// Copyright 2017 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 . // opcountTracer is a sample tracer that just counts the number of instructions // executed by the EVM before the transaction terminated. { // count tracks the number of EVM instructions executed. count: 0, // step is invoked for every opcode that the VM executes. step: function(log, db) { this.count++ }, // fault is invoked when the actual execution of an opcode fails. fault: function(log, db) { }, // result is invoked when all the opcodes have been iterated over and returns // the final result of the tracing. result: function(ctx, db) { return this.count } }