gbnet-hs-0.2.2.0: CHANGELOG.md

# Changelog

## 0.2.2.0

### Bug Fixes

- **Bandwidth tracking now functional**: `recordBytesSent` and `recordBytesReceived` were implemented in `Connection` but never called. Wired into `peerTick`: outgoing bytes recorded after encryption in `drainAllConnectionQueues`, incoming bytes recorded per-packet in `handlePacket`. `BandwidthTracker` and `NetworkStats` byte counters now report real values.
- **Fix O(n^2) list appending** in `encryptOutgoing` and `processPacketsPure`: replaced `acc ++ [x]` with reverse-accumulator pattern.
- **Fix migration cooldowns leak**: `npMigrationCooldowns` map now swept of stale entries in `updateConnections`, preventing unbounded growth on long-running servers.
- **Total function compliance**: replaced partial `Seq.index` with `Seq.lookup` in delta encoding/baseline management.

### Internal

- Codebase-wide elimination of prime-mark variable naming (`x'`, `x''`) in favour of descriptive names and optics composition across all 31 source files, tests, and benchmarks.
- README and EXAMPLES: removed all prime-mark variables, added optics-based configuration examples, fixed section numbering, added `LambdaCase` pragma.

## 0.2.1.0

### Bug Fixes

- **Congestion bypass for small reliable packets**: Small reliable messages (<= 64 bytes) now bypass the congestion window, preventing upgrade/command stalls when heavy unreliable traffic fills the cwnd. Binary rate limit still applies to all traffic.

### New

- `smallReliableThreshold` constant exported from `GBNet.Config`

### Internal

- Refactored `processChannelMessages` from nested if/else to guards + Maybe-monadic pipeline with named where-helpers

## 0.2.0.0

### Breaking Changes

- `NetworkConfig` gains `ncEncryptionKey :: !(Maybe EncryptionKey)` field (defaults to `Nothing`)
- `NetworkStats` gains `nsDecryptionFailures :: !Word64` field
- `TestNetConfig` gains `tncDuplicateChance` and `tncOutOfOrderChance` fields
- `Connection` gains `connEncryptionKey`, `connSendNonce`, `connRecvNonceMax` fields

### New Features

- **ChaCha20-Poly1305 AEAD encryption** (`GBNet.Crypto` module): pre-shared key encryption for post-handshake packets with anti-replay nonce tracking
- **IPv6 socket support**: `newUdpSocket` now detects address family from `SockAddr`; new helpers `localhost6`, `ipv6`, `anyAddr6`
- **TestNet simulation**: packet duplication (`tncDuplicateChance`) and out-of-order delivery (`tncOutOfOrderChance`)

### Internal

- New dependency: `crypton` (ChaCha20-Poly1305), `memory` (ByteArray conversion)

## 0.1.1.0

- Drop `-O2` from benchmark ghc-options (users set optimization in their own cabal.project)
- Add automated Hackage publish to CI pipeline (tag-gated with version validation)
- Add Hackage badge to README

## 0.1.0.0

Initial release.

- Reliable and unreliable UDP channels
- Dual-layer congestion control (binary mode + TCP New Reno CWND)
- Jacobson/Karels RTT estimation with adaptive RTO and fast retransmit
- Fragment reassembly with MTU discovery
- Effect-abstracted design via `MonadNetwork` / `MonadTime` typeclasses
- Pure deterministic testing with `TestNet`
- Template Haskell serialization derive
- Connection lifecycle: handshake, keepalive, migration, timeout
- Rate limiting, connect tokens, CRC32C packet integrity
- Priority accumulator, delta compression, interest management
- Network condition simulator (latency, jitter, packet loss, reordering)