even more size calculation.

lib/bcoin/mtx.js

@@ -696,12 +696,22 @@ MTX.prototype.isScripted = function isScripted() {
   });
 };
 
-MTX.prototype.maxSize = function maxSize(maxM, maxN, force) {
-  var i, j, input, total, size, prev, m, n, witness;
+MTX.prototype.maxSize = function maxSize(options, force) {
+  var i, j, input, total, size, prev, m, n;
+  var witness, hadWitness, redeem, wallet;
 
   if (!force && this.isScripted())
     return this.getVirtualSize();
 
+  if (!options)
+    options = {};
+
+  if (options instanceof bcoin.wallet)
+    options = { wallet: options, m: options.m, n: options.n };
+
+  if (options.wallet)
+    wallet = options.wallet;
+
   // Calculate the size, minus the input scripts.
   total = bcoin.protocol.framer.tx.size(this);
 
@@ -718,6 +728,8 @@ MTX.prototype.maxSize = function maxSize(maxM, maxN, force) {
     size = 0;
     witness = false;
 
+    // We're out of luck here.
+    // Just assume it's a p2pkh.
     if (!input.coin) {
       total += 110;
       continue;
@@ -728,24 +740,46 @@ MTX.prototype.maxSize = function maxSize(maxM, maxN, force) {
 
     // If we have access to the redeem script,
     // we can use it to calculate size much easier.
-    if (input.script.code.length && prev.isScripthash()) {
+    if (prev.isScripthash()) {
       // Need to add the redeem script size
       // here since it will be ignored by
       // the isMultisig clause.
       // OP_PUSHDATA2 [redeem]
-      prev = input.script.getRedeem();
-      size += 3 + prev.getSize();
+      redeem = wallet
+        ? wallet.getRedeem(prev.code[1])
+        : input.script.getRedeem();
+
+      if (redeem) {
+        prev = redeem;
+        size += utils.sizePush(prev.getSize());
+        size += prev.getSize();
+      }
     }
 
     if (prev.isWitnessProgram()) {
       witness = true;
+
       // Now calculating vsize. The regular
       // redeem script (if there was one)
       // is now worth 4 points.
       size *= 4;
-      if (input.witness.items.length && prev.isWitnessScripthash()) {
-        prev = input.witness.getRedeem();
-        size += 3 + prev.getSize();
+
+      // Add 2 bytes for flag and marker.
+      if (!hadWitness)
+        size += 2;
+
+      hadWitness = true;
+
+      if (prev.isWitnessScripthash()) {
+        redeem = wallet
+          ? wallet.getRedeem(prev.code[1])
+          : input.witness.getRedeem();
+
+        if (redeem) {
+          prev = redeem;
+          size += utils.sizePush(prev.getSize());
+          size += prev.getSize();
+        }
       } else if (prev.isWitnessPubkeyhash()) {
         prev = Script.createPubkeyhash(prev.code[1]);
       }
@@ -769,7 +803,7 @@ MTX.prototype.maxSize = function maxSize(maxM, maxN, force) {
       size += 1;
       // OP_PUSHDATA0 [signature] ...
       size += (1 + 73) * m;
-    } else if (prev.isScripthash()) {
+    } else if (prev.isScripthash() || prev.isWitnessScripthash()) {
       // P2SH Multisig
       // This technically won't work well for other
       // kinds of P2SH. It will also over-estimate
@@ -780,9 +814,9 @@ MTX.prototype.maxSize = function maxSize(maxM, maxN, force) {
       // simply add more of the fee to the change
       // output.
       // m value
-      m = maxM || 15;
+      m = options.m || 15;
       // n value
-      n = maxN || 15;
+      n = options.n || 15;
       // OP_0
       size += 1;
       // OP_PUSHDATA0 [signature] ...
@@ -805,12 +839,15 @@ MTX.prototype.maxSize = function maxSize(maxM, maxN, force) {
       }
     }
 
-    // Byte for varint size of input script.
+    // Byte for varint size of input script or witness.
     size += utils.sizeVarint(size);
 
     // Calculate vsize if we're a witness program.
-    if (witness)
+    if (witness) {
+      // Add one byte back for the 0-byte input script.
+      size += 1 * 4;
       size = (size + 3) / 4 | 0;
+    }
 
     total += size;
   }
@@ -871,9 +908,6 @@ MTX.prototype.selectCoins = function selectCoins(coins, options) {
       chosen.push(coins[i]);
       lastAdded++;
 
-      if (options.wallet)
-        options.wallet.scriptInputs(tx, index);
-
       if (options.selection === 'all')
         continue;
 
@@ -905,7 +939,7 @@ MTX.prototype.selectCoins = function selectCoins(coins, options) {
     // bytes (10000 satoshi for every 1024 bytes).
     do {
       // Calculate max possible size after signing.
-      size = tx.maxSize(options.m, options.n, true);
+      size = tx.maxSize(options, true);
 
       if (tryFree) {
         if (tx.isFree(network.height + 1, size)) {

lib/bcoin/utils.js

@@ -1557,6 +1557,19 @@ utils.sizeVarint = function sizeVarint(num) {
   return 9;
 };
 
+utils.sizePush = function sizePush(num) {
+  if (num <= 0x4b)
+    return 1;
+
+  if (num <= 0xff)
+    return 2;
+
+  if (num <= 0xffff)
+    return 3;
+
+  return 5;
+};
+
 utils.cmp = function(a, b) {
   var len, i;
 

lib/bcoin/wallet.js

@@ -59,6 +59,8 @@ function Wallet(options) {
   this.m = options.m || 1;
   this.n = options.n || 1;
 
+  this.cache = new bcoin.lru(20);
+
   if (this.n > 1)
     this.type = 'multisig';
 
@@ -364,6 +366,9 @@ Wallet.prototype.deriveAddress = function deriveAddress(change, index) {
     };
   }
 
+  if (this.cache.has(data.path))
+    return this.cache.get(data.path);
+
   key = this.accountKey.derive(data.path);
 
   options = {
@@ -401,6 +406,8 @@ Wallet.prototype.deriveAddress = function deriveAddress(change, index) {
 
   this.emit('add address', address);
 
+  this.cache.set(data.path, address);
+
   return address;
 };
 
@@ -699,6 +706,32 @@ Wallet.prototype.syncOutputDepth = function syncOutputDepth(tx) {
   return res;
 };
 
+Wallet.prototype.getRedeem = function getRedeem(hash, prefix) {
+  var addr, address;
+
+  if (!prefix) {
+    if (hash.length === 20)
+      prefix = 'scripthash';
+    else if (hash.length === 32)
+      prefix = 'witnessscripthash';
+    else
+      assert(false, 'Unknown hash length.');
+  }
+
+  addr = bcoin.address.compileHash(hash, prefix);
+  address = this.deriveAddress(addr);
+
+  if (!address)
+    return;
+
+  if (address.program && hash.length === 20) {
+    if (utils.isEqual(hash, address.programHash))
+      return address.program;
+  }
+
+  return address.script;
+};
+
 Wallet.prototype.scan = function scan(txByAddress, callback) {
   var self = this;
   var res = false;