Transaction pool

The transaction pool buffers incoming transactions, verifies them, and produces a packable set for block generation. It manages per-sender nonce order and supports two "spaces" (native and EVM).

Main components

• TransactionPool - public API, ties to data manager and executed state.

• TransactionPoolInner - core data structures and packing logic.

• DeferredPool - per-sender nonce pools plus a packing pool.

• PackingPool - randomized packing algorithm with gas/price weighting.

• AccountCache - keeps nonce and balance hints for validation.

Intake and validation flow

1. RPC/P2P submits a SignedTransaction.

2. VerificationConfig and Machine checks validate chain id, gas bounds, epoch bounds, and signature.

3. Transaction is inserted into the sender's NoncePool.

4. Ready contiguous nonces are mirrored into the PackingPool.

Packing model

• Transactions are grouped per sender into PackingBatch objects to preserve nonce order.

• PackingPool is a treap-based structure that supports randomized sampling.

• Sampling considers block gas limits, block size limits, and minimum gas price.

• For EIP-1559 style pricing, the pool estimates the next base price using compute_next_price and adjusts the packing gas limit accordingly.

Space-aware packing

Mazze uses SpaceMap for dual spaces:

• Native space is always packable.

• EVM space is packable only after the configured transition height.

The pool tracks gas usage per space and enforces per-space limits during block validation.

Key source files

• crates/mazzecore/core/src/transaction_pool/mod.rs

• crates/mazzecore/core/src/transaction_pool/transaction_pool_inner.rs

• crates/mazzecore/packing-pool/src/pool.rs

• crates/mazzecore/packing-pool/src/packing_batch.rs