feat(protocol): allow specifying signals per L2 block

packages/protocol/contracts/layer1/based/ITaikoInbox.sol

@@ -27,6 +27,7 @@ interface ITaikoInbox {
         // For all other blocks in the same batch, the block timestamp is its parent block's
         // timestamp plus this time shift value.
         uint8 timeShift;
+        bytes32[] signalSlots;
     }
 
     struct BlobParams {
@@ -52,7 +53,6 @@ interface ITaikoInbox {
         bytes32 anchorInput;
         uint64 lastBlockTimestamp;
         bool revertIfNotFirstProposal;
-        bytes32[] signalSlots;
         // Specifies the number of blocks to be generated from this batch.
         BlobParams blobParams;
         BlockParams[] blocks;
@@ -80,7 +80,6 @@ interface ITaikoInbox {
         bytes32 anchorBlockHash;
         bytes32 anchorInput;
         LibSharedData.BaseFeeConfig baseFeeConfig;
-        bytes32[] signalSlots;
     }
 
     /// @dev This struct holds batch metadata essential for proving the batch.

packages/protocol/contracts/layer1/based/TaikoInbox.sol

@@ -143,11 +143,7 @@ abstract contract TaikoInbox is EssentialContract, ITaikoInbox, ITaiko {
                 anchorBlockId: anchorBlockId,
                 anchorBlockHash: blockhash(anchorBlockId),
                 anchorInput: params.anchorInput,
-                baseFeeConfig: config.baseFeeConfig,
-                //
-                // Signals are applied only to the first block of the batch.
-                // For the remaining blocks, an empty list shall be used by the anchorV3 function.
-                signalSlots: params.signalSlots
+                baseFeeConfig: config.baseFeeConfig
             });
 
             require(info_.anchorBlockHash != 0, ZeroAnchorBlockHash());
@@ -794,8 +790,29 @@ abstract contract TaikoInbox is EssentialContract, ITaikoInbox, ITaiko {
             require(lastBlockTimestamp_ <= block.timestamp, TimestampTooLarge());
 
             uint64 totalShift;
+            address signalService;
+
             for (uint256 i; i < blocksLength; ++i) {
                 totalShift += _params.blocks[i].timeShift;
+
+                uint256 signalSlotsLength = _params.blocks[i].signalSlots.length;
+
+                if (signalSlotsLength != 0) {
+                    require(signalSlotsLength <= _maxSignalsToReceive, TooManySignals());
+
+                    if (signalService == address(0)) {
+                        signalService = resolve(LibStrings.B_SIGNAL_SERVICE, false);
+                    }
+
+                    for (uint256 j; j < signalSlotsLength; ++j) {
+                        require(
+                            ISignalService(signalService).isSignalSent(
+                                _params.blocks[i].signalSlots[j]
+                            ),
+                            SignalNotSent()
+                        );
+                    }
+                }
             }
 
             require(lastBlockTimestamp_ >= totalShift, TimestampTooSmall());
@@ -819,19 +836,6 @@ abstract contract TaikoInbox is EssentialContract, ITaikoInbox, ITaiko {
             );
         }
 
-        uint256 signalSlotsLength = _params.signalSlots.length;
-
-        if (signalSlotsLength != 0) {
-            require(signalSlotsLength <= _maxSignalsToReceive, TooManySignals());
-
-            ISignalService signalService =
-                ISignalService(resolve(LibStrings.B_SIGNAL_SERVICE, false));
-
-            for (uint256 i; i < signalSlotsLength; ++i) {
-                require(signalService.isSignalSent(_params.signalSlots[i]), SignalNotSent());
-            }
-        }
-
         require(blocksLength != 0, BlockNotFound());
         require(blocksLength <= _maxBlocksPerBatch, TooManyBlocks());
     }

packages/protocol/test/layer1/based/InboxTest_Params.t.sol

@@ -86,7 +86,11 @@ contract InboxTest_Params is InboxTestBase {
         ITaikoInbox.Batch memory parent = inbox.getBatch(1);
 
         ITaikoInbox.BlockParams[] memory blocks = new ITaikoInbox.BlockParams[](1);
-        blocks[0] = ITaikoInbox.BlockParams({ numTransactions: 0, timeShift: 0 });
+        blocks[0] = ITaikoInbox.BlockParams({
+            numTransactions: 0,
+            timeShift: 0,
+            signalSlots: new bytes32[](0)
+        });
 
         ITaikoInbox.BatchParams memory params;
         params.blocks = new ITaikoInbox.BlockParams[](1);

packages/protocol/test/layer1/preconf/mocks/MockTaikoInbox.sol

@@ -26,7 +26,6 @@ contract MockTaikoInbox is EssentialContract {
         info_ = ITaikoInbox.BatchInfo({
             txsHash: keccak256(_txList),
             blobHashes: new bytes32[](0),
-            signalSlots: new bytes32[](0),
             blobByteOffset: 0,
             blobByteSize: 0,
             extraData: bytes32(0),

packages/protocol/test/layer1/preconf/router/RouterTest.t.sol

@@ -30,7 +30,11 @@ contract RouterTest is RouterTestBase {
 
         // Setup block params
         ITaikoInbox.BlockParams[] memory blockParams = new ITaikoInbox.BlockParams[](1);
-        blockParams[0] = ITaikoInbox.BlockParams({ numTransactions: 1, timeShift: 1 });
+        blockParams[0] = ITaikoInbox.BlockParams({
+            numTransactions: 1,
+            timeShift: 1,
+            signalSlots: new bytes32[](0)
+        });
 
         ITaikoInbox.BlobParams memory blobParams;
 
@@ -43,7 +47,6 @@ contract RouterTest is RouterTestBase {
             anchorInput: bytes32(0),
             lastBlockTimestamp: uint64(block.timestamp),
             revertIfNotFirstProposal: false,
-            signalSlots: new bytes32[](0),
             blobParams: blobParams,
             blocks: blockParams
         });
@@ -115,7 +118,11 @@ contract RouterTest is RouterTestBase {
 
         // Setup block params
         ITaikoInbox.BlockParams[] memory blockParams = new ITaikoInbox.BlockParams[](1);
-        blockParams[0] = ITaikoInbox.BlockParams({ numTransactions: 1, timeShift: 1 });
+        blockParams[0] = ITaikoInbox.BlockParams({
+            numTransactions: 1,
+            timeShift: 1,
+            signalSlots: new bytes32[](0)
+        });
 
         ITaikoInbox.BlobParams memory blobParams;
 
@@ -128,7 +135,6 @@ contract RouterTest is RouterTestBase {
             anchorInput: bytes32(0),
             lastBlockTimestamp: uint64(block.timestamp),
             revertIfNotFirstProposal: false,
-            signalSlots: new bytes32[](0),
             blobParams: blobParams,
             blocks: blockParams
         });