From dd768ba707747870086e649bcf96b678aff64038 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=C3=A1s=20Gr=C3=BCner?=
 <47506558+MegaRedHand@users.noreply.github.com>
Date: Thu, 6 Aug 2026 13:10:52 -0300
Subject: [PATCH] refactor(types): move the interval grid into ethlambda-types
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ethlambda-storage derives slot and interval from `store.time()` but cannot
depend on ethlambda-blockchain, so it could only document the formula in a
comment rather than use the constants. Housing MILLISECONDS_PER_INTERVAL,
INTERVALS_PER_SLOT and MILLISECONDS_PER_SLOT in ethlambda-types — which both
crates already depend on — removes that asymmetry and keeps a second copy of a
consensus-critical constant from appearing in storage.

Values are unchanged; blockchain re-exports all three so existing imports keep
resolving.
---
 crates/blockchain/src/lib.rs         | 12 ++++++------
 crates/common/types/src/constants.rs |  7 +++++++
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/crates/blockchain/src/lib.rs b/crates/blockchain/src/lib.rs
index 7faa1163..dc4f1268 100644
--- a/crates/blockchain/src/lib.rs
+++ b/crates/blockchain/src/lib.rs
@@ -68,13 +68,13 @@ pub struct BlockChainConfig {
     pub proposer_config: ProposerConfig,
 }
 
-/// Milliseconds per interval (800ms ticks).
-pub const MILLISECONDS_PER_INTERVAL: u64 = 800;
-/// Number of intervals per slot (5 intervals of 800ms = 4 seconds).
-pub const INTERVALS_PER_SLOT: u64 = 5;
-/// Milliseconds in a slot (derived from interval duration and count).
-pub const MILLISECONDS_PER_SLOT: u64 = MILLISECONDS_PER_INTERVAL * INTERVALS_PER_SLOT;
+// The interval grid lives in `ethlambda-types` because `ethlambda-storage` also
+// derives slots from `store.time()` and must not carry a second copy of a
+// consensus-critical constant.
 pub use ethlambda_types::block::MAX_ATTESTATIONS_DATA;
+pub use ethlambda_types::constants::{
+    INTERVALS_PER_SLOT, MILLISECONDS_PER_INTERVAL, MILLISECONDS_PER_SLOT,
+};
 pub use sync_status::SyncStatusController;
 /// Future-slot tolerance for gossip attestations, expressed in intervals.
 ///
diff --git a/crates/common/types/src/constants.rs b/crates/common/types/src/constants.rs
index 3066b344..c3434d9a 100644
--- a/crates/common/types/src/constants.rs
+++ b/crates/common/types/src/constants.rs
@@ -8,3 +8,10 @@
 /// eventually be derived from the fork version and genesis validators root.
 // TODO: derive dynamically once the spec defines fork identification.
 pub const FORK_DIGEST: &str = "12345678";
+
+/// Milliseconds per interval (800ms ticks).
+pub const MILLISECONDS_PER_INTERVAL: u64 = 800;
+/// Number of intervals per slot (5 intervals of 800ms = 4 seconds).
+pub const INTERVALS_PER_SLOT: u64 = 5;
+/// Milliseconds in a slot (derived from interval duration and count).
+pub const MILLISECONDS_PER_SLOT: u64 = MILLISECONDS_PER_INTERVAL * INTERVALS_PER_SLOT;