Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.message.ui / src / org / simantics / message / ui / TailInputStream.java

diff --git a/bundles/org.simantics.message.ui/src/org/simantics/message/ui/TailInputStream.java b/bundles/org.simantics.message.ui/src/org/simantics/message/ui/TailInputStream.java
new file mode 100644 (file)
index 0000000..14c7fed
--- /dev/null
+++ b/bundles/org.simantics.message.ui/src/org/simantics/message/ui/TailInputStream.java
@@ -0,0 +1,65 @@
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ *     VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.message.ui;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.RandomAccessFile;
+
+public class TailInputStream extends InputStream {
+
+       private RandomAccessFile fRaf;
+
+       private long fTail;
+
+       public TailInputStream(File file, long maxLength) throws IOException {
+               super();
+               fTail = maxLength;
+               fRaf = new RandomAccessFile(file, "r"); //$NON-NLS-1$
+               skipHead(file);
+       }
+
+       private void skipHead(File file) throws IOException {
+               if (file.length() > fTail) {
+                       fRaf.seek(file.length() - fTail);
+                       // skip bytes until a new line to be sure we start from a beginnng of valid UTF-8 character
+                       int c = read();
+                       while (c != '\n' && c != 'r' && c != -1) {
+                               c = read();
+                       }
+
+               }
+       }
+
+       public int read() throws IOException {
+               byte[] b = new byte[1];
+               int len = fRaf.read(b, 0, 1);
+               if (len < 0) {
+                       return len;
+               }
+               return b[0];
+       }
+
+       public int read(byte[] b) throws IOException {
+               return fRaf.read(b, 0, b.length);
+       }
+
+       public int read(byte[] b, int off, int len) throws IOException {
+               return fRaf.read(b, off, len);
+       }
+
+       public void close() throws IOException {
+               fRaf.close();
+       }
+
+}