edu.princeton.cs.introcs.BinaryStdOut Maven / Gradle / Ivy
package edu.princeton.cs.introcs;
/*************************************************************************
* Compilation: javac BinaryStdOut.java
* Execution: java BinaryStdOut
*
* Write binary data to standard output, either one 1-bit boolean,
* one 8-bit char, one 32-bit int, one 64-bit double, one 32-bit float,
* or one 64-bit long at a time.
*
* The bytes written are not aligned.
*
*************************************************************************/
import java.io.BufferedOutputStream;
import java.io.IOException;
/**
* Binary standard output. This class provides methods for converting
* primtive type variables (boolean, byte, char,
* int, long, float, and double)
* to sequences of bits and writing them to standard output.
* Uses big-endian (most-significant byte first).
*
* The client must flush() the output stream when finished writing bits.
*
* The client should not intermixing calls to BinaryStdOut with calls
* to StdOut or System.out; otherwise unexpected behavior
* will result.
*
* @author Robert Sedgewick
* @author Kevin Wayne
*/
public final class BinaryStdOut {
private static BufferedOutputStream out = new BufferedOutputStream(System.out);
private static int buffer; // 8-bit buffer of bits to write out
private static int N; // number of bits remaining in buffer
// don't instantiate
private BinaryStdOut() { }
/**
* Write the specified bit to standard output.
*/
private static void writeBit(boolean bit) {
// add bit to buffer
buffer <<= 1;
if (bit) buffer |= 1;
// if buffer is full (8 bits), write out as a single byte
N++;
if (N == 8) clearBuffer();
}
/**
* Write the 8-bit byte to standard output.
*/
private static void writeByte(int x) {
assert x >= 0 && x < 256;
// optimized if byte-aligned
if (N == 0) {
try { out.write(x); }
catch (IOException e) { e.printStackTrace(); }
return;
}
// otherwise write one bit at a time
for (int i = 0; i < 8; i++) {
boolean bit = ((x >>> (8 - i - 1)) & 1) == 1;
writeBit(bit);
}
}
// write out any remaining bits in buffer to standard output, padding with 0s
private static void clearBuffer() {
if (N == 0) return;
if (N > 0) buffer <<= (8 - N);
try { out.write(buffer); }
catch (IOException e) { e.printStackTrace(); }
N = 0;
buffer = 0;
}
/**
* Flush standard output, padding 0s if number of bits written so far
* is not a multiple of 8.
*/
public static void flush() {
clearBuffer();
try { out.flush(); }
catch (IOException e) { e.printStackTrace(); }
}
/**
* Flush and close standard output. Once standard output is closed, you can no
* longer write bits to it.
*/
public static void close() {
flush();
try { out.close(); }
catch (IOException e) { e.printStackTrace(); }
}
/**
* Write the specified bit to standard output.
* @param x the boolean to write.
*/
public static void write(boolean x) {
writeBit(x);
}
/**
* Write the 8-bit byte to standard output.
* @param x the byte to write.
*/
public static void write(byte x) {
writeByte(x & 0xff);
}
/**
* Write the 32-bit int to standard output.
* @param x the int to write.
*/
public static void write(int x) {
writeByte((x >>> 24) & 0xff);
writeByte((x >>> 16) & 0xff);
writeByte((x >>> 8) & 0xff);
writeByte((x >>> 0) & 0xff);
}
/**
* Write the r-bit int to standard output.
* @param x the int to write.
* @param r the number of relevant bits in the char.
* @throws RuntimeException if r is not between 1 and 32.
* @throws RuntimeException if x is not between 0 and 2r - 1.
*/
public static void write(int x, int r) {
if (r == 32) { write(x); return; }
if (r < 1 || r > 32) throw new RuntimeException("Illegal value for r = " + r);
if (x < 0 || x >= (1 << r)) throw new RuntimeException("Illegal " + r + "-bit char = " + x);
for (int i = 0; i < r; i++) {
boolean bit = ((x >>> (r - i - 1)) & 1) == 1;
writeBit(bit);
}
}
/**
* Write the 64-bit double to standard output.
* @param x the double to write.
*/
public static void write(double x) {
write(Double.doubleToRawLongBits(x));
}
/**
* Write the 64-bit long to standard output.
* @param x the long to write.
*/
public static void write(long x) {
writeByte((int) ((x >>> 56) & 0xff));
writeByte((int) ((x >>> 48) & 0xff));
writeByte((int) ((x >>> 40) & 0xff));
writeByte((int) ((x >>> 32) & 0xff));
writeByte((int) ((x >>> 24) & 0xff));
writeByte((int) ((x >>> 16) & 0xff));
writeByte((int) ((x >>> 8) & 0xff));
writeByte((int) ((x >>> 0) & 0xff));
}
/**
* Write the 32-bit float to standard output.
* @param x the float to write.
*/
public static void write(float x) {
write(Float.floatToRawIntBits(x));
}
/**
* Write the 16-bit int to standard output.
* @param x the short to write.
*/
public static void write(short x) {
writeByte((x >>> 8) & 0xff);
writeByte((x >>> 0) & 0xff);
}
/**
* Write the 8-bit char to standard output.
* @param x the char to write.
* @throws RuntimeException if x is not betwen 0 and 255.
*/
public static void write(char x) {
if (x < 0 || x >= 256) throw new RuntimeException("Illegal 8-bit char = " + x);
writeByte(x);
}
/**
* Write the r-bit char to standard output.
* @param x the char to write.
* @param r the number of relevant bits in the char.
* @throws RuntimeException if r is not between 1 and 16.
* @throws RuntimeException if x is not between 0 and 2r - 1.
*/
public static void write(char x, int r) {
if (r == 8) { write(x); return; }
if (r < 1 || r > 16) throw new RuntimeException("Illegal value for r = " + r);
if (x < 0 || x >= (1 << r)) throw new RuntimeException("Illegal " + r + "-bit char = " + x);
for (int i = 0; i < r; i++) {
boolean bit = ((x >>> (r - i - 1)) & 1) == 1;
writeBit(bit);
}
}
/**
* Write the string of 8-bit characters to standard output.
* @param s the String to write.
* @throws RuntimeException if any character in the string is not
* between 0 and 255.
*/
public static void write(String s) {
for (int i = 0; i < s.length(); i++)
write(s.charAt(i));
}
/**
* Write the String of r-bit characters to standard output.
* @param s the String to write.
* @param r the number of relevants bits in each character.
* @throws RuntimeException if r is not between 1 and 16.
* @throws RuntimeException if any character in the string is not
* between 0 and 2r - 1.
*/
public static void write(String s, int r) {
for (int i = 0; i < s.length(); i++)
write(s.charAt(i), r);
}
/**
* Test client.
*/
public static void main(String[] args) {
int T = Integer.parseInt(args[0]);
// write to standard output
for (int i = 0; i < T; i++) {
BinaryStdOut.write(i);
}
BinaryStdOut.flush();
}
}
/*************************************************************************
* Copyright 2002-2012, Robert Sedgewick and Kevin Wayne.
*
* This file is part of stdlib-package.jar, which accompanies the textbook
*
* Introduction to Programming in Java: An Interdisciplinary Approach
* by R. Sedgewick and K. Wayne, Addison-Wesley, 2007. ISBN 0-321-49805-4.
*
* http://introcs.cs.princeton.edu
*
*
* stdlib-package.jar is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* stdlib-package.jar 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 for more details.
* You should have received a copy of the GNU General Public License
* along with stdlib-package.jar. If not, see http://www.gnu.org/licenses.
*************************************************************************/