imported brians code

[nestedvm.git] / src / org / xwt / mips / util / SeekableByteArray.java

diff --git a/src/org/xwt/mips/util/SeekableByteArray.java b/src/org/xwt/mips/util/SeekableByteArray.java
new file mode 100644 (file)
index 0000000..807dd68
--- /dev/null
+++ b/src/org/xwt/mips/util/SeekableByteArray.java
@@ -0,0 +1,37 @@
+package org.xwt.mips.util;
+
+import java.io.IOException;
+
+public class SeekableByteArray implements SeekableData {
+    protected byte[] data;
+    protected int pos;
+    private final boolean writable;
+    
+    public SeekableByteArray(byte[] data, boolean writable) {
+        this.data = data;
+        this.pos = 0;
+        this.writable = writable;
+    }
+    
+    public int read(byte[] buf, int off, int len) {
+        len = Math.min(len,data.length-pos);
+        if(len <= 0) return -1;
+        System.arraycopy(data,pos,buf,off,len);
+        pos += len;
+        return len;
+    }
+    
+    public int write(byte[] buf, int off, int len) throws IOException {
+        if(!writable) throw new IOException("read-only data");
+        len = Math.min(len,data.length-pos);
+        if(len <= 0) throw new IOException("no space");
+        System.arraycopy(buf,off,data,pos,len);        
+        pos += len;
+        return len;
+    }
+    
+    public int length() { return data.length; }
+    public int pos() { return pos; }
+    public void seek(int pos) { this.pos = pos; }
+    public void close() { /*noop*/ }
+}