Utilize EIP-7201 as storage layout

.gas-snapshot

@@ -1,75 +1,75 @@
-IBCBenchmarks:testAcknowledgePacket() (gas: 98678)
-IBCBenchmarks:testCreateMockClient() (gas: 217244)
-IBCBenchmarks:testRecvPacket() (gas: 155487)
-IBCBenchmarks:testSendPacket() (gas: 95329)
+IBCBenchmarks:testAcknowledgePacket() (gas: 98040)
+IBCBenchmarks:testCreateMockClient() (gas: 216997)
+IBCBenchmarks:testRecvPacket() (gas: 154889)
+IBCBenchmarks:testSendPacket() (gas: 94843)
 IBCBenchmarks:testUpdateMockClientDirectly() (gas: 64879)
-IBCBenchmarks:testUpdateMockClientViaHandler() (gas: 148205)
-IBCMockAppTest:testHandshake() (gas: 4343205)
-IBCMockAppTest:testHandshakeBetweenDifferentPorts() (gas: 3286459)
-IBCMockAppTest:testPacketRelay() (gas: 11692905)
-IBCMockAppTest:testPacketTimeout() (gas: 4242242)
+IBCBenchmarks:testUpdateMockClientViaHandler() (gas: 148239)
+IBCMockAppTest:testHandshake() (gas: 4161353)
+IBCMockAppTest:testHandshakeBetweenDifferentPorts() (gas: 3104214)
+IBCMockAppTest:testPacketRelay() (gas: 11460317)
+IBCMockAppTest:testPacketTimeout() (gas: 4059417)
 ICS24HostTest:testValidatePortIdentifier() (gas: 44476)
-TestICS02:testCreateClient() (gas: 30153096)
+TestICS02:testCreateClient() (gas: 30572814)
 TestICS02:testHeightToUint128((uint64,uint64)) (runs: 256, μ: 907, ~: 907)
-TestICS02:testInvalidCreateClient() (gas: 30038762)
-TestICS02:testInvalidUpdateClient() (gas: 30042040)
-TestICS02:testRegisterClient() (gas: 29702122)
-TestICS02:testRegisterClientDuplicatedClientType() (gas: 29688342)
-TestICS02:testRegisterClientInvalidClientType() (gas: 29717304)
-TestICS02:testUpdateClient() (gas: 30208564)
-TestICS03Handshake:testConnOpenAck() (gas: 1811332)
-TestICS03Handshake:testConnOpenConfirm() (gas: 1989221)
-TestICS03Handshake:testConnOpenInit() (gas: 1423613)
-TestICS03Handshake:testConnOpenTry() (gas: 2348126)
-TestICS03Handshake:testInvalidConnOpenAck() (gas: 2323078)
-TestICS03Handshake:testInvalidConnOpenConfirm() (gas: 2421885)
-TestICS03Handshake:testInvalidConnOpenInit() (gas: 777600)
-TestICS03Handshake:testInvalidConnOpenTry() (gas: 2283933)
+TestICS02:testInvalidCreateClient() (gas: 30458130)
+TestICS02:testInvalidUpdateClient() (gas: 30461817)
+TestICS02:testRegisterClient() (gas: 30122086)
+TestICS02:testRegisterClientDuplicatedClientType() (gas: 30108306)
+TestICS02:testRegisterClientInvalidClientType() (gas: 30137268)
+TestICS02:testUpdateClient() (gas: 30628415)
+TestICS03Handshake:testConnOpenAck() (gas: 1810871)
+TestICS03Handshake:testConnOpenConfirm() (gas: 1988723)
+TestICS03Handshake:testConnOpenInit() (gas: 1422940)
+TestICS03Handshake:testConnOpenTry() (gas: 2347689)
+TestICS03Handshake:testInvalidConnOpenAck() (gas: 2322689)
+TestICS03Handshake:testInvalidConnOpenConfirm() (gas: 2421514)
