reorgs, fetch batching (parallel fetch), orphans

include/nets/fetch_scheduler.h

@@ -0,0 +1,10 @@
+#ifndef FETCH_SCHEDULER_H
+#define FETCH_SCHEDULER_H
+
+#include <stdint.h>
+
+// Compute penalty in blocks for a delayed/heavy reorg reported by a peer.
+// Returns the number of penalty blocks to subtract from the peer's advertised work.
+uint64_t FetchScheduler_ComputeReorgPenaltyBlocks(uint64_t delayBlocks);
+
+#endif

include/nets/net_node.h

@@ -15,6 +15,8 @@
 
 #include <dynarr.h>
 
+#include <pthread.h>
+
 #include <block/block.h>
 #include <block/chain.h>
 #include <block/transaction.h>
@@ -27,6 +29,10 @@ typedef struct {
     void (*on_data)(tcp_connection_t* conn, const unsigned char* data, size_t len, void* user);
     void (*on_disconnect)(tcp_connection_t* conn, void* user);
     void* callbackUser;
+    // Maintenance thread for periodic tasks (orphan attach, pruning, metrics)
+    pthread_t maintenanceThread;
+    volatile int maintenanceRunning;
+    int maintenanceIntervalMs;
 } net_node_t;
 
 net_node_t* Node_Create();

include/nets/orphan_pool.h

@@ -0,0 +1,20 @@
+#ifndef ORPHAN_POOL_H
+#define ORPHAN_POOL_H
+
+#include <stdint.h>
+#include <block/block.h>
+#include <block/chain.h>
+
+// Initialize/destroy the global orphan pool
+void OrphanPool_Init(void);
+void OrphanPool_Destroy(void);
+
+// Insert an orphan block into the pool. Ownership of `block` is transferred to the pool.
+// `height` is the block number from the header.
+void OrphanPool_Insert(block_t* block, uint64_t height);
+
+// Attempt to attach any orphans whose parents now exist in `chain`.
+// Returns the number of blocks successfully attached.
+size_t OrphanPool_AttemptAttach(blockchain_t* chain);
+
+#endif