opcode: experiment with using cached opcodes.

lib/script/opcode.js

@@ -15,6 +15,8 @@ const BufferReader = require('../utils/reader');
 const StaticWriter = require('../utils/staticwriter');
 const opcodes = common.opcodes;
 
+const cache = [];
+
 /**
  * A simple struct which contains
  * an opcode and pushdata buffer.
@@ -271,6 +273,16 @@ Opcode.prototype.fromRaw = function fromRaw(data) {
  */
 
 Opcode.fromReader = function fromReader(br) {
+  if (br.offset < br.data.length) {
+    const op = br.data[br.offset];
+    const cached = cache[op];
+
+    if (cached) {
+      br.offset++;
+      return cached;
+    }
+  }
+
   return new Opcode(0, null).fromReader(br);
 };
 
@@ -281,6 +293,14 @@ Opcode.fromReader = function fromReader(br) {
  */
 
 Opcode.fromRaw = function fromRaw(data) {
+  if (data.length > 0) {
+    const op = data[0];
+    const cached = cache[op];
+
+    if (cached)
+      return cached;
+  }
+
   return new Opcode(0, null).fromRaw(data);
 };
 
@@ -291,6 +311,11 @@ Opcode.fromRaw = function fromRaw(data) {
  */
 
 Opcode.fromOp = function fromOp(op) {
+  const cached = cache[op];
+
+  if (cached)
+    return cached;
+
   return new Opcode(op, null);
 };
 
@@ -454,6 +479,23 @@ Opcode.isOpcode = function isOpcode(obj) {
     && (Buffer.isBuffer(obj.data) || obj.data === null);
 };
 
+/*
+ * Fill Cache
+ */
+
+for (let value = 0x00; value <= 0xff; value++) {
+  if (value >= 0x01 && value <= 0x4e) {
+    cache.push(null);
+    continue;
+  }
+
+  const op = new Opcode(value);
+
+  Object.freeze(op);
+
+  cache.push(op);
+}
+
 /*
  * Expose
  */