Class FastByteArrayInputStream

java.lang.Object

java.io.InputStream

it.unimi.dsi.fastutil.io.MeasurableInputStream

it.unimi.dsi.fastutil.io.FastByteArrayInputStream

All Implemented Interfaces:

MeasurableStream, RepositionableStream, Closeable, DataInput, ObjectInput, AutoCloseable

public class FastByteArrayInputStream
extends MeasurableInputStream
implements RepositionableStream, ObjectInput

Simple, fast and repositionable byte-array input stream with built-in ObjectInput support.

Warning: this class implements the correct semantics of read(byte[], int, int) as described in InputStream. The implementation given in ByteArrayInputStream is broken, but it will never be fixed because it's too late.

Author:

Sebastiano Vigna

Field Summary

Fields

Modifier and Type	Field	Description
byte[]	array	The array backing the input stream.
int	length	The number of valid bytes in array starting from offset.
int	offset	The first valid entry.

Constructor Summary

Constructors

Constructor	Description
FastByteArrayInputStream(byte[] array)	Creates a new array input stream using a given array.
FastByteArrayInputStream(byte[] array, int offset, int length)	Creates a new array input stream using a given array fragment.

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()	Closing a fast byte array input stream has no effect.
long	length()	Returns the overall length of this stream (optional operation).
void	mark(int dummy)
boolean	markSupported()
int	peek()
long	position()	Returns the current position in this stream (optional operation).
void	position(long newPosition)	Sets the current stream position.
int	read()
int	read(byte[] b)
int	read(byte[] b, int offset, int length)	Reads bytes from this byte-array input stream as specified in InputStream.read(byte[], int, int).
boolean	readBoolean()
byte	readByte()
char	readChar()
double	readDouble()
float	readFloat()
void	readFully(byte[] b)
void	readFully(byte[] b, int off, int len)
int	readInt()
String	readLine()	Deprecated.
long	readLong()
Object	readObject()	not efficient!
short	readShort()
int	readUnsignedByte()
int	readUnsignedShort()
String	readUTF()
void	reset()
long	skip(long n)
int	skipBytes(int n)

Methods inherited from class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Field Details

array

public byte[] array

The array backing the input stream.

offset

public int offset

The first valid entry.

length

public int length

The number of valid bytes in array starting from offset.

Constructor Details

FastByteArrayInputStream

public FastByteArrayInputStream(byte[] array,
 int offset,
 int length)

Creates a new array input stream using a given array fragment.

Parameters:

array - the backing array.

offset - the first valid entry of the array.

length - the number of valid bytes.

FastByteArrayInputStream

public FastByteArrayInputStream(byte[] array)

Creates a new array input stream using a given array.

Parameters:

array - the backing array.

Method Details

markSupported

public boolean markSupported()

Overrides:

markSupported in class InputStream

reset

public void reset()

Overrides:

reset in class InputStream

close

public void close()

Closing a fast byte array input stream has no effect.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface ObjectInput

Overrides:

close in class InputStream

mark

public void mark(int dummy)

Overrides:

mark in class InputStream

available

public int available()

Specified by:

available in interface ObjectInput

Overrides:

available in class InputStream

skip

public long skip(long n)

Specified by:

skip in interface ObjectInput

Overrides:

skip in class InputStream

read

public int read()

Specified by:

read in interface ObjectInput

Specified by:

read in class InputStream

read

public int read(byte[] b,
 int offset,
 int length)

Reads bytes from this byte-array input stream as specified in InputStream.read(byte[], int, int). Note that the implementation given in ByteArrayInputStream.read(byte[], int, int) will return -1 on a zero-length read at EOF, contrarily to the specification. We won't.

Specified by:

read in interface ObjectInput

Overrides:

read in class InputStream

position

public long position()

Description copied from interface: MeasurableStream

Returns the current position in this stream (optional operation).

Usually, the position is just the number of bytes read or written since the stream was opened, but in the case of a RepositionableStream it represent the current position.

Specified by:

position in interface MeasurableStream

Specified by:

position in interface RepositionableStream

Returns:

the current stream position.

position

public void position(long newPosition)

Description copied from interface: RepositionableStream

Sets the current stream position.

Specified by:

position in interface RepositionableStream

Parameters:

newPosition - the new stream position.

length

public long length()

Description copied from interface: MeasurableStream

Returns the overall length of this stream (optional operation). In most cases, this will require the stream to perform some extra action, possibly changing the state of the input stream itself (typically, reading all the bytes up to the end, or flushing on output stream). Implementing classes should always document what state will the input stream be in after calling this method, and which kind of exception could be thrown.

Specified by:

length in interface MeasurableStream

read

public int read(byte[] b)

Specified by:

read in interface ObjectInput

Overrides:

read in class InputStream

peek

public int peek()

readFully

public void readFully(byte[] b)

Specified by:

readFully in interface DataInput

readFully

public void readFully(byte[] b,
 int off,
 int len)

Specified by:

readFully in interface DataInput

skipBytes

public int skipBytes(int n)

Specified by:

skipBytes in interface DataInput

readBoolean

public boolean readBoolean()

Specified by:

readBoolean in interface DataInput

readByte

public byte readByte()

Specified by:

readByte in interface DataInput

readUnsignedByte

public int readUnsignedByte()

Specified by:

readUnsignedByte in interface DataInput

readShort

public short readShort()

Specified by:

readShort in interface DataInput

readUnsignedShort

public int readUnsignedShort()

Specified by:

readUnsignedShort in interface DataInput

readChar

public char readChar()

Specified by:

readChar in interface DataInput

readInt

public int readInt()

Specified by:

readInt in interface DataInput

readLong

public long readLong()

Specified by:

readLong in interface DataInput

readFloat

public float readFloat()

Specified by:

readFloat in interface DataInput

readDouble

public double readDouble()

Specified by:

readDouble in interface DataInput

readLine

@Deprecated
public String readLine()

Deprecated.

Specified by:

readLine in interface DataInput

readUTF

public String readUTF()
               throws UTFDataFormatException

Specified by:

readUTF in interface DataInput

Throws:

UTFDataFormatException

readObject

public Object readObject()
                  throws ClassNotFoundException,
IOException

not efficient! Only added to support custom Externalizable

Specified by:

readObject in interface ObjectInput

Throws:

ClassNotFoundException

IOException