Read nonce

foundry_test/modules/utils/L2CompressorHuffReadNonce.sol

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.13;
+
+import "foundry_test/base/AdvTest.sol";
+
+import "forge-std/console.sol";
+import "forge-std/console2.sol";
+
+import { HuffConfig } from "foundry-huff/HuffConfig.sol";
+import { HuffDeployer } from "foundry-huff/HuffDeployer.sol";
+
+import "contracts/modules/commons/interfaces/IModuleCalls.sol";
+
+uint256 constant FMS = 0xa0;
+
+import "./L2CompressorEncoder.sol";
+
+contract L2CompressorHuffReadNonceTest is AdvTest {
+  address public imp;
+
+  function setUp() public {
+    imp = address(
+      HuffDeployer
+        .config()
+        .with_evm_version("paris")
+        .deploy("imps/L2CompressorReadNonce")
+    );
+  }
+
+  function test_read_simple_nonce() external {
+    uint256 space = 76518466025766696338879503773554426820412884125;
+    uint256 nonce = 29095922913147819529123945996;
+
+    bytes32 compact = 0x0d6734e95e00251b768924d47d52db3270fcc49d5e039555a5312d84eb305e0c;
+
+    bytes memory encoded = abi.encodePacked(
+      encodeWord(space), encodeWord(nonce)
+    );
+
+    (bool s, bytes memory r) = imp.staticcall(encoded);
+
+    assertTrue(s);
+    (uint256 rindex, uint256 windex, bytes memory res) = abi.decode(r, (uint256, uint256, bytes));
+    assertEq(rindex, encoded.length);
+    assertEq(windex, res.length + FMS);
+
+    assertEq(compact, abi.decode(res, (bytes32)));
+  }
+
+  function test_read_nonce(uint160 _space, uint96 _nonce) external {
+    bytes memory encoded = abi.encodePacked(
+      encodeWord(_space), encodeWord(_nonce)
+    );
+
+    (bool s, bytes memory r) = imp.staticcall(encoded);
+
+    assertTrue(s);
+    (uint256 rindex, uint256 windex, bytes memory res) = abi.decode(r, (uint256, uint256, bytes));
+    assertEq(rindex, encoded.length);
+    assertEq(windex, res.length + FMS);
+
+    assertEq(abi.encodePacked(_space, _nonce), res);
+  }
+}

src/L2Compressor.huff

@@ -451,6 +451,46 @@
   0x03 eq ASSERT() // []
 }
 
+#define macro READ_NONCE_STANDALONE() = takes (2) returns (2) {
+  skip jump
+  rf:
+  READ_FLAG()
+  skip:
+  READ_NONCE(rf)
+}
+
+#define macro READ_NONCE(nrfs) = takes (2) returns (2) {
+  // input stack: [windex, rindex]
+
+  PERFORM_NESTED_READ_FLAG(<nrfs>) // [windex, rindex]
+  BACKREAD_SINGLE_VALUE()          // [val, windex, rindex]
+
+  0x60 shl                         // [space, windex, rindex]
+
+  swap2                            // [rindex, windex, space]
+  swap1                            // [windex, rindex, space]
+
+  PERFORM_NESTED_READ_FLAG(<nrfs>) // [windex, rindex, space]
+  BACKREAD_SINGLE_VALUE()          // [nonce, windex, rindex, space]
+
+  // Assume that we are reading the nonce already masked
+
+  swap1                            // [windex, nonce, rindex, space]
+  swap2                            // [rindex, nonce, windex, space]
+  swap3                            // [space, nonce, windex, rindex]
+  or                               // [(space | nonce), windex, rindex]
+
+  // Now we have the compact representation of the nonce
+  // we can write it to memory on windex
+
+  dup2                             // [windex, (space | nonce), windex, rindex]
+  mstore                           // [windex, rindex]
+
+  0x20 add                         // [windex + 0x20, rindex]
+
+  // output stack: [windex, rindex]
+}
+
 #define macro READ_TRANSACTIONS_STANDALONE() = takes (2) returns (2) {
   skip jump
   rf:

src/imps/L2CompressorReadNonce.huff

@@ -0,0 +1,30 @@
+#include "../L2Compressor.huff"
+
+#define constant FMS = 0xa0
+
+// Function Dispatching
+#define macro MAIN() = takes (1) returns (1) {
+  // readAdvanced with whatever calldata is passed
+  // first 32 bytes returns the new rindex and the next 32 bytes returns the new windex
+
+  0x00          // [rindex]
+  [FMS]         // [windex, rindex]
+
+  READ_NONCE_STANDALONE()   // [windex, rindex]
+
+  [FMS]         // [0xa0, windex, rindex]
+  dup2          // [windex, 0xa0, windex, rindex]
+  sub           // [len, windex, rindex]
+
+  swap2         // [rindex, windex, len]
+
+  0x80 [FMS] sub mstore   // [windex, len]
+  0x60 [FMS] sub mstore   // [len]
+
+  0x60 0x40 [FMS] sub mstore  // [len]
+  dup1 0x20 [FMS] sub mstore  // [len]
+
+  0x80 add      // [len + 0x80]
+
+  0x80 [FMS] sub return
+}