public abstract class ByteBufferIndexInput extends IndexInput implements RandomAccessInput
Because Java's ByteBuffer uses an int to address the values, it's necessary to access a file greater Integer.MAX_VALUE in size using multiple byte buffers.
For efficiency, this class requires that the buffers
are a power-of-two (chunkSizePower
).
Modifier and Type | Class and Description |
---|---|
(package private) static class |
ByteBufferIndexInput.MultiBufferImpl
This class adds offset support to ByteBufferIndexInput, which is needed for slices.
|
(package private) static class |
ByteBufferIndexInput.SingleBufferImpl
Optimization of ByteBufferIndexInput for when there is only one buffer
|
Modifier and Type | Field and Description |
---|---|
protected java.nio.ByteBuffer[] |
buffers |
protected long |
chunkSizeMask |
protected int |
chunkSizePower |
protected java.nio.ByteBuffer |
curBuf |
protected int |
curBufIndex |
protected ByteBufferGuard |
guard |
protected boolean |
isClone |
protected long |
length |
Constructor and Description |
---|
ByteBufferIndexInput(java.lang.String resourceDescription,
java.nio.ByteBuffer[] buffers,
long length,
int chunkSizePower,
ByteBufferGuard guard) |
Modifier and Type | Method and Description |
---|---|
private java.nio.ByteBuffer[] |
buildSlice(java.nio.ByteBuffer[] buffers,
long offset,
long length)
Returns a sliced view from a set of already-existing buffers:
the last buffer's limit() will be correct, but
you must deal with offset separately (the first buffer will not be adjusted)
|
protected ByteBufferIndexInput |
buildSlice(java.lang.String sliceDescription,
long offset,
long length)
Builds the actual sliced IndexInput (may apply extra offset in subclasses).
|
ByteBufferIndexInput |
clone()
Returns a clone of this stream.
|
void |
close()
Closes the stream to further operations.
|
long |
getFilePointer()
Returns the current position in this file, where the next read will
occur.
|
long |
length()
The number of bytes in the file.
|
protected ByteBufferIndexInput |
newCloneInstance(java.lang.String newResourceDescription,
java.nio.ByteBuffer[] newBuffers,
int offset,
long length)
Factory method that creates a suitable implementation of this class for the given ByteBuffers.
|
static ByteBufferIndexInput |
newInstance(java.lang.String resourceDescription,
java.nio.ByteBuffer[] buffers,
long length,
int chunkSizePower,
ByteBufferGuard guard) |
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.
|
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
|
short |
readShort()
Reads two bytes and returns a short.
|
short |
readShort(long pos)
Reads a short at the given position in the file
|
void |
seek(long pos)
Sets current position in this file, where the next read will occur.
|
private void |
setPos(long pos,
int bi) |
ByteBufferIndexInput |
slice(java.lang.String sliceDescription,
long offset,
long length)
Creates a slice of this index input, with the given description, offset, and length.
|
private void |
unsetBuffers()
Called to remove all references to byte buffers, so we can throw AlreadyClosed on NPE.
|
getFullSliceDescription, randomAccessSlice, toString
readBytes, readMapOfStrings, readSetOfStrings, readString, readVInt, readVLong, readZInt, readZLong, skipBytes
protected final long length
protected final long chunkSizeMask
protected final int chunkSizePower
protected final ByteBufferGuard guard
protected java.nio.ByteBuffer[] buffers
protected int curBufIndex
protected java.nio.ByteBuffer curBuf
protected boolean isClone
ByteBufferIndexInput(java.lang.String resourceDescription, java.nio.ByteBuffer[] buffers, long length, int chunkSizePower, ByteBufferGuard guard)
public static ByteBufferIndexInput newInstance(java.lang.String resourceDescription, java.nio.ByteBuffer[] buffers, long length, int chunkSizePower, ByteBufferGuard guard)
public final byte readByte() throws java.io.IOException
DataInput
readByte
in class DataInput
java.io.IOException
DataOutput.writeByte(byte)
public final void readBytes(byte[] b, int offset, int len) throws java.io.IOException
DataInput
readBytes
in class DataInput
b
- the array to read bytes intooffset
- the offset in the array to start storing byteslen
- the number of bytes to readjava.io.IOException
DataOutput.writeBytes(byte[],int)
public final short readShort() throws java.io.IOException
DataInput
readShort
in class DataInput
java.io.IOException
DataOutput.writeByte(byte)
public final int readInt() throws java.io.IOException
DataInput
readInt
in class DataInput
java.io.IOException
DataOutput.writeInt(int)
public final long readLong() throws java.io.IOException
DataInput
readLong
in class DataInput
java.io.IOException
DataOutput.writeLong(long)
public long getFilePointer()
IndexInput
getFilePointer
in class IndexInput
IndexInput.seek(long)
public void seek(long pos) throws java.io.IOException
IndexInput
EOFException
and then the
stream is in an undetermined state.seek
in class IndexInput
java.io.IOException
IndexInput.getFilePointer()
public byte readByte(long pos) throws java.io.IOException
RandomAccessInput
readByte
in interface RandomAccessInput
java.io.IOException
DataInput.readByte()
private void setPos(long pos, int bi) throws java.io.IOException
java.io.IOException
public short readShort(long pos) throws java.io.IOException
RandomAccessInput
readShort
in interface RandomAccessInput
java.io.IOException
DataInput.readShort()
public int readInt(long pos) throws java.io.IOException
RandomAccessInput
readInt
in interface RandomAccessInput
java.io.IOException
DataInput.readInt()
public long readLong(long pos) throws java.io.IOException
RandomAccessInput
readLong
in interface RandomAccessInput
java.io.IOException
DataInput.readLong()
public final long length()
IndexInput
length
in class IndexInput
public final ByteBufferIndexInput clone()
IndexInput
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
IndexInput
s, 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.
clone
in class IndexInput
public final ByteBufferIndexInput slice(java.lang.String sliceDescription, long offset, long length)
slice
in class IndexInput
protected ByteBufferIndexInput buildSlice(java.lang.String sliceDescription, long offset, long length)
protected ByteBufferIndexInput newCloneInstance(java.lang.String newResourceDescription, java.nio.ByteBuffer[] newBuffers, int offset, long length)
private java.nio.ByteBuffer[] buildSlice(java.nio.ByteBuffer[] buffers, long offset, long length)
public final void close() throws java.io.IOException
IndexInput
close
in interface java.io.Closeable
close
in interface java.lang.AutoCloseable
close
in class IndexInput
java.io.IOException
private void unsetBuffers()