From 38c913bb1e10ec33c84494325ce8427d5bbbf847 Mon Sep 17 00:00:00 2001
From: Michael Meckelein <mmeckelein@hq.adiscon.com>
Date: Mon, 25 Feb 2008 23:18:05 +0100
Subject: [PATCH] added new classes

---
 classes/enums.class.php               |  16 ++++
 classes/logstream.class.php           |  78 ++++++++++++++++
 classes/logstreamconfig.class.php     |  12 +++
 classes/logstreamconfigdisk.class.php |  14 +++
 classes/logstreamdisk.class.php       | 128 ++++++++++++++++++++++++++
 5 files changed, 248 insertions(+)
 create mode 100644 classes/enums.class.php
 create mode 100644 classes/logstream.class.php
 create mode 100644 classes/logstreamconfig.class.php
 create mode 100644 classes/logstreamconfigdisk.class.php
 create mode 100644 classes/logstreamdisk.class.php

diff --git a/classes/enums.class.php b/classes/enums.class.php
new file mode 100644
index 0000000..a3f0cc7
--- /dev/null
+++ b/classes/enums.class.php
@@ -0,0 +1,16 @@
+<?php
+
+/*
+* Since php does not support enums we emulate it
+* using a abstract class. 
+*/
+
+/**
+* ENUM of available ReadDirection.
+*/
+abstract class EnumReadDirection {
+	const Forward = 1;
+	const Backward = 2;
+}
+
+?>
\ No newline at end of file
diff --git a/classes/logstream.class.php b/classes/logstream.class.php
new file mode 100644
index 0000000..7931711
--- /dev/null
+++ b/classes/logstream.class.php
@@ -0,0 +1,78 @@
+<?php
+
+/**
+* LogStream provides access to the log data. Be sure to always
+* use LogStream if you want to access a text file or database.
+*/
+abstract class LogStream {
+	protected $_readDirection = EnumReadDirection::Forward;
+	protected $_filter = null;
+	protected $_current_uId = -1;
+	protected $_logStreamConfigObj = null;
+	protected $_arrProperties = null;
+
+	/**
+	* Open the stream for read access.
+	*
+	* @param arrProperties string in: properties of interest. There can be no guarantee the logstream can actually deliver them.
+	* @return integer Error stat
+	*/
+	public abstract function Open($arrProperties);
+
+	/**
+	* Close the current stream.
+	*
+	* @return integer Error stat
+	*/
+	public abstract function Close();
+
+	/**
+	* Read the next data from the current stream. If it reads
+	* forwards or backwards depends on the current read direction.
+	*
+	* Example for reading forward:
+	* Is the current uID == 4, readDirection set to forwards
+	* ReadNext will provide uID 5 or EOS if no more data exist.
+	*
+	* Exampe for reading backward:
+	* Is the current uID == 4, readDirection set to backwards
+	* ReadNext will provide uID 3.
+	*
+	* Hint: If the current stream becomes unavailable an error
+	* stated is retuned. A typical case is if a log rotation
+	* changed the original data source.
+	*
+	* @param uID integer out: unique id of the data row 
+	* @param logLine string out: data row
+	* @return integer Error state
+	*/
+	public abstract function ReadNext(&$uID, &$logLine);
+
+	/**
+	* Read the data from a specific uID.
+	* 
+	* @param uID integer in: unique id of the data row 
+	* @param logLine string out: data row
+	* @return integer Error state
+	* @see ReadNext()
+	*/
+	public abstract function Read($uID, &$logLine);
+
+	/**
+	* Set the filter for the current stream.
+	* 
+	* @param filter object in: filter object
+	* @return integer Error state
+	*/
+	public abstract function SetFilter($filter);
+
+	/**
+	* Set the direction the stream should read data.
+	*
+	* @param enumReadDirectionfilter EnumReadDirection in: The new direction.
+	* @return integer Error state
+	*/
+	public abstract function SetReadDirection($enumReadDirection);
+}
+
+?>
\ No newline at end of file
diff --git a/classes/logstreamconfig.class.php b/classes/logstreamconfig.class.php
new file mode 100644
index 0000000..508cb71
--- /dev/null
+++ b/classes/logstreamconfig.class.php
@@ -0,0 +1,12 @@
+<?php
+/**
+* StreamConfig has the capability to create a specific LogStream 
+* object depending on a configured LogStream*Config object.
