[Jrobin-commits] src/org/jrobin/core RrdFileBackend.java,1.5,1.6

[Sasa M. <sa...@us...>]

Update of /cvsroot/jrobin/src/org/jrobin/core
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv3086/org/jrobin/core

Modified Files:
	RrdFileBackend.java 
Log Message:
Minor change in the code to disallow R/W access to the same file from two different RrdDb objects

Index: RrdFileBackend.java
===================================================================
RCS file: /cvsroot/jrobin/src/org/jrobin/core/RrdFileBackend.java,v
retrieving revision 1.5
retrieving revision 1.6
diff -C2 -d -r1.5 -r1.6
*** RrdFileBackend.java	29 Jun 2004 09:02:22 -0000	1.5
--- RrdFileBackend.java	29 Jun 2004 12:20:55 -0000	1.6
***************
*** 31,34 ****
--- 31,35 ----
  import java.nio.channels.FileChannel;
  import java.nio.channels.FileLock;
+ import java.util.HashSet;
  
  /**
***************
*** 41,44 ****
--- 42,47 ----
  	static final long LOCK_DELAY = 100; // 0.1sec
  
+ 	private static HashSet openFiles = new HashSet();
+ 
  	protected RandomAccessFile file;
  	protected FileLock fileLock;
***************
*** 46,49 ****
--- 49,55 ----
  	protected RrdFileBackend(String path, boolean readOnly, int lockMode) throws IOException {
  		super(path);
+ 		if(!readOnly) {
+ 			registerWriter(path);
+ 		}
  		file = new RandomAccessFile(path, readOnly? "r": "rw");
  		// We'll try to lock the file only in "rw" mode
***************
*** 54,57 ****
--- 60,74 ----
  	}
  
+ 	private static synchronized void registerWriter(String path) throws IOException {
+ 		String canonicalPath = getCanonicalPath(path);
+ 		if(openFiles.contains(canonicalPath)) {
+ 			throw new IOException("File \"" + path + "\" already open for R/W access. " +
+ 					"You cannot open the same file for R/W access twice");
+ 		}
+ 		else {
+ 			openFiles.add(canonicalPath);
+ 		}
+ 	}
+ 
  	private void lockFile(int lockMode) throws IOException {
  		if(lockMode == RrdDb.WAIT_IF_LOCKED || lockMode == RrdDb.EXCEPTION_IF_LOCKED) {
***************
*** 86,89 ****
--- 103,112 ----
  		unlockFile();
  		file.close();
+ 		unregisterWriter(getPath());
+ 	}
+ 
+ 	private static synchronized void unregisterWriter(String path) throws IOException {
+ 		String canonicalPath = getCanonicalPath(path);
+ 		openFiles.remove(canonicalPath);
  	}