Package org.apache.lucene.store

Class ByteBuffersIndexInput

java.lang.Object

org.apache.lucene.store.DataInput

org.apache.lucene.store.IndexInput

org.apache.lucene.store.ByteBuffersIndexInput

All Implemented Interfaces:

Closeable, AutoCloseable, Cloneable, RandomAccessInput

public final class ByteBuffersIndexInput
extends IndexInput
implements RandomAccessInput

An IndexInput implementing RandomAccessInput and backed by a ByteBuffersDataInput.

Field Summary

Fields

Modifier and Type	Field	Description
private ByteBuffersDataInput	in

Constructor Summary

Constructors

Constructor	Description
ByteBuffersIndexInput(ByteBuffersDataInput in, String resourceDescription)

Method Summary

Modifier and Type	Method	Description
IndexInput	clone()	Returns a clone of this stream.
void	close()	Closes the stream to further operations.
private void	ensureOpen()
long	getFilePointer()	Returns the current position in this file, where the next read will occur.
long	length()	The number of bytes in the file.
RandomAccessInput	randomAccessSlice(long offset, long length)	Creates a random-access slice of this index input, with the given offset and length.
byte	readByte()	Reads and returns a single byte.
byte	readByte(long pos)	Reads a byte at the given position in the file
void	readBytes(byte[] b, int offset, int len)	Reads a specified number of bytes into an array at the specified offset.
void	readBytes(byte[] b, int offset, int len, boolean useBuffer)	Reads a specified number of bytes into an array at the specified offset with control over whether the read should be buffered (callers who have their own buffer should pass in "false" for useBuffer).
int	readInt()	Reads four bytes and returns an int.
int	readInt(long pos)	Reads an integer at the given position in the file
long	readLong()	Reads eight bytes and returns a long.
long	readLong(long pos)	Reads a long at the given position in the file
Map<String,String>	readMapOfStrings()	Reads a Map<String,String> previously written with DataOutput.writeMapOfStrings(Map).
Set<String>	readSetOfStrings()	Reads a Set<String> previously written with DataOutput.writeSetOfStrings(Set).
short	readShort()	Reads two bytes and returns a short.
short	readShort(long pos)	Reads a short at the given position in the file
String	readString()	Reads a string.
int	readVInt()	Reads an int stored in variable-length format.
long	readVLong()	Reads a long stored in variable-length format.
int	readZInt()	Read a zig-zag-encoded variable-length integer.
long	readZLong()	Read a zig-zag-encoded variable-length integer.
void	seek(long pos)	Sets current position in this file, where the next read will occur.
void	skipBytes(long numBytes)	Skip over numBytes bytes.
ByteBuffersIndexInput	slice(String sliceDescription, long offset, long length)	Creates a slice of this index input, with the given description, offset, and length.

Methods inherited from class org.apache.lucene.store.IndexInput

getFullSliceDescription, toString

Methods inherited from class org.apache.lucene.store.DataInput

readLELongs

Methods inherited from class java.lang.Object

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

Field Details

in

private ByteBuffersDataInput in

Constructor Details

ByteBuffersIndexInput

public ByteBuffersIndexInput(ByteBuffersDataInput in,
 String resourceDescription)

Method Details

close

public void close()
           throws IOException

Description copied from class: IndexInput

Closes the stream to further operations.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in class IndexInput

Throws:

IOException

getFilePointer

public long getFilePointer()

Description copied from class: IndexInput

Returns the current position in this file, where the next read will occur.

Specified by:

getFilePointer in class IndexInput

See Also:

• IndexInput.seek(long)

seek

public void seek(long pos)
          throws IOException

Description copied from class: IndexInput

Sets current position in this file, where the next read will occur. If this is beyond the end of the file then this will throw EOFException and then the stream is in an undetermined state.

Specified by:

seek in class IndexInput

Throws:

IOException

See Also:

• IndexInput.getFilePointer()

length

public long length()

Description copied from class: IndexInput

The number of bytes in the file.

Specified by:

length in class IndexInput

slice

public ByteBuffersIndexInput slice(String sliceDescription,
 long offset,
 long length)
                            throws IOException

Description copied from class: IndexInput

Creates a slice of this index input, with the given description, offset, and length. The slice is sought to the beginning.

Specified by:

slice in class IndexInput

Throws:

IOException

readByte

public byte readByte()
              throws IOException

Description copied from class: DataInput

Reads and returns a single byte.

Specified by:

readByte in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeByte(byte)

readBytes

public void readBytes(byte[] b,
 int offset,
 int len)
               throws IOException

Description copied from class: DataInput

Reads a specified number of bytes into an array at the specified offset.

Specified by:

readBytes in class DataInput

Parameters:

b - the array to read bytes into

offset - the offset in the array to start storing bytes

len - the number of bytes to read

Throws:

IOException

See Also:

• DataOutput.writeBytes(byte[],int)

randomAccessSlice

public RandomAccessInput randomAccessSlice(long offset,
 long length)
                                    throws IOException

Description copied from class: IndexInput

Creates a random-access slice of this index input, with the given offset and length.

