Package org.apache.commons.io.input

Class UnsynchronizedBufferedInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.io.input.UnsynchronizedFilterInputStream

org.apache.commons.io.input.UnsynchronizedBufferedInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public final class UnsynchronizedBufferedInputStream
extends UnsynchronizedFilterInputStream

An unsynchronized version of BufferedInputStream, not thread-safe.

Wraps an existing InputStream and buffers the input. Expensive interaction with the underlying input stream is minimized, since most (smaller) requests can be satisfied by accessing the buffer alone. The drawback is that some extra space is required to hold the buffer and that copying takes place when filling that buffer, but this is usually outweighed by the performance benefits.

To build an instance, use UnsynchronizedBufferedInputStream.Builder.

A typical application pattern for the class looks like this:

 UnsynchronizedBufferedInputStream s = new UnsynchronizedBufferedInputStream.Builder().
   .setInputStream(new FileInputStream("file.java"))
   .setBufferSize(8192)
   .get();
 

Provenance: Apache Harmony and modified.

Since:

2.12.0

See Also:

• UnsynchronizedBufferedInputStream.Builder
• BufferedInputStream

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	UnsynchronizedBufferedInputStream.Builder	Builds a new UnsynchronizedBufferedInputStream.

Field Summary

Fields

Modifier and Type	Field	Description
protected byte[]	buffer	The buffer containing the current bytes read from the target InputStream.
protected int	count	The total number of bytes inside the byte array buffer.
protected int	markLimit	The current limit, which when passed, invalidates the current mark.
protected int	markPos	The currently marked position.
protected int	pos	The current position within the byte array buffer.

Fields inherited from class org.apache.commons.io.input.UnsynchronizedFilterInputStream

inputStream

Method Summary

Modifier and Type	Method	Description
int	available()	Returns the number of bytes that are available before this stream will block.
void	close()	Closes this stream.
void	mark(int readLimit)	Sets a mark position in this stream.
boolean	markSupported()	Indicates whether BufferedInputStream supports the mark() and reset() methods.
int	read()	Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
int	read(byte[] dest, int offset, int length)	Reads at most length bytes from this stream and stores them in byte array buffer starting at offset offset.
void	reset()	Resets this stream to the last marked location.
long	skip(long amount)	Skips amount number of bytes in this stream.

Methods inherited from class org.apache.commons.io.input.UnsynchronizedFilterInputStream

builder, read

Methods inherited from class java.lang.Object

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

Field Details

buffer

protected volatile byte[] buffer

The buffer containing the current bytes read from the target InputStream.

count

protected int count

The total number of bytes inside the byte array buffer.

markLimit

protected int markLimit

The current limit, which when passed, invalidates the current mark.

markPos

protected int markPos

The currently marked position. -1 indicates no mark has been set or the mark has been invalidated.

pos

protected int pos

The current position within the byte array buffer.

Method Details

available

public int available()
              throws IOException

Returns the number of bytes that are available before this stream will block. This method returns the number of bytes available in the buffer plus those available in the source stream.

Overrides:

available in class UnsynchronizedFilterInputStream

Returns:

the number of bytes available before blocking.

Throws:

IOException - if this stream is closed.

close

public void close()
           throws IOException

Closes this stream. The source stream is closed and any resources associated with it are released.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class UnsynchronizedFilterInputStream

Throws:

IOException - if an error occurs while closing this stream.

mark

public void mark(int readLimit)

Sets a mark position in this stream. The parameter readLimit indicates how many bytes can be read before a mark is invalidated. Calling reset() will reposition the stream back to the marked position if readLimit has not been surpassed. The underlying buffer may be increased in size to allow readLimit number of bytes to be supported.

Overrides:

mark in class UnsynchronizedFilterInputStream

Parameters:

readLimit - the number of bytes that can be read before the mark is invalidated.

See Also:

• reset()

markSupported

public boolean markSupported()

Indicates whether BufferedInputStream supports the mark() and reset() methods.

Overrides:

markSupported in class UnsynchronizedFilterInputStream

Returns:

true for BufferedInputStreams.

See Also:

• mark(int)
• reset()

read

public int read()
         throws IOException

Reads a single byte from this stream and returns it as an integer in the range from 0 to 255. Returns -1 if the end of the source string has been reached. If the internal buffer does not contain any available bytes then it is filled from the source stream and the first byte is returned.

Overrides:

read in class UnsynchronizedFilterInputStream

Returns:

the byte read or -1 if the end of the source stream has been reached.

Throws:

IOException - if this stream is closed or another IOException occurs.

read

public int read(byte[] dest,
 int offset,
 int length)
         throws IOException

Reads at most length bytes from this stream and stores them in byte array buffer starting at offset offset. Returns the number of bytes actually read or -1 if no bytes were read and the end of the stream was encountered. If all the buffered bytes have been used, a mark has not been set and the requested number of bytes is larger than the receiver's buffer size, this implementation bypasses the buffer and simply places the results directly into buffer.

Overrides:

read in class UnsynchronizedFilterInputStream

Parameters:

dest - the byte array in which to store the bytes read.

offset - the initial position in buffer to store the bytes read from this stream.

length - the maximum number of bytes to store in buffer.

Returns:

the number of bytes actually read or -1 if end of stream.

Throws:

IndexOutOfBoundsException - if offset < 0 or length < 0, or if offset + length is greater than the size of buffer.

IOException - if the stream is already closed or another IOException occurs.

reset

public void reset()
           throws IOException

Resets this stream to the last marked location.

Overrides:

reset in class UnsynchronizedFilterInputStream

Throws:

IOException - if this stream is closed, no mark has been set or the mark is no longer valid because more than readLimit bytes have been read since setting the mark.

See Also:

• mark(int)

skip

public long skip(long amount)
          throws IOException

Skips amount number of bytes in this stream. Subsequent read()'s will not return these bytes unless reset() is used.

Overrides:

skip in class UnsynchronizedFilterInputStream

Parameters:

amount - the number of bytes to skip. skip does nothing and returns 0 if amount is less than zero.

Returns:

the number of bytes actually skipped.

Throws:

IOException - if this stream is closed or another IOException occurs.

See Also:

• UnsynchronizedFilterInputStream.mark(int)
• UnsynchronizedFilterInputStream.reset()