1 files changed, 32 insertions, 0 deletions
diff --git a/eth/tracers/internal/tracers/opcount_tracer.js b/eth/tracers/internal/tracers/opcount_tracer.js
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+++ b/eth/tracers/internal/tracers/opcount_tracer.js
@@ -0,0 +1,32 @@
+// 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 <http://www.gnu.org/licenses/>.
+
+// 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 }
+}