feat(protocol): temporarily force an oracle prover to be the first prover

packages/protocol/contracts/L1/TaikoData.sol

@@ -40,6 +40,7 @@ library TaikoData {
         uint64 initialUncleDelay;
         bool enableTokenomics;
         bool enablePublicInputsCheck;
+        bool enableOracleProver;
     }
 
     struct BlockMetadata {

packages/protocol/contracts/L1/libs/LibProposing.sol

@@ -59,10 +59,10 @@ library LibProposing {
         // the tokenomics.
 
         // TODO(daniel): remove this special address.
-        address specialProposer = resolver.resolve("special_proposer", true);
+        address soloProposer = resolver.resolve("solo_proposer", true);
         require(
-            specialProposer == address(0) || specialProposer == msg.sender,
-            "L1:specialProposer"
+            soloProposer == address(0) || soloProposer == msg.sender,
+            "L1:soloProposer"
         );
 
         assert(!LibUtils.isHalted(state));

packages/protocol/contracts/L1/libs/LibProving.sol

@@ -248,15 +248,27 @@ library LibProving {
             meta: evidence.meta
         });
 
-        bytes32 blockHash = evidence.header.hashBlockHeader();
-
         // For alpha-2 testnet, the network allows any address to submit ZKP,
         // but a special prover can skip ZKP verification if the ZKP is empty.
 
+        bool skipZKPVerification;
+
         // TODO(daniel): remove this special address.
-        if (msg.sender == resolver.resolve("special_prover", true)) {
-            // Skip ZKP verification
-        } else {
+        if (config.enableOracleProver) {
+            bytes32 _blockHash = state
+            .forkChoices[target.id][evidence.header.parentHash].blockHash;
+
+            if (msg.sender == resolver.resolve("oracle_prover", false)) {
+                require(_blockHash == 0, "L1:mustBeFirstProver");
+                skipZKPVerification = true;
+            } else {
+                require(_blockHash != 0, "L1:mustNotBeFirstProver");
+            }
+        }
+
+        bytes32 blockHash = evidence.header.hashBlockHeader();
+
+        if (!skipZKPVerification) {
             for (uint256 i = 0; i < config.zkProofsPerBlock; ++i) {
                 require(
                     proofVerifier.verifyZKP({
@@ -301,23 +313,25 @@ library LibProving {
         ];
 
         if (fc.blockHash == 0) {
+            // This is the first proof for this block.
             fc.blockHash = blockHash;
-            fc.provenAt = uint64(block.timestamp);
-        } else {
-            if (fc.blockHash != blockHash) {
-                // We have a problem here: two proofs are both valid but claims
-                // the new block has different hashes.
-                LibUtils.halt(state, true);
-                return;
-            }
 
+            if (!config.enableOracleProver) {
+                // If the oracle prover is not enabled
+                // we use the first prover's timestamp
+                fc.provenAt = uint64(block.timestamp);
+            } else {
+                // We keep fc.provenAt as 0.
+            }
+        } else {
             require(
                 fc.provers.length < config.maxProofsPerForkChoice,
                 "L1:proof:tooMany"
             );
 
             require(
-                block.timestamp <
+                fc.provenAt == 0 ||
+                    block.timestamp <
                     LibUtils.getUncleProofDeadline({
                         state: state,
                         config: config,
@@ -330,6 +344,23 @@ library LibProving {
             for (uint256 i = 0; i < fc.provers.length; ++i) {
                 require(fc.provers[i] != prover, "L1:prover:dup");
             }
+
+            if (fc.blockHash != blockHash) {
+                // We have a problem here: two proofs are both valid but claims
+                // the new block has different hashes.
+                if (config.enableOracleProver) {
+                    revert("L1:proof:conflict");
+                } else {
+                    LibUtils.halt(state, true);
+                    return;
+                }
+            }
+
+            if (config.enableOracleProver && fc.provenAt == 0) {
+                // If the oracle prover is enabled, we
+                // use the second prover's timestamp.
+                fc.provenAt = uint64(block.timestamp);
+            }
         }
 
         fc.provers.push(prover);

packages/protocol/contracts/L1/libs/LibVerifying.sol

@@ -153,22 +153,35 @@ library LibVerifying {
     }
 
     function _rewardProvers(
+        TaikoData.Config memory config,
         TaikoData.ForkChoice storage fc,
         uint256 reward,
         TkoToken tkoToken
     ) private {
-        uint sum = 2 ** fc.provers.length - 1;
-        for (uint i = 0; i < fc.provers.length; ++i) {
-            uint weight = (1 << (fc.provers.length - i - 1));
+        uint start;
+        uint count = fc.provers.length;
+
+        if (config.enableOracleProver) {
+            start = 1;
+            count -= 1;
+        }
+
+        uint sum = (1 << count) - 1;
+        uint weight = 1 << (count - 1);
+        for (uint i = 0; i < count; ++i) {
             uint proverReward = (reward * weight) / sum;
+            if (proverReward == 0) {
+                break;
+            }
 
