- Per-DC latency tracking in UpstreamState (array of 5 EMA instances, one per DC):
- Added `dc_latency: [LatencyEma; 5]` – per‑DC tracking instead of a single global EMA
- `effective_latency(dc_idx)` – returns DC‑specific latency, falls back to average if unavailable
- `select_upstream(dc_idx)` – now performs latency‑weighted selection: effective_weight = config_weight × (1000 / latency_ms)
- Example: two upstreams with equal config weight but latencies of 50ms and 200ms → selection probabilities become 80% / 20%
- `connect(target, dc_idx)` – extended signature, dc_idx used for upstream selection and per‑DC RTT recording
- All ping/health‑check operations now record RTT into `dc_latency[dc_zero_index]`
- `upstream_manager.connect(dc_addr)` changed to `upstream_manager.connect(dc_addr, Some(success.dc_idx))` – DC index now participates in upstream selection and per‑DC RTT logging
- `client.rs` – passes dc_idx when connecting to Telegram
- Summary: Upstream selection now accounts for per‑DC latency using the formula weight × (1000/ms). With multiple upstreams (e.g., direct + socks5), traffic automatically flows to the faster route for each specific DC. With a single upstream, the data is used for monitoring without affecting routing.
Co-Authored-By: brekotis <93345790+brekotis@users.noreply.github.com>
