/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.io;
import java.nio.ByteOrder;
import java.nio.charset.ModifiedUtf8;
import libcore.io.Memory;
import libcore.io.SizeOf;
/**
* Wraps an existing {@link OutputStream} and writes big-endian typed data to it.
* Typically, this stream can be read in by DataInputStream. Types that can be
* written include byte, 16-bit short, 32-bit int, 32-bit float, 64-bit long,
* 64-bit double, byte strings, and {@link DataInput MUTF-8} encoded strings.
*
* @see DataInputStream
*/
public class DataOutputStream extends FilterOutputStream implements DataOutput {
private final byte[] scratch = new byte[8];
/**
* The number of bytes written out so far.
*/
protected int written;
/**
* Constructs a new {@code DataOutputStream} on the {@code OutputStream}
* {@code out}. Note that data written by this stream is not in a human
* readable form but can be reconstructed by using a {@link DataInputStream}
* on the resulting output.
*
* @param out
* the target stream for writing.
*/
public DataOutputStream(OutputStream out) {
super(out);
}
/**
* Flushes this stream to ensure all pending data is sent out to the target
* stream. This implementation then also flushes the target stream.
*
* @throws IOException
* if an error occurs attempting to flush this stream.
*/
@Override
public void flush() throws IOException {
super.flush();
}
/**
* Returns the total number of bytes written to the target stream so far.
*
* @return the number of bytes written to the target stream.
*/
public final int size() {
if (written < 0) {
written = Integer.MAX_VALUE;
}
return written;
}
/**
* Writes {@code count} bytes from the byte array {@code buffer} starting at
* {@code offset} to the target stream.
*
* @param buffer
* the buffer to write to the target stream.
* @param offset
* the index of the first byte in {@code buffer} to write.
* @param count
* the number of bytes from the {@code buffer} to write.
* @throws IOException
* if an error occurs while writing to the target stream.
* @throws NullPointerException
* if {@code buffer} is {@code null}.
*/
@Override
public void write(byte[] buffer, int offset, int count) throws IOException {
if (buffer == null) {
throw new NullPointerException("buffer == null");
}
out.write(buffer, offset, count);
written += count;
}
/**
* Writes a byte to the target stream. Only the least significant byte of
* the integer {@code oneByte} is written.
*
* @param oneByte
* the byte to write to the target stream.
* @throws IOException
* if an error occurs while writing to the target stream.
* @see DataInputStream#readByte()
*/
@Override
public void write(int oneByte) throws IOException {
out.write(oneByte);
written++;
}
/**
* Writes a boolean to the target stream.
*
* @param val
* the boolean value to write to the target stream.
* @throws IOException
* if an error occurs while writing to the target stream.
* @see DataInputStream#readBoolean()
*/
public final void writeBoolean(boolean val) throws IOException {
out.write(val ? 1 : 0);
written++;
}
/**
* Writes an 8-bit byte to the target stream. Only the least significant
* byte of the integer {@code val} is written.
*
* @param val
* the byte value to write to the target stream.
* @throws IOException
* if an error occurs while writing to the target stream.
* @see DataInputStream#readByte()
* @see DataInputStream#readUnsignedByte()
*/
public final void writeByte(int val) throws IOException {
out.write(val);
written++;
}
public final void writeBytes(String str) throws IOException {
if (str.length() == 0) {
return;
}
byte[] bytes = new byte[str.length()];
for (int index = 0; index < str.length(); index++) {
bytes[index] = (byte) str.charAt(index);
}
out.write(bytes);
written += bytes.length;
}
public final void writeChar(int val) throws IOException {
writeShort(val);
}
public final void writeChars(String str) throws IOException {
byte[] bytes = str.getBytes("UTF-16BE");
out.write(bytes);
written += bytes.length;
}
public final void writeDouble(double val) throws IOException {
writeLong(Double.doubleToLongBits(val));
}
public final void writeFloat(float val) throws IOException {
writeInt(Float.floatToIntBits(val));
}
public final void writeInt(int val) throws IOException {
Memory.pokeInt(scratch, 0, val, ByteOrder.BIG_ENDIAN);
out.write(scratch, 0, SizeOf.INT);
written += SizeOf.INT;
}
public final void writeLong(long val) throws IOException {
Memory.pokeLong(scratch, 0, val, ByteOrder.BIG_ENDIAN);
out.write(scratch, 0, SizeOf.LONG);
written += SizeOf.LONG;
}
public final void writeShort(int val) throws IOException {
Memory.pokeShort(scratch, 0, (short) val, ByteOrder.BIG_ENDIAN);
out.write(scratch, 0, SizeOf.SHORT);
written += SizeOf.SHORT;
}
public final void writeUTF(String str) throws IOException {
write(ModifiedUtf8.encode(str));
}
}