Added a utxo cache.

lib/addresses.js

@@ -6,6 +6,7 @@ var async = require('async');
 var TxController = require('./transactions');
 var Common = require('./common');
 var _ = require('lodash');
+var LRU = require('lru-cache');
 
 function AddressController(node) {
   this.node = node;
@@ -14,6 +15,14 @@ function AddressController(node) {
   this.txController = new TxController(node);
   this.common = new Common({log: this.node.log});
   this._block = this.node.services.block;
+  this._utxoCache = new LRU({
+    max: 250,
+    maxAge: 1000 * 10
+  });
+  // limit the size of the request to about 100,000 bytes
+  // we'll use 34 bytes as the size of each address.
+  this._maxAddresses = Math.floor(100000/34);
+
 }
 
 AddressController.prototype.show = function(req, res) {
@@ -142,73 +151,25 @@ AddressController.prototype.check = function(addresses) {
 AddressController.prototype.utxo = function(req, res) {
   var self = this;
 
+  var cachedUtxos = this._utxoCache.get(req.addr);
+
+  if (cachedUtxos) {
+    return res.jsonp(cachedUtxos);
+  }
+
   this._address.getAddressUnspentOutputs(req.addr, {}, function(err, utxos) {
+    var results;
     if(err) {
       return self.common.handleErrors(err, res);
     } else if (!utxos.length) {
-      return res.jsonp([]);
+      results = [];
     }
-    res.jsonp(utxos.map(self.transformUtxo.bind(self)));
+    results = utxos.map(self.transformUtxo.bind(self));
+    self._utxoCache.set(req.addr, results);
+    res.jsonp(results);
   });
 };
 
-// this call could take a while to run depending on what addresses are used
-// considering memory constraints,  we will streaming out the results for addresses
-// not necessarily in the order we received them
-AddressController.prototype.multiutxo = function(req, res) {
-  var self = this;
-
-  var addresses;
-
-  if (_.isArray(req.addrs)) {
-    addresses = _.uniq(req.addrs);
-  } else {
-    addresses = req.addrs.split(',');
-  }
-
-  var addressesLeft = addresses.length;
-  var startedWriting = false;
-  res.write('[');
-
-  var sep = ',';
-
-  async.eachLimit(addresses, 4, function(addr, next) {
-
-    self._address.getAddressUnspentOutputs(addr, {}, function(err, utxos) {
-
-      if (err) {
-        return next(err);
-      }
-
-      if (addressesLeft-- > 0 && utxos.length > 0 && startedWriting) {
-        res.write(sep);
-      }
-
-      for(var i = 0; i < utxos.length; i++) {
-        startedWriting = true;
-        if (utxos.length - 1 === i) {
-          sep = '';
-        }
-        res.write(JSON.stringify(self.transformUtxo(utxos[i])) + sep);
-      }
-
-      sep = ',';
-      next();
-
-    });
-
-  }, function(err) {
-
-      if (err) {
-        return self.common.handleErrors(err, res);
-      }
-
-      res.write(']');
-      res.end();
-  });
-
-};
-
 AddressController.prototype.transformUtxo = function(utxoArg) {
   var utxo = {
     address: utxoArg.address,
@@ -238,6 +199,81 @@ AddressController.prototype._getTransformOptions = function(req) {
   };
 };
 