The default implementation calls IndexInput.slice(java.lang.String, long, long), and it doesn't support random access, it implements absolute reads as seek+read.

Overrides:

randomAccessSlice in class IndexInput

Throws:

IOException

readBytes

public void readBytes(byte[] b,
 int offset,
 int len,
 boolean useBuffer)
               throws IOException

Description copied from class: DataInput

Reads a specified number of bytes into an array at the specified offset with control over whether the read should be buffered (callers who have their own buffer should pass in "false" for useBuffer). Currently only BufferedIndexInput respects this parameter.

Overrides:

readBytes in class DataInput

Parameters:

b - the array to read bytes into

offset - the offset in the array to start storing bytes

len - the number of bytes to read

useBuffer - set to false if the caller will handle buffering.

Throws:

IOException

See Also:

• DataOutput.writeBytes(byte[],int)

readShort

public short readShort()
                throws IOException

Description copied from class: DataInput

Reads two bytes and returns a short.

Overrides:

readShort in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeByte(byte)

readInt

public int readInt()
            throws IOException

Description copied from class: DataInput

Reads four bytes and returns an int.

Overrides:

readInt in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeInt(int)

readVInt

public int readVInt()
             throws IOException

Description copied from class: DataInput

Reads an int stored in variable-length format. Reads between one and five bytes. Smaller values take fewer bytes. Negative numbers are supported, but should be avoided.

The format is described further in DataOutput.writeVInt(int).

Overrides:

readVInt in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeVInt(int)

readZInt

public int readZInt()
             throws IOException

Description copied from class: DataInput

Read a zig-zag-encoded variable-length integer.

Overrides:

readZInt in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeZInt(int)

readLong

public long readLong()
              throws IOException

Description copied from class: DataInput

Reads eight bytes and returns a long.

Overrides:

readLong in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeLong(long)

readVLong

public long readVLong()
               throws IOException

Description copied from class: DataInput

Reads a long stored in variable-length format. Reads between one and nine bytes. Smaller values take fewer bytes. Negative numbers are not supported.

The format is described further in DataOutput.writeVInt(int).

Overrides:

readVLong in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeVLong(long)

readZLong

public long readZLong()
               throws IOException

Description copied from class: DataInput

Read a zig-zag-encoded variable-length integer. Reads between one and ten bytes.

Overrides:

readZLong in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeZLong(long)

readString

public String readString()
                  throws IOException

Description copied from class: DataInput

Reads a string.

Overrides:

readString in class DataInput

Throws:

IOException

See Also:

• DataOutput.writeString(String)

readMapOfStrings

public Map<String,String> readMapOfStrings()
                                    throws IOException

Description copied from class: DataInput

Reads a Map<String,String> previously written with DataOutput.writeMapOfStrings(Map).

Overrides:

readMapOfStrings in class DataInput

Returns:

An immutable map containing the written contents.

Throws:

IOException

readSetOfStrings

public Set<String> readSetOfStrings()
                             throws IOException

Description copied from class: DataInput

Reads a Set<String> previously written with DataOutput.writeSetOfStrings(Set).

Overrides:

readSetOfStrings in class DataInput

Returns:

An immutable set containing the written contents.

Throws:

IOException

skipBytes

public void skipBytes(long numBytes)
               throws IOException

Description copied from class: DataInput

Skip over numBytes bytes. The contract on this method is that it should have the same behavior as reading the same number of bytes into a buffer and discarding its content. Negative values of numBytes are not supported.

Overrides:

skipBytes in class DataInput

Throws:

IOException

readByte

public byte readByte(long pos)
              throws IOException

Description copied from interface: RandomAccessInput

Reads a byte at the given position in the file

Specified by:

readByte in interface RandomAccessInput

Throws:

IOException

See Also:

• DataInput.readByte()

readShort

public short readShort(long pos)
                throws IOException

Description copied from interface: RandomAccessInput

Reads a short at the given position in the file

Specified by:

readShort in interface RandomAccessInput

Throws:

IOException

See Also:

• DataInput.readShort()

readInt

public int readInt(long pos)
            throws IOException

Description copied from interface: RandomAccessInput

Reads an integer at the given position in the file

Specified by:

readInt in interface RandomAccessInput

Throws:

IOException

See Also:

• DataInput.readInt()

readLong

public long readLong(long pos)
              throws IOException

Description copied from interface: RandomAccessInput

Reads a long at the given position in the file

Specified by:

readLong in interface RandomAccessInput

Throws:

IOException

See Also:

• DataInput.readLong()

clone

public IndexInput clone()

Description copied from class: IndexInput

Returns a clone of this stream.

Clones of a stream access the same data, and are positioned at the same point as the stream they were cloned from.

Expert: Subclasses must ensure that clones may be positioned at different points in the input from each other and from the stream they were cloned from.

Warning: Lucene never closes cloned IndexInputs, it will only call IndexInput.close() on the original object.

If you access the cloned IndexInput after closing the original object, any readXXX methods will throw AlreadyClosedException.

This method is NOT thread safe, so if the current IndexInput is being used by one thread while clone is called by another, disaster could strike.

Overrides:

clone in class IndexInput

ensureOpen

private void ensureOpen()