Package it.unimi.dsi.fastutil.io

Class FastMultiByteArrayInputStream

java.lang.Object

java.io.InputStream

it.unimi.dsi.fastutil.io.MeasurableInputStream

it.unimi.dsi.fastutil.io.FastMultiByteArrayInputStream

All Implemented Interfaces:

MeasurableStream, RepositionableStream, Closeable, AutoCloseable

public class FastMultiByteArrayInputStream
extends MeasurableInputStream
implements RepositionableStream

Simple, fast and repositionable byte array input stream that multiplexes its content among several arrays. This class is significantly slower than FastByteArrayInputStream, but it can hold 256 PiB of data. The relevant constructor is FastMultiByteArrayInputStream(InputStream, long), which fetches a stream and loads it into a sequence of byte arrays.

Author:

Sebastiano Vigna, Paolo Boldi s

Field Summary

Fields

Modifier and Type	Field	Description
byte[][]	array	The array of arrays backing the input stream, plus an additional null entry.
byte[]	current	The current array.
long	length	The number of valid bytes in array.
static int	SLICE_BITS	The number of bits of an array slice index.
static int	SLICE_MASK	The mask to retrieve a slice offset.
static int	SLICE_SIZE	The maximum length of an array slice.

Constructor Summary

Constructors

Constructor	Description
FastMultiByteArrayInputStream(byte[] array)	Creates a new multi-array input stream using a given array.
FastMultiByteArrayInputStream(FastMultiByteArrayInputStream is)	Creates a new multi-array input stream sharing the backing arrays of another multi-array input stream.
FastMultiByteArrayInputStream(MeasurableInputStream is)	Creates a new multi-array input stream loading it from a measurable input stream.
FastMultiByteArrayInputStream(InputStream is, long size)	Creates a new multi-array input stream loading it from an input stream.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns the number of bytes that can be read (or skipped over) from this input stream without blocking.
void	close()	NOP.
long	length()	Returns the overall length of this stream (optional operation).
void	mark(int dummy)
boolean	markSupported()
long	position()	Returns the current stream position.
void	position(long newPosition)	Sets the current stream position.
int	read()
int	read(byte[] b, int offset, int length)
void	reset()
long	skip(long n)

Methods inherited from class java.io.InputStream

nullInputStream, read, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Field Details

SLICE_BITS

public static final int SLICE_BITS

The number of bits of an array slice index.

See Also:

Constant Field Values

SLICE_SIZE

public static final int SLICE_SIZE

The maximum length of an array slice.

See Also:

Constant Field Values

SLICE_MASK

public static final int SLICE_MASK

The mask to retrieve a slice offset.

See Also:

Constant Field Values

array

public byte[][] array

The array of arrays backing the input stream, plus an additional null entry.

current

public byte[] current

The current array.

length

public long length

The number of valid bytes in array.

Constructor Details

FastMultiByteArrayInputStream

public FastMultiByteArrayInputStream(MeasurableInputStream is) throws IOException

Creates a new multi-array input stream loading it from a measurable input stream.

Parameters:

is - the input stream that will fill the array.

Throws:

IOException

FastMultiByteArrayInputStream

public FastMultiByteArrayInputStream(InputStream is, long size) throws IOException

Creates a new multi-array input stream loading it from an input stream.

Parameters:

is - the input stream that will fill the array.

size - the number of bytes to be read from is.

Throws:

IOException

FastMultiByteArrayInputStream

public FastMultiByteArrayInputStream(FastMultiByteArrayInputStream is)

Creates a new multi-array input stream sharing the backing arrays of another multi-array input stream.

Parameters:

is - the multi-array input stream to replicate.

FastMultiByteArrayInputStream

public FastMultiByteArrayInputStream(byte[] array)

Creates a new multi-array input stream using a given array.

Parameters:

array - the backing array.

Method Details

available

public int available()

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

Note that this number may be smaller than the number of bytes actually available from the stream if this number exceeds Integer.MAX_VALUE.

Overrides:

available in class InputStream

Returns:

the minimum among the number of available bytes and Integer.MAX_VALUE.

skip

public long skip(long n)

Overrides:

skip in class InputStream

read

public int read()

Specified by:

read in class InputStream

read

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

Overrides:

read in class InputStream

position

public long position()

Description copied from interface: RepositionableStream

Returns the current stream 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() throws IOException

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

Throws:

IOException

close

public void close()

NOP.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

markSupported

public boolean markSupported()

Overrides:

markSupported in class InputStream

mark

public void mark(int dummy)

Overrides:

mark in class InputStream

reset

public void reset()

Overrides:

reset in class InputStream