6 files changed, 1040 insertions, 0 deletions
diff --git a/library/Icinga/File/Ini/Dom/Comment.php b/library/Icinga/File/Ini/Dom/Comment.php
new file mode 100644
index 0000000..c202d0f
--- /dev/null
+++ b/library/Icinga/File/Ini/Dom/Comment.php
@@ -0,0 +1,37 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\File\Ini\Dom;
+
+/**
+ * A single comment-line in an INI file
+ */
+class Comment
+{
+    /**
+     * The comment text
+     *
+     * @var string
+     */
+    protected $content;
+
+    /**
+     * Set the text content of this comment
+     *
+     * @param $content
+     */
+    public function setContent($content)
+    {
+        $this->content = $content;
+    }
+
+    /**
+     * Render this comment into INI markup
+     *
+     * @return string
+     */
+    public function render()
+    {
+        return ';' . $this->content;
+    }
+}
diff --git a/library/Icinga/File/Ini/Dom/Directive.php b/library/Icinga/File/Ini/Dom/Directive.php
new file mode 100644
index 0000000..4279a5f
--- /dev/null
+++ b/library/Icinga/File/Ini/Dom/Directive.php
@@ -0,0 +1,166 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\File\Ini\Dom;
+
+use Icinga\Exception\ConfigurationError;
+
+/**
+ * A key value pair in a Section
+ */
+class Directive
+{
+    /**
+     * The value of this configuration directive
+     *
+     * @var string
+     */
+    protected $key;
+
+    /**
+     * The immutable name of this configuration directive
+     *
+     * @var string
+     */
+    protected $value;
+
+    /**
+     * Comments added one line before this directive
+     *
+     * @var Comment[]   The comment lines
+     */
+    protected $commentsPre = null;
+
+    /**
+     * Comment added at the end of the same line
+     *
+     * @var Comment
+     */
+    protected $commentPost = null;
+
+    /**
+     * @param   string    $key  The name of this configuration directive
+     *
+     * @throws  ConfigurationError
+     */
+    public function __construct($key)
+    {
+        $this->key = trim($key);
+        if (strlen($this->key) < 1) {
+            throw new ConfigurationError(sprintf('Ini error: empty directive key.'));
+        }
+    }
+
+    /**
+     * Return the name of this directive
+     *
+     * @return string
+     */
+    public function getKey()
+    {
+        return $this->key;
+    }
+
+    /**
+     * Return the value of this configuration directive
+     *
+     * @return  string
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+
+    /**
+     * Set the value of this configuration directive
+     *
+     * @param   string      $value
+     */
+    public function setValue($value)
+    {
+        $this->value = trim($value);
+    }
+
+    /**
+     * Set the comments to be rendered on the line before this directive
+     *
+     * @param   Comment[]   $comments
+     */
+    public function setCommentsPre(array $comments)
+    {
+        $this->commentsPre = $comments;
+    }
+
+    /**
+     * Return the comments to be rendered on the line before this directive
+     *
+     * @return Comment[]
+     */
+    public function getCommentsPre()
+    {
+        return $this->commentsPre;
+    }
+
+    /**
+     * Set the comment rendered on the same line of this directive
+     *
+     * @param   Comment     $comment
+     */
+    public function setCommentPost(Comment $comment)
+    {
+        $this->commentPost = $comment;
+    }
+
+    /**
+     * Render this configuration directive into INI markup
+     *
+     * @return  string
+     */
+    public function render()
+    {
+        $str = '';
+        if (! empty($this->commentsPre)) {
+            $comments = array();
+            foreach ($this->commentsPre as $comment) {
+                $comments[] = $comment->render();
+            }
+            $str = implode(PHP_EOL, $comments) . PHP_EOL;
+        }
+        $str .= sprintf('%s = "%s"', $this->sanitizeKey($this->key), $this->sanitizeValue($this->value));
+        if (isset($this->commentPost)) {
+            $str .= ' ' . $this->commentPost->render();
+        }
+        return $str;
+    }
+
+    /**
+     * Assure that the given identifier contains no newlines and pending or trailing whitespaces
+     *
+     * @param   $str    The string to sanitize
+     *
+     * @return string
+     */
+    protected function sanitizeKey($str)
+    {
+        return trim(str_replace(PHP_EOL, ' ', $str));
+    }
+
+    /**