+TestICS03Handshake:testInvalidConnOpenInit() (gas: 776893)
+TestICS03Handshake:testInvalidConnOpenTry() (gas: 2283346)
 TestICS03Version:testCopyVersions() (gas: 570207)
 TestICS03Version:testFindSupportedVersion() (gas: 34452)
 TestICS03Version:testIsSupportedVersion() (gas: 13568)
 TestICS03Version:testPickVersion() (gas: 37836)
 TestICS03Version:testVerifyProposedVersion() (gas: 21308)
 TestICS03Version:testVerifySupportedFeature() (gas: 10229)
-TestICS04Handshake:testBindPort() (gas: 456271)
-TestICS04Handshake:testChanClose() (gas: 12800640)
-TestICS04Handshake:testChanOpenAck() (gas: 3428597)
-TestICS04Handshake:testChanOpenConfirm() (gas: 3724273)
-TestICS04Handshake:testChanOpenInit() (gas: 2535741)
-TestICS04Handshake:testChanOpenTry() (gas: 3083807)
-TestICS04Handshake:testInvalidChanOpenAck() (gas: 2411670)
-TestICS04Handshake:testInvalidChanOpenConfirm() (gas: 2486327)
-TestICS04Handshake:testInvalidChanOpenInit() (gas: 1730517)
-TestICS04Handshake:testInvalidChanOpenTry() (gas: 1742638)
-TestICS04Packet:testAcknowledgementPacket() (gas: 3316365)
-TestICS04Packet:testInvalidSendPacket() (gas: 3476451)
-TestICS04Packet:testRecvPacket() (gas: 9965223)
-TestICS04Packet:testRecvPacketTimeoutHeight() (gas: 3236945)
-TestICS04Packet:testRecvPacketTimeoutTimestamp() (gas: 3261000)
-TestICS04Packet:testSendPacket() (gas: 4583983)
-TestICS04Packet:testTimeoutOnClose() (gas: 3488144)
-TestICS04Upgrade:testCrossingHelloInconsistentVersions() (gas: 9918550)
-TestICS04Upgrade:testUpgradeAuthorityCancel() (gas: 46157666)
-TestICS04Upgrade:testUpgradeCannotCancelWithOldErrorReceipt() (gas: 3392338)
-TestICS04Upgrade:testUpgradeCannotRecvNextUpgradePacket() (gas: 5230053)
-TestICS04Upgrade:testUpgradeCounterpartyAdvanceNextSequenceBeforeOpen() (gas: 5191254)
-TestICS04Upgrade:testUpgradeCrossingHelloIncompatibleProposals() (gas: 4944387)
-TestICS04Upgrade:testUpgradeFull() (gas: 55984957)
-TestICS04Upgrade:testUpgradeInit() (gas: 3018393)
-TestICS04Upgrade:testUpgradeNoChanges() (gas: 2433786)
-TestICS04Upgrade:testUpgradeNotUpgradableModule() (gas: 3533495)
-TestICS04Upgrade:testUpgradeOutOfSync() (gas: 3826003)
-TestICS04Upgrade:testUpgradeRelaySuccessAtCounterpartyFlushComplete() (gas: 5201982)
-TestICS04Upgrade:testUpgradeRelaySuccessAtFlushing() (gas: 5575834)
-TestICS04Upgrade:testUpgradeSendPacketFailAtFlushingOrFlushComplete() (gas: 4012928)
-TestICS04Upgrade:testUpgradeTimeoutAbortAck() (gas: 17445807)
-TestICS04Upgrade:testUpgradeTimeoutAbortConfirm() (gas: 21062598)
-TestICS04Upgrade:testUpgradeTimeoutUpgrade() (gas: 70448064)
-TestICS04Upgrade:testUpgradeToOrdered() (gas: 53937015)
-TestICS04Upgrade:testUpgradeToUnordered() (gas: 43053273)
+TestICS04Handshake:testBindPort() (gas: 456448)