+*/
+abstract class LogStreamConfig {
+	protected $_logStreamConfigObj = null;
+
+	public abstract function LogStreamFactory($o);
+
+}
+?>
\ No newline at end of file
diff --git a/classes/logstreamconfigdisk.class.php b/classes/logstreamconfigdisk.class.php
new file mode 100644
index 0000000..c437904
--- /dev/null
+++ b/classes/logstreamconfigdisk.class.php
@@ -0,0 +1,14 @@
+<?php
+/**
+* StreamConfig has the capability to create a specific LogStream 
+* object depending on a configured LogStream*Config object.
+*/
+class LogStreamConfigDisk extends LogStreamConfig {
+	public $FileName = '';
+
+	public function LogStreamFactory($o) {
+		return new LogStreamDisk($o);
+	}
+
+}
+?>
\ No newline at end of file
diff --git a/classes/logstreamdisk.class.php b/classes/logstreamdisk.class.php
new file mode 100644
index 0000000..b1d588e
--- /dev/null
+++ b/classes/logstreamdisk.class.php
@@ -0,0 +1,128 @@
+<?php
+
+/**
+* LogStreamDisk provides access to the data on disk. In the most
+* cases this will be plain text files. If we need access to e.g.
+* zipped files, this will be handled by a separate driver.
+*
+* \version 1.0.1 2nd Version
+* \version 1.0.0 Init Version
+*
+*/
+class LogStreamDisk extends LogStream {
+	private $_currentOffset = -1;
+	private $_fp = null;
+
+	// Constructor
+	public function LogStreamDisk($streamConfigObj) {
+		$this->_logStreamConfigObj = $streamConfigObj;
+	}
+
+	/**
+	* Open the file with read access.
+	*
+	* @param streamConfigObj object in: It has to be a LogSteamDiskConfig object.
+	* @return integer Error stat
+	*/
+	public function Open($arrProperties) {
+		if(!file_exists($this->_logStreamConfigObj->FileName)) {
+			return ERROR_FILE_NOT_FOUND;
+		}
+		
+		$this->_fp = fopen($this->_logStreamConfigObj->FileName, 'r');
+		$this->_currentOffset = 0;
+		$this->_arrProperties = $arrProperties;
+		return SUCCESS;
+	}
+
+	/**
+	* Close the file.
+	*
+	* @return integer Error state
+	*/
+	public function Close() {
+		
+		if (!fclose($this->_fp)) {
+			return ERROR_FILE_CANT_CLOSE;
+		}
+		return SUCCESS;
+	}
+
+	
+	/**
+	* Read the next line from the file depending on the current
+	* read direction.
+	*
+	* Hint: If the current stream becomes unavailable an error
+	* stated is retuned. A typical case is if a log rotation
+	* changed the original data source.
+	*
+	* @param uID integer out: uID is the offset of data row
+	* @param logLine string out: data row
+	* @return integer Error state
+	* @see ReadNext
+	*/
+	public function ReadNext(&$uID, &$logLine) {
+
+		$uID = $this->_currentOffset;
+
+		if (feof($this->_fp)) {
+			return ERROR_FILE_EOF;
+		}
+
+		$logLine = fgets($this->_fp);
+		if ($logLine === false) {
+			// ToDo: error occurs, or EOF
+			return 1;
+		}
+		
+		$this->_currentOffset = $this->_currentOffset + sizeof($logLine);
+		
+		return 0;
+	}
+
+	/**
+	* Read the data from a specific uID which means in this
+	* case from a given offset of the file.
+	* 
+	* @param uID integer in/out: unique id of the data row 
+	* @param logLine string out: data row
+	* @return integer Error state
+	* @see ReadNext()
+	*/
+	public function Read($uID, &$logLine) {
+		$this->_currentOffset = $uID;
+		fseek($fp, $this->_currentOffset);
+
+		// with Read we can only read forwards.
+		// so we have to remember the current read
+		// direction
+		$tmp = $this->_readDirection;
+		$iRet = $this->ReadNext($uID, $logLine);
+		$this->_readDirection = $tmp;
+
+		return $iRet;
+	}
+
+	/**
+	* Set the filter for the current stream.
+	* 
+	* @param filter object in: filter object
+	* @return integer Error state
+	*/
+	public function SetFilter($filter) {
+		return 0;	
+	}
+
+	/**
+	* Set the direction the stream should read data.
+	*
+	* @param enumReadDirectionfilter EnumReadDirection in: The new direction.
+	* @return integer Error state
+	*/
+	public function SetReadDirection($enumReadDirection) {
+		return 0;
+	}
+}
+
+?>
\ No newline at end of file