copy buffer as a client option

Author: Jorge Bay Gondra

lib/client.js

@@ -14,10 +14,15 @@ var clientOptions = require('./client-options');
 /**
  * Client options
  * @typedef {Object} ClientOptions
- * @property {Array.<string>} contactPoints Array of addresses or host names of the nodes to add as contact points.
- * Contact points are addresses of Cassandra nodes that the driver uses to discover the cluster topology.
- * Only one contact point is required (the driver will retrieve the address of the other nodes automatically),
+ * @property {Array.<string>} contactPoints
+ * Array of addresses or host names of the nodes to add as contact points.
+ * <p>
+ *  Contact points are addresses of Cassandra nodes that the driver uses to discover the cluster topology.
+ * </p>
+ * <p>
+ *  Only one contact point is required (the driver will retrieve the address of the other nodes automatically),
  *  but it is usually a good idea to provide more than one contact point, because if that single contact point is unavailable, the driver will not be able to initialize correctly.
+ * </p>
  * @property {Object} policies
  * @property {LoadBalancingPolicy} policies.loadBalancing The load balancing policy instance to be used to determine the coordinator per query.
  * @property {RetryPolicy} policies.retry The retry policy.
@@ -41,10 +46,19 @@ var clientOptions = require('./client-options');
  * @property {Object} sslOptions Client-to-node ssl options, when set the driver will use the secure layer.
  * You can specify cert, ca, ... options named after the Node.js tls.connect options.
  * @property {Object} encoding
- * @property {Function} encoding.map Map constructor to use for Cassandra map<k,v> types encoding and decoding.
+ * @property {Function} encoding.map Map constructor to use for Cassandra map<k,v> type encoding and decoding.
  * If not set, it will default to Javascript Object with map keys as property names.
- * @property {Function} encoding.set Set constructor to use for Cassandra set<k> types encoding and decoding.
- * If not set, it will default to Javascript Array
+ * @property {Function} encoding.set Set constructor to use for Cassandra set<k> type encoding and decoding.
+ * If not set, it will default to Javascript Array.
+ * @property {Boolean} encoding.copyBuffer Determines if the network buffer should be copied.
+ * <p>
+ *   Setting it to true will cause that the network buffer is copied for each row value, causing an additional allocations but freeing the network buffer to be reused.
+ *   Setting it to true is a good choice for cases where the Row and ResultSet returned by the queries are long-lived objects.
+ * </p>
+ * <p>
+ *  Setting it to false will cause less overhead and the reference of the network buffer to be maintained until the row / result set are de-referenced.
+ *  Default: true.
+ * </p>
  */
 
 /**

lib/encoder.js

@@ -61,6 +61,12 @@ function Encoder(protocolVersion, options) {
   this.encodingOptions = options.encoding || utils.emptyObject;
   this.setProtocolVersion(protocolVersion);
   this.setEncoders();
+  if (this.encodingOptions.copyBuffer) {
+    this.handleBuffer = this.handleBufferCopy;
+  }
+  else {
+    this.handleBuffer = this.handleBufferRef;
+  }
 }
 
 /**
@@ -319,7 +325,7 @@ Encoder.prototype.setProtocolVersion = function (value) {
 };
 
 Encoder.prototype.decodeBlob = function (bytes) {
-  return utils.copyBuffer(bytes);
+  return bytes;
 };
 
 Encoder.prototype.decodeUtf8String = function (bytes) {
@@ -448,15 +454,15 @@ Encoder.prototype.decodeCollectionLengthV2 = function (bytes, offset) {
 };
 
 Encoder.prototype.decodeUuid = function (bytes) {
-  return new types.Uuid(utils.copyBuffer(bytes));
+  return new types.Uuid(bytes);
 };
 
 Encoder.prototype.decodeTimeUuid = function (bytes) {
-  return new types.TimeUuid(utils.copyBuffer(bytes));
+  return new types.TimeUuid(bytes);
 };
 
 Encoder.prototype.decodeInet = function (bytes) {
-  return new types.InetAddress(utils.copyBuffer(bytes));
+  return new types.InetAddress(bytes);
 };
 
 /**
@@ -843,6 +849,14 @@ Encoder.prototype.getLengthBufferV3 = function (value) {
   return lengthBuffer;
 };
 
+Encoder.prototype.handleBufferCopy = function (buffer) {
+  return utils.copyBuffer(buffer);
+};
+
+Encoder.prototype.handleBufferRef = function (buffer) {
+  return buffer;
+};
+
 /**
  * Parses a given Cassandra type name to get the data type information
  * @param {String} typeName

lib/streams.js

@@ -274,6 +274,10 @@ Parser.prototype.parseResult = function (frameInfo, reader) {
   }
 };
 
+/**
+ * @param frameInfo
+ * @param {FrameReader} reader
+ */
 Parser.prototype.parseRows = function (frameInfo, reader) {
   if (typeof frameInfo.rowLength === 'undefined') {
     try {
@@ -299,7 +303,7 @@ Parser.prototype.parseRows = function (frameInfo, reader) {
     var rowValues = new Array(meta.columns.length);
     for(var j = 0; j < meta.columns.length; j++ ) {
       try {
-        rowValues[j] = reader.readBytes();
+        rowValues[j] = this.encoder.handleBuffer(reader.readBytes());
       }
       catch (e) {
         if (e instanceof RangeError) {