ethdb, rpc: support building on js/wasm (#17709)

The changes allow building WebAssembly applications which use ethclient.Client.

ethdb/table_batch.go

@@ -0,0 +1,51 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// 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/>.
+
+package ethdb
+
+type tableBatch struct {
+	batch  Batch
+	prefix string
+}
+
+// NewTableBatch returns a Batch object which prefixes all keys with a given string.
+func NewTableBatch(db Database, prefix string) Batch {
+	return &tableBatch{db.NewBatch(), prefix}
+}
+
+func (dt *table) NewBatch() Batch {
+	return &tableBatch{dt.db.NewBatch(), dt.prefix}
+}
+
+func (tb *tableBatch) Put(key, value []byte) error {
+	return tb.batch.Put(append([]byte(tb.prefix), key...), value)
+}
+
+func (tb *tableBatch) Delete(key []byte) error {
+	return tb.batch.Delete(append([]byte(tb.prefix), key...))
+}
+
+func (tb *tableBatch) Write() error {
+	return tb.batch.Write()
+}
+
+func (tb *tableBatch) ValueSize() int {
+	return tb.batch.ValueSize()
+}
+
+func (tb *tableBatch) Reset() {
+	tb.batch.Reset()
+}