-            if (tkoToken.balanceOf(fc.provers[i]) == 0) {
+            if (tkoToken.balanceOf(fc.provers[start + i]) == 0) {
                 // Reduce reward to 1 wei as a penalty if the prover
                 // has 0 TKO balance. This allows the next prover reward
                 // to be fully paid.
                 proverReward = uint256(1);
             }
-            tkoToken.mint(fc.provers[i], proverReward);
+            tkoToken.mint(fc.provers[start + i], proverReward);
+            weight = weight >> 1;
         }
     }
 
@@ -197,7 +210,7 @@ library LibVerifying {
                     resolver.resolve("tko_token", false)
                 );
 
-                _rewardProvers(fc, reward, tkoToken);
+                _rewardProvers(config, fc, reward, tkoToken);
                 _refundProposerDeposit(target, tRelBp, tkoToken);
             }
             // Update feeBase and avgProofTime
@@ -241,6 +254,8 @@ library LibVerifying {
         uint256 blockId
     ) private view returns (bool) {
         return
+            // TODO(daniel): remove the next line.
+            (!config.enableOracleProver || fc.provers.length > 1) &&
             fc.blockHash != 0 &&
             block.timestamp >
             LibUtils.getUncleProofDeadline({

packages/protocol/contracts/libs/LibSharedConfig.sol

@@ -41,8 +41,9 @@ library LibSharedConfig {
                 proofTimeCap: 60 minutes,
                 bootstrapDiscountHalvingPeriod: 180 days,
                 initialUncleDelay: 60 minutes,
-                enableTokenomics: false,
-                enablePublicInputsCheck: true
+                enableTokenomics: true,
+                enablePublicInputsCheck: true,
+                enableOracleProver: true
             });
     }
 }

packages/protocol/contracts/libs/LibZKP.sol

@@ -18,8 +18,9 @@ library LibZKP {
         address prover,
         bytes32 txListHash
     ) internal view returns (bool verified) {
-        // TODO(david):public input is assembled in client software for testing purposes right now, move this part of logic
-        //    to here.
+        // TODO(david):public input is assembled in client software
+        // for testing purposes right now, move this part of logic
+        // here in this contract.
         (verified, ) = plonkVerifier.staticcall(zkproof);
     }
 }

packages/protocol/contracts/test/L1/TestTaikoL1.sol

@@ -49,6 +49,7 @@ contract TestTaikoL1 is TaikoL1, IProofVerifier {
         config.initialUncleDelay = 1 minutes;
         config.enableTokenomics = false;
         config.enablePublicInputsCheck = true;
+        config.enableOracleProver = false;
     }
 
     function verifyZKP(

packages/protocol/contracts/test/L1/TestTaikoL1EnableTokenomics.sol

@@ -49,6 +49,7 @@ contract TestTaikoL1EnableTokenomics is TaikoL1, IProofVerifier {
         config.initialUncleDelay = 1 seconds;
         config.enableTokenomics = true;
         config.enablePublicInputsCheck = false;
+        config.enableOracleProver = false;
     }
 
     function verifyZKP(

packages/protocol/contracts/test/L1/TestTaikoL2.sol

@@ -50,5 +50,6 @@ contract TestTaikoL2 is TaikoL2 {
         config.initialUncleDelay = 1 minutes;
         config.enableTokenomics = true;
         config.enablePublicInputsCheck = false;
+        config.enableOracleProver = false;
     }
 }

packages/protocol/contracts/test/L1/TestTaikoL2EnablePublicInputsCheck.sol

@@ -50,5 +50,6 @@ contract TestTaikoL2EnablePublicInputsCheck is TaikoL2 {
         config.initialUncleDelay = 1 minutes;
         config.enableTokenomics = true;
         config.enablePublicInputsCheck = true;
+        config.enableOracleProver = false;
     }
 }