services/airpass_sync_engine library

Airpass Protocol — Sync Engine

The core business logic for epidemic (gossip) routing.

Two-Phase Sync Protocol

When two devices connect, the sync engine performs a two-phase exchange:

Phase 1 — Filter Exchange: Each side builds a Bloom filter of its known message IDs and sends it. This is a tiny payload (~1.2 KB for 1000 messages).

Phase 2 — Filtered Sync: Each side uses the received Bloom filter to exclude messages the peer already has, then sends only the novel messages + full routing table.

This dramatically reduces bandwidth in dense meshes where most nodes share a large percentage of their message stores.

Classes

AirpassSyncEngine

Orchestrates the epidemic data exchange between two connected peers.

SyncMessageEntry

A message entry within a SyncPayload.

SyncNodeEntry

A node entry within a SyncPayload.

SyncPayload

The serializable envelope exchanged between peers during a sync.