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 void resize(long length) throws IOException {
18 throw new IOException("resize not implemented for " + getClass());
21 public int read() throws IOException {
22 byte[] buf = new byte[1];
23 int n = read(buf,0,1);
24 return n == -1 ? -1 : buf[0]&0xff;
27 public int tryReadFully(byte[] buf, int off, int len) throws IOException {
30 int n = read(buf,off,len);
36 return total == 0 ? -1 : total;
39 public static class ByteArray extends Seekable {
40 protected byte[] data;
42 private final boolean writable;
44 public ByteArray(byte[] data, boolean writable) {
47 this.writable = writable;
50 public int read(byte[] buf, int off, int len) {
51 len = Math.min(len,data.length-pos);
52 if(len <= 0) return -1;
53 System.arraycopy(data,pos,buf,off,len);
58 public int write(byte[] buf, int off, int len) throws IOException {
59 if(!writable) throw new IOException("read-only data");
60 len = Math.min(len,data.length-pos);
61 if(len <= 0) throw new IOException("no space");
62 System.arraycopy(buf,off,data,pos,len);
67 public int length() { return data.length; }
68 public int pos() { return pos; }
69 public void seek(int pos) { this.pos = pos; }
70 public void close() { /*noop*/ }
73 public static class File extends Seekable {
74 private final RandomAccessFile raf;
76 public File(String fileName) throws IOException { this(fileName,false); }
77 public File(String fileName, boolean writable) throws IOException { this(new java.io.File(fileName),writable,false); }
79 public File(java.io.File file, boolean writable, boolean truncate) throws IOException {
80 String mode = writable ? "rw" : "r";
81 raf = truncate ? Platform.truncatedRandomAccessFile(file,mode) : new RandomAccessFile(file,mode);
84 public int read(byte[] buf, int offset, int length) throws IOException { return raf.read(buf,offset,length); }
85 public int write(byte[] buf, int offset, int length) throws IOException { raf.write(buf,offset,length); return length; }
86 public void seek(int pos) throws IOException{ raf.seek(pos); }
87 public int pos() throws IOException { return (int) raf.getFilePointer(); }
88 public int length() throws IOException { return (int)raf.length(); }
89 public void close() throws IOException { raf.close(); }
90 public void resize(long length) throws IOException { raf.setLength(length); }
93 public static class InputStream extends Seekable {
94 private byte[] buffer = new byte[4096];
95 private int bytesRead = 0;
96 private boolean eof = false;
98 private java.io.InputStream is;
100 public InputStream(java.io.InputStream is) { this.is = is; }
102 public int read(byte[] outbuf, int off, int len) throws IOException {
103 if(pos >= bytesRead && !eof) readTo(pos + 1);
104 len = Math.min(len,bytesRead-pos);
105 if(len <= 0) return -1;
106 System.arraycopy(buffer,pos,outbuf,off,len);
111 private void readTo(int target) throws IOException {
112 if(target >= buffer.length) {
113 byte[] buf2 = new byte[Math.max(buffer.length+Math.min(buffer.length,65536),target)];
114 System.arraycopy(buffer,0,buf2,0,bytesRead);
117 while(bytesRead < target) {
118 int n = is.read(buffer,bytesRead,buffer.length-bytesRead);
127 public int length() throws IOException {
128 while(!eof) readTo(bytesRead+4096);
132 public int write(byte[] buf, int off, int len) throws IOException { throw new IOException("read-only"); }
133 public void seek(int pos) { this.pos = pos; }
134 public int pos() { return pos; }
135 public void close() throws IOException { is.close(); }