chore(fast-inbox): emit inbox lag and checkpoint cap from the constants generator (A-1434)

Add INBOX_LAG_SECONDS and MAX_L1_TO_L2_MSGS_PER_CHECKPOINT to the Solidity
constants allowlist so the generator emits them into ConstantsGen.sol, matching
the values already present in constants.gen.ts. ProposeLib and its consumption
test now read the generated Constants library instead of the hand-declared
file-scope copies, giving L1 and TS a single source of truth.

Author: spalladino

l1-contracts/src/core/libraries/ConstantsGen.sol

@@ -16,6 +16,8 @@ library Constants {
   uint256 internal constant MAX_FIELD_VALUE =
     21_888_242_871_839_275_222_246_405_745_257_275_088_548_364_400_416_034_343_698_204_186_575_808_495_616;
   uint256 internal constant L1_TO_L2_MSG_SUBTREE_HEIGHT = 10;
+  uint256 internal constant MAX_L1_TO_L2_MSGS_PER_CHECKPOINT = 1024;
+  uint256 internal constant INBOX_LAG_SECONDS = 12;
   uint256 internal constant MAX_L2_TO_L1_MSGS_PER_TX = 8;
   uint256 internal constant INITIAL_CHECKPOINT_NUMBER = 1;
   uint256 internal constant MAX_CHECKPOINTS_PER_EPOCH = 32;

l1-contracts/src/core/libraries/rollup/ProposeLib.sol

@@ -3,6 +3,7 @@
 pragma solidity >=0.8.27;
 
 import {BlobLib} from "@aztec-blob-lib/BlobLib.sol";
+import {Constants} from "@aztec/core/libraries/ConstantsGen.sol";
 import {IEscapeHatch} from "@aztec/core/interfaces/IEscapeHatch.sol";
 import {RollupStore, IRollupCore, CheckpointHeaderValidationFlags} from "@aztec/core/interfaces/IRollup.sol";
 import {IInbox} from "@aztec/core/interfaces/messagebridge/IInbox.sol";
@@ -22,14 +23,6 @@ import {SafeCast} from "@oz/utils/math/SafeCast.sol";
 import {ProposedHeader, ProposedHeaderLib} from "./ProposedHeaderLib.sol";
 import {STFLib} from "./STFLib.sol";
 
-// Streaming-inbox protocol constants (AZIP-22 Fast Inbox). These mirror the protocol circuit constants and
-// should move into the generated Constants library once the Solidity emitter includes them.
-// Minimum bucket age, in seconds, at the start of a checkpoint's build frame for its consumption to be
-// mandatory. One L1 slot: validators cannot be required to act on buckets they may not have seen.
-uint256 constant INBOX_LAG_SECONDS = 12;
-// Maximum number of L1 to L2 messages a single checkpoint can insert.
-uint256 constant MAX_L1_TO_L2_MSGS_PER_CHECKPOINT = 1024;
-
 struct ProposeArgs {
   bytes32 archive;
   OracleInput oracleInput;
@@ -453,17 +446,17 @@ library ProposeLib {
     );
 
     require(
-      bucket.totalMsgCount - _parentTotalMsgCount <= MAX_L1_TO_L2_MSGS_PER_CHECKPOINT,
+      bucket.totalMsgCount - _parentTotalMsgCount <= Constants.MAX_L1_TO_L2_MSGS_PER_CHECKPOINT,
       Errors.Rollup__TooManyInboxMessagesConsumed(bucket.totalMsgCount - _parentTotalMsgCount)
     );
 
     if (_bucketHint < _inbox.getCurrentBucketSeq()) {
       IInbox.InboxBucket memory next = _inbox.getBucket(_bucketHint + 1);
       Timestamp buildFrameStart = TimeLib.toTimestamp(_slotNumber - Slot.wrap(1));
-      Timestamp cutoff = buildFrameStart - Timestamp.wrap(INBOX_LAG_SECONDS);
+      Timestamp cutoff = buildFrameStart - Timestamp.wrap(Constants.INBOX_LAG_SECONDS);
       require(
         next.timestamp > Timestamp.unwrap(cutoff)
-          || next.totalMsgCount - _parentTotalMsgCount > MAX_L1_TO_L2_MSGS_PER_CHECKPOINT,
+          || next.totalMsgCount - _parentTotalMsgCount > Constants.MAX_L1_TO_L2_MSGS_PER_CHECKPOINT,
         Errors.Rollup__UnconsumedInboxMessages(_bucketHint + 1)
       );
     }

