4 files changed, 62 insertions, 11 deletions

diff --git a/ethdb/batch.go b/ethdb/batch.go
index a9c406354..e261415bf 100644
--- a/ethdb/batch.go
+++ b/ethdb/batch.go
@@ -23,7 +23,7 @@ const IdealBatchSize = 100 * 1024
 // Batch is a write-only database that commits changes to its host database
 // when Write is called. A batch cannot be used concurrently.
 type Batch interface {
-	Writer
+	KeyValueWriter
 
 	// ValueSize retrieves the amount of data queued up for writing.
 	ValueSize() int
@@ -35,7 +35,7 @@ type Batch interface {
 	Reset()
 
 	// Replay replays the batch contents.
-	Replay(w Writer) error
+	Replay(w KeyValueWriter) error
 }
 
 // Batcher wraps the NewBatch method of a backing data store.
diff --git a/ethdb/database.go b/ethdb/database.go
index bab99aed1..1ba169bcf 100644
--- a/ethdb/database.go
+++ b/ethdb/database.go
@@ -19,8 +19,8 @@ package ethdb
 
 import "io"
 
-// Reader wraps the Has and Get method of a backing data store.
-type Reader interface {
+// KeyValueReader wraps the Has and Get method of a backing data store.
+type KeyValueReader interface {
 	// Has retrieves if a key is present in the key-value data store.
 	Has(key []byte) (bool, error)
 
@@ -28,8 +28,8 @@ type Reader interface {
 	Get(key []byte) ([]byte, error)
 }
 
-// Writer wraps the Put method of a backing data store.
-type Writer interface {
+// KeyValueWriter wraps the Put method of a backing data store.
+type KeyValueWriter interface {
 	// Put inserts the given value into the key-value data store.
 	Put(key []byte, value []byte) error
 
@@ -58,8 +58,8 @@ type Compacter interface {
 // KeyValueStore contains all the methods required to allow handling different
 // key-value data stores backing the high level database.
 type KeyValueStore interface {
-	Reader
-	Writer
+	KeyValueReader
+	KeyValueWriter
 	Batcher
 	Iteratee
 	Stater
@@ -67,6 +67,57 @@ type KeyValueStore interface {
 	io.Closer
 }
 
+// AncientReader contains the methods required to read from immutable ancient data.
+type AncientReader interface {
+	// HasAncient returns an indicator whether the specified data exists in the
+	// ancient store.
+	HasAncient(kind string, number uint64) (bool, error)
+
+	// Ancient retrieves an ancient binary blob from the append-only immutable files.
+	Ancient(kind string, number uint64) ([]byte, error)
+
+	// Ancients returns the ancient item numbers in the ancient store.
+	Ancients() (uint64, error)
+
+	// AncientSize returns the ancient size of the specified category.
+	AncientSize(kind string) (uint64, error)
+}
+
+// AncientWriter contains the methods required to write to immutable ancient data.
+type AncientWriter interface {
+	// AppendAncient injects all binary blobs belong to block at the end of the
+	// append-only immutable table files.
+	AppendAncient(number uint64, hash, header, body, receipt, td []byte) error
+
+	// TruncateAncients discards all but the first n ancient data from the ancient store.
+	TruncateAncients(n uint64) error
+
+	// Sync flushes all in-memory ancient store data to disk.
+	Sync() error
+}
+
+// Reader contains the methods required to read data from both key-value as well as
+// immutable ancient data.
+type Reader interface {
+	KeyValueReader
+	AncientReader
+}
+
+// Writer contains the methods required to write data to both key-value as well as
+// immutable ancient data.
+type Writer interface {
+	KeyValueWriter
+	AncientWriter
+}
+
+// AncientStore contains all the methods required to allow handling different
+// ancient data stores backing immutable chain data store.
+type AncientStore interface {
+	AncientReader
+	AncientWriter
+	io.Closer
+}
+
 // Database contains all the methods required by the high level database to not
 // only access the key-value data store but also the chain freezer.
 type Database interface {
diff --git a/ethdb/leveldb/leveldb.go b/ethdb/leveldb/leveldb.go
index 8eabee50e..f74e94d92 100644
--- a/ethdb/leveldb/leveldb.go
+++ b/ethdb/leveldb/leveldb.go
@@ -425,13 +425,13 @@ func (b *batch) Reset() {
 }
 
 // Replay replays the batch contents.
-func (b *batch) Replay(w ethdb.Writer) error {
+func (b *batch) Replay(w ethdb.KeyValueWriter) error {
 	return b.b.Replay(&replayer{writer: w})
 }
 
 // replayer is a small wrapper to implement the correct replay methods.
 type replayer struct {
-	writer  ethdb.Writer
+	writer  ethdb.KeyValueWriter
 	failure error
 }
 
diff --git a/ethdb/memorydb/memorydb.go b/ethdb/memorydb/memorydb.go
index cb8b27f3b..caa9b02a1 100644
--- a/ethdb/memorydb/memorydb.go
+++ b/ethdb/memorydb/memorydb.go
@@ -270,7 +270,7 @@ func (b *batch) Reset() {
 }
 
 // Replay replays the batch contents.
-func (b *batch) Replay(w ethdb.Writer) error {
+func (b *batch) Replay(w ethdb.KeyValueWriter) error {
 	for _, keyvalue := range b.writes {
 		if keyvalue.delete {
 			if err := w.Delete(keyvalue.key); err != nil {