Module org.apache.arrow.vector
Package org.apache.arrow.vector

Class NullVector

java.lang.Object
org.apache.arrow.vector.NullVector
All Implemented Interfaces:
Closeable, AutoCloseable, Iterable<ValueVector>, FieldVector, ValueIterableVector<Object>, ValueVector
Direct Known Subclasses:
ZeroVector
public class NullVector extends Object implements FieldVector, ValueIterableVector<Object>
A null type vector.

  • Field Details

    • field

      protected Field field

  • Constructor Details

    • NullVector

      public NullVector(String name)
      Instantiate a NullVector.
      Parameters:
      name - name of the vector

    • NullVector

      public NullVector(String name, int valueCount)
      Instantiate a NullVector with the given number of values.
      Parameters:
      name - name of the vector
      valueCount - number of values (i.e., nulls) in this vector.

    • NullVector

      public NullVector(String name, FieldType fieldType)
      Instantiate a NullVector.
      Parameters:
      name - name of the vector
      fieldType - type of Field materialized by this vector.

    • NullVector

      public NullVector(Field field)
      Instantiate a NullVector.
      Parameters:
      field - field materialized by this vector.

    • NullVector

      public NullVector(Field field, int valueCount)
      Instantiate a NullVector with the given number of values.
      Parameters:
      field - field materialized by this vector.
      valueCount - number of values (i.e., nulls) in this vector.

    • NullVector

      @Deprecated public NullVector()
      Deprecated.

  • Method Details

    • close

      public void close()
      Description copied from interface: ValueVector
      Alternative to clear(). Allows use as an AutoCloseable in try-with-resources.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface ValueVector

    • clear

      public void clear()
      Description copied from interface: ValueVector
      Release any owned ArrowBuf and reset the ValueVector to the initial state. If the vector has any child vectors, they will also be cleared.
      Specified by:
      clear in interface ValueVector

    • reset

      public void reset()
      Description copied from interface: ValueVector
      Reset the ValueVector to the initial state without releasing any owned ArrowBuf. Buffer capacities will remain unchanged and any previous data will be zeroed out. This includes buffers for data, validity, offset, etc. If the vector has any child vectors, they will also be reset.
      Specified by:
      reset in interface ValueVector

    • getField

      public Field getField()
      Description copied from interface: ValueVector
      Get information about how this field is materialized.
      Specified by:
      getField in interface ValueVector
      Returns:
      the field corresponding to this vector

    • getMinorType

      public Types.MinorType getMinorType()
      Specified by:
      getMinorType in interface ValueVector

    • getTransferPair

      public TransferPair getTransferPair(BufferAllocator allocator)
      Description copied from interface: ValueVector
      To transfer quota responsibility.
      Specified by:
      getTransferPair in interface ValueVector
      Parameters:
      allocator - the target allocator
      Returns:
      a transfer pair, creating a new target vector of the same type.

    • iterator

      public Iterator<ValueVector> iterator()
      Specified by:
      iterator in interface Iterable<ValueVector>

    • getBufferSize

      public int getBufferSize()
      Description copied from interface: ValueVector
      Get the number of bytes used by this vector.
      Specified by:
      getBufferSize in interface ValueVector
      Returns:
      the number of bytes that is used by this vector instance.

    • getBufferSizeFor

      public int getBufferSizeFor(int valueCount)
      Description copied from interface: ValueVector
      Returns the number of bytes that is used by this vector if it holds the given number of values. The result will be the same as if setValueCount() were called, followed by calling getBufferSize(), but without any of the closing side-effects that setValueCount() implies wrt finishing off the population of a vector. Some operations might wish to use this to determine how much memory has been used by a vector so far, even though it is not finished being populated.
      Specified by:
      getBufferSizeFor in interface ValueVector
      Parameters:
      valueCount - the number of values to assume this vector contains
      Returns:
      the buffer size if this vector is holding valueCount values

    • getBuffers

      public ArrowBuf[] getBuffers(boolean clear)
      Description copied from interface: ValueVector
      Return the underlying buffers associated with this vector. Note that this doesn't impact the reference counts for this buffer so it only should be used for in-context access. Also note that this buffer changes regularly thus external classes shouldn't hold a reference to it (unless they change it).
      Specified by:
      getBuffers in interface ValueVector
      Parameters:
      clear - Whether to clear vector before returning; the buffers will still be refcounted; but the returned array will be the only reference to them
      Returns:
      The underlying buffers that is used by this vector instance.

    • allocateNew

      public void allocateNew() throws OutOfMemoryException
      Description copied from interface: ValueVector
      Allocate new buffers. ValueVector implements logic to determine how much to allocate.
      Specified by:
      allocateNew in interface ValueVector
      Throws:
      OutOfMemoryException - Thrown if no memory can be allocated.

    • allocateNewSafe

      public boolean allocateNewSafe()
      Description copied from interface: ValueVector
      Allocates new buffers. ValueVector implements logic to determine how much to allocate.
      Specified by:
      allocateNewSafe in interface ValueVector
      Returns:
      Returns true if allocation was successful.