+TestICS04Handshake:testChanClose() (gas: 12159113)
+TestICS04Handshake:testChanOpenAck() (gas: 3242588)
+TestICS04Handshake:testChanOpenConfirm() (gas: 3538396)
+TestICS04Handshake:testChanOpenInit() (gas: 2395187)
+TestICS04Handshake:testChanOpenTry() (gas: 2897666)
+TestICS04Handshake:testInvalidChanOpenAck() (gas: 2317011)
+TestICS04Handshake:testInvalidChanOpenConfirm() (gas: 2391668)
+TestICS04Handshake:testInvalidChanOpenInit() (gas: 1677250)
+TestICS04Handshake:testInvalidChanOpenTry() (gas: 1692203)
+TestICS04Packet:testAcknowledgementPacket() (gas: 3111231)
+TestICS04Packet:testInvalidSendPacket() (gas: 3294851)
+TestICS04Packet:testRecvPacket() (gas: 9485947)
+TestICS04Packet:testRecvPacketTimeoutHeight() (gas: 3053625)
+TestICS04Packet:testRecvPacketTimeoutTimestamp() (gas: 3077674)
+TestICS04Packet:testSendPacket() (gas: 4393823)
+TestICS04Packet:testTimeoutOnClose() (gas: 3304892)
+TestICS04Upgrade:testCrossingHelloInconsistentVersions() (gas: 9730721)
+TestICS04Upgrade:testUpgradeAuthorityCancel() (gas: 44972623)
+TestICS04Upgrade:testUpgradeCannotCancelWithOldErrorReceipt() (gas: 3296637)
+TestICS04Upgrade:testUpgradeCannotRecvNextUpgradePacket() (gas: 5124643)
+TestICS04Upgrade:testUpgradeCounterpartyAdvanceNextSequenceBeforeOpen() (gas: 5087713)
+TestICS04Upgrade:testUpgradeCrossingHelloIncompatibleProposals() (gas: 4843978)
+TestICS04Upgrade:testUpgradeFull() (gas: 55696695)
+TestICS04Upgrade:testUpgradeInit() (gas: 2925072)
+TestICS04Upgrade:testUpgradeNoChanges() (gas: 2342343)
+TestICS04Upgrade:testUpgradeNotUpgradableModule() (gas: 3442666)
+TestICS04Upgrade:testUpgradeOutOfSync() (gas: 3727867)
+TestICS04Upgrade:testUpgradeRelaySuccessAtCounterpartyFlushComplete() (gas: 5097250)
+TestICS04Upgrade:testUpgradeRelaySuccessAtFlushing() (gas: 5469407)
+TestICS04Upgrade:testUpgradeSendPacketFailAtFlushingOrFlushComplete() (gas: 3907425)
+TestICS04Upgrade:testUpgradeTimeoutAbortAck() (gas: 17323669)
+TestICS04Upgrade:testUpgradeTimeoutAbortConfirm() (gas: 20920588)
+TestICS04Upgrade:testUpgradeTimeoutUpgrade() (gas: 68891924)
+TestICS04Upgrade:testUpgradeToOrdered() (gas: 52805680)
+TestICS04Upgrade:testUpgradeToUnordered() (gas: 42151776)
 TestICS04UpgradeApp:testUpgradeAuthorizationChanneNotFound() (gas: 62062)
-TestICS04UpgradeApp:testUpgradeAuthorizationRePropose() (gas: 2456047)
-TestICS04UpgradeApp:testUpgradeAuthorizationRemove() (gas: 2436473)
+TestICS04UpgradeApp:testUpgradeAuthorizationRePropose() (gas: 2365121)
+TestICS04UpgradeApp:testUpgradeAuthorizationRemove() (gas: 2345567)
 TestICS20:testAddressToHex(address) (runs: 256, μ: 26850, ~: 27044)
 TestICS20:testHexToAddress(string) (runs: 256, μ: 4636, ~: 4595)
 TestICS20:testIsEscapedString() (gas: 62745)

