added txpool func

Former-commit-id: ce9c444b973f4c856987e3393b76dceb4676bb10 [formerly 89fc90106f425a943ee1c556b0904eff5c96dda4]
Former-commit-id: c3a97c1421c394b9aaa15aaecdb2dd7a1aea75a2

sharding/client.go

@@ -72,8 +72,14 @@ func (c *Client) Start() error {
 		return err
 	}
 
-	// Listens to incoming transactions from the geth node's txpool
+	// TODO: Wait to be selected as a collator, then start listening to the
+	// geth node's txpool.
 
+	// Listens to incoming transactions from the geth node's txpool and directs
+	// them into the VMC if node is a collator
+	if err := listenTXPool(c); err != nil {
+		return err
+	}
 	return nil
 }
 

sharding/txpool.go

@@ -0,0 +1,13 @@
+package sharding
+
+import (
+	"fmt"
+)
+
+// listenTXPool finds the pending tx's from the running geth node
+// and sorts them by descending order of gas price, eliminates those
+// that ask for too much gas, and routes them over to the VMC if the current
+// node is a collator
+func listenTXPool(c *Client) error {
+	return fmt.Errorf("Not Implemented")
+}