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/*
* Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* questions.
*/
package com.sun.tools.javac.util;
import java.io.*;
/** A byte buffer is a flexible array which grows when elements are
* appended. There are also methods to append names to byte buffers
* and to convert byte buffers to names.
*
* This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.
*/
public class ByteBuffer {
/** An array holding the bytes in this buffer; can be grown.
*/
public byte[] elems;
/** The current number of defined bytes in this buffer.
*/
public int length;
/** Create a new byte buffer.
*/
public ByteBuffer() {
this(64);
}
/** Create a new byte buffer with an initial elements array
* of given size.
*/
public ByteBuffer(int initialSize) {
elems = new byte[initialSize];
length = 0;
}
/** Append byte to this buffer.
*/
public void appendByte(int b) {
elems = ArrayUtils.ensureCapacity(elems, length);
elems[length++] = (byte)b;
}
/** Append `len' bytes from byte array,
* starting at given `start' offset.
*/
public void appendBytes(byte[] bs, int start, int len) {
elems = ArrayUtils.ensureCapacity(elems, length + len);
System.arraycopy(bs, start, elems, length, len);
length += len;
}
/** Append all bytes from given byte array.
*/
public void appendBytes(byte[] bs) {
appendBytes(bs, 0, bs.length);
}
/** Append a character as a two byte number.
*/
public void appendChar(int x) {
elems = ArrayUtils.ensureCapacity(elems, length + 1);
elems[length ] = (byte)((x >> 8) & 0xFF);
elems[length+1] = (byte)((x ) & 0xFF);
length = length + 2;
}
/** Append an integer as a four byte number.
*/
public void appendInt(int x) {
elems = ArrayUtils.ensureCapacity(elems, length + 3);
elems[length ] = (byte)((x >> 24) & 0xFF);
elems[length+1] = (byte)((x >> 16) & 0xFF);
elems[length+2] = (byte)((x >> 8) & 0xFF);
elems[length+3] = (byte)((x ) & 0xFF);
length = length + 4;
}
/** Append a long as an eight byte number.
*/
public void appendLong(long x) {
ByteArrayOutputStream buffer = new ByteArrayOutputStream(8);
DataOutputStream bufout = new DataOutputStream(buffer);
try {
bufout.writeLong(x);
appendBytes(buffer.toByteArray(), 0, 8);
} catch (IOException e) {
throw new AssertionError("write");
}
}
/** Append a float as a four byte number.
*/
public void appendFloat(float x) {
ByteArrayOutputStream buffer = new ByteArrayOutputStream(4);
DataOutputStream bufout = new DataOutputStream(buffer);
try {
bufout.writeFloat(x);
appendBytes(buffer.toByteArray(), 0, 4);
} catch (IOException e) {
throw new AssertionError("write");
}
}
/** Append a double as a eight byte number.
*/
public void appendDouble(double x) {
ByteArrayOutputStream buffer = new ByteArrayOutputStream(8);
DataOutputStream bufout = new DataOutputStream(buffer);
try {
bufout.writeDouble(x);
appendBytes(buffer.toByteArray(), 0, 8);
} catch (IOException e) {
throw new AssertionError("write");
}
}
/** Append a name.
*/
public void appendName(Name name) {
appendBytes(name.getByteArray(), name.getByteOffset(), name.getByteLength());
}
/** Append the content of a given input stream.
*/
public void appendStream(InputStream is) throws IOException {
try {
int start = length;
int initialSize = is.available();
elems = ArrayUtils.ensureCapacity(elems, length + initialSize);
int r = is.read(elems, start, initialSize);
int bp = start;
while (r != -1) {
bp += r;
elems = ArrayUtils.ensureCapacity(elems, bp);
r = is.read(elems, bp, elems.length - bp);
}
} finally {
try {
is.close();
} catch (IOException e) {
/* Ignore any errors, as this stream may have already
* thrown a related exception which is the one that
* should be reported.
*/
}
}
}
/** Extract an integer at position bp from elems.
*/
public int getInt(int bp) {
return
((elems[bp] & 0xFF) << 24) +
((elems[bp+1] & 0xFF) << 16) +
((elems[bp+2] & 0xFF) << 8) +
(elems[bp+3] & 0xFF);
}
/** Extract a long integer at position bp from elems.
*/
public long getLong(int bp) {
DataInputStream elemsin =
new DataInputStream(new ByteArrayInputStream(elems, bp, 8));
try {
return elemsin.readLong();
} catch (IOException e) {
throw new AssertionError(e);
}
}
/** Extract a float at position bp from elems.
*/
public float getFloat(int bp) {
DataInputStream elemsin =
new DataInputStream(new ByteArrayInputStream(elems, bp, 4));
try {
return elemsin.readFloat();
} catch (IOException e) {
throw new AssertionError(e);
}
}
/** Extract a double at position bp from elems.
*/
public double getDouble(int bp) {
DataInputStream elemsin =
new DataInputStream(new ByteArrayInputStream(elems, bp, 8));
try {
return elemsin.readDouble();
} catch (IOException e) {
throw new AssertionError(e);
}
}
/** Extract a character at position bp from elems.
*/
public char getChar(int bp) {
return
(char)(((elems[bp] & 0xFF) << 8) + (elems[bp+1] & 0xFF));
}
public byte getByte(int bp) {
return elems[bp];
}
/** Reset to zero length.
*/
public void reset() {
length = 0;
}
/** Convert contents to name.
*/
public Name toName(Names names) {
return names.fromUtf(elems, 0, length);
}
}