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Merged
ozwaldorf merged 2 commits into from
Feb 10, 2026
Merged

refactor: eliminate memory allocations in calldata parsing #18

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593b37d
refactor: eliminate memory allocations in calldata parsing
g4titanx Feb 10, 2026
13ee790
chore: update artifacts
g4titanx Feb 10, 2026
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2 changes: 1 addition & 1 deletion artifacts/erc20_deployment.hex
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2 changes: 1 addition & 1 deletion artifacts/erc20_runtime.hex
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2 changes: 1 addition & 1 deletion out/EscrowERC20.sol/EscrowERC20.json
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2 changes: 1 addition & 1 deletion out/EscrowNative.sol/EscrowNative.json
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114 changes: 12 additions & 102 deletions src/BlockHeaderParser.sol
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Original file line number Diff line number Diff line change
Expand Up @@ -17,8 +17,6 @@ library BlockHeaderParser {

error InvalidRLPList();
error InvalidRLPEncoding();
error RLPOffsetOutOfBounds();
error ExpectedStringItem();

/**
* @dev Get offset to inner header (skips Tempo wrapper if present)
Expand Down Expand Up @@ -75,15 +73,18 @@ library BlockHeaderParser {
}
}

// Extract block number
(bytes memory numBytes,) = parseItemFromCalldata(blockHeader, offset);

// Decode big-endian number
uint256 blockNumber = 0;
for (uint256 i = 0; i < numBytes.length;) {
blockNumber = (blockNumber << 8) | uint8(numBytes[i]);
unchecked {
++i;
// Extract block number directly from calldata
uint8 prefix = uint8(blockHeader[offset]);
uint256 blockNumber;
if (prefix < 0x80) {
blockNumber = prefix;
} else {
uint256 len = prefix - 0x80;
for (uint256 i = 0; i < len;) {
blockNumber = (blockNumber << 8) | uint8(blockHeader[offset + 1 + i]);
unchecked {
++i;
}
}
}

Expand Down Expand Up @@ -119,97 +120,6 @@ library BlockHeaderParser {
return receiptsRoot;
}

/**
* @dev Parse RLP item from calldata (helper function)
* @param data Calldata containing RLP item
* @param offset Current offset in the data
* @return result Parsed item content
* @return length Total length consumed
*/
function parseItemFromCalldata(bytes calldata data, uint256 offset)
private
pure
returns (bytes memory result, uint256 length)
{
if (offset >= data.length) revert RLPOffsetOutOfBounds();

uint8 prefix = uint8(data[offset]);

if (prefix < 0x80) {
// Single byte
result = new bytes(1);
result[0] = bytes1(prefix);
return (result, 1);
} else if (prefix < 0xb8) {
// Short string
uint256 itemLength = prefix - 0x80;
result = new bytes(itemLength);
for (uint256 i = 0; i < itemLength;) {
result[i] = data[offset + 1 + i];
unchecked {
++i;
}
}
return (result, 1 + itemLength);
} else if (prefix < 0xc0) {
// Long string
uint256 lengthBytes = prefix - 0xb7;
uint256 itemLength = 0;
for (uint256 i = 0; i < lengthBytes;) {
itemLength = (itemLength << 8) | uint8(data[offset + 1 + i]);
unchecked {
++i;
}
}
result = new bytes(itemLength);
for (uint256 i = 0; i < itemLength;) {
result[i] = data[offset + 1 + lengthBytes + i];
unchecked {
++i;
}
}
return (result, 1 + lengthBytes + itemLength);
} else {
revert ExpectedStringItem();
}
}

/**
* @dev Extract state root from block header
* @param blockHeader RLP-encoded block header
* @return State root hash
*/
function extractStateRoot(bytes calldata blockHeader) internal pure returns (bytes32) {
uint256 offset = 0;

// Skip RLP list prefix
if (blockHeader[offset] < 0xc0) revert InvalidRLPList();
if (blockHeader[offset] >= 0xf8) {
offset += 1 + (uint8(blockHeader[offset]) - 0xf7);
} else {
offset += 1;
}

// Skip first 3 fields to get to stateRoot (index 3)
for (uint256 i = 0; i < 3;) {
offset = blockHeader.skipItem(offset);
unchecked {
++i;
}
}

// Extract stateRoot (32 bytes)
if (blockHeader[offset] != 0xa0) revert InvalidRLPEncoding();
offset += 1;

bytes32 stateRoot;
assembly {
stateRoot := calldataload(add(blockHeader.offset, offset))
}

return stateRoot;
}

/**
* @dev Extract transactions root from block header
* @param blockHeader RLP-encoded block header
Expand Down
122 changes: 20 additions & 102 deletions src/ReceiptValidator.sol
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Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,6 @@ library ReceiptValidator {
error WrongEventSignature();
error ToAddressMismatch();
error AmountMismatch();
error ExpectedStringData();
error ReceiptStatusNotSuccess();
error UnsupportedTxType();
error RecipientMismatch();
Expand Down Expand Up @@ -111,52 +110,18 @@ library ReceiptValidator {
}