+     * Escape the significant characters in directive values, normalize line breaks and assure that
+     * the character contains no linebreaks
+     *
+     * @param   $str    The string to sanitize
+     *
+     * @return mixed|string
+     */
+    protected function sanitizeValue($str)
+    {
+        $str = trim($str);
+        $str = str_replace('\\', '\\\\', $str);
+        $str = str_replace('"', '\"', $str);
+        $str = str_replace("\r", '\r', $str);
+        $str = str_replace("\n", '\n', $str);
+
+        return $str;
+    }
+}
diff --git a/library/Icinga/File/Ini/Dom/Document.php b/library/Icinga/File/Ini/Dom/Document.php
new file mode 100644
index 0000000..f38f33e
--- /dev/null
+++ b/library/Icinga/File/Ini/Dom/Document.php
@@ -0,0 +1,132 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\File\Ini\Dom;
+
+class Document
+{
+    /**
+     * The sections of this INI file
+     *
+     * @var Section[]
+     */
+    protected $sections = array();
+
+    /**
+     * The comemnts at file end that belong to no particular section
+     *
+     * @var Comment[]
+     */
+    protected $commentsDangling;
+
+    /**
+     * Append a section to the end of this INI file
+     *
+     * @param Section $section
+     */
+    public function addSection(Section $section)
+    {
+        $this->sections[$section->getName()] = $section;
+    }
+
+    /**
+     * Return whether this INI file has the section with the given key
+     *
+     * @param   string  $name
+     *
+     * @return  bool
+     */
+    public function hasSection($name)
+    {
+        return isset($this->sections[trim($name)]);
+    }
+
+    /**
+     * Return the section with the given name
+     *
+     * @param   string  $name
+     *
+     * @return Section
+     */
+    public function getSection($name)
+    {
+        return $this->sections[trim($name)];
+    }
+
+    /**
+     * Set the section with the given name
+     *
+     * @param string  $name
+     * @param Section $section
+     *
+     * @return Section
+     */
+    public function setSection($name, Section $section)
+    {
+        return $this->sections[trim($name)] = $section;
+    }
+
+    /**
+     * Remove the section with the given name
+     *
+     * @param string $name
+     */
+    public function removeSection($name)
+    {
+        unset($this->sections[trim($name)]);
+    }
+
+    /**
+     * Set the dangling comments at file end that belong to no particular directive
+     *
+     * @param Comment[] $comments
+     */
+    public function setCommentsDangling(array $comments)
+    {
+        $this->commentsDangling = $comments;
+    }
+
+    /**
+     * Get the dangling comments at file end that belong to no particular directive
+     *
+     * @return array
+     */
+    public function getCommentsDangling()
+    {
+        return $this->commentsDangling;
+    }
+
+    /**
+     * Render this document into the corresponding INI markup
+     *
+     * @return string
+     */
+    public function render()
+    {
+        $sections = array();
+        foreach ($this->sections as $section) {
+            $sections []=  $section->render();
+        }
+        $str = implode(PHP_EOL, $sections);
+        if (! empty($this->commentsDangling)) {
+            foreach ($this->commentsDangling as $comment) {
+                $str .= PHP_EOL . $comment->render();
+            }
+        }
+        return $str;
+    }
+
+    /**
+     * Convert $this to an array
+     *
+     * @return  array
+     */
+    public function toArray()
+    {
+        $a = array();
+        foreach ($this->sections as $section) {
+            $a[$section->getName()] = $section->toArray();
+        }
+        return $a;
+    }
+}
diff --git a/library/Icinga/File/Ini/Dom/Section.php b/library/Icinga/File/Ini/Dom/Section.php
new file mode 100644
index 0000000..f877c87
--- /dev/null
+++ b/library/Icinga/File/Ini/Dom/Section.php
@@ -0,0 +1,190 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\File\Ini\Dom;
+
+use Icinga\Exception\ConfigurationError;
+
+/**
+ * A section in an INI file
+ */
+class Section
+{
+    /**
+     * The immutable name of this section
+     *
+     * @var string
+     */
+    protected $name;
+
+    /**
+     * All configuration directives of this section
+     *
+     * @var Directive[]
+     */
+    protected $directives = array();
+
+    /**
+     * Comments added one line before this section
+     *
+     * @var Comment[]
+     */
+    protected $commentsPre;
+
+    /**
