Imported existing code

indra/llcommon/lllivefile.cpp

@@ -0,0 +1,169 @@
+/** 
+ * @file lllivefile.cpp
+ *
+ * $LicenseInfo:firstyear=2006&license=viewergpl$
+ * 
+ * Copyright (c) 2006-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "lllivefile.h"
+#include "llframetimer.h"
+#include "lltimer.h"
+
+class LLLiveFile::Impl
+{
+public:
+	Impl(const std::string &filename, const F32 refresh_period);
+	~Impl();
+	
+	bool check();
+	
+	
+	bool mForceCheck;
+	F32 mRefreshPeriod;
+	LLFrameTimer mRefreshTimer;
+
+	std::string mFilename;
+	time_t mLastModTime;
+	bool mLastExists;
+	
+	LLEventTimer* mEventTimer;
+};
+
+LLLiveFile::Impl::Impl(const std::string &filename, const F32 refresh_period)
+	: mForceCheck(true),
+	mRefreshPeriod(refresh_period),
+	mFilename(filename),
+	mLastModTime(0),
+	mLastExists(false),
+	mEventTimer(NULL)
+{
+}
+
+LLLiveFile::Impl::~Impl()
+{
+	delete mEventTimer;
+}
+
+LLLiveFile::LLLiveFile(const std::string &filename, const F32 refresh_period)
+	: impl(* new Impl(filename, refresh_period))
+{
+}
+
+LLLiveFile::~LLLiveFile()
+{
+	delete &impl;
+}
+
+
+bool LLLiveFile::Impl::check()
+{
+	if (!mForceCheck && mRefreshTimer.getElapsedTimeF32() < mRefreshPeriod)
+	{
+		// Skip the check if not enough time has elapsed and we're not
+		// forcing a check of the file
+		return false;
+	}
+	mForceCheck = false;
+	mRefreshTimer.reset();
+
+	// Stat the file to see if it exists and when it was last modified.
+	llstat stat_data;
+	int res = LLFile::stat(mFilename, &stat_data);
+
+	if (res)
+	{
+		// Couldn't stat the file, that means it doesn't exist or is
+		// broken somehow.  Clear flags and return.
+		if (mLastExists)
+		{
+			mLastExists = false;
+			return true;	// no longer existing is a change!
+		}
+		return false;
+	}
+
+	// The file exists, decide if we want to load it.
+	if (mLastExists)
+	{
+		// The file existed last time, don't read it if it hasn't changed since
+		// last time.
+		if (stat_data.st_mtime <= mLastModTime)
+		{
+			return false;
+		}
+	}
+
+	// We want to read the file.  Update status info for the file.
+	mLastExists = true;
+	mLastModTime = stat_data.st_mtime;
+	
+	return true;
+}
+
+bool LLLiveFile::checkAndReload()
+{
+	bool changed = impl.check();
+	if (changed)
+	{
+		loadFile();
+	}
+	return changed;
+}
+
+std::string LLLiveFile::filename() const
+{
+	return impl.mFilename;
+}
+
+namespace
+{
+	class LiveFileEventTimer : public LLEventTimer
+	{
+	public:
+		LiveFileEventTimer(LLLiveFile& f, F32 refresh)
+			: LLEventTimer(refresh), mLiveFile(f)
+			{ }
+			
+		BOOL tick()
+		{ 
+			mLiveFile.checkAndReload(); 
+			return FALSE;
+		}
+	
+	private:
+		LLLiveFile& mLiveFile;
+	};
+	
+}
+
+void LLLiveFile::addToEventTimer()
+{
+	impl.mEventTimer = new LiveFileEventTimer(*this, impl.mRefreshPeriod);
+}
+