contracts/clients/qbft/QBFTClient.sol

@@ -71,7 +71,8 @@ contract QBFTClient is ILightClient, ILightClientErrors {
     bytes32 internal constant CONSENSUS_STATE_TYPE_URL_HASH =
         keccak256(abi.encodePacked("/ibc.lightclients.qbft.v1.ConsensusState"));
 
-    uint256 internal constant COMMITMENT_SLOT = 0;
+    // keccak256(abi.encode(uint256(keccak256("ibc.commitment")) - 1)) & ~bytes32(uint256(0xff))
+    bytes32 internal constant COMMITMENT_SLOT = 0x1ee222554989dda120e26ecacf756fe1235cd8d726706b57517715dde4f0c900;
     uint8 internal constant ACCOUNT_STORAGE_ROOT_INDEX = 2;
 
     address public immutable ibcHandler;

contracts/core/02-client/IBCClient.sol

@@ -17,16 +17,18 @@ contract IBCClient is IBCHost, IIBCClient, IIBCClientErrors {
      * @dev createClient creates a new client state and populates it with a given consensus state
      */
     function createClient(MsgCreateClient calldata msg_) external override returns (string memory clientId) {
-        address clientImpl = clientRegistry[msg_.clientType];
+        address clientImpl = getHostStorage().clientRegistry[msg_.clientType];
         if (clientImpl == address(0)) {
             revert IBCClientUnregisteredClientType(msg_.clientType);
         }
         clientId = generateClientIdentifier(msg_.clientType);
-        clientTypes[clientId] = msg_.clientType;
-        clientImpls[clientId] = clientImpl;
+        ClientStorage storage client = getClientStorage()[clientId];
+        client.clientType = msg_.clientType;
+        client.clientImpl = clientImpl;
         Height.Data memory height =
             ILightClient(clientImpl).initializeClient(clientId, msg_.protoClientState, msg_.protoConsensusState);
         // update commitments
+        mapping(bytes32 => bytes32) storage commitments = getCommitments();
         commitments[IBCCommitment.clientStateCommitmentKey(clientId)] = keccak256(msg_.protoClientState);
         commitments[IBCCommitment.consensusStateCommitmentKey(clientId, height.revision_number, height.revision_height)]
         = keccak256(msg_.protoConsensusState);
@@ -83,6 +85,7 @@ contract IBCClient is IBCHost, IIBCClient, IIBCClientErrors {
         if (!found) {
             revert IBCClientClientNotFound(clientId);
         }
+        mapping(bytes32 => bytes32) storage commitments = getCommitments();
         commitments[IBCCommitment.clientStateCommitmentKey(clientId)] = keccak256(clientState);
         for (uint256 i = 0; i < heights.length; i++) {
             (consensusState, found) = lc.getConsensusState(clientId, heights[i]);
@@ -102,9 +105,11 @@ contract IBCClient is IBCHost, IIBCClient, IIBCClientErrors {
     /**
      * @dev generateClientIdentifier generates a new client identifier for a given client type
      */
-    function generateClientIdentifier(string calldata clientType) private returns (string memory) {
-        string memory identifier = string(abi.encodePacked(clientType, "-", Strings.toString(nextClientSequence)));
-        nextClientSequence++;
+    function generateClientIdentifier(string calldata clientType) internal returns (string memory) {
+        HostStorage storage hostStorage = getHostStorage();
+        string memory identifier =
+            string(abi.encodePacked(clientType, "-", Strings.toString(hostStorage.nextClientSequence)));
+        hostStorage.nextClientSequence++;
         return identifier;
     }
 }

contracts/core/03-connection/IBCConnection.sol

@@ -26,7 +26,7 @@ abstract contract IBCConnection is IBCHost, IBCSelfStateValidator, IIBCConnectio
         returns (string memory)
     {
         string memory connectionId = generateConnectionIdentifier();
-        ConnectionEnd.Data storage connection = connections[connectionId];
+        ConnectionEnd.Data storage connection = getConnectionStorage()[connectionId].connection;
         if (connection.state != ConnectionEnd.State.STATE_UNINITIALIZED_UNSPECIFIED) {
             revert IBCConnectionAlreadyConnectionExists();
         }
@@ -71,7 +71,7 @@ abstract contract IBCConnection is IBCHost, IBCSelfStateValidator, IIBCConnectio
         bytes memory selfConsensusState = getSelfConsensusState(msg_.consensusHeight, msg_.hostConsensusStateProof);
 