+     * Comment added at the end of the same line
+     *
+     * @var string
+     */
+    protected $commentPost;
+
+    /**
+     * @param   string  $name       The immutable name of this section
+     *
+     * @throws  ConfigurationError  When the section name is empty or contains brackets
+     */
+    public function __construct($name)
+    {
+        $this->name = trim($name);
+        if (strlen($this->name) < 1) {
+            throw new ConfigurationError('Ini file error: empty section identifier');
+        } elseif (strpos($name, '[') !== false || strpos($name, ']') !== false) {
+            throw new ConfigurationError(
+                'Ini file error: Section name "%s" must not contain any brackets ([, ])',
+                $name
+            );
+        }
+    }
+
+    /**
+     * Append a directive to the end of this section
+     *
+     * @param   Directive   $directive  The directive to append
+     */
+    public function addDirective(Directive $directive)
+    {
+        $this->directives[$directive->getKey()] = $directive;
+    }
+
+    /**
+     * Remove the directive with the given name
+     *
+     * @param   string      $key        They name of the directive to remove
+     */
+    public function removeDirective($key)
+    {
+        unset($this->directives[$key]);
+    }
+
+    /**
+     * Return whether this section has a directive with the given key
+     *
+     * @param   string  $key            The name of the directive
+     *
+     * @return  bool
+     */
+    public function hasDirective($key)
+    {
+        return isset($this->directives[$key]);
+    }
+
+    /**
+     * Get the directive with the given key
+     *
+     * @param $key  string
+     *
+     * @return Directive
+     */
+    public function getDirective($key)
+    {
+        return $this->directives[$key];
+    }
+
+    /**
+     * Return the name of this section
+     *
+     * @return string   The name
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Set the comments to be rendered on the line before this section
+     *
+     * @param   Comment[]   $comments
+     */
+    public function setCommentsPre(array $comments)
+    {
+        $this->commentsPre = $comments;
+    }
+
+    /**
+     * Set the comment rendered on the same line of this section
+     *
+     * @param   Comment     $comment
+     */
+    public function setCommentPost(Comment $comment)
+    {
+        $this->commentPost = $comment;
+    }
+
+    /**
+     * Render this section into INI markup
+     *
+     * @return string
+     */
+    public function render()
+    {
+        $dirs = '';
+        $i = 0;
+        foreach ($this->directives as $directive) {
+            $comments = $directive->getCommentsPre();
+            $dirs .= (($i++ > 0 && ! empty($comments)) ? PHP_EOL : '')
+                    . $directive->render() . PHP_EOL;
+        }
+        $cms = '';
+        if (! empty($this->commentsPre)) {
+            foreach ($this->commentsPre as $comment) {
+                $comments[] = $comment->render();
+            }
+            $cms = implode(PHP_EOL, $comments) . PHP_EOL;
+        }
+        $post = '';
+        if (isset($this->commentPost)) {
+            $post = ' ' . $this->commentPost->render();
+        }
+        return $cms . sprintf('[%s]', $this->sanitize($this->name)) . $post . PHP_EOL . $dirs;
+    }
+
+    /**
+     * Escape the significant characters in sections and normalize line breaks
+     *
+     * @param   $str    The string to sanitize
+     *
+     * @return  mixed
+     */
+    protected function sanitize($str)
+    {
+        $str = trim($str);
+        $str = str_replace('\\', '\\\\', $str);
+        $str = str_replace('"', '\\"', $str);
+        $str = str_replace(';', '\\;', $str);
+        return str_replace(PHP_EOL, ' ', $str);
+    }
+
+    /**
+     * Convert $this to an array
+     *
+     * @return  array
+     */
+    public function toArray()
+    {
+        $a = array();
+        foreach ($this->directives as $directive) {
+            $a[$directive->getKey()] = $directive->getValue();
+        }
+        return $a;
+    }
+}
diff --git a/library/Icinga/File/Ini/IniParser.php b/library/Icinga/File/Ini/IniParser.php
new file mode 100644
index 0000000..279aa45
--- /dev/null
+++ b/library/Icinga/File/Ini/IniParser.php
@@ -0,0 +1,310 @@
+<?php
+/* Icinga Web 2 | (c) 2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\File\Ini;
+
+use ErrorException;
