Package com.helger.commons.io.stream

Class NonBlockingBufferedInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

com.helger.commons.io.stream.WrappedInputStream

com.helger.commons.io.stream.NonBlockingBufferedInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class NonBlockingBufferedInputStream
extends WrappedInputStream

Non-synchronized version of BufferedInputStream.

Author:

Philip Helger

Field Summary

Fields

Modifier and Type	Field	Description
protected byte[]	m_aBuf	The internal buffer array where the data is stored.
protected int	m_nCount	The index one greater than the index of the last valid byte in the buffer.
protected int	m_nMarkLimit	The maximum read ahead allowed after a call to the mark method before subsequent calls to the reset method fail.
protected int	m_nMarkPos	The value of the pos field at the time the last mark method was called.
protected int	m_nPos	The current position in the buffer.

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
NonBlockingBufferedInputStream(InputStream aIS)	Creates a BufferedInputStream and saves its argument, the input stream in, for later use.
NonBlockingBufferedInputStream(InputStream aIS, int nSize)	Creates a BufferedInputStream with the specified buffer size, and saves its argument, the input stream in, for later use.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.
void	close()	Closes this input stream and releases any system resources associated with the stream.
void	mark(int nReadlimit)	See the general contract of the mark method of InputStream.
boolean	markSupported()	Tests if this input stream supports the mark and reset methods.
int	read()	See the general contract of the read method of InputStream.
int	read(byte[] aBuf, int nOfs, int nLen)	Reads bytes from this byte-input stream into the specified byte array, starting at the given offset.
void	reset()	See the general contract of the reset method of InputStream.
long	skip(long nBytesToSkip)	See the general contract of the skip method of InputStream.

Methods inherited from class com.helger.commons.io.stream.WrappedInputStream

getWrappedInputStream, toString

Methods inherited from class java.io.FilterInputStream

read

Methods inherited from class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Field Details

m_aBuf

protected volatile byte[] m_aBuf

The internal buffer array where the data is stored. When necessary, it may be replaced by another array of a different size.

m_nCount

protected int m_nCount

The index one greater than the index of the last valid byte in the buffer. This value is always in the range 0 through buf.length; elements buf[0] through buf[count-1] contain buffered input data obtained from the underlying input stream.

m_nPos

protected int m_nPos

The current position in the buffer. This is the index of the next character to be read from the buf array.

This value is always in the range 0 through count . If it is less than count, then buf[pos] is the next byte to be supplied as input; if it is equal to count, then the next read or skip operation will require more bytes to be read from the contained input stream.

See Also:

• m_aBuf

m_nMarkPos

protected int m_nMarkPos

The value of the pos field at the time the last mark method was called.

This value is always in the range -1 through pos. If there is no marked position in the input stream, this field is -1. If there is a marked position in the input stream, then buf[markpos] is the first byte to be supplied as input after a reset operation. If markpos is not -1, then all bytes from positions buf[markpos] through buf[pos-1] must remain in the buffer array (though they may be moved to another place in the buffer array, with suitable adjustments to the values of count, pos, and markpos); they may not be discarded unless and until the difference between pos and markpos exceeds marklimit.

See Also:

• mark(int)
• m_nPos

m_nMarkLimit

protected int m_nMarkLimit

The maximum read ahead allowed after a call to the mark method before subsequent calls to the reset method fail. Whenever the difference between pos and markpos exceeds marklimit, then the mark may be dropped by setting markpos to -1.

See Also:

• mark(int)
• reset()

Constructor Details

NonBlockingBufferedInputStream

public NonBlockingBufferedInputStream(@Nonnull
 InputStream aIS)

Creates a BufferedInputStream and saves its argument, the input stream in, for later use. An internal buffer array is created and stored in buf.

Parameters:

aIS - the underlying input stream.

NonBlockingBufferedInputStream

public NonBlockingBufferedInputStream(@Nonnull
 InputStream aIS,
 @Nonnegative
 int nSize)

Creates a BufferedInputStream with the specified buffer size, and saves its argument, the input stream in, for later use. An internal buffer array of length size is created and stored in buf.

Parameters:

aIS - the underlying input stream.

nSize - the buffer size.

Throws:

IllegalArgumentException - if size ≤ 0.

Method Details

read

public int read()
         throws IOException

See the general contract of the read method of InputStream.

Overrides:

read in class FilterInputStream

Returns:

the next byte of data, or -1 if the end of the stream is reached.

Throws:

IOException - if this input stream has been closed by invoking its close() method, or an I/O error occurs.

read

public int read(byte[] aBuf,
 int nOfs,
 int nLen)
         throws IOException

Reads bytes from this byte-input stream into the specified byte array, starting at the given offset.

This method implements the general contract of the corresponding read method of the InputStream class. As an additional convenience, it attempts to read as many bytes as possible by repeatedly invoking the read method of the underlying stream. This iterated read continues until one of the following conditions becomes true:

• The specified number of bytes have been read,
• The read method of the underlying stream returns -1, indicating end-of-file, or
• The available method of the underlying stream returns zero, indicating that further input requests would block.

If the first read on the underlying stream returns -1 to indicate end-of-file then this method returns -1. Otherwise this method returns the number of bytes actually read.

Subclasses of this class are encouraged, but not required, to attempt to read as many bytes as possible in the same fashion.

Overrides:

read in class FilterInputStream

Parameters:

aBuf - destination buffer.

nOfs - offset at which to start storing bytes.

nLen - maximum number of bytes to read.

Returns:

the number of bytes read, or -1 if the end of the stream has been reached.

Throws:

IOException - if this input stream has been closed by invoking its close() method, or an I/O error occurs.

skip

public long skip(long nBytesToSkip)
          throws IOException

See the general contract of the skip method of InputStream.

Overrides:

skip in class FilterInputStream

Throws:

IOException - if the stream does not support seek, or if this input stream has been closed by invoking its close() method, or an I/O error occurs.

available

public int available()
              throws IOException

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

This method returns the sum of the number of bytes remaining to be read in the buffer (count - pos) and the result of calling the in.available().

Overrides:

available in class FilterInputStream

Returns:

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking.

Throws:

IOException - if this input stream has been closed by invoking its close() method, or an I/O error occurs.

mark

public void mark(int nReadlimit)

See the general contract of the mark method of InputStream.

Overrides:

mark in class FilterInputStream

Parameters:

nReadlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.

See Also:

• reset()

reset

public void reset()
           throws IOException

See the general contract of the reset method of InputStream.

If markpos is -1 (no mark has been set or the mark has been invalidated), an IOException is thrown. Otherwise, pos is set equal to markpos.

Overrides:

reset in class FilterInputStream

Throws:

IOException - if this stream has not been marked or, if the mark has been invalidated, or the stream has been closed by invoking its close() method, or an I/O error occurs.

See Also:

• mark(int)

markSupported

public boolean markSupported()

Tests if this input stream supports the mark and reset methods. The markSupported method of BufferedInputStream returns true.

Overrides:

markSupported in class FilterInputStream

Returns:

a boolean indicating if this stream type supports the mark and reset methods.

See Also:

• InputStream.mark(int)
• InputStream.reset()

close

public void close()
           throws IOException

Closes this input stream and releases any system resources associated with the stream. Once the stream has been closed, further read(), available(), reset(), or skip() invocations will throw an IOException. Closing a previously closed stream has no effect.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class FilterInputStream

Throws:

IOException - if an I/O error occurs.