From e7f850b4ba5f038e8977538046efcc51243cfd47 Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Tue, 28 Feb 2017 16:57:45 -0800
Subject: [PATCH] fees: refactor estimator.

---
 lib/mempool/fees.js  | 101 +++++++++++++++++++++++++++++--------------
 lib/node/fullnode.js |   5 +--
 2 files changed, 70 insertions(+), 36 deletions(-)

diff --git a/lib/mempool/fees.js b/lib/mempool/fees.js
index 19cd7b4f..3208a9b8 100644
--- a/lib/mempool/fees.js
+++ b/lib/mempool/fees.js
@@ -39,14 +39,13 @@ var MAX_PRIORITY = 1e16;
 var INF_PRIORITY = 1e9 * consensus.MAX_MONEY;
 var FEE_SPACING = 1.1;
 var PRI_SPACING = 2;
-var FREE_THRESHOLD = policy.FREE_THRESHOLD;
 
 /**
  * Confirmation stats.
  * @alias module:mempool.ConfirmStats
  * @constructor
  * @param {String} type
- * @param {Logger} logger
+ * @param {Logger?} logger
  */
 
 function ConfirmStats(type, logger) {
@@ -345,15 +344,15 @@ ConfirmStats.prototype.toRaw = function toRaw() {
 };
 
 /**
- * Instantiate confirm stats from serialized data.
+ * Inject properties from serialized data.
+ * @private
  * @param {Buffer} data
- * @param {String} type
  * @returns {ConfirmStats}
  */
 
-ConfirmStats.fromRaw = function fromRaw(data, type, logger) {
+ConfirmStats.prototype.fromRaw = function fromRaw(data) {
   var br = new BufferReader(data);
-  var i, decay, buckets, avg, txAvg, maxConfirms, confAvg, stats;
+  var i, decay, buckets, avg, txAvg, maxConfirms, confAvg;
 
   decay = br.readDouble();
   buckets = readArray(br);
@@ -385,39 +384,49 @@ ConfirmStats.fromRaw = function fromRaw(data, type, logger) {
       throw new Error('Mismatch in fee/pri conf average bucket count.');
   }
 
-  stats = new ConfirmStats(type, logger);
+  this.init(buckets, maxConfirms, decay);
 
-  stats.init(buckets, maxConfirms, decay);
+  this.avg = avg;
+  this.txAvg = txAvg;
+  this.confAvg = confAvg;
 
-  stats.avg = avg;
-  stats.txAvg = txAvg;
-  stats.confAvg = confAvg;
+  return this;
+};
 
-  return stats;
+/**
+ * Instantiate confirm stats from serialized data.
+ * @param {Buffer} data
+ * @param {String} type
+ * @param {Logger?} logger
+ * @returns {ConfirmStats}
+ */
+
+ConfirmStats.fromRaw = function fromRaw(data, type, logger) {
+  return new ConfirmStats(type, logger).fromRaw(data);
 };
 
 /**
  * Estimator for fees and priority.
  * @alias module:mempool.PolicyEstimator
  * @constructor
- * @param {Rate} minRelay
  * @param {Network|NetworkType} network
+ * @param {Logger?} logger
  */
 
-function PolicyEstimator(minRelay, network, logger) {
+function PolicyEstimator(network, logger) {
   if (!(this instanceof PolicyEstimator))
-    return new PolicyEstimator(minRelay, network, logger);
+    return new PolicyEstimator(network, logger);
 
   this.network = Network.get(network);
   this.logger = logger || Logger.global;
 
-  this.minTrackedFee = minRelay < MIN_FEERATE
-    ? MIN_FEERATE
-    : minRelay;
+  this.minTrackedFee = policy.MIN_RELAY >= MIN_FEERATE
+    ? policy.MIN_RELAY
+    : MIN_FEERATE;
 
-  this.minTrackedPri = FREE_THRESHOLD < MIN_PRIORITY
-    ? MIN_PRIORITY
-    : FREE_THRESHOLD;
+  this.minTrackedPri = policy.FREE_THRESHOLD >= MIN_PRIORITY
+    ? policy.FREE_THRESHOLD
+    : MIN_PRIORITY;
 
   this.feeStats = new ConfirmStats('FeeRate', this.logger);
   this.priStats = new ConfirmStats('Priority', this.logger);
@@ -817,26 +826,54 @@ PolicyEstimator.prototype.toRaw = function toRaw() {
 };
 
 /**
- * Instantiate a policy estimator from serialized data.
+ * Inject properties from serialized data.
+ * @private
  * @param {Buffer} data
- * @param {Rate} minRelay
- * @param {Network|NetworkType} network
  * @returns {PolicyEstimator}
  */
 
-PolicyEstimator.fromRaw = function fromRaw(data, minRelay, logger) {
+PolicyEstimator.prototype.fromRaw = function fromRaw(data) {
   var br = new BufferReader(data);
   var network = Network.fromMagic(br.readU32());
   var bestHeight = br.readU32();
-  var estimator = new PolicyEstimator(minRelay, network, logger);
-  var feeStats = ConfirmStats.fromRaw(br.readVarBytes(), 'FeeRate', logger);
-  var priStats = ConfirmStats.fromRaw(br.readVarBytes(), 'Priority', logger);
 
-  estimator.bestHeight = bestHeight;
-  estimator.feeStats = feeStats;
-  estimator.priStats = priStats;
+  assert(this.network === network,
+    'Network mistmatch for policy estimator.');
 
-  return estimator;
+  this.bestHeight = bestHeight;
+  this.feeStats.fromRaw(br.readVarBytes());
+  this.priStats.fromRaw(br.readVarBytes());
+
+  return this;
+};
+
+/**
+ * Instantiate a policy estimator from serialized data.
+ * @param {Buffer} data
+ * @param {Network?} network
+ * @param {Logger?} logger
+ * @returns {PolicyEstimator}
+ */
+
+PolicyEstimator.fromRaw = function fromRaw(data, network, logger) {
+  return new PolicyEstimator(network, logger).fromRaw(data);
+};
+
+/**
+ * Inject properties from estimator.
+ * @param {PolicyEstimator} estimator
+ * @returns {PolicyEstimator}
+ */
+
+PolicyEstimator.prototype.inject = function inject(estimator) {
+  assert(this.network === estimator.network,
+    'Network mismatch for policy estimator.');
+
+  this.bestHeight = estimator.bestHeight;
+  this.feeStats = estimator.feeStats;
+  this.priStats = estimator.priStats;
+
+  return this;
 };
 
 /**
diff --git a/lib/node/fullnode.js b/lib/node/fullnode.js
index db29af2e..bdf0692e 100644
--- a/lib/node/fullnode.js
+++ b/lib/node/fullnode.js
@@ -64,10 +64,7 @@ function FullNode(options) {
   });
 
   // Fee estimation.
-  this.fees = new Fees(
-    policy.MIN_RELAY,
-    this.network,
-    this.logger);
+  this.fees = new Fees(this.network, this.logger);
 
   // Mempool needs access to the chain.
   this.mempool = new Mempool({