+use Icinga\File\Ini\Dom\Section;
+use Icinga\File\Ini\Dom\Comment;
+use Icinga\File\Ini\Dom\Document;
+use Icinga\File\Ini\Dom\Directive;
+use Icinga\Application\Logger;
+use Icinga\Exception\ConfigurationError;
+use Icinga\Exception\NotReadableError;
+use Icinga\Application\Config;
+
+class IniParser
+{
+    const LINE_START = 0;
+    const SECTION = 1;
+    const ESCAPE = 2;
+    const DIRECTIVE_KEY = 4;
+    const DIRECTIVE_VALUE_START = 5;
+    const DIRECTIVE_VALUE = 6;
+    const DIRECTIVE_VALUE_QUOTED = 7;
+    const COMMENT = 8;
+    const COMMENT_END = 9;
+    const LINE_END = 10;
+
+    /**
+     * Cancel the parsing with an error
+     *
+     * @param $message  The error description
+     * @param $line     The line in which the error occured
+     *
+     * @throws ConfigurationError
+     */
+    private static function throwParseError($message, $line)
+    {
+        throw new ConfigurationError(sprintf('Ini parser error: %s. (l. %d)', $message, $line));
+    }
+
+    /**
+     * Read the ini file contained in a string and return a mutable DOM that can be used
+     * to change the content of an INI file.
+     *
+     * @param $str                  A string containing the whole ini file
+     *
+     * @return Document             The mutable DOM object.
+     * @throws ConfigurationError   In case the file is not parseable
+     */
+    public static function parseIni($str)
+    {
+        $doc = new Document();
+        $sec = null;
+        $dir = null;
+        $coms = array();
+        $state = self::LINE_START;
+        $escaping = null;
+        $token = '';
+        $line = 0;
+
+        for ($i = 0; $i < strlen($str); $i++) {
+            $s = $str[$i];
+            switch ($state) {
+                case self::LINE_START:
+                    if (ctype_space($s)) {
+                        continue 2;
+                    }
+                    switch ($s) {
+                        case '[':
+                            $state = self::SECTION;
+                            break;
+                        case ';':
+                            $state = self::COMMENT;
+                            break;
+                        default:
+                            $state = self::DIRECTIVE_KEY;
+                            $token = $s;
+                            break;
+                    }
+                    break;
+
+                case self::ESCAPE:
+                    $token .= $s;
+                    $state = $escaping;
+                    $escaping = null;
+                    break;
+
+                case self::SECTION:
+                    if ($s === "\n") {
+                        self::throwParseError('Unterminated SECTION', $line);
+                    } elseif ($s === '\\') {
+                        $state = self::ESCAPE;
+                        $escaping = self::SECTION;
+                    } elseif ($s !== ']') {
+                        $token .= $s;
+                    } else {
+                        $sec = new Section($token);
+                        $sec->setCommentsPre($coms);
+                        $doc->addSection($sec);
+                        $dir = null;
+                        $coms = array();
+
+                        $state = self::LINE_END;
+                        $token = '';
+                    }
+                    break;
+
+                case self::DIRECTIVE_KEY:
+                    if ($s !== '=') {
+                        $token .= $s;
+                    } else {
+                        $dir = new Directive($token);
+                        $dir->setCommentsPre($coms);
+                        if (isset($sec)) {
+                            $sec->addDirective($dir);
+                        } else {
+                            Logger::warning(sprintf(
+                                'Ini parser warning: section-less directive "%s" ignored. (l. %d)',
+                                $token,
+                                $line
+                            ));
+                        }
+
+                        $coms = array();
+                        $state = self::DIRECTIVE_VALUE_START;
+                        $token = '';
+                    }
+                    break;
+
+                case self::DIRECTIVE_VALUE_START:
+                    if (ctype_space($s)) {
+                        continue 2;
+                    } elseif ($s === '"') {
+                        $state = self::DIRECTIVE_VALUE_QUOTED;
