1 files changed, 97 insertions, 21 deletions

diff --git a/core/db/level-db.go b/core/db/level-db.go
index 6983d3a..238c38e 100644
--- a/core/db/level-db.go
+++ b/core/db/level-db.go
@@ -18,14 +18,23 @@
 package db
 
 import (
-	"encoding/json"
-
 	"github.com/syndtr/goleveldb/leveldb"
 
 	"github.com/dexon-foundation/dexon-consensus/common"
 	"github.com/dexon-foundation/dexon-consensus/core/types"
+	"github.com/dexon-foundation/dexon/rlp"
+)
+
+var (
+	blockKeyPrefix            = []byte("b-")
+	compactionChainTipInfoKey = []byte("cc-tip")
 )
 
+type compactionChainTipInfo struct {
+	Height uint64      `json:"height"`
+	Hash   common.Hash `json:"hash"`
+}
+
 // LevelDBBackedDB is a leveldb backed DB implementation.
 type LevelDBBackedDB struct {
 	db *leveldb.DB
@@ -50,7 +59,7 @@ func (lvl *LevelDBBackedDB) Close() error {
 
 // HasBlock implements the Reader.Has method.
 func (lvl *LevelDBBackedDB) HasBlock(hash common.Hash) bool {
-	exists, err := lvl.db.Has([]byte(hash[:]), nil)
+	exists, err := lvl.internalHasBlock(lvl.getBlockKey(hash))
 	if err != nil {
 		// TODO(missionliao): Modify the interface to return error.
 		panic(err)
@@ -58,18 +67,25 @@ func (lvl *LevelDBBackedDB) HasBlock(hash common.Hash) bool {
 	return exists
 }
 
+func (lvl *LevelDBBackedDB) internalHasBlock(key []byte) (bool, error) {
+	exists, err := lvl.db.Has(key, nil)
+	if err != nil {
+		return false, err
+	}
+	return exists, nil
+}
+
 // GetBlock implements the Reader.GetBlock method.
 func (lvl *LevelDBBackedDB) GetBlock(
 	hash common.Hash) (block types.Block, err error) {
-
-	queried, err := lvl.db.Get([]byte(hash[:]), nil)
+	queried, err := lvl.db.Get(lvl.getBlockKey(hash), nil)
 	if err != nil {
 		if err == leveldb.ErrNotFound {
 			err = ErrBlockDoesNotExist
 		}
 		return
 	}
-	err = json.Unmarshal(queried, &block)
+	err = rlp.DecodeBytes(queried, &block)
 	if err != nil {
 		return
 	}
@@ -80,20 +96,20 @@ func (lvl *LevelDBBackedDB) GetBlock(
 func (lvl *LevelDBBackedDB) UpdateBlock(block types.Block) (err error) {
 	// NOTE: we didn't handle changes of block hash (and it
 	//       should not happen).
-	marshaled, err := json.Marshal(&block)
+	marshaled, err := rlp.EncodeToBytes(&block)
 	if err != nil {
 		return
 	}
-
-	if !lvl.HasBlock(block.Hash) {
+	blockKey := lvl.getBlockKey(block.Hash)
+	exists, err := lvl.internalHasBlock(blockKey)
+	if err != nil {
+		return
+	}
+	if !exists {
 		err = ErrBlockDoesNotExist
 		return
 	}
-	err = lvl.db.Put(
-		[]byte(block.Hash[:]),
-		marshaled,
-		nil)
-	if err != nil {
+	if err = lvl.db.Put(blockKey, marshaled, nil); err != nil {
 		return
 	}
 	return
@@ -101,19 +117,20 @@ func (lvl *LevelDBBackedDB) UpdateBlock(block types.Block) (err error) {
 
 // PutBlock implements the Writer.PutBlock method.
 func (lvl *LevelDBBackedDB) PutBlock(block types.Block) (err error) {
-	marshaled, err := json.Marshal(&block)
+	marshaled, err := rlp.EncodeToBytes(&block)
+	if err != nil {
+		return
+	}
+	blockKey := lvl.getBlockKey(block.Hash)
+	exists, err := lvl.internalHasBlock(blockKey)
 	if err != nil {
 		return
 	}
-	if lvl.HasBlock(block.Hash) {
+	if exists {
 		err = ErrBlockExists
 		return
 	}
-	err = lvl.db.Put(
-		[]byte(block.Hash[:]),
-		marshaled,
-		nil)
-	if err != nil {
+	if err = lvl.db.Put(blockKey, marshaled, nil); err != nil {
 		return
 	}
 	return
@@ -125,3 +142,62 @@ func (lvl *LevelDBBackedDB) GetAllBlocks() (BlockIterator, error) {
 	// TODO (mission): Implement this part via goleveldb's iterator.
 	return nil, ErrNotImplemented
 }
+
+// PutCompactionChainTipInfo saves tip of compaction chain into the database.
+func (lvl *LevelDBBackedDB) PutCompactionChainTipInfo(
+	blockHash common.Hash, height uint64) error {
+	marshaled, err := rlp.EncodeToBytes(&compactionChainTipInfo{
+		Hash:   blockHash,
+		Height: height,
+	})
+	if err != nil {
+		return err
+	}
+	// Check current cached tip info to make sure the one to be updated is
+	// valid.
+	info, err := lvl.internalGetCompactionChainTipInfo()
+	if err != nil {
+		return err
+	}
+	if info.Height >= height {
+		return ErrInvalidCompactionChainTipHeight
+	}
+	if err = lvl.db.Put(compactionChainTipInfoKey, marshaled, nil); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (lvl *LevelDBBackedDB) internalGetCompactionChainTipInfo() (
+	info compactionChainTipInfo, err error) {
+	queried, err := lvl.db.Get(compactionChainTipInfoKey, nil)
+	if err != nil {
+		if err == leveldb.ErrNotFound {
+			err = nil
+		}
+		return
+	}
+	if err = rlp.DecodeBytes(queried, &info); err != nil {
+		return
+	}
+	return
+}
+
+// GetCompactionChainTipInfo get the tip info of compaction chain into the
+// database.
+func (lvl *LevelDBBackedDB) GetCompactionChainTipInfo() (
+	hash common.Hash, height uint64) {
+	info, err := lvl.internalGetCompactionChainTipInfo()
+	if err != nil {
+		panic(err)
+	}
+	hash, height = info.Hash, info.Height
+	return
+}
+
+func (lvl *LevelDBBackedDB) getBlockKey(hash common.Hash) (ret []byte) {
+	ret = make([]byte, len(blockKeyPrefix)+len(hash[:]))
+	copy(ret, blockKeyPrefix)
+	copy(ret[len(blockKeyPrefix):], hash[:])
+	return
+}