txdb: handle coins and double spenders differently.

lib/wallet/txdb.js

@@ -510,6 +510,9 @@ TXDB.prototype.verifyInputs = co(function* verifyInputs(tx) {
       continue;
     }
 
+    if (tx.height === -1)
+      return false;
+
     coin = yield this.getSpentCoin(spent, prevout);
     assert(coin);
 
@@ -625,90 +628,30 @@ TXDB.prototype.resolveOutputs = co(function* resolveOutputs(tx, resolved) {
  * @returns {Promise}
  */
 
-TXDB.prototype.getInputs = co(function* getInputs(tx, info) {
+TXDB.prototype.removeConflicts = co(function* removeConflicts(tx, info) {
-  var spends = [];
+  var hash = tx.hash('hex');
-  var coins = [];
+  var i, input, prevout, spent;
-  var removed = {};
-  var i, input, prevout, coin, spent, conflict;
 
   if (tx.isCoinbase())
-    return coins;
+    return;
 
   for (i = 0; i < tx.inputs.length; i++) {
     input = tx.inputs[i];
     prevout = input.prevout;
 
-    // Try to get the coin we're redeeming.
-    coin = yield this.getCoin(prevout.hash, prevout.index);
-
-    if (coin) {
-      input.coin = coin;
-      coins.push(coin);
-      continue;
-    }
-
     // Is it already spent?
     spent = yield this.isSpent(prevout.hash, prevout.index);
 
-    // If we have no coin or spend
-    // record, this is not our input.
-    // This is assuming everything came
-    // in order!
-    if (!spent) {
-      coins.push(null);
-      continue;
-    }
-
-    // Yikes, we're double spending. We
-    // still need the coin for after we
-    // resolve the conflict.
-    coin = yield this.getSpentCoin(spent, prevout);
-    assert(coin);
-
-    input.coin = coin;
-    coins.push(coin);
-
-    spends[i] = spent;
-  }
-
-  // Once we've verified everything to the
-  // best of our ability, go through and
-  // attempt to remove double-spenders.
-  for (i = 0; i < tx.inputs.length; i++) {
-    input = tx.inputs[i];
-    prevout = input.prevout;
-    spent = spends[i];
-
     if (!spent)
       continue;
 
-    this.logger.warning('Handling conflicting tx: %s.',
+    // Did _we_ spend it?
-      utils.revHex(spent.hash));
+    if (spent.hash === hash)
+      continue;
 
-    // Remove the older double spender.
+    // Remove the double spender.
-    // We have to maintain a spent list
+    yield this.removeConflict(spent.hash, tx);
-    // and pass it in. It needs to know
-    // which txs are considered "deleted"
-    // within this context.
-    conflict = yield this.removeConflict(spent.hash, tx, removed);
-
-    // Spender was not removed, the current
-    // transaction is not elligible to be added.
-    // Be sure to clear the batch, lest we
-    // remove other transactions on behalf of
-    // a non-eligible tx.
-    if (!conflict) {
-      this.clear();
-      return;
-    }
-
-    this.logger.warning('Removed conflict: %s.', conflict.tx.rhash);
-
-    // Emit the _removed_ transaction.
-    this.emit('conflict', conflict.tx, conflict.info);
   }
-
-  return coins;
 });
 
 /**
@@ -751,6 +694,14 @@ TXDB.prototype._add = co(function* add(tx, info) {
 
   assert(!tx.mutable, 'Cannot add mutable TX to wallet.');
 
+  if (tx.height === -1) {
+    if (yield this.isDoubleSpend(tx))
+      return false;
+  } else {
+    // This potentially removes double-spenders.
+    yield this.removeConflicts(tx, info);
+  }
+
   // Attempt to confirm tx before adding it.
   result = yield this.confirm(tx, info);
 
@@ -758,13 +709,6 @@ TXDB.prototype._add = co(function* add(tx, info) {
   if (result)
     return true;
 
-  // Verify and get coins.
-  // This potentially removes double-spenders.
-  coins = yield this.getInputs(tx, info);
-
-  if (!coins)
-    return false;
-
   hash = tx.hash('hex');
 
   this.put(layout.t(hash), tx.toExtended());
@@ -794,7 +738,7 @@ TXDB.prototype._add = co(function* add(tx, info) {
     for (i = 0; i < tx.inputs.length; i++) {
       input = tx.inputs[i];
       prevout = input.prevout;
-      coin = coins[i];
+      coin = yield this.getCoin(prevout.hash, prevout.index);
 
       // Only bother if this input is ours.
       if (!coin)
@@ -868,37 +812,24 @@ TXDB.prototype._add = co(function* add(tx, info) {
  * @returns {Promise} - Returns Boolean.
  */
 
-TXDB.prototype.removeConflict = co(function* removeConflict(hash, ref, removed) {
+TXDB.prototype.removeConflict = co(function* removeConflict(hash, ref) {
   var tx = yield this.getTX(hash);
   var info;
 
-  if (!tx)
+  assert(tx);
-    throw new Error('Could not find spender.');
 
-  if (tx.height !== -1) {
+  this.logger.warning('Handling conflicting tx: %s.', utils.revHex(hash));
-    // If spender is confirmed and replacement
-    // is not confirmed, do nothing.
-    if (ref.height === -1)
-      return;
 
-    // If both are confirmed but replacement
+  this.drop();
-    // is older than spender, do nothing.
-    if (ref.height < tx.height)
-      return;
-  } else {
-    // If spender is unconfirmed and replacement
-    // is confirmed, do nothing.
-    if (ref.height === -1) {
-      // If both are unconfirmed but replacement
-      // is older than spender, do nothing.
-      if (ref.ps < tx.ps)
-        return;
-    }
-  }
 
-  info = yield this.removeRecursive(tx, removed);
+  info = yield this.removeRecursive(tx);
 
-  return new Conflict(tx, info);
+  this.start();
+
+  this.logger.warning('Removed conflict: %s.', tx.rhash);
+
+  // Emit the _removed_ transaction.
+  this.emit('conflict', tx, info);
 });
 
 /**
@@ -909,38 +840,32 @@ TXDB.prototype.removeConflict = co(function* removeConflict(hash, ref, removed)
  * @returns {Promise} - Returns Boolean.
  */
 
-TXDB.prototype.removeRecursive = co(function* removeRecursive(tx, removed) {
+TXDB.prototype.removeRecursive = co(function* removeRecursive(tx) {
   var hash = tx.hash('hex');
   var i, spent, stx, info;
 
-  if (!removed)
-    removed = {};
-
   for (i = 0; i < tx.outputs.length; i++) {
     spent = yield this.isSpent(hash, i);
 
     if (!spent)
       continue;
 
-    if (removed[spent.hash])
-      continue;
-
-    removed[spent.hash] = true;
-
     // Remove all of the spender's spenders first.
     stx = yield this.getTX(spent.hash);
 
-    if (!stx)
+    assert(stx);
-      throw new Error('Could not find spender.');
 
-    yield this.removeRecursive(stx, removed);
+    yield this.removeRecursive(stx);
   }
 
+  this.start();
+
   // Remove the spender.
   info = yield this.lazyRemove(tx);
 
-  if (!info)
+  assert(info);
-    throw new Error('Cannot remove spender.');
+
+  yield this.commit();
 
   return info;
 });
@@ -1106,8 +1031,12 @@ TXDB.prototype._remove = co(function* remove(hash) {
   if (!tx)
     return;
 
+  this.drop();
+
   info = yield this.removeRecursive(tx);
 
+  this.start();
+
   if (!info)
     return;