1 // Copyright 2000-2005 the Contributors, as shown in the revision logs.
2 // Licensed under the Apache Public Source License 2.0 ("the License").
3 // You may not use this file except in compliance with the License.
5 package org.ibex.nestedvm.util;
9 public abstract class Seekable {
10 public abstract int read(byte[] buf, int offset, int length) throws IOException;
11 public abstract int write(byte[] buf, int offset, int length) throws IOException;
12 public abstract int length() throws IOException;
13 public abstract void seek(int pos) throws IOException;
14 public abstract void close() throws IOException;
15 public abstract int pos() throws IOException;
17 public int read() throws IOException {
18 byte[] buf = new byte[1];
19 int n = read(buf,0,1);
20 return n == -1 ? -1 : buf[0]&0xff;
23 public int tryReadFully(byte[] buf, int off, int len) throws IOException {
26 int n = read(buf,off,len);
32 return total == 0 ? -1 : total;
35 public static class ByteArray extends Seekable {
36 protected byte[] data;
38 private final boolean writable;
40 public ByteArray(byte[] data, boolean writable) {
43 this.writable = writable;
46 public int read(byte[] buf, int off, int len) {
47 len = Math.min(len,data.length-pos);
48 if(len <= 0) return -1;
49 System.arraycopy(data,pos,buf,off,len);
54 public int write(byte[] buf, int off, int len) throws IOException {
55 if(!writable) throw new IOException("read-only data");
56 len = Math.min(len,data.length-pos);
57 if(len <= 0) throw new IOException("no space");
58 System.arraycopy(buf,off,data,pos,len);
63 public int length() { return data.length; }
64 public int pos() { return pos; }
65 public void seek(int pos) { this.pos = pos; }
66 public void close() { /*noop*/ }
69 public static class File extends Seekable {
70 private final RandomAccessFile raf;
72 public File(String fileName) throws IOException { this(fileName,false); }
73 public File(String fileName, boolean writable) throws IOException { this(new java.io.File(fileName),writable,false); }
75 public File(java.io.File file, boolean writable, boolean truncate) throws IOException {
76 String mode = writable ? "rw" : "r";
77 raf = truncate ? Platform.truncatedRandomAccessFile(file,mode) : new RandomAccessFile(file,mode);
80 public int read(byte[] buf, int offset, int length) throws IOException { return raf.read(buf,offset,length); }
81 public int write(byte[] buf, int offset, int length) throws IOException { raf.write(buf,offset,length); return length; }
82 public void seek(int pos) throws IOException{ raf.seek(pos); }
83 public int pos() throws IOException { return (int) raf.getFilePointer(); }
84 public int length() throws IOException { return (int)raf.length(); }
85 public void close() throws IOException { raf.close(); }
88 public static class InputStream extends Seekable {
89 private byte[] buffer = new byte[4096];
90 private int bytesRead = 0;
91 private boolean eof = false;
93 private java.io.InputStream is;
95 public InputStream(java.io.InputStream is) { this.is = is; }
97 public int read(byte[] outbuf, int off, int len) throws IOException {
98 if(pos >= bytesRead && !eof) readTo(pos + 1);
99 len = Math.min(len,bytesRead-pos);
100 if(len <= 0) return -1;
101 System.arraycopy(buffer,pos,outbuf,off,len);
106 private void readTo(int target) throws IOException {
107 if(target >= buffer.length) {
108 byte[] buf2 = new byte[Math.max(buffer.length+Math.min(buffer.length,65536),target)];
109 System.arraycopy(buffer,0,buf2,0,bytesRead);
112 while(bytesRead < target) {
113 int n = is.read(buffer,bytesRead,buffer.length-bytesRead);
122 public int length() throws IOException {
123 while(!eof) readTo(bytesRead+4096);
127 public int write(byte[] buf, int off, int len) throws IOException { throw new IOException("read-only"); }
128 public void seek(int pos) { this.pos = pos; }
129 public int pos() { return pos; }
130 public void close() throws IOException { is.close(); }