+ blockHeader, err := c.store.GetBlockHeader(&hash)
+ if err != nil {
+ return false
+ }
+
+ blockHash, err := c.store.GetMainChainHash(blockHeader.Height)
+ if err != nil {
+ log.WithFields(log.Fields{"module": logModule, "height": blockHeader.Height}).Debug("not contain block hash in main chain for specified height")
+ return false
+ }
+ return *blockHash == hash
+}
+
+// trace back to the tail of the chain from the given block header
+func (c *Chain) traceLongestChainTail(blockHeader *types.BlockHeader) (*types.BlockHeader, error) {
+ longestTail, workQueue := blockHeader, []*types.BlockHeader{blockHeader}
+
+ for ; len(workQueue) > 0; workQueue = workQueue[1:] {
+ currentHeader := workQueue[0]
+ currentHash := currentHeader.Hash()
+ hashes, err := c.store.GetBlockHashesByHeight(currentHeader.Height + 1)
+ if err != nil {
+ return nil, err
+ }
+
+ for _, h := range hashes {
+ if header, err := c.store.GetBlockHeader(h); err != nil {
+ return nil, err
+ } else if header.PreviousBlockHash == currentHash {
+ if longestTail.Height < header.Height {
+ longestTail = header
+ }
+ workQueue = append(workQueue, header)
+ }
+ }
+ }
+ return longestTail, nil
+}
+
+func (c *Chain) hasSeenTx(tx *types.Tx) bool {
+ return c.knownTxs.Has(tx.ID.String())
+}
+
+func (c *Chain) markTransactions(txs ...*types.Tx) {
+ for _, tx := range txs {
+ c.knownTxs.Add(tx.ID.String())
+ }