com.facebook.presto.spi.block

Class VariableWidthCursor

java.lang.Object

com.facebook.presto.spi.block.VariableWidthCursor

All Implemented Interfaces:

BlockCursor

public class VariableWidthCursor
extends Object
implements BlockCursor

Constructor Summary

Constructors

Constructor and Description
VariableWidthCursor(VariableWidthCursor cursor)
VariableWidthCursor(VariableWidthType type, int positionCount, io.airlift.slice.Slice slice, int[] offsets)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	advanceNextPosition() Attempts to advance to the next position in this stream.
boolean	advanceToPosition(int newPosition) Attempts to advance to the requested position.
void	appendTo(BlockBuilder blockBuilder) Appends the value at the current position to the block builder.
int	compareTo(io.airlift.slice.Slice otherSlice, int otherOffset) Compares the value at the current position to the value at the other offset in the other slice.
VariableWidthCursor	duplicate() Creates a new cursor at the same position of as this cursor.
int	entrySize()
boolean	getBoolean() Gets the current value as a boolean.
double	getDouble() Gets the current value as a double.
long	getLong() Gets the current value as a long.
Object	getObjectValue(ConnectorSession session) Gets the current value as an Object.
int	getPosition() Returns the current position of this cursor.
Block	getRegionAndAdvance(int length) Creates a block view port starting at the next position and extending the specified length.
int	getRemainingPositions() Gets the number of positions remaining in this cursor.
Block	getSingleValueBlock() Gets the current value as a single element block.
io.airlift.slice.Slice	getSlice() Gets the current value as a Slice.
Type	getType() Gets the type of this cursor
int	hash() Calculates the hash code of the value at the current position.
boolean	isFinished() Returns true if the cursor has advanced beyond its last position.
boolean	isNull() Is the current value null?
boolean	isValid() Returns true if the current position of the cursor is valid; false if the cursor has not been advanced yet, or if the cursor has advanced beyond the last position.

Methods inherited from class java.lang.Object

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

Constructor Detail

VariableWidthCursor

public VariableWidthCursor(VariableWidthType type,
                   int positionCount,
                   io.airlift.slice.Slice slice,
                   int[] offsets)

VariableWidthCursor

public VariableWidthCursor(VariableWidthCursor cursor)

Method Detail

duplicate

public VariableWidthCursor duplicate()

Description copied from interface: BlockCursor

Creates a new cursor at the same position of as this cursor.

Specified by:

duplicate in interface BlockCursor

getType

public Type getType()

Description copied from interface: BlockCursor

Gets the type of this cursor

Specified by:

getType in interface BlockCursor

getRemainingPositions

public int getRemainingPositions()

Description copied from interface: BlockCursor

Gets the number of positions remaining in this cursor.

Specified by:

getRemainingPositions in interface BlockCursor

isValid

public boolean isValid()

Description copied from interface: BlockCursor

Returns true if the current position of the cursor is valid; false if the cursor has not been advanced yet, or if the cursor has advanced beyond the last position. INVARIANT 1: isValid is false if isFinished is true INVARIANT 2: all get* and data access methods will throw java.util.IllegalStateException while isValid is false

Specified by:

isValid in interface BlockCursor

isFinished

public boolean isFinished()

Description copied from interface: BlockCursor

Returns true if the cursor has advanced beyond its last position. INVARIANT 1: isFinished will only return true once advance* has returned false. INVARIANT 2: all get* and data access methods will throw java.util.IllegalStateException once isFinished is true

Specified by:

isFinished in interface BlockCursor

advanceNextPosition

public boolean advanceNextPosition()

Description copied from interface: BlockCursor

Attempts to advance to the next position in this stream.

Specified by:

advanceNextPosition in interface BlockCursor

advanceToPosition

public boolean advanceToPosition(int newPosition)

Description copied from interface: BlockCursor

Attempts to advance to the requested position.

Specified by:

advanceToPosition in interface BlockCursor

getRegionAndAdvance

public Block getRegionAndAdvance(int length)

Description copied from interface: BlockCursor

Creates a block view port starting at the next position and extending the specified length. If the length is greater than the remaining positions, the length wil be reduced. This method advances the cursor to the last position in the view port, so repeated calls to this method will result in distinct chunks covering all positions of the cursor.

For example, to get a sequence of regions with 1024 positions, use the following code:

Cursor cursor = ...;
 <p/>
  while (cursor.getRemainingPositions() > 0) {
     Block block = cursor.getRegionAndAdvance(1024);
     ...
  }
 

Specified by:

getRegionAndAdvance in interface BlockCursor

getPosition

public int getPosition()

Description copied from interface: BlockCursor

Returns the current position of this cursor.

Specified by:

getPosition in interface BlockCursor

getSingleValueBlock

public Block getSingleValueBlock()

Description copied from interface: BlockCursor

Gets the current value as a single element block.

Specified by:

getSingleValueBlock in interface BlockCursor

getBoolean

public boolean getBoolean()

Description copied from interface: BlockCursor

Gets the current value as a boolean.

Specified by:

getBoolean in interface BlockCursor

getLong

public long getLong()

Description copied from interface: BlockCursor

Gets the current value as a long.

Specified by:

getLong in interface BlockCursor

getDouble

public double getDouble()

Description copied from interface: BlockCursor

Gets the current value as a double.

Specified by:

getDouble in interface BlockCursor

getSlice

public io.airlift.slice.Slice getSlice()

Description copied from interface: BlockCursor

Gets the current value as a Slice.

Specified by:

getSlice in interface BlockCursor

getObjectValue

public Object getObjectValue(ConnectorSession session)

Description copied from interface: BlockCursor

Gets the current value as an Object.

Specified by:

getObjectValue in interface BlockCursor

isNull

public boolean isNull()

Description copied from interface: BlockCursor

Is the current value null?

Specified by:

isNull in interface BlockCursor

compareTo

public int compareTo(io.airlift.slice.Slice otherSlice,
            int otherOffset)

Description copied from interface: BlockCursor

Compares the value at the current position to the value at the other offset in the other slice.

Specified by:

compareTo in interface BlockCursor

hash

public int hash()

Description copied from interface: BlockCursor

Calculates the hash code of the value at the current position.

Specified by:

hash in interface BlockCursor

appendTo

public void appendTo(BlockBuilder blockBuilder)

Description copied from interface: BlockCursor

Appends the value at the current position to the block builder.

Specified by:

appendTo in interface BlockCursor

entrySize

public int entrySize()