List of Features

This page provides a comprehensive summary of all capabilities built into AirDB.

1. Local Persistence & Storage

Built-in Durable SQLite Engine:
Out-of-the-box storage engine for Android/JVM (SqliteDbAdapter) and Apple platforms (SqliteDbAdapter in AirDbKit).
Automatically enables Write-Ahead Logging (PRAGMA journal_mode = WAL) and normal disk syncing (PRAGMA synchronous = NORMAL) for concurrent, non-blocking reads and writes.
Automatically manages indexed changes in an append-only changelog table.
Pluggable BYOD (Bring Your Own Database) Seam:
Connect your existing application database via the simple AirDbAdapter interface.
Ready-to-use recipes for Android Jetpack Room, SQLDelight, Apple GRDB.swift, SwiftData, CoreData, and in-memory key-value maps.
Soft-Delete Tombstone Lifecycle:
Records deleted locally retain an authoritative tombstone timestamp.
Outdated mutations from disconnected devices are safely dropped, preventing deleted entities from resurrecting.

Hybrid Logical Clocks (HLC):
Generates strictly monotonic timestamps combining physical wall-clock time, an internal counter, and a node tie-breaker.
Tolerates device clock drift, dead batteries, and devices resetting to the year 1970 without corrupting ordering.
Vector Clock State Tracking:
Every device maintains a compact knowledge map of the latest timestamp seen from every peer.
When two devices meet, they compute the exact missing delta set in \(\mathcal{O}(|\Delta|)\) instead of transferring the entire database.
Deterministic Conflict Resolution (Last-Write-Wins):
When two users edit the same entity while separated, the change with the higher HLC timestamp wins deterministically across all nodes.
Guarantees eventual mathematical convergence without needing central consensus rounds.

Cluster-Level AEAD Encryption (RFC 8439):
Protects data in transit using symmetric ChaCha20-Poly1305 encryption with a 256-bit cluster key.
The entire binary packet header is bound into the authentication tag as Authenticated Additional Data (\(AAD\)), immediately rejecting tampered headers or spoofed sender IDs.
Generates a fresh 12-byte CSPRNG nonce for every transmitted packet.
Record-Level Digital Signatures (RFC 8032):
The original author digitally signs each mutation using an Ed25519 private key.
Prevents untrusted or compromised intermediate gossip relay phones from tampering with, forging, or backdating records.
Key Derivation (RFC 5869):
Derives operational cluster keys and session keys deterministically using HKDF-SHA256.

Dual-Role BLE Concurrency:
Devices simultaneously operate as a GATT Central (scanning for peers) and a GATT Peripheral (advertising presence).
Single-Flight GATT Queue (GattOperationQueue):
Enforces strict one-at-a-time operation dispatching per link on Android.
Eliminates native Fluoride/BlueDroid driver packet drops and race conditions.
Swift Actor Concurrency:
On Apple platforms, AirDbKit runs the core engine inside a Swift actor for compile-time thread safety and non-blocking CoreBluetooth callbacks.
Automatic Payload Compression:
Payloads exceeding 256 bytes are automatically compressed with zlib Deflate, cutting transmission airtime and battery consumption by up to 70%.
MTU Fragmentation & Assembly Buffer:
Automatically slices packets larger than the link MTU into 13-byte fragment envelopes.
Reassembles chunks on the receiver with a sliding 30-second TTL to prevent memory leaks from abandoned connections.

Zero-Radio In-Memory Simulation:
Core synchronization logic is 100% decoupled from hardware sockets and OS drivers.
Simulate multi-node mesh networks with variable packet drop rates and delays directly in JVM unit tests in milliseconds.
Zero Third-Party Dependencies on Apple:
AirDbKit relies exclusively on Apple standard frameworks (CryptoKit, CoreBluetooth, Compression, and native libsqlite3).
Interactive CLI Demo:
Includes a runnable multi-node disaster relief simulation (:airdb-samples:airdb-sim-demo) demonstrating real-time offline edits, peer discovery, and convergence.