         string memory connectionId = generateConnectionIdentifier();
-        ConnectionEnd.Data storage connection = connections[connectionId];
+        ConnectionEnd.Data storage connection = getConnectionStorage()[connectionId].connection;
         if (connection.state != ConnectionEnd.State.STATE_UNINITIALIZED_UNSPECIFIED) {
             revert IBCConnectionAlreadyConnectionExists();
         }
@@ -120,7 +120,7 @@ abstract contract IBCConnection is IBCHost, IBCSelfStateValidator, IIBCConnectio
      * to chain A (this code is executed on chain A).
      */
     function connectionOpenAck(IIBCConnection.MsgConnectionOpenAck calldata msg_) external override {
-        ConnectionEnd.Data storage connection = connections[msg_.connectionId];
+        ConnectionEnd.Data storage connection = getConnectionStorage()[msg_.connectionId].connection;
         if (connection.state != ConnectionEnd.State.STATE_INIT) {
             revert IBCConnectionUnexpectedConnectionState(connection.state);
         }
@@ -169,7 +169,7 @@ abstract contract IBCConnection is IBCHost, IBCSelfStateValidator, IIBCConnectio
      * which the connection is open on both chains (this code is executed on chain B).
      */
     function connectionOpenConfirm(IIBCConnection.MsgConnectionOpenConfirm calldata msg_) external override {
-        ConnectionEnd.Data storage connection = connections[msg_.connectionId];
+        ConnectionEnd.Data storage connection = getConnectionStorage()[msg_.connectionId].connection;
         if (connection.state != ConnectionEnd.State.STATE_TRYOPEN) {
             revert IBCConnectionUnexpectedConnectionState(connection.state);
         }
@@ -194,12 +194,29 @@ abstract contract IBCConnection is IBCHost, IBCSelfStateValidator, IIBCConnectio
         updateConnectionCommitment(msg_.connectionId);
     }
 
-    function updateConnectionCommitment(string memory connectionId) private {
-        commitments[IBCCommitment.connectionCommitmentKey(connectionId)] =
-            keccak256(ConnectionEnd.encode(connections[connectionId]));
+    /**
+     * @dev getCompatibleVersions returns the supported versions of the host chain.
+     */
+    function getCompatibleVersions() public pure virtual returns (Version.Data[] memory) {
+        Version.Data[] memory versions = new Version.Data[](1);
+        versions[0] = IBCConnectionLib.defaultIBCVersion();
+        return versions;
     }
 
-    /* Verification functions */
+    // --------- Private Functions --------- //
+
+    function generateConnectionIdentifier() private returns (string memory) {
+        HostStorage storage hostStorage = getHostStorage();
+        string memory identifier =
+            string(abi.encodePacked("connection-", Strings.toString(hostStorage.nextConnectionSequence)));
+        hostStorage.nextConnectionSequence++;
+        return identifier;
+    }
+
+    function updateConnectionCommitment(string memory connectionId) private {
+        getCommitments()[IBCCommitment.connectionCommitmentKey(connectionId)] =
+            keccak256(ConnectionEnd.encode(getConnectionStorage()[connectionId].connection));
+    }
 
     function verifyClientState(
         ConnectionEnd.Data storage connection,
@@ -294,21 +311,4 @@ abstract contract IBCConnection is IBCHost, IBCSelfStateValidator, IIBCConnectio
             height
         );
     }
-
-    /**
-     * @dev getCompatibleVersions returns the supported versions of the host chain.
-     */
-    function getCompatibleVersions() public pure virtual returns (Version.Data[] memory) {
-        Version.Data[] memory versions = new Version.Data[](1);
-        versions[0] = IBCConnectionLib.defaultIBCVersion();
-        return versions;
-    }
-
-    /* Internal functions */
-
-    function generateConnectionIdentifier() private returns (string memory) {
-        string memory identifier = string(abi.encodePacked("connection-", Strings.toString(nextConnectionSequence)));
-        nextConnectionSequence++;
-        return identifier;
-    }
 }