Implement Icinga\Protocol\File\LogFileIterator

library/Icinga/Protocol/File/LogFileIterator.php

@@ -0,0 +1,154 @@
+<?php
+/* Icinga Web 2 | (c) 2013-2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Protocol\File;
+
+use Icinga\Exception\IcingaException;
+use SplFileObject;
+use Iterator;
+
+/**
+ * Iterate over a log file, yielding the regex fields of the log messages
+ */
+class LogFileIterator implements Iterator
+{
+    /**
+     * Log file
+     *
+     * @var SplFileObject
+     */
+    protected $file;
+
+    /**
+     * A PCRE string with the fields to extract
+     * from the log messages as named subpatterns
+     *
+     * @var string
+     */
+    protected $fields;
+
+    /**
+     * Value for static::current()
+     *
+     * @var string
+     */
+    protected $current;
+
+    /**
+     * Index for static::key()
+     *
+     * @var int
+     */
+    protected $index;
+
+    /**
+     * Value for static::valid()
+     *
+     * @var boolean
+     */
+    protected $valid;
+
+    /**
+     * @var string
+     */
+    protected $next = null;
+
+    /**
+     * @param string $filename      The log file's name
+     * @param string $fields        A PCRE string with the fields to extract
+     *                              from the log messages as named subpatterns
+     */
+    public function __construct($filename, $fields)
+    {
+        $this->file = new SplFileObject($filename);
+        $this->file->setFlags(
+            SplFileObject::DROP_NEW_LINE |
+            SplFileObject::READ_AHEAD
+        );
+        $this->fields = $fields;
+    }
+
+    public function rewind()
+    {
+        $this->file->rewind();
+        $this->index = 0;
+        $this->nextMessage();
+    }
+
+    public function next()
+    {
+        $this->file->next();
+        ++$this->index;
+        $this->nextMessage();
+    }
+
+    /**
+     * @return string
+     */
+    public function current()
+    {
+        return $this->current;
+    }
+
+    /**
+     * @return int
+     */
+    public function key()
+    {
+        return $this->index;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function valid()
+    {
+        return $this->valid;
+    }
+
+    protected function nextMessage()
+    {
+        $message = $this->next === null ? array() : array($this->next);
+        $this->valid = null;
+        while ($this->file->valid()) {
+            if (false === ($res = preg_match(
+                $this->fields, $current = $this->file->current()
+            ))) {
+                throw new IcingaException('Failed at preg_match()');
+            }
+            if (empty($message)) {
+                if ($res === 1) {
+                    $message[] = $current;
+                }
+            } else if ($res === 1) {
+                $this->next = $current;
+                $this->valid = true;
+                break;
+            } else {
+                $message[] = $current;
+            }
+
+            $this->file->next();
+        }
+        if ($this->valid === null) {
+            $this->next = null;
+            $this->valid = ! empty($message);
+        }
+
+        if ($this->valid) {
+            while (! empty($message)) {
+                $matches = array();
+                if (false === ($res = preg_match(
+                    $this->fields, implode(PHP_EOL, $message), $matches
+                ))) {
+                    throw new IcingaException('Failed at preg_match()');
+                }
+                if ($res === 1) {
+                    $this->current = $matches;
+                    return;
+                }
+                array_pop($message);
+            }
+            $this->valid = false;
+        }
+    }