+// this call could take a while to run depending on what addresses are used
+// considering memory constraints,  we will streaming out the results for addresses
+// not necessarily in the order we received them
+AddressController.prototype.multiutxo = function(req, res) {
+
+  var self = this;
+
+  var addresses;
+
+  if (_.isArray(req.addrs)) {
+    addresses = _.uniq(req.addrs);
+  } else {
+    addresses = _.compact(req.addrs.split(','));
+  }
+
+  var cacheKey  = addresses.join('');
+
+  if (addresses.length > this._maxAddresses) {
+    return self.common.handleErrors(new Error('Too many addresses.'), res);
+  }
+
+  var cachedUtxos = this._utxoCache.get(cacheKey);
+
+  if (cachedUtxos) {
+    return res.jsonp(cachedUtxos);
+  }
+
+  var addressesLeft = addresses.length;
+  var startedWriting = false;
+  var cache = [];
+
+  res.write('[');
+
+  var sep = ',';
+
+  async.eachLimit(addresses, 4, function(addr, next) {
+
+    self._address.getAddressUnspentOutputs(addr, {}, function(err, utxos) {
+
+      if (err) {
+        return next(err);
+      }
+
+      if (addressesLeft-- > 0 && utxos.length > 0 && startedWriting) {
+        res.write(sep);
+      }
+
+      for(var i = 0; i < utxos.length; i++) {
+        startedWriting = true;
+        if (utxos.length - 1 === i) {
+          sep = '';
+        }
+        cache.push(utxos[i]);
+        res.write(JSON.stringify(self.transformUtxo(utxos[i])) + sep);
+      }
+
+      sep = ',';
+      next();
+
+    });
+
+  }, function(err) {
+
+      if (err) {
+        return self.common.handleErrors(err, res);
+      }
+
+      self._utxoCache.set(cacheKey, cache);
+
+      res.write(']');
+      res.end();
+  });
+
+};
+
 AddressController.prototype.multitxs = function(req, res) {
   var self = this;
 

package-lock.json

@@ -1063,24 +1063,12 @@
       "integrity": "sha1-+t2DS5aDBz2hebPq5tnA0VBT9z4="
     },
     "lru-cache": {
-      "version": "4.0.1",
+      "version": "4.1.1",
-      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-4.0.1.tgz",
+      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-4.1.1.tgz",
-      "integrity": "sha1-E0OVXtry432bnn7nJB4nxLn7cr4=",
+      "integrity": "sha512-q4spe4KTfsAS1SUHLO0wz8Qiyf1+vMIAgpRYioFYDMNqKfHQbg+AVDH3i4fvpl71/P1L0dBl+fQi+P37UYf0ew==",
       "requires": {
         "pseudomap": "1.0.2",
-        "yallist": "2.0.0"
+        "yallist": "2.1.2"
-      },
-      "dependencies": {
-        "pseudomap": {
-          "version": "1.0.2",
-          "resolved": "https://registry.npmjs.org/pseudomap/-/pseudomap-1.0.2.tgz",
-          "integrity": "sha1-8FKijacOYYkX7wqKw0wa5aaChrM="
-        },
-        "yallist": {
-          "version": "2.0.0",
-          "resolved": "https://registry.npmjs.org/yallist/-/yallist-2.0.0.tgz",
-          "integrity": "sha1-MGxUODXwnuGkyyO3vOmrNByRzdQ="
-        }
       }
     },
     "mime-db": {
@@ -1542,6 +1530,11 @@
         }
       }
     },
+    "pseudomap": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/pseudomap/-/pseudomap-1.0.2.tgz",
+      "integrity": "sha1-8FKijacOYYkX7wqKw0wa5aaChrM="
+    },
     "pump": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/pump/-/pump-1.0.2.tgz",
@@ -2417,6 +2410,11 @@
       "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.1.tgz",
       "integrity": "sha1-pcbVMr5lbiPbgg77lDofBJmNY68="
     },
+    "yallist": {
+      "version": "2.1.2",
+      "resolved": "https://registry.npmjs.org/yallist/-/yallist-2.1.2.tgz",
+      "integrity": "sha1-HBH5IY8HYImkfdUS+TxmmaaoHVI="
+    },
     "yeast": {
       "version": "0.1.2",
       "resolved": "https://registry.npmjs.org/yeast/-/yeast-0.1.2.tgz",

package.json

@@ -36,7 +36,7 @@
     "body-parser": "^1.13.3",
     "compression": "^1.6.1",
     "lodash": "^2.4.1",
-    "lru-cache": "^4.0.1",
+    "lru-cache": "^4.1.1",
     "morgan": "^1.7.0",
     "request": "^2.64.0"
   },