Merge pull request #396 from nspcc-dev/network-reconnections-and-fixes

This one fixes #390 and some connected problems. After this patchset the node reconnects to some other nodes if anything goes wrong and it better senses when something goes wrong. It also fixes some block handling problems based on the testnet connection experience.

pkg/core/blockchain.go

@@ -357,8 +357,7 @@ func (bc *Blockchain) persistBlock(block *Block) error {
 				Email:       t.Email,
 				Description: t.Description,
 			}
-
-			fmt.Printf("%+v", contract)
+			_ = contract
 
 		case *transaction.InvocationTX:
 		}
@@ -430,6 +429,15 @@ func (bc *Blockchain) persist(ctx context.Context) (err error) {
 			"blockHeight":  bc.BlockHeight(),
 			"took":         time.Since(start),
 		}).Info("blockchain persist completed")
+	} else {
+		// So we have some blocks in cache but can't persist them?
+		// Either there are some stale blocks there or the other way
+		// around (which was seen in practice) --- there are some fresh
+		// blocks that we can't persist yet. Some of the latter can be useful
+		// or can be bogus (higher than the header height we expect at
+		// the moment). So try to reap oldies and strange newbies, if
+		// there are any.
+		bc.blockCache.ReapStrangeBlocks(bc.BlockHeight(), bc.HeaderHeight())
 	}
 
 	return

pkg/core/cache.go

@@ -71,3 +71,17 @@ func (c *Cache) Delete(h util.Uint256) {
 	defer c.lock.Unlock()
 	delete(c.m, h)
 }
+
+// ReapStrangeBlocks drops blocks from cache that don't fit into the
+// blkHeight-headHeight interval. Cache should only contain blocks that we
+// expect to get and store.
+func (c *Cache) ReapStrangeBlocks(blkHeight, headHeight uint32) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+	for i, b := range c.m {
+		block, ok := b.(*Block)
+		if ok && (block.Index < blkHeight || block.Index > headHeight) {
+			delete(c.m, i)
+		}
+	}
+}