l1-contracts/test/rollup/ProposeInboxConsumption.t.sol

@@ -6,11 +6,8 @@ import {Test} from "forge-std/Test.sol";
 import {TestERC20} from "src/mock/TestERC20.sol";
 import {IERC20} from "@oz/token/ERC20/IERC20.sol";
 import {IInbox} from "@aztec/core/interfaces/messagebridge/IInbox.sol";
-import {
-  ProposeLib,
-  INBOX_LAG_SECONDS,
-  MAX_L1_TO_L2_MSGS_PER_CHECKPOINT
-} from "@aztec/core/libraries/rollup/ProposeLib.sol";
+import {ProposeLib} from "@aztec/core/libraries/rollup/ProposeLib.sol";
+import {Constants} from "@aztec/core/libraries/ConstantsGen.sol";
 import {TimeLib, Slot, Timestamp} from "@aztec/core/libraries/TimeLib.sol";
 import {Errors} from "@aztec/core/libraries/Errors.sol";
 import {DataStructures} from "@aztec/core/libraries/DataStructures.sol";
@@ -50,7 +47,7 @@ contract ProposeInboxConsumptionTest is Test {
   // Start of the build frame for a checkpoint proposed in SLOT: it is built during the previous slot.
   uint256 internal buildFrameStart = GENESIS_TIME + (Slot.unwrap(SLOT) - 1) * SLOT_DURATION;
   // Buckets at or before the cutoff must be consumed by the checkpoint.
-  uint256 internal cutoff = buildFrameStart - INBOX_LAG_SECONDS;
+  uint256 internal cutoff = buildFrameStart - Constants.INBOX_LAG_SECONDS;
 
   function setUp() public {
     vm.warp(GENESIS_TIME);
@@ -123,7 +120,7 @@ contract ProposeInboxConsumptionTest is Test {
     // One more message than the checkpoint cap, all before the cutoff. They spill over into buckets
     // 1..4 of 256 (the per-bucket cap) plus bucket 5 with the single excess message.
     vm.warp(cutoff - 100);
-    _sendMany(MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1);
+    _sendMany(Constants.MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1);
     assertEq(inbox.getCurrentBucketSeq(), 5, "expected five buckets");
 
     vm.warp(GENESIS_TIME + Slot.unwrap(SLOT) * SLOT_DURATION);
@@ -132,12 +129,12 @@ contract ProposeInboxConsumptionTest is Test {
     // even though it is old.
     bytes32 endHash = inbox.getBucket(4).rollingHash;
     uint256 consumed = rollup.validateInboxConsumption(inbox, endHash, 4, SLOT, 0);
-    assertEq(consumed, MAX_L1_TO_L2_MSGS_PER_CHECKPOINT, "consumed the full cap");
+    assertEq(consumed, Constants.MAX_L1_TO_L2_MSGS_PER_CHECKPOINT, "consumed the full cap");
   }
 
   function testNoCapEscapeAtExactCap() public {
     vm.warp(cutoff - 100);
-    _sendMany(MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1);
+    _sendMany(Constants.MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1);
 
     vm.warp(GENESIS_TIME + Slot.unwrap(SLOT) * SLOT_DURATION);
 
@@ -152,7 +149,7 @@ contract ProposeInboxConsumptionTest is Test {
     // Same layout as testCapEscape, but the parent checkpoint had already consumed one message:
     // buckets 2..5 then hold cap messages total, which fit in one checkpoint, so no escape from bucket 1.
     vm.warp(cutoff - 100);
-    _sendMany(MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1);
+    _sendMany(Constants.MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1);
 
     vm.warp(GENESIS_TIME + Slot.unwrap(SLOT) * SLOT_DURATION);
 
@@ -254,14 +251,16 @@ contract ProposeInboxConsumptionTest is Test {
     // One more message than the checkpoint cap, all before the cutoff, referenced in a single proposal from
     // a fresh parent: the consumed delta exceeds what the circuits can insert.
     vm.warp(cutoff - 100);
-    _sendMany(MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1);
+    _sendMany(Constants.MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1);
     assertEq(inbox.getCurrentBucketSeq(), 5, "expected five buckets");
 
     bytes32 endHash = inbox.getBucket(5).rollingHash;
 
     vm.warp(GENESIS_TIME + Slot.unwrap(SLOT) * SLOT_DURATION);
     vm.expectRevert(
-      abi.encodeWithSelector(Errors.Rollup__TooManyInboxMessagesConsumed.selector, MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1)
+      abi.encodeWithSelector(
+        Errors.Rollup__TooManyInboxMessagesConsumed.selector, Constants.MAX_L1_TO_L2_MSGS_PER_CHECKPOINT + 1
+      )
     );
     rollup.validateInboxConsumption(inbox, endHash, 5, SLOT, 0);
   }

yarn-project/constants/src/scripts/constants.in.ts

@@ -352,6 +352,8 @@ const SOLIDITY_CONSTANTS = [
   'MAX_L2_TO_L1_MSGS_PER_TX',
   'EMPTY_EPOCH_OUT_HASH',
   'L1_TO_L2_MSG_SUBTREE_HEIGHT',
+  'MAX_L1_TO_L2_MSGS_PER_CHECKPOINT',
+  'INBOX_LAG_SECONDS',
   'BLS12_POINT_COMPRESSED_BYTES',
   'ROOT_ROLLUP_PUBLIC_INPUTS_LENGTH',
   'INITIAL_CHECKPOINT_NUMBER',