[Box Backup-dev] COMMIT r896 - box/chris/merge/lib/raidfile

[boxbackup-dev at fluffy.co.uk]

Author: chris
Date: 2006-08-31 23:50:02 +0100 (Thu, 31 Aug 2006)
New Revision: 896

Modified:
   box/chris/merge/lib/raidfile/RaidFileWrite.cpp
Log:
(refs #3)

Open files in binary mode (Win32)

Disable the lock failure block when we don't have any locking mechanism

Close and delete files before renaming over them on Win32. This breaks 
Ben's desired recovery semantics, so it's not done on other platforms, 
but Win32 requires it.


Modified: box/chris/merge/lib/raidfile/RaidFileWrite.cpp
===================================================================
--- box/chris/merge/lib/raidfile/RaidFileWrite.cpp	2006-08-31 22:44:18 UTC (rev 895)
+++ box/chris/merge/lib/raidfile/RaidFileWrite.cpp	2006-08-31 22:50:02 UTC (rev 896)
@@ -104,7 +104,8 @@
 	writeFilename += 'X';
 
 	// Attempt to open
-	mOSFileHandle = ::open(writeFilename.c_str(), O_WRONLY | O_CREAT,
+	mOSFileHandle = ::open(writeFilename.c_str(), 
+		O_WRONLY | O_CREAT | O_BINARY,
 		S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
 	if(mOSFileHandle == -1)
 	{
@@ -115,7 +116,7 @@
 #ifdef HAVE_FLOCK
 	int errnoBlock = EWOULDBLOCK;
 	if(::flock(mOSFileHandle, LOCK_EX | LOCK_NB) != 0)
-#else
+#elif HAVE_DECL_F_SETLK
 	int errnoBlock = EAGAIN;
 	struct flock desc;
 	desc.l_type = F_WRLCK;
@@ -123,6 +124,9 @@
 	desc.l_start = 0;
 	desc.l_len = 0;
 	if(::fcntl(mOSFileHandle, F_SETLK, &desc) != 0)
+#else
+	int errnoBlock = ENOSYS;
+	if (0)
 #endif
 	{
 		// Lock was not obtained.
@@ -242,23 +246,46 @@
 	}
 	
 	// Rename it into place -- BEFORE it's closed so lock remains
+
+#ifdef WIN32
+	// Except on Win32 which doesn't allow renaming open files
+	// Close file...
+	if(::close(mOSFileHandle) != 0)
+	{
+		THROW_EXCEPTION(RaidFileException, OSError)
+	}
+	mOSFileHandle = -1;
+#endif // WIN32
+
 	RaidFileController &rcontroller(RaidFileController::GetController());
 	RaidFileDiscSet rdiscSet(rcontroller.GetDiscSet(mSetNumber));
 	// Get the filename for the write file
 	std::string renameTo(RaidFileUtil::MakeWriteFileName(rdiscSet, mFilename));
 	// And the current name
 	std::string renameFrom(renameTo + 'X');
+
+#ifdef WIN32
+	// need to delete the target first
+	if(::unlink(renameTo.c_str()) != 0 && 
+		GetLastError() != ERROR_FILE_NOT_FOUND)
+	{
+		THROW_EXCEPTION(RaidFileException, OSError)
+	}
+#endif
+
 	if(::rename(renameFrom.c_str(), renameTo.c_str()) != 0)
 	{
 		THROW_EXCEPTION(RaidFileException, OSError)
 	}
 	
+#ifndef WIN32	
 	// Close file...
 	if(::close(mOSFileHandle) != 0)
 	{
 		THROW_EXCEPTION(RaidFileException, OSError)
 	}
 	mOSFileHandle = -1;
+#endif // !WIN32
 	
 	// Raid it?
 	if(ConvertToRaidNow)
@@ -292,8 +319,15 @@
 	writeFilename += 'X';
 	
 	// Unlink and close it
-	if((::unlink(writeFilename.c_str()) != 0)
-		|| (::close(mOSFileHandle) != 0))
+
+#ifdef WIN32
+	// On Win32 we must close it first
+	if (::close(mOSFileHandle) != 0 ||
+		::unlink(writeFilename.c_str()) != 0)
+#else // !WIN32
+	if (::unlink(writeFilename.c_str()) != 0 ||
+		::close(mOSFileHandle) != 0)
+#endif // !WIN32
 	{
 		THROW_EXCEPTION(RaidFileException, OSError)
 	}
@@ -388,13 +422,13 @@
 	try
 	{
 #if HAVE_DECL_O_EXLOCK
-		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_EXLOCK)> stripe1(stripe1FilenameW.c_str());
-		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_EXLOCK)> stripe2(stripe2FilenameW.c_str());
-		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_EXLOCK)> parity(parityFilenameW.c_str());
+		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_EXLOCK | O_BINARY)> stripe1(stripe1FilenameW.c_str());
+		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_EXLOCK | O_BINARY)> stripe2(stripe2FilenameW.c_str());
+		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_EXLOCK | O_BINARY)> parity(parityFilenameW.c_str());
 #else
-		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL)> stripe1(stripe1FilenameW.c_str());
-		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL)> stripe2(stripe2FilenameW.c_str());
-		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL)> parity(parityFilenameW.c_str());
+		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_BINARY)> stripe1(stripe1FilenameW.c_str());
+		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_BINARY)> stripe2(stripe2FilenameW.c_str());
+		FileHandleGuard<(O_WRONLY | O_CREAT | O_EXCL | O_BINARY)> parity(parityFilenameW.c_str());
 #endif
 
 		// Then... read in data...
@@ -530,6 +564,22 @@
 		parity.Close();
 		stripe2.Close();
 		stripe1.Close();
+
+#ifdef WIN32
+		// Must delete before renaming
+		if (::unlink(stripe1Filename.c_str()) != 0 && errno != ENOENT)
+		{
+			THROW_EXCEPTION(RaidFileException, OSError);
+		}
+		if (::unlink(stripe2Filename.c_str()) != 0 && errno != ENOENT)
+		{
+			THROW_EXCEPTION(RaidFileException, OSError);
+		}
+		if (::unlink(parityFilename.c_str()) != 0 && errno != ENOENT)
+		{
+			THROW_EXCEPTION(RaidFileException, OSError);
+		}
+#endif
 		
 		// Rename them into place
 		if(::rename(stripe1FilenameW.c_str(), stripe1Filename.c_str()) != 0