estimator serialization.

lib/bcoin/fees.js

@@ -12,6 +12,8 @@ var bcoin = require('./env');
 var utils = bcoin.utils;
 var assert = require('assert');
 var constants = bcoin.protocol.constants;
+var BufferReader = require('./reader');
+var BufferWriter = require('./writer');
 var global = bcoin.utils.global;
 var Float64Array = global.Float64Array || Array;
 var Int32Array = global.Int32Array || Array;
@@ -38,7 +40,7 @@ var FREE_THRESHOLD = constants.tx.FREE_THRESHOLD;
 
 /**
  * Confirmation stats.
- * @exposes ConfirmStats
+ * @exports ConfirmStats
  * @constructor
  * @param {Number} buckets
  * @param {Number} maxConfirms
@@ -286,9 +288,99 @@ ConfirmStats.prototype.removeTX = function removeTX(entryHeight, bestHeight, buc
   }
 };
 
+/**
+ * Serialize confirm stats.
+ * @returns {Buffer}
+ */
+
+ConfirmStats.prototype.toRaw = function toRaw() {
+  var p = new BufferWriter();
+  var i;
+
+  function writeArray(buckets) {
+    var i;
+
+    p.writeVarint(buckets.length);
+
+    for (i = 0; i < buckets.length; i++)
+      p.writeDouble(buckets[i]);
+  }
+
+  p.writeDouble(this.decay);
+  writeArray(this.buckets);
+  writeArray(this.avg);
+  writeArray(this.txAvg);
+  p.writeVarint(this.maxConfirms);
+
+  for (i = 0; i < this.maxConfirms; i++)
+    writeArray(this.confAvg[i]);
+
+  return p.render();
+};
+
+/**
+ * Instantiate confirm stats from serialized data.
+ * @param {Buffer} data
+ * @param {String} type
+ * @returns {ConfirmStats}
+ */
+
+ConfirmStats.fromRaw = function fromRaw(data, type) {
+  var p = new BufferReader(data);
+  var i, decay, buckets, avg, txAvg, maxConfirms, confAvg, stats;
+
+  function readArray() {
+    var buckets = new Float64Array(p.readVarint());
+    var i;
+
+    for (i = 0; i < buckets.length; i++)
+      buckets[i] = p.readDouble();
+
+    return buckets;
+  }
+
+  decay = p.readDouble();
+  buckets = readArray();
+  avg = readArray();
+  txAvg = readArray();
+  maxConfirms = p.readVarint();
+  confAvg = new Array(maxConfirms);
+
+  for (i = 0; i < maxConfirms; i++)
+    confAvg[i] = readArray();
+
+  if (decay <= 0 || decay >= 1)
+    throw new Error('Decay must be between 0 and 1 (non-inclusive).');
+
+  if (buckets.length <= 1 || buckets.length > 1000)
+    throw new Error('Must have between 2 and 1000 fee/pri buckets.');
+
+  if (avg.length !== buckets.length)
+    throw new Error('Mismatch in fee/pri average bucket count.');
+
+  if (txAvg.length !== buckets.length)
+    throw new Error('Mismatch in tx count bucket count.');
+
+  if (maxConfirms <= 0 || maxConfirms > 6 * 24 * 7)
+    throw new Error('Must maintain estimates for between 1 and 1008 confirms.');
+
+  for (i = 0; i < maxConfirms; i++) {
+    if (confAvg[i].length !== buckets.length)
+      throw new Error('Mismatch in fee/pri conf average bucket count.');
+  }
+
+  stats = new ConfirmStats(buckets, maxConfirms, decay, type);
+
+  stats.avg = avg;
+  stats.txAvg = txAvg;
+  stats.confAvg = confAvg;
+
+  return stats;
+};
+
 /**
  * Estimator for fees and priority.
- * @exposes PolicyEstimator
+ * @exports PolicyEstimator
  * @constructor
  * @param {Rate} minRelay
  * @param {Network|NetworkType} network
@@ -641,6 +733,41 @@ PolicyEstimator.prototype.estimatePriority = function estimatePriority(target, s
   return Math.floor(priority);
 };
 
+/**
+ * Serialize the estimator.
+ * @returns {Buffer}
+ */
+
+PolicyEstimator.prototype.toRaw = function toRaw() {
+  var p = new BufferWriter();
+  p.writeU32(this.bestHeight);
+  p.writeVarBytes(this.feeStats.toRaw());
+  p.writeVarBytes(this.priStats.toRaw());
+  return p.render();
+};
+
+/**
+ * Instantiate a policy estimator from serialized data.
+ * @param {Buffer} data
+ * @param {Rate} minRelay
+ * @param {Network|NetworkType} network
+ * @returns {PolicyEstimator}
+ */
+
+PolicyEstimator.fromRaw = function fromRaw(data, minRelay, network) {
+  var p = new BufferReader(data);
+  var bestHeight = p.readU32();
+  var feeStats = ConfirmStats.fromRaw(p.readVarBytes(), 'FeeRate');
+  var priStats = ConfirmStats.fromRaw(p.readVarBytes(), 'Priority');
+  var estimator = new PolicyEstimator(minRelay, network);
+
+  estimator.bestHeight = bestHeight;
+  estimator.feeStats = feeStats;
+  estimator.priStats = priStats;
+
+  return estimator;
+};
+
 /**
  * DoubleMap
  * @private