feat: adds actual parent_blockhash to ReplicaBlockInfoV4

[0xzrf]

Summary

Adds actual parent_blockhash in ReplicaBlockInfoV4 in stead of a dummy value

Changes

• Added a new LatestBlockInner::new_with_parent() that takes a parent_blockhash(to avoid breaking existing tests) and a new field LatestBlockInner::parent_blockhash
• Supply the parent_blockhash from apply_replayed_block and prepare_block_as_primary before it's updated to the latest blockhash
• uses the applied parent_blockhash inside notify_block instead of a dummy placeholder

Breaking Changes

• None

Test Plan

Extended existing tests and added new tests to verify the changes. You can run the new tests using:

cargo test -p magicblock-ledger --test get_block test_write_block_stores_parent_blockhash
cargo test -p magicblock-processor --test replica_ordering test_replay_block
cargo test -p magicblock-processor --test scheduling test_primary_slot_transition_sets_parent_blockhash

Summary by CodeRabbit

Release Notes

• Bug Fixes

  • Block metadata now correctly includes parent block information instead of placeholder values, ensuring proper block linkage and chain integrity.

• Tests

  • Added tests to verify parent block hash persistence and correctness during block transitions.

[coderabbitai]

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

Run ID: 30b86a3d-18b0-4b82-9e62-dd8f0b033d55

📥 Commits

Reviewing files that changed from the base of the PR and between 4e6c79c and 00fa35f.

📒 Files selected for processing (6)

• magicblock-aperture/src/geyser.rs
• magicblock-ledger/src/lib.rs
• magicblock-ledger/tests/get_block.rs
• magicblock-processor/src/scheduler/mod.rs
• magicblock-processor/tests/replica_ordering.rs
• magicblock-processor/tests/scheduling.rs

📝 Walkthrough

Walkthrough

The PR propagates real parent block hashes through the validator stack. LatestBlockInner in magicblock-ledger gains a parent_blockhash: Hash field; its existing new constructor initializes it to Hash::default(), and a new new_with_parent constructor accepts an explicit parent hash. Both the replica replay path (apply_replayed_block) and the primary production path (prepare_block_as_primary) in TransactionScheduler now read the current ledger block's hash before creating the next block, passing it as parent_blockhash via new_with_parent. In magicblock-aperture, notify_block replaces the hardcoded "11111111111111111111111111111111" placeholder with the real parent_blockhash from the block. Tests cover ledger persistence, replica ordering invariants, and primary slot transitions.

Suggested reviewers

• thlorenz
• lucacillario
• GabrielePicco

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

magicblock-processor/src/scheduler/mod.rs (1)

589-592: 🩺 Stability & Availability | 🟠 Major

Remove panic-on-time-source failure from production block preparation.

Using .unwrap() on duration_since(UNIX_EPOCH) can crash the scheduler thread. Replace with explicit error handling or a safe fallback. Per coding guidelines, .unwrap() in production Rust code within this file path is a major issue that requires proper error handling with logging or a sensible fallback for system time failures.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@magicblock-processor/src/scheduler/mod.rs` around lines 589 - 592, The
`.unwrap()` call on `duration_since(UNIX_EPOCH)` in the timestamp assignment can
cause the scheduler thread to panic if system time is before UNIX_EPOCH. Replace
the unwrap() with proper error handling by either using a match statement or
unwrap_or() with a sensible fallback value (such as a default timestamp of 0 or
the current system time clamped to UNIX_EPOCH). Include appropriate logging if
an error occurs to help with debugging system time issues.

Source: Path instructions

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@magicblock-processor/src/scheduler/mod.rs`:
- Around line 395-396: The parent_blockhash derivation at line 395 uses only
ledger.latest_block().load().blockhash, but this can diverge from the
scheduler's actual chain seed which uses fallback logic to SlotHashes when the
ledger hash is default in initial_blockhash(...). To fix this, refactor the
parent_blockhash assignment to use the same fallback logic pattern as
initial_blockhash(...), checking whether the ledger hash is default and falling
back to SlotHashes accordingly. Apply this same fix to the other occurrence
mentioned at lines 585-586 to ensure consistency across all parent_blockhash
derivations.

---

Outside diff comments:
In `@magicblock-processor/src/scheduler/mod.rs`:
- Around line 589-592: The `.unwrap()` call on `duration_since(UNIX_EPOCH)` in
the timestamp assignment can cause the scheduler thread to panic if system time
is before UNIX_EPOCH. Replace the unwrap() with proper error handling by either
using a match statement or unwrap_or() with a sensible fallback value (such as a
default timestamp of 0 or the current system time clamped to UNIX_EPOCH).
Include appropriate logging if an error occurs to help with debugging system
time issues.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

Run ID: db6be923-e6c5-4ea1-802c-45ddcd49a2f4

📥 Commits

Reviewing files that changed from the base of the PR and between f1d9c25 and 4e6c79c.

📒 Files selected for processing (6)

• magicblock-aperture/src/geyser.rs
• magicblock-ledger/src/lib.rs
• magicblock-ledger/tests/get_block.rs
• magicblock-processor/src/scheduler/mod.rs
• magicblock-processor/tests/replica_ordering.rs
• magicblock-processor/tests/scheduling.rs

[0xzrf]

@GabrielePicco @bmuddha thoughts on the PR?