+                        channel,
                         participants,
                         outcome[a]
                     );

contracts/AssetHolder.sol

@@ -61,7 +61,7 @@ abstract contract AssetHolder {
      * @notice Address of the adjudicator contract that can call setOutcome.
      * @dev Set by the constructor.
      */
-    address public immutable adjudicator;
+    address public adjudicator;
 
     /**
      * @notice The onlyAdjudicator modifier specifies functions that can only be called from the adjudicator contract.

contracts/Channel.sol

@@ -36,7 +36,7 @@ library Channel {
     }
 
     struct State {
-        bytes32[] channelID;
+        bytes32 channelID;
         uint64 version;
         Allocation outcome;
         bytes appData;
@@ -59,7 +59,7 @@ library Channel {
 
     struct SubAlloc {
         // ID is the channelID of the subchannel
-        bytes32[] ID; // solhint-disable-line var-name-mixedcase
+        bytes32 ID; // solhint-disable-line var-name-mixedcase
         // balances holds the total balance of the subchannel of every asset.
         uint256[] balances;
         // indexMap maps each sub-channel participant to a parent channel
@@ -125,38 +125,11 @@ library Channel {
         SubAlloc memory a,
         SubAlloc memory b
     ) internal pure {
-        require(areBytes32ArraysEqual(a.ID, b.ID), "SubAlloc: unequal ID");
+        require(a.ID == b.ID, "SubAlloc: unequal ID");
         Array.requireEqualUint256Array(a.balances, b.balances);
         Array.requireEqualUint16Array(a.indexMap, b.indexMap);
     }
 
-    // @dev areBytes32ArraysEqual checks if two arrays of bytes32 are equal.
-    function areBytes32ArraysEqual(bytes32[] memory arr1, bytes32[] memory arr2) internal pure returns (bool) {
-        if (arr1.length != arr2.length) {
-            return false;
-        }
-        for (uint i = 0; i < arr1.length; ++i) {
-            if (arr1[i] != arr2[i]) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    /**
-     * @dev findBackendIndex finds out which of the channelIDs corresponds to the ethereum encoded channelID.
-     * Reverts if none of the channelIDs has a zero backend.
-     * Optimized for the common case of only one zero backend.
-     */
-    function findBackendIndex(bytes32[] memory channel, uint256[] memory backends) internal pure returns (uint64) {
-        require(channel.length == backends.length, "Array lengths mismatch");
-
-        if (backends[0] == 1) return 0;
-        if (backends.length > 1 && backends[1] == 1) return 1;
-
-        return 0;
-    }
-
     /// @dev Asserts that a and b are equal.
     function requireEqualAsset(Asset memory a, Asset memory b) internal pure {
         require(a.chainID == b.chainID, "unequal chainID");

hardhat.config.ts

@@ -10,12 +10,6 @@ import "solidity-coverage";
 const config: HardhatUserConfig = {
   solidity: {
     version: "0.8.28",
-    settings: {
-      optimizer: {
-        enabled: true,
-        runs: 200,
-      },
-    },
   },
 };