+                    } else {
+                        $state = self::DIRECTIVE_VALUE;
+                        $token = $s;
+                    }
+                    break;
+
+                case self::DIRECTIVE_VALUE:
+                    /*
+                        Escaping non-quoted values is not supported by php_parse_ini, it might
+                        be reasonable to include in case we are switching completely our own
+                        parser implementation
+                    */
+                    if ($s === "\n" || $s === ";") {
+                        $dir->setValue($token);
+                        $token = '';
+
+                        if ($s === "\n") {
+                            $state = self::LINE_START;
+                            $line ++;
+                        } elseif ($s === ';') {
+                            $state = self::COMMENT;
+                        }
+                    } else {
+                        $token .= $s;
+                    }
+                    break;
+
+                case self::DIRECTIVE_VALUE_QUOTED:
+                    if ($s === '\\') {
+                        $state = self::ESCAPE;
+                        $escaping = self::DIRECTIVE_VALUE_QUOTED;
+                    } elseif ($s !== '"') {
+                        $token .= $s;
+                    } else {
+                        $dir->setValue($token);
+                        $token = '';
+                        $state = self::LINE_END;
+                    }
+                    break;
+
+                case self::COMMENT:
+                case self::COMMENT_END:
+                    if ($s !== "\n") {
+                        $token .= $s;
+                    } else {
+                        $com = new Comment();
+                        $com->setContent($token);
+                        $token = '';
+
+                        // Comments at the line end belong to the current line's directive or section. Comments
+                        // on empty lines belong to the next directive that shows up.
+                        if ($state === self::COMMENT_END) {
+                            if (isset($dir)) {
+                                $dir->setCommentPost($com);
+                            } else {
+                                $sec->setCommentPost($com);
+                            }
+                        } else {
+                            $coms[] = $com;
+                        }
+                        $state = self::LINE_START;
+                        $line ++;
+                    }
+                    break;
+
+                case self::LINE_END:
+                    if ($s === "\n") {
+                        $state = self::LINE_START;
+                        $line ++;
+                    } elseif ($s === ';') {
+                        $state = self::COMMENT_END;
+                    }
+                    break;
+            }
+        }
+
+        // process the last token
+        switch ($state) {
+            case self::COMMENT:
+            case self::COMMENT_END:
+                $com = new Comment();
+                $com->setContent($token);
+                if ($state === self::COMMENT_END) {
+                    if (isset($dir)) {
+                        $dir->setCommentPost($com);
+                    } else {
+                        $sec->setCommentPost($com);
+                    }
+                } else {
+                    $coms[] = $com;
+                }
+                break;
+
+            case self::DIRECTIVE_VALUE:
+                $dir->setValue($token);
+                $sec->addDirective($dir);
+                break;
+
+            case self::ESCAPE:
+            case self::DIRECTIVE_VALUE_QUOTED:
+            case self::DIRECTIVE_KEY:
+            case self::SECTION:
+                self::throwParseError('File ended in unterminated state ' . $state, $line);
+        }
+        if (! empty($coms)) {
+            $doc->setCommentsDangling($coms);
+        }
+        return $doc;
+    }
+
+    /**
+     * Read the ini file and parse it with ::parseIni()
+     *
+     * @param   string  $file       The ini file to read
+     *
+     * @return  Config
+     * @throws  NotReadableError    When the file cannot be read
+     */
+    public static function parseIniFile($file)
+    {
+        if (($path = realpath($file)) === false) {
