Merge pull request #700 from bas-vk/issue_650

Added blockchain DB versioning support, closes #650

core/block_processor.go

@@ -18,6 +18,12 @@ import (
 	"gopkg.in/fatih/set.v0"
 )
 
+const (
+	// must be bumped when consensus algorithm is changed, this forces the upgradedb
+	// command to be run (forces the blocks to be imported again using the new algorithm)
+	BlockChainVersion = 1
+)
+
 var statelogger = logger.NewLogger("BLOCK")
 
 type BlockProcessor struct {

core/chain_manager.go

@@ -284,11 +284,14 @@ func (self *ChainManager) Export(w io.Writer) error {
 	defer self.mu.RUnlock()
 	glog.V(logger.Info).Infof("exporting %v blocks...\n", self.currentBlock.Header().Number)
 
-	for block := self.currentBlock; block != nil; block = self.GetBlock(block.Header().ParentHash) {
-		if err := block.EncodeRLP(w); err != nil {
+	last := self.currentBlock.NumberU64()
+
+	for nr := uint64(0); nr <= last; nr++ {
+		if err := self.GetBlockByNumber(nr).EncodeRLP(w); err != nil {
 			return err
 		}
 	}
+
 	return nil
 }