QUB Core v1.8.0 HF123 — Fast Chain Engine

HF123 / v1.8.0 is the QUB Core storage, synchronization and GUI-performance release. It introduces no new consensus activation.

Protocol Epoch 2 remains active exactly as deployed:

• blocks below mainnet height #24000 use block version 1;
• blocks at and above #24000 require block version 2;
• DAA, checkpoints, genesis, economics and QUB/JIN consensus rules are unchanged.

Fast Chain Engine

HF123 replaces the monolithic chain.json hot path with QUB-FCE-1:

chain-v2/
├── CURRENT.json
├── PREVIOUS.json
├── WRITE.lock
├── blocks-<generation>.jsonl
├── state-<generation>-<revision>.json
└── legacy-export-status.json

Key properties:

• append-only committed block journal;
• immutable state snapshots and atomic current/previous pointers;
• one-time validated migration from the existing chain.json;
• recovery from the previous fully validated committed generation;
• fail-closed behavior if both committed generations are unusable;
• truncation of uncommitted journal suffixes after interrupted writes;
• one canonical in-memory ChainState shared by P2P, embedded RPC and GUI snapshots;
• copy-on-write block, UTXO and mempool snapshots;
• batched catch-up persistence instead of repeated full-chain rewrites;
• infrequent compatibility chain.json export for external tools;
• status-fast, storage-stats and export-chain-json operator commands.

GUI and synchronization

HF123 removes repeated full-chain JSON loading from hot P2P and GUI paths. It adds:

• true single-flight chain catch-up and snapshot workers;
• cached derived QNS, pool, JIN, governance and QUB/JIN views per canonical tip;
• stable timestamped status history;
• lightweight local height detection through Fast Chain Engine metadata;
• immutable Explorer API cache keyed by the committed storage identity.

Headless RPC and reference miner

HF122 authenticated infrastructure remains included:

• embedded, token-authenticated RPC in qubd node;
• canonical chain, block, transaction and mempool endpoints;
• tracked solo and existing on-chain pool templates;
• compact parallel template batches;
• guarded tracked block submission;
• qub-rpc-miner reference CPU worker.

Standard mainnet/testnet RPC remains disabled by default. The supplied headless configuration is loopback-only. Raw RPC has no built-in TLS and must not be exposed directly to the public Internet.

Mining observability is intentionally neutral and aggregate-only: payout/pool label distribution, top-label share, HHI, effective label count, coinbase-only rate, block intervals and block-version distribution. A payout label is not proof of a unique operator or exact hashrate share.

Build and mandatory release gates

cargo test
cargo build --release --bin qubd
cargo build --release --bin qub-core
cargo build --release --bin qub-rpc-miner

Fast Chain Engine E2E:

python3 scripts/test-hf123-fast-chain-regtest.py \
  --qubd target/release/qubd

RPC/miner E2E:

python3 scripts/test-hf123-rpc-regtest.py \
  --qubd target/release/qubd \
  --miner target/release/qub-rpc-miner

Windows PowerShell:

py .\scripts\test-hf123-fast-chain-regtest.py `
  --qubd .\target\release\qubd.exe

py .\scripts\test-hf123-rpc-regtest.py `
  --qubd .\target\release\qubd.exe `
  --miner .\target\release\qub-rpc-miner.exe

Expected endings:

HF123 FAST CHAIN ENGINE REGTEST E2E: PASS
HF123 RPC REGTEST E2E: PASS

Documentation

• README-FAST-CHAIN-ENGINE.md — storage format, migration and recovery model.
• README-RPC-MINER.md — headless RPC and reference-miner usage.
• HF123-v180-ENTERPRISE-REVIEW.md — safety and architecture review.
• HF123-v180-DEPLOY-RUNBOOK.md — end-to-end deployment procedure.
• RELEASE_NOTES-v1.8.0-HF123.md — release notes.

No-assets package

Runtime image, audio and font assets are intentionally excluded. Copy the known-good assets directory from the currently deployed QUB Core source tree before producing the Windows distribution.