PSRandomAccessFile.java

// Copyright 2001, FreeHEP.
package org.freehep.postscript;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;

/**
 * Objects for PostScript Processor, as defined in 3.3 Data Types and Objects
 *
 * @author Mark Donszelmann
 * @version $Id: PSRandomAccessFile.java 8958 2006-09-12 23:37:43Z duns $
 */
public class PSRandomAccessFile extends PSFile {
    protected RandomAccessFile raf = null;
    protected boolean write;
    protected boolean append;
    
    protected PSRandomAccessFile(String n, boolean f, RandomAccessFile r) {
        super(n, f);
        raf = r;
    }
    
    public PSRandomAccessFile(String filename, boolean write, boolean append, boolean secure) throws FileNotFoundException, IOException {
        super(filename, false);
            
        if (!secure) throw new IOException();
        this.write = write;
        this.append = append;
        File file = new File(filename);
        if (!write && !file.exists()) throw new IOException();
        raf = new RandomAccessFile(file, "rw");
        if (append) {
            raf.seek(raf.length());
        }
        if (write) {
            // FIXME: not really truncated!
            raf.seek(0);
        }
    }
        
    public void close() throws IOException {
        if (raf != null) {
            raf.close();
            raf = null;
        }
    }
    
    public int read() throws IOException {
        return (raf != null) ? raf.read() : -1;
    }
    
    public String readLine() throws IOException {
        return (raf != null) ? raf.readLine() : null;
    }
    
    public void write(int b, boolean secure) throws IOException {
        if (!secure) throw new IOException();
        if (raf != null) {
            raf.write(b);
        } else {
            throw new IOException();
        }
    }
    
    public void seek(long pos) throws IOException {
        if (raf != null) {
            raf.seek(pos);
        } else {
            throw new IOException();
        }
    }
    
    public long getFilePointer() throws IOException {
        return (raf != null) ? raf.getFilePointer() : -1;
    }
    
    public int available() throws IOException {
        return (raf != null) ? (int)(raf.length() - raf.getFilePointer()) : -1;
    }        
    
    public void flush() throws IOException {
        // ignored
    }

    public void reset() throws IOException {
        if (raf != null) {
            raf.seek(0);
        } else {
            throw new IOException();
        }
    }
    
    public boolean isValid() {
        return (raf != null);
    }
    
    public int hashCode() {
        return raf.hashCode();
    }

    public boolean equals(Object o) {
        if (o instanceof PSRandomAccessFile) {
            return (raf == ((PSRandomAccessFile)o).raf);
        }
        return false;
    }

    public Object clone() {
        return new PSRandomAccessFile(filename, filter, raf);
    }
    
    public PSObject copy() {
        if (filter) throw new RuntimeException("Filters cannot be copied");
        
        try {
            return new PSRandomAccessFile(filename, write, append, true);
        } catch (FileNotFoundException e) {
            throw new RuntimeException("Cannot find file while copying: "+filename);
        } catch (IOException e) {
            throw new RuntimeException("IOException for file while copying: "+filename);
        }
    }    
}