Merge pull request #5 from tendermint/iterate-data

Exposed an iterator to access all of the underlying key/value pairs for all databases.

c_level_db.go

@@ -106,6 +106,24 @@ func (db *CLevelDB) Print() {
 	}
 }
 
+func (db *CLevelDB) Stats() map[string]string {
+	// TODO: Find the available properties for the C LevelDB implementation
+	keys := []string{}
+
+	stats := make(map[string]string)
+	for _, key := range keys {
+		str, err := db.db.GetProperty(key)
+		if err == nil {
+			stats[key] = str
+		}
+	}
+	return stats
+}
+
+func (db *CLevelDB) Iterator() Iterator {
+	return db.db.NewIterator(nil, nil)
+}
+
 func (db *CLevelDB) NewBatch() Batch {
 	batch := levigo.NewWriteBatch()
 	return &cLevelDBBatch{db, batch}

db.go

@@ -13,6 +13,8 @@ type DB interface {
 
 	// For debugging
 	Print()
+	Iterator() Iterator
+	Stats() map[string]string
 }
 
 type Batch interface {
@@ -21,6 +23,13 @@ type Batch interface {
 	Write()
 }
 
+type Iterator interface {
+	Next() bool
+
+	Key() []byte
+	Value() []byte
+}
+
 //-----------------------------------------------------------------------------
 
 const (

go_level_db.go

@@ -82,6 +82,9 @@ func (db *GoLevelDB) Close() {
 }
 
 func (db *GoLevelDB) Print() {
+	str, _ := db.db.GetProperty("leveldb.stats")
+	fmt.Printf("%v\n", str)
+
 	iter := db.db.NewIterator(nil, nil)
 	for iter.Next() {
 		key := iter.Key()
@@ -90,6 +93,32 @@ func (db *GoLevelDB) Print() {
 	}
 }
 
+func (db *GoLevelDB) Stats() map[string]string {
+	keys := []string{
+		"leveldb.num-files-at-level{n}",
+		"leveldb.stats",
+		"leveldb.sstables",
+		"leveldb.blockpool",
+		"leveldb.cachedblock",
+		"leveldb.openedtables",
+		"leveldb.alivesnaps",
+		"leveldb.aliveiters",
+	}
+
+	stats := make(map[string]string)
+	for _, key := range keys {
+		str, err := db.db.GetProperty(key)
+		if err == nil {
+			stats[key] = str
+		}
+	}
+	return stats
+}
+
+func (db *GoLevelDB) Iterator() Iterator {
+	return db.db.NewIterator(nil, nil)
+}
+
 func (db *GoLevelDB) NewBatch() Batch {
 	batch := new(leveldb.Batch)
 	return &goLevelDBBatch{db, batch}

mem_db.go

@@ -65,6 +65,53 @@ func (db *MemDB) Print() {
 	}
 }
 
+func (db *MemDB) Stats() map[string]string {
+	stats := make(map[string]string)
+	stats["database.type"] = "memDB"
+	return stats
+}
+
+type memDBIterator struct {
+	last int
+	keys []string
+	db   *MemDB
+}
+
+func newMemDBIterator() *memDBIterator {
+	return &memDBIterator{}
+}
+
+func (it *memDBIterator) Next() bool {
+	if it.last >= len(it.keys) {
+		return false
+	}
+	it.last++
+	return true
+}
+
+func (it *memDBIterator) Key() []byte {
+	return []byte(it.keys[it.last])
+}
+
+func (it *memDBIterator) Value() []byte {
+	return it.db.Get(it.Key())
+}
+
+func (db *MemDB) Iterator() Iterator {
+	it := newMemDBIterator()
+	it.db = db
+	it.last = -1
+
+	db.mtx.Lock()
+	defer db.mtx.Unlock()
+
+	// unfortunately we need a copy of all of the keys
+	for key, _ := range db.db {
+		it.keys = append(it.keys, key)
+	}
+	return it
+}
+
 func (db *MemDB) NewBatch() Batch {
 	return &memDBBatch{db, nil}
 }