Merge branch 'staging' into batch-historical-headers

pkg/history/populate_blocks.go

@@ -10,6 +10,11 @@ import (
 func PopulateMissingBlocks(blockchain core.BlockChain, blockRepository datastore.BlockRepository, startingBlockNumber int64) int {
 	lastBlock := blockchain.LastBlock().Int64()
 	blockRange := blockRepository.MissingBlockNumbers(startingBlockNumber, lastBlock, blockchain.Node().ID)
+
+	if len(blockRange) == 0 {
+		return 0
+	}
+
 	log.Printf("Backfilling %d blocks\n\n", len(blockRange))
 	RetrieveAndUpdateBlocks(blockchain, blockRepository, blockRange)
 	return len(blockRange)

pkg/history/populate_headers.go

@@ -10,13 +10,20 @@ import (
 
 func PopulateMissingHeaders(blockchain core.BlockChain, headerRepository datastore.HeaderRepository, startingBlockNumber int64) (int, error) {
 	lastBlock := blockchain.LastBlock().Int64()
-	blockRange := headerRepository.MissingBlockNumbers(startingBlockNumber, lastBlock, blockchain.Node().ID)
-	log.Printf("Backfilling %d blocks\n\n", len(blockRange))
-	_, err := RetrieveAndUpdateHeaders(blockchain, headerRepository, blockRange)
+	headerAlreadyExists, err := headerRepository.HeaderExists(lastBlock)
+	if err != nil {
+		return 0, err
+	} else if headerAlreadyExists {
+		return 0, nil
+	}
+
+	blockNumbers := headerRepository.MissingBlockNumbers(startingBlockNumber, lastBlock, blockchain.Node().ID)
+	log.Printf("Backfilling %d blocks\n\n", len(blockNumbers))
+	_, err = RetrieveAndUpdateHeaders(blockchain, headerRepository, blockNumbers)
 	if err != nil {
 		return 0, err
 	}
-	return len(blockRange), nil
+	return len(blockNumbers), nil
 }
 
 func RetrieveAndUpdateHeaders(chain core.BlockChain, headerRepository datastore.HeaderRepository, blockNumbers []int64) (int, error) {

pkg/history/populate_headers_test.go

@@ -39,4 +39,14 @@ var _ = Describe("Populating headers", func() {
 		Expect(err).NotTo(HaveOccurred())
 		headerRepository.AssertCreateOrUpdateHeaderCallCountAndPassedBlockNumbers(1, []int64{2})
 	})
+
+	It("returns early if the db is already synced up to the head of the chain", func() {
+		blockChain := fakes.NewMockBlockChain()
+		blockChain.SetLastBlock(big.NewInt(2))
+		headerRepository.SetHeaderExists(true)
+		headersAdded, err := history.PopulateMissingHeaders(blockChain, headerRepository, 2)
+
+		Expect(err).NotTo(HaveOccurred())
+		Expect(headersAdded).To(Equal(0))
+	})
 })