nom.tam.util
Class BufferedDataOutputStream

java.lang.Object
  extended by java.io.OutputStream
      extended by java.io.FilterOutputStream
          extended by java.io.BufferedOutputStream
              extended by nom.tam.util.BufferedDataOutputStream
All Implemented Interfaces:
java.io.Closeable, java.io.DataOutput, java.io.Flushable

public class BufferedDataOutputStream
extends java.io.BufferedOutputStream
implements java.io.DataOutput

This class is intended for high performance I/O in scientific applications. It combines the functionality of the BufferedOutputStream and the DataOutputStream as well as more efficient handling of arrays. This minimizes the number of method calls that are required to write data. Informal tests of this method show that it can be as much as 10 times faster than using a DataOutputStream layered on a BufferedOutputStream for writing large arrays. The performance gain on scalars or small arrays will be less but there should probably never be substantial degradation of performance. One routine is added to the public interface of DataOutput, writePrimitiveArray. This routine provides efficient protocols for writing arrays. Note that there is substantial duplication of code to minimize method invocations.


Field Summary
 
Fields inherited from class java.io.BufferedOutputStream
buf, count
 
Fields inherited from class java.io.FilterOutputStream
out
 
Constructor Summary
BufferedDataOutputStream(java.io.OutputStream o)
          Use the BufferedOutputStream constructor
BufferedDataOutputStream(java.io.OutputStream o, int bufLength)
          Use the BufferedOutputStream constructor
 
Method Summary
static void main(java.lang.String[] args)
          Test this class
 void writeBoolean(boolean b)
          Write a boolean value
protected  void writeBooleanArray(boolean[] b)
          Write an array of booleans.
 void writeByte(int b)
          Write a byte value.
 void writeBytes(java.lang.String s)
          Write a string using the local protocol to convert char's to bytes.
 void writeChar(int c)
          Write a char value.
protected  void writeCharArray(char[] c)
          Write an array of char's.
 void writeChars(java.lang.String s)
          Write a string as an array of chars.
 void writeDouble(double d)
          Write a double value.
protected  void writeDoubleArray(double[] d)
          Write an array of doubles.
 void writeFloat(float f)
          Write a float value.
protected  void writeFloatArray(float[] f)
          Write an array of floats.
 void writeInt(int i)
          Write an integer value.
protected  void writeIntArray(int[] i)
          Write an array of int's.
 void writeLong(long l)
          Write a long value.
protected  void writeLongArray(long[] l)
          Write an array of longs.
 void writePrimitiveArray(java.lang.Object o)
          This routine provides efficient writing of arrays of any primitive type.
 void writeShort(int s)
          Write a short value.
protected  void writeShortArray(short[] s)
          Write an array of shorts.
protected  void writeStringArray(java.lang.String[] s)
          Write an array of Strings -- equivalent to calling writeBytes for each string.
 void writeUTF(java.lang.String s)
          Write a string as a UTF.
 
Methods inherited from class java.io.BufferedOutputStream
flush, write, write
 
Methods inherited from class java.io.FilterOutputStream
close, write
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface java.io.DataOutput
write, write, write
 

Constructor Detail

BufferedDataOutputStream

public BufferedDataOutputStream(java.io.OutputStream o)
Use the BufferedOutputStream constructor

Parameters:
o - An open output stream.

BufferedDataOutputStream

public BufferedDataOutputStream(java.io.OutputStream o,
                                int bufLength)
Use the BufferedOutputStream constructor

Parameters:
o - An open output stream.
bufLength - The buffer size.
Method Detail

writeBoolean

public void writeBoolean(boolean b)
                  throws java.io.IOException
Write a boolean value

Specified by:
writeBoolean in interface java.io.DataOutput
Parameters:
b - The value to be written. Externally true is represented as a byte of 1 and false as a byte value of 0.
Throws:
java.io.IOException

writeByte

public void writeByte(int b)
               throws java.io.IOException
Write a byte value.

Specified by:
writeByte in interface java.io.DataOutput
Throws:
java.io.IOException

writeInt

public void writeInt(int i)
              throws java.io.IOException
Write an integer value.

Specified by:
writeInt in interface java.io.DataOutput
Throws:
java.io.IOException

writeShort

public void writeShort(int s)
                throws java.io.IOException
Write a short value.

Specified by:
writeShort in interface java.io.DataOutput
Throws:
java.io.IOException

writeChar

public void writeChar(int c)
               throws java.io.IOException
Write a char value.

Specified by:
writeChar in interface java.io.DataOutput
Throws:
java.io.IOException

writeLong

public void writeLong(long l)
               throws java.io.IOException
Write a long value.

Specified by:
writeLong in interface java.io.DataOutput
Throws:
java.io.IOException

writeFloat

public void writeFloat(float f)
                throws java.io.IOException
Write a float value.

Specified by:
writeFloat in interface java.io.DataOutput
Throws:
java.io.IOException

writeDouble

public void writeDouble(double d)
                 throws java.io.IOException
Write a double value.

Specified by:
writeDouble in interface java.io.DataOutput
Throws:
java.io.IOException

writeBytes

public void writeBytes(java.lang.String s)
                throws java.io.IOException
Write a string using the local protocol to convert char's to bytes.

Specified by:
writeBytes in interface java.io.DataOutput
Parameters:
s - The string to be written.
Throws:
java.io.IOException

writeChars

public void writeChars(java.lang.String s)
                throws java.io.IOException
Write a string as an array of chars.

Specified by:
writeChars in interface java.io.DataOutput
Throws:
java.io.IOException

writeUTF

public void writeUTF(java.lang.String s)
              throws java.io.IOException
Write a string as a UTF. Note that this class does not handle this situation efficiently since it creates new DataOutputStream to handle each call.

Specified by:
writeUTF in interface java.io.DataOutput
Throws:
java.io.IOException

writePrimitiveArray

public void writePrimitiveArray(java.lang.Object o)
                         throws java.io.IOException
This routine provides efficient writing of arrays of any primitive type. The String class is also handled but it is an error to invoke this method with an object that is not an array of these types. If the array is multidimensional, then it calls itself recursively to write the entire array. Strings are written using the standard 1 byte format (i.e., as in writeBytes). If the array is an array of objects, then writePrimitiveArray will be called for each element of the array.

Parameters:
o - The object to be written. It must be an array of a primitive type, Object, or String.
Throws:
java.io.IOException

writeBooleanArray

protected void writeBooleanArray(boolean[] b)
                          throws java.io.IOException
Write an array of booleans.

Throws:
java.io.IOException

writeShortArray

protected void writeShortArray(short[] s)
                        throws java.io.IOException
Write an array of shorts.

Throws:
java.io.IOException

writeCharArray

protected void writeCharArray(char[] c)
                       throws java.io.IOException
Write an array of char's.

Throws:
java.io.IOException

writeIntArray

protected void writeIntArray(int[] i)
                      throws java.io.IOException
Write an array of int's.

Throws:
java.io.IOException

writeLongArray

protected void writeLongArray(long[] l)
                       throws java.io.IOException
Write an array of longs.

Throws:
java.io.IOException

writeFloatArray

protected void writeFloatArray(float[] f)
                        throws java.io.IOException
Write an array of floats.

Throws:
java.io.IOException

writeDoubleArray

protected void writeDoubleArray(double[] d)
                         throws java.io.IOException
Write an array of doubles.

Throws:
java.io.IOException

writeStringArray

protected void writeStringArray(java.lang.String[] s)
                         throws java.io.IOException
Write an array of Strings -- equivalent to calling writeBytes for each string.

Throws:
java.io.IOException

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception
Test this class

Throws:
java.lang.Exception