restore Tx back to Tx pool when chain is reorganized

diff --git a/protocol/block.go b/protocol/block.go
index b29a3d9..97ea244 100644 (file)
--- a/protocol/block.go
+++ b/protocol/block.go
@@ -102,6 +102,7 @@ func (c *Chain) reorganizeChain(node *state.BlockNode) error {
        attachNodes, detachNodes := c.calcReorganizeNodes(node)
        utxoView := state.NewUtxoViewpoint()
 
+       txsToRestore := map[bc.Hash]*types.Tx{}
        for _, detachNode := range detachNodes {
                b, err := c.store.GetBlock(&detachNode.Hash)
                if err != nil {
@@ -120,9 +121,13 @@ func (c *Chain) reorganizeChain(node *state.BlockNode) error {
                        return err
                }
 
+               for _, tx := range b.Transactions {
+                       txsToRestore[tx.ID] = tx
+               }
                log.WithFields(log.Fields{"module": logModule, "height": node.Height, "hash": node.Hash.String()}).Debug("detach from mainchain")
        }
 
+       txsToRemove := map[bc.Hash]*types.Tx{}
        for _, attachNode := range attachNodes {
                b, err := c.store.GetBlock(&attachNode.Hash)
                if err != nil {
@@ -141,10 +146,39 @@ func (c *Chain) reorganizeChain(node *state.BlockNode) error {
                        return err
                }
 
+               for _, tx := range b.Transactions {
+                       if _, ok := txsToRestore[tx.ID]; !ok {
+                               txsToRemove[tx.ID] = tx
+                       } else {
+                               delete(txsToRestore, tx.ID)
+                       }
+               }
+
                log.WithFields(log.Fields{"module": logModule, "height": node.Height, "hash": node.Hash.String()}).Debug("attach from mainchain")
        }
 
-       return c.setState(node, utxoView)
+       if err := c.setState(node, utxoView); err != nil {
+               return err
+       }
+
+       for txHash := range txsToRemove {
+               c.txPool.RemoveTransaction(&txHash)
+       }
+
+       for _, tx := range txsToRestore {
+               // the number of restored Tx should be very small or most of time ZERO
+               // Error returned from validation is ignored, tx could still be lost if validation fails.
+               // TODO: adjust tx timestamp so that it won't starve in pool.
+               if _, err := c.ValidateTx(tx); err != nil {
+                       log.WithFields(log.Fields{"module": logModule, "tx_id": tx.Tx.ID.String(), "error": err}).Info("restore tx fail")
+               }
+       }
+
+       if len(txsToRestore) > 0 {
+               log.WithFields(log.Fields{"module": logModule, "num": len(txsToRestore)}).Debug("restore txs back to pool")
+       }
+
+       return nil
 }
 
 // SaveBlock will validate and save block into storage