Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Signed-off-by: Giuliano Mega <[email protected]>

…wledge updates

…or getBlocks; limit memory usage for fetchBatched when used as prefetcher

…nsumption

…ellation handling

Part of #974

Use probabilistic distribution based on peer quality scores, giving all peers
opportunity while favoring better-performing ones. Selection probability is
inversely proportional to score.

Part of #974

- Reduce DefaultFetchBatch to prevent blockData explosion
- Add chunked onBatch processing to prevent memory accumulation
- Implement memory buffer reuse to reduce GC allocation churn
- Fix short-circuit evaluation

Part of #974

This prevents unbounded peer accumulation while maintaining redundancy.
When peer count exceeds the maximum, the least active peers are removed from
tracking to free resources.

Part of #974

Achieves significant memory reduction with equivalent network
performance. The reduced batch size prevents memory pressure
while preserving transfer efficiency, improving overall system
resource utilization.

Part of #974

- Add codex_block_exchange_discovery_requests_total counter to track peer
  discovery frequency
- Add codex_block_exchange_peer_timeouts_total counter to monitor peer
  reliability issues
- Add codex_block_exchange_requests_failed_total counter to track request
  failure rates

Part of #974

This prevents peers from becoming permanently invisible to block discovery when
they fail to respond to WantHave requests.

Part of #974

Returns false on duplicate marking attempts instead of logging errors,
eliminating duplicate marking loop in blockPresenceHandler and
preventing duplicate block requests across concurrent flows.

Part of #974

Part of #974

Signed-off-by: Chrysostomos Nanakos <[email protected]>

Part of #974

Signed-off-by: Chrysostomos Nanakos <[email protected]>

Now fetchBatched maintains a sliding window of batchSize blocks in-flight.
When 50% complete, adds next chunk (batchSize/2) to maintain constant window
size. This ensures blocks are already pending or have been fetched when
StoreStream needs them.

Signed-off-by: Chrysostomos Nanakos <[email protected]>