Initial commit

#pma/libraries/Linter.php

@@ -0,0 +1,180 @@
+<?php
+/* vim: set expandtab sw=4 ts=4 sts=4: */
+/**
+ * Analyzes a query and gives user feedback.
+ *
+ * @package PhpMyAdmin
+ */
+namespace PMA\libraries;
+
+use SqlParser\Lexer;
+use SqlParser\Parser;
+use SqlParser\UtfString;
+use SqlParser\Utils\Error as ParserError;
+
+/**
+ * The linter itself.
+ *
+ * @package PhpMyAdmin
+ */
+class Linter
+{
+
+    /**
+     * Gets the starting position of each line.
+     *
+     * @param string $str String to be analyzed.
+     *
+     * @return array
+     */
+    public static function getLines($str)
+    {
+        if ((!($str instanceof UtfString))
+            && (defined('USE_UTF_STRINGS')) && (USE_UTF_STRINGS)
+        ) {
+            // If the lexer uses UtfString for processing then the position will
+            // represent the position of the character and not the position of
+            // the byte.
+            $str = new UtfString($str);
+        }
+
+        // The reason for using the strlen is that the length
+        // required is the length in bytes, not characters.
+        //
+        // Given the following string: `????+`, where `?` represents a
+        // multi-byte character (lets assume that every `?` is a 2-byte
+        // character) and `+` is a newline, the first value of `$i` is `0`
+        // and the last one is `4` (because there are 5 characters). Bytes
+        // `$str[0]` and `$str[1]` are the first character, `$str[2]` and
+        // `$str[3]` are the second one and `$str[4]` is going to be the
+        // first byte of the third character. The fourth and the last one
+        // (which is actually a new line) aren't going to be processed at
+        // all.
+        $len = ($str instanceof UtfString) ?
+            $str->length() : strlen($str);
+
+        $lines = array(0);
+        for ($i = 0; $i < $len; ++$i) {
+            if ($str[$i] === "\n") {
+                $lines[] = $i + 1;
+            }
+        }
+        return $lines;
+    }
+
+    /**
+     * Computes the number of the line and column given an absolute position.
+     *
+     * @param array $lines The starting position of each line.
+     * @param int   $pos   The absolute position
+     *
+     * @return array
+     */
+    public static function findLineNumberAndColumn($lines, $pos)
+    {
+        $line = 0;
+        foreach ($lines as $lineNo => $lineStart) {
+            if ($lineStart > $pos) {
+                break;
+            }
+            $line = $lineNo;
+        }
+        return array($line, $pos - $lines[$line]);
+    }
+
+    /**
+     * Runs the linting process.
+     *
+     * @param string $query The query to be checked.
+     *
+     * @return array
+     */
+    public static function lint($query)
+    {
+        // Disabling lint for huge queries to save some resources.
+        if (mb_strlen($query) > 10000) {
+            return array(
+                array(
+                    'message' => __(
+                        'Linting is disabled for this query because it exceeds the '
+                        . 'maximum length.'
+                    ),
+                    'fromLine' => 0,
+                    'fromColumn' => 0,
+                    'toLine' => 0,
+                    'toColumn' => 0,
+                    'severity' => 'warning',
+                )
+            );
+        }
+
+        /**
+         * Lexer used for tokenizing the query.
+         *
+         * @var Lexer
+         */
+        $lexer = new Lexer($query);
+
+        /**
+         * Parsed used for analysing the query.
+         *
+         * @var Parser
+         */
+        $parser = new Parser($lexer->list);
+
+        /**
+         * Array containing all errors.
+         *
+         * @var array
+         */
+        $errors = ParserError::get(array($lexer, $parser));
+
+        /**
+         * The response containing of all errors.
+         *
+         * @var array
+         */
+        $response = array();
+
+        /**
+         * The starting position for each line.
+         *
+         * CodeMirror requires relative position to line, but the parser stores
+         * only the absolute position of the character in string.
+         *
+         * @var array
+         */
+        $lines = static::getLines($query);
+
+        // Building the response.
+        foreach ($errors as $idx => $error) {
+
+            // Starting position of the string that caused the error.
+            list($fromLine, $fromColumn) = static::findLineNumberAndColumn(
+                $lines, $error[3]
+            );
+
+            // Ending position of the string that caused the error.
+            list($toLine, $toColumn) = static::findLineNumberAndColumn(
+                $lines, $error[3] + mb_strlen($error[2])
+            );
+
+            // Building the response.
+            $response[] = array(
+                'message' => sprintf(
+                    __('%1$s (near <code>%2$s</code>)'),
+                    $error[0], $error[2]
+                ),
+                'fromLine' => $fromLine,
+                'fromColumn' => $fromColumn,
+                'toLine' => $toLine,
+                'toColumn' => $toColumn,
+                'severity' => 'error',
+            );
+        }
+
+        // Sending back the answer.
+        return $response;
+    }
+
+}