mempool: handle trimming differently.

lib/mempool/mempool.js

@@ -366,39 +366,43 @@ Mempool.prototype._reset = co(function* reset() {
 
 Mempool.prototype.limitSize = function limitSize(added) {
   var maxSize = this.options.maxSize;
+  var threshold = maxSize - (maxSize / 10);
   var expiryTime = this.options.expiryTime;
   var now = util.now();
-  var trimmed = false;
-  var i, queue, entry, keys, hash, start;
+  var i, queue, hashes, hash, entry, start;
 
   if (this.size <= maxSize)
-    return trimmed;
+    return false;
 
   queue = new Heap(cmpRate);
-  keys = this.getSnapshot();
+  hashes = this.getSnapshot();
 
   start = util.hrtime();
 
-  for (i = 0; i < keys.length; i++) {
-    hash = keys[i];
+  for (i = 0; i < hashes.length; i++) {
+    hash = hashes[i];
     entry = this.getEntry(hash);
 
     if (!entry)
       continue;
 
+    if (this.hasDepends(entry.tx))
+      continue;
+
     if (now < entry.ts + expiryTime) {
       queue.insert(entry);
       continue;
     }
 
-    if (entry === added)
-      trimmed = true;
+    this.logger.debug(
+      'Removing package %s from mempool (too old).',
+      entry.txid());
 
     this.evictEntry(entry);
   }
 
-  if (this.size <= maxSize)
-    return trimmed;
+  if (this.size <= threshold)
+    return !this.hasEntry(added);
 
   this.logger.debug(
     '(bench) Heap mempool traversal: %d.',
@@ -406,19 +410,23 @@ Mempool.prototype.limitSize = function limitSize(added) {
 
   start = util.hrtime();
 
+  this.logger.debug(
+    '(bench) Heap mempool queue size: %d.',
+    queue.size());
+
   while (queue.size() > 0) {
     entry = queue.shift();
     hash = entry.hash('hex');
 
-    if (!this.hasEntry(hash))
-      continue;
+    assert(this.hasEntry(hash));
+
+    this.logger.debug(
+      'Removing package %s from mempool (low fee).',
+      entry.txid());
 
     this.evictEntry(entry);
 
-    if (entry === added)
-      trimmed = true;
-
-    if (this.size <= maxSize - (maxSize / 10))
+    if (this.size <= threshold)
       break;
   }
 
@@ -426,7 +434,7 @@ Mempool.prototype.limitSize = function limitSize(added) {
     '(bench) Heap mempool map removal: %d.',
     util.hrtime(start));
 
-  return trimmed;
+  return !this.hasEntry(added);
 };
 
 /**
@@ -877,7 +885,7 @@ Mempool.prototype.insertTX = co(function* insertTX(tx) {
   yield this.addEntry(entry, view);
 
   // Trim size if we're too big.
-  if (this.limitSize(entry)) {
+  if (this.limitSize(hash)) {
     throw new VerifyError(tx,
       'insufficientfee',
       'mempool full',
@@ -1132,19 +1140,14 @@ Mempool.prototype.removeEntry = function removeEntry(entry) {
 };
 
 /**
- * Evict a transaction from the mempool.
+ * Remove a transaction from the mempool.
  * Recursively remove its spenders.
  * @param {MempoolEntry} entry
  */
 
 Mempool.prototype.evictEntry = function evictEntry(entry) {
-  var tx = entry.tx;
-
-  this.logger.debug('Evicting %s from the mempool.', tx.txid());
-
   this.removeSpenders(entry);
   this.updateAncestors(entry, removeFee);
-
   this.removeEntry(entry);
 };
 
@@ -1388,6 +1391,25 @@ Mempool.prototype.getDepends = function getDepends(tx) {
   return depends;
 };
 
+/**
+ * Test whether a transaction has dependencies.
+ * @param {TX} tx
+ * @returns {Boolean}
+ */
+
+Mempool.prototype.hasDepends = function hasDepends(tx) {
+  var i, input, hash;
+
+  for (i = 0; i < tx.inputs.length; i++) {
+    input = tx.inputs[i];
+    hash = input.prevout.hash;
+    if (this.hasEntry(hash))
+      return true;
+  }
+
+  return false;
+};
+
 /**
  * Return the full balance of all unspents in the mempool
  * (not very useful in practice, only used for testing).
@@ -1900,7 +1922,7 @@ Mempool.prototype.removeDoubleSpends = function removeDoubleSpends(tx) {
 
     this.logger.debug(
       'Removing double spender from mempool: %s.',
-      spent.tx.rhash());
+      spent.txid());
 
     this.evictEntry(spent);
 

lib/mempool/mempoolentry.js

@@ -142,6 +142,15 @@ MempoolEntry.prototype.hash = function hash(enc) {
   return this.tx.hash(enc);
 };
 
+/**
+ * Calculate reverse transaction hash.
+ * @returns {Hash}
+ */
+
+MempoolEntry.prototype.txid = function txid() {
+  return this.tx.txid();
+};
+
 /**
  * Calculate priority, taking into account
  * the entry height delta, modified size,