+            throw new NotReadableError('Couldn\'t compute the absolute path of `%s\'', $file);
+        }
+
+        if (($content = file_get_contents($path)) === false) {
+            throw new NotReadableError('Couldn\'t read the file `%s\'', $path);
+        }
+
+        try {
+            $configArray = parse_ini_string($content, true, INI_SCANNER_RAW);
+        } catch (ErrorException $e) {
+            throw new ConfigurationError('Couldn\'t parse the INI file `%s\'', $path, $e);
+        }
+
+        $unescaped = array();
+        foreach ($configArray as $section => $options) {
+            $unescaped[self::unescapeSectionName($section)] = array_map([__CLASS__, 'unescapeOptionValue'], $options);
+        }
+
+        return Config::fromArray($unescaped)->setConfigFile($file);
+    }
+
+    /**
+     * Unescape significant characters in the given section name
+     *
+     * @param   string  $str
+     *
+     * @return  string
+     */
+    protected static function unescapeSectionName($str)
+    {
+        $str = str_replace('\"', '"', $str);
+        $str = str_replace('\;', ';', $str);
+
+        return str_replace('\\\\', '\\', $str);
+    }
+
+    /**
+     * Unescape significant characters in the given option value
+     *
+     * @param   string  $str
+     *
+     * @return  string
+     */
+    protected static function unescapeOptionValue($str)
+    {
+        $str = str_replace('\n', "\n", $str);
+        $str = str_replace('\r', "\r", $str);
+        $str = str_replace('\"', '"', $str);
+        $str = str_replace('\\\\', '\\', $str);
+
+        // This replacement is a work-around for PHP bug #76965. Fixed with versions 7.1.24, 7.2.12 and 7.3.0.
+        return preg_replace('~^([\'"])(.*?)\1\s+$~', '$2', $str);
+    }
+}
diff --git a/library/Icinga/File/Ini/IniWriter.php b/library/Icinga/File/Ini/IniWriter.php
new file mode 100644
index 0000000..f00040e
--- /dev/null
+++ b/library/Icinga/File/Ini/IniWriter.php
@@ -0,0 +1,205 @@
+<?php
+/* Icinga Web 2 | (c) 2013 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\File\Ini;
+
+use Icinga\Application\Logger;
+use Icinga\Data\ConfigObject;
+use Icinga\Exception\ProgrammingError;
+use Icinga\File\Ini\Dom\Directive;
+use Icinga\File\Ini\Dom\Document;
+use Icinga\File\Ini\Dom\Section;
+use Zend_Config_Exception;
+use Icinga\Application\Config;
+
+/**
+ * A INI file adapter that respects the file structure and the comments of already existing ini files
+ */
+class IniWriter
+{
+    /**
+     * Stores the options
+     *
+     * @var array
+     */
+    protected $options;
+
+    /**
+     * The configuration object to write
+     *
+     * @var Config
+     */
+    protected $config;
+
+    /**
+     * The mode to set on new files
+     *
+     * @var int
+     */
+    protected $fileMode;
+
+    /**
+     * The path to write to
+     *
+     * @var string
+     */
+    protected $filename;
+
+    /**
+     * Create a new INI writer
+     *
+     * @param Config    $config    The configuration to write
+     * @param string    $filename  The file name to write to
+     * @param int       $filemode  Octal file persmissions
+     *
+     * @link http://framework.zend.com/apidoc/1.12/files/Config.Writer.html#\Zend_Config_Writer
+     */
+    public function __construct(Config $config, $filename, $filemode = 0660, $options = array())
+    {
+        $this->config = $config;
+        $this->filename = $filename;
+        $this->fileMode = $filemode;
+        $this->options = $options;
+    }
+
+    /**
+     * Render the Zend_Config into a config filestring
+     *
+     * @return  string
+     */
+    public function render()
+    {
+        if (file_exists($this->filename)) {
+            $oldconfig = Config::fromIni($this->filename);
+            $content = trim(file_get_contents($this->filename));
+        } else {
+            $oldconfig = Config::fromArray(array());
+            $content = '';
+        }
+        $doc = IniParser::parseIni($content);
+        $this->diffPropertyUpdates($this->config, $doc);
+        $this->diffPropertyDeletions($oldconfig, $this->config, $doc);
+        $doc = $this->updateSectionOrder($this->config, $doc);
+        return $doc->render();
+    }
+
+    /**
+     * Write configuration to file and set file mode in case it does not exist yet
+     *
+     * @param string $filename
+     * @param bool $exclusiveLock
+     *
+     * @throws Zend_Config_Exception
+     */
+    public function write($filename = null, $exclusiveLock = false)
