GUACAMOLE-1170: Support sized IntegerPool to maximize time between stream index reuse.

guacamole-common-js/src/main/webapp/modules/Client.js

@@ -139,8 +139,25 @@ Guacamole.Client = function(tunnel) {
      */
     var objects = [];
 
-    // Pool of available stream indices
-    var stream_indices = new Guacamole.IntegerPool();
+    /**
+     * The maximum number of streams supported by any one guac_user. This must
+     * match GUAC_USER_MAX_STREAMS defined in guacamole-server's user.h to
+     * ensure we stay within the server's stream index limits.
+     *
+     * @private
+     * @constant
+     * @type {!number}
+     */
+    var GUAC_USER_MAX_STREAMS = 512;
+
+    /**
+     * Pool of available stream indices. Initialized with min_size set to
+     * GUAC_USER_MAX_STREAMS to delay index reuse.
+     *
+     * @private
+     * @type {!Guacamole.IntegerPool}
+     */
+    var stream_indices = new Guacamole.IntegerPool(GUAC_USER_MAX_STREAMS);
 
     // Array of allocated output streams by index
     var output_streams = [];

guacamole-common-js/src/main/webapp/modules/IntegerPool.js

@@ -22,9 +22,16 @@ var Guacamole = Guacamole || {};
 /**
  * Integer pool which returns consistently increasing integers while integers
  * are in use, and previously-used integers when possible.
- * @constructor 
+ *
+ * When a minimum pool size is specified, new integers are preferred over reused
+ * integers until the minimum size is reached.
+ *
+ * @constructor
+ * @param {number} [min_size]
+ *     The minimum number of integers which must have been returned before
+ *     previously-used and freed integers are allowed to be returned.
  */
-Guacamole.IntegerPool = function() {
+Guacamole.IntegerPool = function(min_size) {
 
     /**
      * Reference to this integer pool.
@@ -51,14 +58,14 @@ Guacamole.IntegerPool = function() {
     /**
      * Returns the next available integer in the pool. If possible, a previously
      * used integer will be returned.
-     * 
+     *
      * @return {!number}
      *     The next available integer.
      */
     this.next = function() {
 
-        // If free'd integers exist, return one of those
-        if (pool.length > 0)
+        // If free'd integers exist and we've allocated the minimum, reuse it
+        if (pool.length > 0 && (!min_size || guac_pool.next_int >= min_size))
             return pool.shift();
 
         // Otherwise, return a new integer