first version

tools/parser_sql/processors/ExplainProcessor.php

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+<?php
+/**
+ * ExplainProcessor.php
+ *
+ * This file implements the processor for the EXPLAIN statements.
+ *
+ * Copyright (c) 2010-2012, Justin Swanhart
+ * with contributions by André Rothe <arothe@phosco.info, phosco@gmx.de>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright notice,
+ *     this list of conditions and the following disclaimer in the documentation
+ *     and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+ * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ */
+
+require_once(dirname(__FILE__) . '/AbstractProcessor.php');
+require_once(dirname(__FILE__) . '/../utils/ExpressionType.php');
+
+/**
+ * 
+ * This class processes the EXPLAIN statements.
+ * 
+ * @author arothe
+ * 
+ */
+class ExplainProcessor extends AbstractProcessor {
+
+    protected function isStatement($keys, $needle = "EXPLAIN") {
+        $pos = array_search($needle, $keys);
+        if (isset($keys[$pos + 1])) {
+            return in_array($keys[$pos + 1], array('SELECT', 'DELETE', 'INSERT', 'REPLACE', 'UPDATE'), true);
+        }
+        return false;
+    }
+
+    // TODO: refactor that function
+    public function process($tokens, $keys = array()) {
+
+        $base_expr = "";
+        $expr = array();
+        $currCategory = "";
+
+        if ($this->isStatement($keys)) {
+            foreach ($tokens as $token) {
+
+                $trim = trim($token);
+                $base_expr .= $token;
+
+                if ($trim === '') {
+                    continue;
+                }
+
+                $upper = strtoupper($trim);
+
+                switch ($upper) {
+
+                case 'EXTENDED':
+                case 'PARTITIONS':
+                    return array('expr_type' => ExpressionType::RESERVED, 'base_expr' => $token);
+                    break;
+
+                case 'FORMAT':
+                    if ($currCategory === '') {
+                        $currCategory = $upper;
+                        $expr[] = array('expr_type' => ExpressionType::RESERVED, 'base_expr' => $trim);
+                    }
+                    // else?
+                    break;
+
+                case '=':
+                    if ($currCategory === 'FORMAT') {
+                        $expr[] = array('expr_type' => ExpressionType::OPERATOR, 'base_expr' => $trim);
+                    }
+                    // else?
+                    break;
+
+                case 'TRADITIONAL':
+                case 'JSON':
+                    if ($currCategory === 'FORMAT') {
+                        $expr[] = array('expr_type' => ExpressionType::RESERVED, 'base_expr' => $trim);
+                        return array('expr_type' => ExpressionType::EXPRESSION, 'base_expr' => trim($base_expr),
+                                     'sub_tree' => $expr);
+                    }
+                    // else?
+                    break;
+
+                default:
+                // ignore the other stuff
+                    break;
+                }
+            }
+            return empty($expr) ? null : $expr;
+        }
+
+        foreach ($tokens as $token) {
+
+            $trim = trim($token);
+
+            if ($trim === '') {
+                continue;
+            }
+
+            switch ($currCategory) {
+
+            case 'TABLENAME':
+                $currCategory = 'WILD';
+                $expr[] = array('expr_type' => ExpressionType::COLREF, 'base_expr' => $trim);
+                break;
+
+            case '':
+                $currCategory = 'TABLENAME';
+                $expr[] = array('expr_type' => ExpressionType::TABLE, 'base_expr' => $trim);
+                break;
+
+            default:
+                break;
+            }
+        }
+        return empty($expr) ? null : $expr;
+    }
+}
+?>