+    {
+        $filePath = isset($filename) ? $filename : $this->filename;
+        $setMode = false === file_exists($filePath);
+
+        if (file_put_contents($filePath, $this->render(), $exclusiveLock ? LOCK_EX : 0) === false) {
+            throw new Zend_Config_Exception('Could not write to file "' . $filePath . '"');
+        }
+
+        if ($setMode) {
+            // file was newly created
+            $mode = $this->fileMode;
+            if (is_int($this->fileMode) && false === @chmod($filePath, $this->fileMode)) {
+                throw new Zend_Config_Exception(sprintf('Failed to set file mode "%o" on file "%s"', $mode, $filePath));
+            }
+        }
+    }
+
+    /**
+     * Update the order of the sections in the ini file to match the order of the new config
+     *
+     * @return Document     A new document with the changed section order applied
+     */
+    protected function updateSectionOrder(Config $newconfig, Document $oldDoc)
+    {
+        $doc = new Document();
+        $dangling = $oldDoc->getCommentsDangling();
+        if (isset($dangling)) {
+            $doc->setCommentsDangling($dangling);
+        }
+        foreach ($newconfig->toArray() as $section => $directives) {
+            $doc->addSection($oldDoc->getSection($section));
+        }
+        return $doc;
+    }
+
+    /**
+     * Search for created and updated properties and use the editor to create or update these entries
+     *
+     * @param Config     $newconfig  The config representing the state after the change
+     * @param Document   $doc
+     *
+     * @throws ProgrammingError
+     */
+    protected function diffPropertyUpdates(Config $newconfig, Document $doc)
+    {
+        foreach ($newconfig->toArray() as $section => $directives) {
+            if (! is_array($directives)) {
+                Logger::warning('Section-less property ' . (string)$directives . ' was ignored.');
+                continue;
+            }
+            if (!$doc->hasSection($section)) {
+                $domSection = new Section($section);
+                $doc->addSection($domSection);
+            } else {
+                $domSection = $doc->getSection($section);
+            }
+            foreach ($directives as $key => $value) {
+                if ($value === null) {
+                    continue;
+                }
+
+                if ($value instanceof ConfigObject) {
+                    throw new ProgrammingError('Cannot diff recursive configs');
+                }
+                if ($domSection->hasDirective($key)) {
+                    $domSection->getDirective($key)->setValue($value);
+                } else {
+                    $dir = new Directive($key);
+                    $dir->setValue($value);
+                    $domSection->addDirective($dir);
+                }
+            }
+        }
+    }
+
+    /**
+     * Search for deleted properties and use the editor to delete these entries
+     *
+     * @param Config    $oldconfig  The config representing the state before the change
+     * @param Config    $newconfig  The config representing the state after the change
+     * @param Document  $doc
+     *
+     * @throws ProgrammingError
+     */
+    protected function diffPropertyDeletions(Config $oldconfig, Config $newconfig, Document $doc)
+    {
+        // Iterate over all properties in the old configuration file and remove those that don't
+        // exist in the new config
+        foreach ($oldconfig->toArray() as $section => $directives) {
+            if (! is_array($directives)) {
+                Logger::warning('Section-less property ' . (string)$directives . ' was ignored.');
+                continue;
+            }
+
+            if ($newconfig->hasSection($section)) {
+                $newSection = $newconfig->getSection($section);
+                $oldDomSection = $doc->getSection($section);
+                foreach ($directives as $key => $value) {
+                    if ($value instanceof ConfigObject) {
+                        throw new ProgrammingError('Cannot diff recursive configs');
+                    }
+                    if (null === $newSection->get($key) && $oldDomSection->hasDirective($key)) {
+                        $oldDomSection->removeDirective($key);
+                    }
+                }
+            } else {
+                $doc->removeSection($section);
+            }
+        }
+    }
+}