fix vote result (#94)

[bytom/vapor.git] / protocol / state / blockindex.go

diff --git a/protocol/state/blockindex.go b/protocol/state/blockindex.go
index f1810b6..3bccd84 100644 (file)
--- a/protocol/state/blockindex.go
+++ b/protocol/state/blockindex.go
@@ -118,6 +118,24 @@ func (bi *BlockIndex) GetNode(hash *bc.Hash) *BlockNode {
        return bi.index[*hash]
 }
 
+// NodeByHeightInSameChain return the node of specified height
+// And the node satisfies the same chain as the node that specifies the hash 
+// Height of the block of the specified node hash must greater than height parameter
+func (bi *BlockIndex) NodeByHeightInSameChain(nodeHash *bc.Hash, height uint64) *BlockNode {
+       bi.RLock()
+       defer bi.RUnlock()
+
+       blockNode := bi.index[*nodeHash]
+       prevBlockNode := blockNode
+       for prevBlockNode != nil && prevBlockNode.Height != height {
+               if prevBlockNode.Height < height {
+                       return nil
+               }
+               prevBlockNode = bi.index[prevBlockNode.Parent.Hash]
+       }
+       return prevBlockNode
+}
+
 func (bi *BlockIndex) BestNode() *BlockNode {
        bi.RLock()
        defer bi.RUnlock()