clarify licensing

[nestedvm.git] / src / org / ibex / nestedvm / util / Platform.java

diff --git a/src/org/ibex/nestedvm/util/Platform.java b/src/org/ibex/nestedvm/util/Platform.java
index b81e3ac..8f27af2 100644 (file)
--- a/src/org/ibex/nestedvm/util/Platform.java
+++ b/src/org/ibex/nestedvm/util/Platform.java
@@ -1,10 +1,11 @@
 // Copyright 2000-2005 the Contributors, as shown in the revision logs.
-// Licensed under the Apache Public Source License 2.0 ("the License").
+// Licensed under the Apache License 2.0 ("the License").
 // You may not use this file except in compliance with the License.
 
 package org.ibex.nestedvm.util;
 
 import java.io.*;
+import java.nio.channels.*;
 import java.net.*;
 import java.util.*;
 
@@ -58,6 +59,10 @@ public abstract class Platform {
     
     abstract boolean _atomicCreateFile(File f) throws IOException;
     public static boolean atomicCreateFile(File f) throws IOException { return p._atomicCreateFile(f); }
+
+    abstract Seekable.Lock _lockFile(Seekable s, RandomAccessFile raf, long pos, long size, boolean shared) throws IOException;
+    public static Seekable.Lock lockFile(Seekable s, RandomAccessFile raf, long pos, long size, boolean shared) throws IOException {
+        return p._lockFile(s, raf, pos, size, shared); }
     
     abstract void _socketHalfClose(Socket s, boolean output) throws IOException;
     public static void socketHalfClose(Socket s, boolean output) throws IOException { p._socketHalfClose(s,output); }
@@ -71,9 +76,11 @@ public abstract class Platform {
     abstract String _timeZoneGetDisplayName(TimeZone tz, boolean dst, boolean showlong, Locale l);
     public static String timeZoneGetDisplayName(TimeZone tz, boolean dst, boolean showlong, Locale l) { return p._timeZoneGetDisplayName(tz,dst,showlong,l); }
     public static String timeZoneGetDisplayName(TimeZone tz, boolean dst, boolean showlong) { return timeZoneGetDisplayName(tz,dst,showlong,Locale.getDefault()); }
-    
-    abstract RandomAccessFile _truncatedRandomAccessFile(File f, String mode) throws IOException;
-    public static RandomAccessFile truncatedRandomAccessFile(File f, String mode) throws IOException { return p._truncatedRandomAccessFile(f,mode); }
+
+    abstract void _setFileLength(RandomAccessFile f, int length)
+        throws IOException;
+    public static void setFileLength(RandomAccessFile f, int length)
+        throws IOException { p._setFileLength(f, length); }
     
     abstract File[] _listRoots();
     public static File[] listRoots() { return p._listRoots(); }
@@ -88,6 +95,9 @@ public abstract class Platform {
             new FileOutputStream(f).close();
             return true;
         }
+        Seekable.Lock _lockFile(Seekable s, RandomAccessFile raf, long p, long size, boolean shared) throws IOException {
+            throw new IOException("file locking requires jdk 1.4+");
+        }
         void _socketHalfClose(Socket s, boolean output) throws IOException {
             throw new IOException("half closing sockets not supported");
         }
@@ -113,7 +123,27 @@ public abstract class Platform {
             if(off > 0) sb.append(":").append(off);
             return sb.toString();
         }
-        
+
+        void _setFileLength(RandomAccessFile f, int length) throws IOException{
+            InputStream in = new FileInputStream(f.getFD());
+            OutputStream out = new FileOutputStream(f.getFD());
+
+            byte[] buf = new byte[1024];
+            for (int len; length > 0; length -= len) {
+                len = in.read(buf, 0, Math.min(length, buf.length));
+                if (len == -1) break;
+                out.write(buf, 0, len);
+            }
+            if (length == 0) return;
+
+            // fill the rest of the space with zeros
+            for (int i=0; i < buf.length; i++) buf[i] = 0;
+            while (length > 0) {
+                out.write(buf, 0, Math.min(length, buf.length));
+                length -= buf.length;
+            }
+        }
+
         RandomAccessFile _truncatedRandomAccessFile(File f, String mode) throws IOException {
             new FileOutputStream(f).close();
             return new RandomAccessFile(f,mode);
@@ -162,13 +192,11 @@ public abstract class Platform {
         String _timeZoneGetDisplayName(TimeZone tz, boolean dst, boolean showlong, Locale l) {
             return tz.getDisplayName(dst,showlong ? TimeZone.LONG : TimeZone.SHORT, l);
         }
-        
-        RandomAccessFile _truncatedRandomAccessFile(File f, String mode) throws IOException {
-            RandomAccessFile raf = new RandomAccessFile(f,mode);
-            raf.setLength(0);
-            return raf;
+
+        void _setFileLength(RandomAccessFile f, int length) throws IOException {
+            f.setLength(length);
         }
-        
+
         File[] _listRoots() { return File.listRoots(); }
     }
     
@@ -185,5 +213,29 @@ public abstract class Platform {
     
     static class Jdk14 extends Jdk13 {
         InetAddress _inetAddressFromBytes(byte[] a) throws UnknownHostException { return InetAddress.getByAddress(a); } 
+
+        Seekable.Lock _lockFile(Seekable s, RandomAccessFile r, long pos, long size, boolean shared) throws IOException {
+            FileLock flock;
+            try {
+                flock = pos == 0 && size == 0 ? r.getChannel().lock() :
+                    r.getChannel().tryLock(pos, size, shared);
+            } catch (OverlappingFileLockException e) { flock = null; }
+            if (flock == null) return null; // region already locked
+            return new Jdk14FileLock(s, flock);
+        }
+    }
+
+    private static final class Jdk14FileLock extends Seekable.Lock {
+        private final Seekable s;
+        private final FileLock l;
+
+        Jdk14FileLock(Seekable sk, FileLock flock) { s = sk; l = flock; }
+        public Seekable seekable() { return s; }
+        public boolean isShared() { return l.isShared(); }
+        public boolean isValid() { return l.isValid(); }
+        public void release() throws IOException { l.release(); }
+        public long position() { return l.position(); }
+        public long size() { return l.size(); }
+        public String toString() { return l.toString(); }
     }
 }