ethdb: add pebble for experiment

ethdb/pebble: disable sync-style db write

ethdb/pebble: update configs

ethdb/pebble: fixes and tests

ethdb/pebble: update configs

Author: rjl493456442

core/rawdb/database.go

@@ -28,6 +28,7 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethdb/leveldb"
 	"github.com/ethereum/go-ethereum/ethdb/memorydb"
+	"github.com/ethereum/go-ethereum/ethdb/pebble"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/olekukonko/tablewriter"
 )
@@ -251,6 +252,16 @@ func NewLevelDBDatabase(file string, cache int, handles int, namespace string, r
 	return NewDatabase(db), nil
 }
 
+// NewPebbleDBDatabase creates a persistent key-value database without a freezer
+// moving immutable chain segments into cold storage.
+func NewPebbleDBDatabase(file string, cache int, handles int, namespace string, readonly bool) (ethdb.Database, error) {
+	db, err := pebble.New(file, cache, handles, namespace, readonly)
+	if err != nil {
+		return nil, err
+	}
+	return NewDatabase(db), nil
+}
+
 // NewLevelDBDatabaseWithFreezer creates a persistent key-value database with a
 // freezer moving immutable chain segments into cold storage.
 func NewLevelDBDatabaseWithFreezer(file string, cache int, handles int, freezer string, namespace string, readonly bool) (ethdb.Database, error) {
@@ -266,6 +277,21 @@ func NewLevelDBDatabaseWithFreezer(file string, cache int, handles int, freezer
 	return frdb, nil
 }
 
+// NewPebbleDBDatabaseWithFreezer creates a persistent key-value database with a
+// freezer moving immutable chain segments into cold storage.
+func NewPebbleDBDatabaseWithFreezer(file string, cache int, handles int, freezer string, namespace string, readonly bool) (ethdb.Database, error) {
+	kvdb, err := pebble.New(file, cache, handles, namespace, readonly)
+	if err != nil {
+		return nil, err
+	}
+	frdb, err := NewDatabaseWithFreezer(kvdb, freezer, namespace, readonly)
+	if err != nil {
+		kvdb.Close()
+		return nil, err
+	}
+	return frdb, nil
+}
+
 type counter uint64
 
 func (c counter) String() string {