org.postgresql.core
Class VisibleBufferedInputStream

java.lang.Object
  java.io.InputStream
      org.postgresql.core.VisibleBufferedInputStream

All Implemented Interfaces:

Closeable

public class VisibleBufferedInputStream
extends InputStream

A faster version of BufferedInputStream. Does no synchronisation and allows direct access to the used byte[] buffer.

Author:

Mikko Tiihonen

Constructor Summary

VisibleBufferedInputStream(InputStream in, int bufferSize)
Creates a new buffer around the given stream.

Method Summary

int	available()
void	close()
boolean	ensureBytes(int n) Ensures that the buffer contains at least n bytes.
byte[]	getBuffer() Returns direct handle to the used buffer.
int	getIndex() Returns the current read position in the buffer.
int	peek() Reads a byte from the buffer without advancing the index pointer.
int	read()
int	read(byte[] to, int off, int len)
byte	readRaw() Reads byte from the buffer without any checks.
int	scanCStringLength() Scans the length of the next null terminated string (C-style string) from the stream.
long	skip(long n)

Methods inherited from class java.io.InputStream

mark, markSupported, read, reset

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VisibleBufferedInputStream

public VisibleBufferedInputStream(InputStream in,
                                  int bufferSize)

Creates a new buffer around the given stream.

Parameters:

in - The stream to buffer.

bufferSize - The initial size of the buffer.

Method Detail

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

peek

public int peek()
         throws IOException

Reads a byte from the buffer without advancing the index pointer.

Returns:

byte from the buffer without advancing the index pointer

Throws:

IOException - if something wrong happens

readRaw

public byte readRaw()

Reads byte from the buffer without any checks. This method never reads from the underlaying stream. Before calling this method the ensureBytes(int) method must have been called.

Returns:

The next byte from the buffer.

Throws:

ArrayIndexOutOfBoundsException - If ensureBytes was not called to make sure the buffer contains the byte.

ensureBytes

public boolean ensureBytes(int n)
                    throws IOException

Ensures that the buffer contains at least n bytes. This method invalidates the buffer and index fields.

Parameters:

n - The amount of bytes to ensure exists in buffer

Returns:

true if required bytes are available and false if EOF

Throws:

IOException - If reading of the wrapped stream failed.

read

public int read(byte[] to,
                int off,
                int len)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Throws:

IOException

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

getBuffer

public byte[] getBuffer()

Returns direct handle to the used buffer. Use the ensureBytes(int) to prefill required bytes the buffer and getIndex() to fetch the current position of the buffer.

Returns:

The underlaying buffer.

getIndex

public int getIndex()

Returns the current read position in the buffer.

Returns:

the current read position in the buffer.

scanCStringLength

public int scanCStringLength()
                      throws IOException

Scans the length of the next null terminated string (C-style string) from the stream.

Returns:

The length of the next null terminated string.

Throws:

IOException - If reading of stream fails.

EOFException - If the stream did not contain any null terminators.