1 files changed, 0 insertions, 56 deletions
diff --git a/library/HTMLPurifier/Queue.php b/library/HTMLPurifier/Queue.php
deleted file mode 100644
index f58db9042..000000000
--- a/library/HTMLPurifier/Queue.php
+++ /dev/null
@@ -1,56 +0,0 @@
-<?php
-
-/**
- * A simple array-backed queue, based off of the classic Okasaki
- * persistent amortized queue.  The basic idea is to maintain two
- * stacks: an input stack and an output stack.  When the output
- * stack runs out, reverse the input stack and use it as the output
- * stack.
- *
- * We don't use the SPL implementation because it's only supported
- * on PHP 5.3 and later.
- *
- * Exercise: Prove that push/pop on this queue take amortized O(1) time.
- *
- * Exercise: Extend this queue to be a deque, while preserving amortized
- * O(1) time.  Some care must be taken on rebalancing to avoid quadratic
- * behaviour caused by repeatedly shuffling data from the input stack
- * to the output stack and back.
- */
-class HTMLPurifier_Queue {
-    private $input;
-    private $output;
-
-    public function __construct($input = array()) {
-        $this->input = $input;
-        $this->output = array();
-    }
-
-    /**
-     * Shifts an element off the front of the queue.
-     */
-    public function shift() {
-        if (empty($this->output)) {
-            $this->output = array_reverse($this->input);
-            $this->input = array();
-        }
-        if (empty($this->output)) {
-            return NULL;
-        }
-        return array_pop($this->output);
-    }
-
-    /**
-     * Pushes an element onto the front of the queue.
-     */
-    public function push($x) {
-        array_push($this->input, $x);
-    }
-
-    /**
-     * Checks if it's empty.
-     */
-    public function isEmpty() {
-        return empty($this->input) && empty($this->output);
-    }
-}