// Parse emitter address (should be the token contract)
(bytes memory addrBytes, uint256 addrLen) = parseAddressFromRLP(receiptRlp, offset);
if (addrBytes.length != 20) revert InvalidAddress();

// Extract emitter address
if (uint8(receiptRlp[offset]) != 0x94) revert InvalidAddress();
address emitter;
assembly {
emitter := mload(add(addrBytes, 20))
emitter := shr(96, calldataload(add(receiptRlp.offset, add(offset, 1))))
}
if (emitter != tokenContract) revert WrongTokenContract();
offset += addrLen;
offset += 21;

// Parse and validate topics
return validateTransferTopics(receiptRlp, offset, toAddress, expectedAmount);
}

/**
* @dev Parse address from RLP data
* @param data RLP encoded data
* @param offset Current offset
* @return result Parsed address bytes
* @return length Length consumed
*/
function parseAddressFromRLP(bytes calldata data, uint256 offset)
private
pure
returns (bytes memory result, uint256 length)
{
if (offset >= data.length) revert InvalidRLP();

uint8 prefix = uint8(data[offset]);

if (prefix == 0x94) {
// Address is 20 bytes with prefix 0x94
result = new bytes(20);
for (uint256 i = 0; i < 20;) {
result[i] = data[offset + 1 + i];
unchecked {
++i;
}
}
return (result, 21);
} else {
revert InvalidAddress();
}
}

/**
* @dev Validate event topics for Transfer event
* @param receiptRlp The receipt data
Expand Down Expand Up @@ -195,77 +160,30 @@ library ReceiptValidator {

// Parse and validate data payload (amount)
offset = receiptRlp.skipItem(topicsOffset); // Skip entire topics array
(bytes memory dataBytes,) = parseDataFromRLP(receiptRlp, offset);

// Convert data bytes to uint256 (amount)
if (dataBytes.length > 32) revert InvalidRLP();
uint256 logAmount = 0;
for (uint256 i = 0; i < dataBytes.length;) {
logAmount = (logAmount << 8) | uint8(dataBytes[i]);
unchecked {
++i;
uint256 logAmount;
{
uint8 dataPrefix = uint8(receiptRlp[offset]);
if (dataPrefix < 0x80) {
logAmount = dataPrefix;
} else if (dataPrefix == 0x80) {
logAmount = 0;
} else if (dataPrefix <= 0xa0) {
uint256 len = dataPrefix - 0x80;
for (uint256 i = 0; i < len;) {
logAmount = (logAmount << 8) | uint8(receiptRlp[offset + 1 + i]);
unchecked {
++i;
}
}
} else {
revert InvalidRLP();
}
}
if (logAmount != expectedAmount) revert AmountMismatch();

return true;
}

/**
* @dev Parse data field from RLP
* @param data RLP encoded data
* @param offset Current offset
* @return result Parsed data bytes
* @return length Length consumed
*/
function parseDataFromRLP(bytes calldata data, uint256 offset)
private
pure
returns (bytes memory result, uint256 length)
{
if (offset >= data.length) revert InvalidRLP();

uint8 prefix = uint8(data[offset]);

if (prefix < 0x80) {
// Single byte
result = new bytes(1);
result[0] = bytes1(prefix);
return (result, 1);
} else if (prefix < 0xb8) {
// Short string
uint256 dataLength = prefix - 0x80;
result = new bytes(dataLength);
for (uint256 i = 0; i < dataLength;) {
result[i] = data[offset + 1 + i];
unchecked {
++i;
}
}
return (result, 1 + dataLength);
} else if (prefix < 0xc0) {
// Long string
uint256 lengthBytes = prefix - 0xb7;
uint256 dataLength = 0;
for (uint256 i = 0; i < lengthBytes;) {
dataLength = (dataLength << 8) | uint8(data[offset + 1 + i]);
unchecked {
++i;
}
}
result = new bytes(dataLength);
for (uint256 i = 0; i < dataLength;) {
result[i] = data[offset + 1 + lengthBytes + i];
unchecked {
++i;
}
}
return (result, 1 + lengthBytes + dataLength);
} else {
revert ExpectedStringData();
}
}

/**
* @dev Validate receipt status == 1 (successful execution)
* Receipt structure: [status, cumulativeGasUsed, logsBloom, logs]
Expand Down