cmd, core, ethdb: enable Pebble on 32 bits and OpenBSD too (#28335)

* cmd, core, ethdb: enable Pebble on 32 bits and OpenBSD too

* ethdb/pebble: use Pebble's internal constant calculation

Author: karalabe

cmd/utils/flags.go

@@ -961,17 +961,12 @@ var (
 		DataDirFlag,
 		AncientFlag,
 		RemoteDBFlag,
+		DBEngineFlag,
 		StateSchemeFlag,
 		HttpHeaderFlag,
 	}
 )
 
-func init() {
-	if rawdb.PebbleEnabled {
-		DatabaseFlags = append(DatabaseFlags, DBEngineFlag)
-	}
-}
-
 // MakeDataDir retrieves the currently requested data directory, terminating
 // if none (or the empty string) is specified. If the node is starting a testnet,
 // then a subdirectory of the specified datadir will be used.

core/rawdb/database.go

@@ -30,6 +30,7 @@ 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"
 )
@@ -321,6 +322,16 @@ 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, ephemeral bool) (ethdb.Database, error) {
+	db, err := pebble.New(file, cache, handles, namespace, readonly, ephemeral)
+	if err != nil {
+		return nil, err
+	}
+	return NewDatabase(db), nil
+}
+
 const (
 	dbPebble  = "pebble"
 	dbLeveldb = "leveldb"
@@ -375,26 +386,16 @@ func openKeyValueDatabase(o OpenOptions) (ethdb.Database, error) {
 		return nil, fmt.Errorf("db.engine choice was %v but found pre-existing %v database in specified data directory", o.Type, existingDb)
 	}
 	if o.Type == dbPebble || existingDb == dbPebble {
-		if PebbleEnabled {
-			log.Info("Using pebble as the backing database")
-			return NewPebbleDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly, o.Ephemeral)
-		} else {
-			return nil, errors.New("db.engine 'pebble' not supported on this platform")
-		}
+		log.Info("Using pebble as the backing database")
+		return NewPebbleDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly, o.Ephemeral)
 	}
 	if o.Type == dbLeveldb || existingDb == dbLeveldb {
 		log.Info("Using leveldb as the backing database")
 		return NewLevelDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly)
 	}
-	// No pre-existing database, no user-requested one either. Default to Pebble
-	// on supported platforms and LevelDB on anything else.
-	if PebbleEnabled {
-		log.Info("Defaulting to pebble as the backing database")
-		return NewPebbleDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly, o.Ephemeral)
-	} else {
-		log.Info("Defaulting to leveldb as the backing database")
-		return NewLevelDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly)
-	}
+	// No pre-existing database, no user-requested one either. Default to Pebble.
+	log.Info("Defaulting to pebble as the backing database")
+	return NewPebbleDBDatabase(o.Directory, o.Cache, o.Handles, o.Namespace, o.ReadOnly, o.Ephemeral)
 }
 
 // Open opens both a disk-based key-value database such as leveldb or pebble, but also

core/rawdb/databases_64bit.go

@@ -14,8 +14,6 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
-//go:build (arm64 || amd64) && !openbsd
-
 // Package pebble implements the key-value database layer based on pebble.
 package pebble
 
@@ -148,8 +146,15 @@ func New(file string, cache int, handles int, namespace string, readonly bool, e
 
 	// The max memtable size is limited by the uint32 offsets stored in
 	// internal/arenaskl.node, DeferredBatchOp, and flushableBatchEntry.
-	// Taken from https://github.com/cockroachdb/pebble/blob/master/open.go#L38
-	maxMemTableSize := 4<<30 - 1 // Capped by 4 GB
+	//
+	// - MaxUint32 on 64-bit platforms;
+	// - MaxInt on 32-bit platforms.
+	//
+	// It is used when slices are limited to Uint32 on 64-bit platforms (the
+	// length limit for slices is naturally MaxInt on 32-bit platforms).
+	//
+	// Taken from https://github.com/cockroachdb/pebble/blob/master/internal/constants/constants.go
+	maxMemTableSize := (1<<31)<<(^uint(0)>>63) - 1
 
 	// Two memory tables is configured which is identical to leveldb,
 	// including a frozen memory table and another live one.

core/rawdb/databases_non64bit.go

@@ -14,8 +14,6 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
-//go:build (arm64 || amd64) && !openbsd
-
 package pebble
 
 import (