Merge pull request #1276 from greggzigler/feature/get-sigops-count

get-signature-count needed to measure txs with many inputs

lib/script/script.js

@@ -838,4 +838,45 @@ Script.prototype.checkMinimalPush = function(i) {
   return true;
 };
 
+/**
+ * Comes from bitcoind's script DecodOP_N function
+ * @param {number} opcode
+ * @returns {number} numeric value in range of 0 to 16
+ */
+Script.prototype._decodeOP_N = function(opcode) {
+  if (opcode === Opcode.OP_0) {
+    return 0;
+  } else if (opcode >= Opcode.OP_1 && opcode <= Opcode.OP_16) {
+    return opcode - (Opcode.OP_1 - 1);
+  } else {
+    throw new Error('Invalid opcode: ' + JSON.stringify(opcode));
+  }
+};
+
+/**
+ * Comes from bitcoind's script GetSigOpCount(boolean) function
+ * @param {boolean} use current (true) or pre-version-0.6 (false) logic
+ * @returns {number} number of signature operations required by this script
+ */
+Script.prototype.getSignatureOperationsCount = function(accurate) {
+  accurate = (_.isUndefined(accurate) ? true : accurate);
+  var self = this;
+  var n = 0;
+  var lastOpcode = Opcode.OP_INVALIDOPCODE;
+  _.each(self.chunks, function getChunk(chunk) {
+    var opcode = chunk.opcodenum;
+    if (opcode == Opcode.OP_CHECKSIG || opcode == Opcode.OP_CHECKSIGVERIFY) {
+      n++;
+    } else if (opcode == Opcode.OP_CHECKMULTISIG || opcode == Opcode.OP_CHECKMULTISIGVERIFY) {
+      if (accurate && lastOpcode >= Opcode.OP_1 && lastOpcode <= Opcode.OP_16) {
+        n += self._decodeOP_N(lastOpcode);
+      } else {
+        n += 20;
+      }
+    }
+    lastOpcode = opcode;
+  });
+  return n;
+};
+
 module.exports = Script;

test/script/script.js

@@ -471,7 +471,7 @@ describe('Script', function() {
   });
 
   describe('#buildMultisigOut', function() {
-    var pubkey_hexs = [
+    var pubKeyHexes = [
       '022df8750480ad5b26950b25c7ba79d3e37d75f640f8e5d9bcd5b150a0f85014da',
       '03e3818b65bcc73a7d64064106a859cc1a5a728c4345ff0b641209fba0d90de6e9',
       '021f2f6e1e50cb6a953935c3601284925decd3fd21bc445712576873fb8c6ebc18',
@@ -479,7 +479,7 @@ describe('Script', function() {
       '036a98a36aa7665874b1ba9130bc6d318e52fd3bdb5969532d7fc09bf2476ff842',
       '033aafcbead78c08b0e0aacc1b0cdb40702a7c709b660bebd286e973242127e15b',
     ];
-    var sortkeys = pubkey_hexs.slice(0, 3).map(PublicKey);
+    var sortkeys = pubKeyHexes.slice(0, 3).map(PublicKey);
     it('should create sorted script by default', function() {
       var s = Script.buildMultisigOut(sortkeys, 2);
       s.toString().should.equal('OP_2 33 0x021f2f6e1e50cb6a953935c3601284925decd3fd21bc445712576873fb8c6ebc18 33 0x022df8750480ad5b26950b25c7ba79d3e37d75f640f8e5d9bcd5b150a0f85014da 33 0x03e3818b65bcc73a7d64064106a859cc1a5a728c4345ff0b641209fba0d90de6e9 OP_3 OP_CHECKMULTISIG');
@@ -501,7 +501,7 @@ describe('Script', function() {
       s.isMultisigOut().should.equal(true);
     });
     var test_mn = function(m, n) {
-      var pubkeys = pubkey_hexs.slice(0, n).map(PublicKey);
+      var pubkeys = pubKeyHexes.slice(0, n).map(PublicKey);
       var s = Script.buildMultisigOut(pubkeys, m);
       s.isMultisigOut().should.equal(true);
     };
@@ -775,5 +775,46 @@ describe('Script', function() {
     });
   });
 
-
+  describe('#getSignatureOperationsCount', function() {
+    // comes from bitcoind src/test/sigopcount_tests
+    // only test calls to function with boolean param, not signature ref param
+    var pubKeyHexes = [
+      '022df8750480ad5b26950b25c7ba79d3e37d75f640f8e5d9bcd5b150a0f85014da',
+      '03e3818b65bcc73a7d64064106a859cc1a5a728c4345ff0b641209fba0d90de6e9',
+      '021f2f6e1e50cb6a953935c3601284925decd3fd21bc445712576873fb8c6ebc18',
+    ];
+    it('should return zero for empty scripts', function() {
+      Script().getSignatureOperationsCount(false).should.equal(0);
+      Script().getSignatureOperationsCount(true).should.equal(0);
+    });
+    it('should handle multi-sig multisig scripts from string', function() {
+      var s1 = 'OP_1 01 FF OP_2 OP_CHECKMULTISIG';
+      Script(s1).getSignatureOperationsCount(true).should.equal(2);
+      s1 += ' OP_IF OP_CHECKSIG OP_ENDIF';
+      Script(s1).getSignatureOperationsCount(true).should.equal(3);
+      Script(s1).getSignatureOperationsCount(false).should.equal(21);
+    });
+    it('should handle multi-sig-out scripts from utility function', function() {
+      var sortKeys = pubKeyHexes.slice(0, 3).map(PublicKey);
+      var s2 = Script.buildMultisigOut(sortKeys, 1);
+      Script(s2).getSignatureOperationsCount(true).should.equal(3);
+      Script(s2).getSignatureOperationsCount(false).should.equal(20);
+    });
+    it('should handle P2SH-multisig-in scripts from utility', function() {
+      // create a well-formed signature, does not need to match pubkeys
+      var signature = bitcore.crypto.Signature.fromString('30060201FF0201FF');
+      var signatures = [ signature.toBuffer() ];
+      var p2sh = Script.buildP2SHMultisigIn(pubKeyHexes, 1, signatures, {});
+      p2sh.getSignatureOperationsCount(true).should.equal(0);
+      p2sh.getSignatureOperationsCount(false).should.equal(0);
+    });
+    it('should default the one and only argument to true', function() {
+      var s1 = 'OP_1 01 FF OP_2 OP_CHECKMULTISIG';
+      var trueCount = Script(s1).getSignatureOperationsCount(true);
+      var falseCount = Script(s1).getSignatureOperationsCount(false);
+      var defaultCount = Script(s1).getSignatureOperationsCount();
+      trueCount.should.not.equal(falseCount);
+      trueCount.should.equal(defaultCount);
+    });
+  });
 });