    • reAlloc

      public void reAlloc()
      Description copied from interface: ValueVector
      Allocate new buffer with double capacity, and copy data into the new buffer. Replace vector's buffer with new buffer, and release old one
      Specified by:
      reAlloc in interface ValueVector

    • getAllocator

      public BufferAllocator getAllocator()
      Description copied from interface: ValueVector
      Get the allocator associated with the vector. CAVEAT: Some ValueVector subclasses (e.g. NullVector) do not require an allocator for data storage and may return null.
      Specified by:
      getAllocator in interface ValueVector
      Returns:
      Returns nullable allocator.

    • setInitialCapacity

      public void setInitialCapacity(int numRecords)
      Description copied from interface: ValueVector
      Set the initial record capacity.
      Specified by:
      setInitialCapacity in interface ValueVector
      Parameters:
      numRecords - the initial record capacity.

    • getValueCapacity

      public int getValueCapacity()
      Description copied from interface: ValueVector
      Returns the maximum number of values that can be stored in this vector instance.
      Specified by:
      getValueCapacity in interface ValueVector
      Returns:
      the maximum number of values that can be stored in this vector instance.

    • getTransferPair

      public TransferPair getTransferPair(String ref, BufferAllocator allocator)
      Description copied from interface: ValueVector
      To transfer quota responsibility.
      Specified by:
      getTransferPair in interface ValueVector
      Parameters:
      ref - the name of the vector
      allocator - the target allocator
      Returns:
      a transfer pair, creating a new target vector of the same type.

    • getTransferPair

      public TransferPair getTransferPair(Field field, BufferAllocator allocator)
      Description copied from interface: ValueVector
      To transfer quota responsibility.
      Specified by:
      getTransferPair in interface ValueVector
      Parameters:
      field - the Field object used by the target vector
      allocator - the target allocator
      Returns:
      a transfer pair, creating a new target vector of the same type.

    • getTransferPair

      public TransferPair getTransferPair(String ref, BufferAllocator allocator, CallBack callBack)
      Description copied from interface: ValueVector
      To transfer quota responsibility.
      Specified by:
      getTransferPair in interface ValueVector
      Parameters:
      ref - the name of the vector
      allocator - the target allocator
      callBack - A schema change callback.
      Returns:
      a transfer pair, creating a new target vector of the same type.

    • getTransferPair

      public TransferPair getTransferPair(Field field, BufferAllocator allocator, CallBack callBack)
      Description copied from interface: ValueVector
      To transfer quota responsibility.
      Specified by:
      getTransferPair in interface ValueVector
      Parameters:
      field - the Field object used by the target vector
      allocator - the target allocator
      callBack - A schema change callback.
      Returns:
      a transfer pair, creating a new target vector of the same type.

    • makeTransferPair

      public TransferPair makeTransferPair(ValueVector target)
      Description copied from interface: ValueVector
      Makes a new transfer pair used to transfer underlying buffers.
      Specified by:
      makeTransferPair in interface ValueVector
      Parameters:
      target - the target for the transfer
      Returns:
      a new transfer pair that is used to transfer underlying buffers into the target vector.

    • getReader

      public FieldReader getReader()
      Description copied from interface: ValueVector
      Get a reader for this vector.
      Specified by:
      getReader in interface ValueVector
      Returns:
      a field reader that supports reading values from this vector.

    • initializeChildrenFromFields

      public void initializeChildrenFromFields(List<Field> children)
      Description copied from interface: FieldVector
      Initializes the child vectors to be later loaded with loadBuffers.
      Specified by:
      initializeChildrenFromFields in interface FieldVector
      Parameters:
      children - the schema

    • getChildrenFromFields

      public List<FieldVector> getChildrenFromFields()
      Description copied from interface: FieldVector
      The returned list is the same size as the list passed to initializeChildrenFromFields.
      Specified by:
      getChildrenFromFields in interface FieldVector
      Returns:
      the children according to schema (empty for primitive types)

    • loadFieldBuffers

      public void loadFieldBuffers(ArrowFieldNode fieldNode, List<ArrowBuf> ownBuffers)
      Description copied from interface: FieldVector
      Loads data in the vectors. (ownBuffers must be the same size as getFieldVectors())
      Specified by:
      loadFieldBuffers in interface FieldVector
      Parameters:
      fieldNode - the fieldNode
      ownBuffers - the buffers for this Field (own buffers only, children not included)

    • getFieldBuffers

      public List<ArrowBuf> getFieldBuffers()
      Description copied from interface: FieldVector
      Get the buffers of the fields, (same size as getFieldVectors() since it is their content).
      Specified by:
      getFieldBuffers in interface FieldVector
      Returns:
      the buffers containing the data for this vector (ready for reading)

    • getFieldInnerVectors

      @Deprecated public List<BufferBacked> getFieldInnerVectors()
      Deprecated.
      This API will be removed as the current implementations no longer support inner vectors.
      Get the inner vectors.
      Specified by:
      getFieldInnerVectors in interface FieldVector
      Returns:
      the inner vectors for this field as defined by the TypeLayout

    • getValidityBufferAddress

      public long getValidityBufferAddress()
      Description copied from interface: FieldVector
      Gets the starting address of the underlying buffer associated with validity vector.
      Specified by:
      getValidityBufferAddress in interface FieldVector
      Returns:
      buffer address

    • getDataBufferAddress

      public long getDataBufferAddress()
      Description copied from interface: FieldVector
      Gets the starting address of the underlying buffer associated with data vector.
      Specified by:
      getDataBufferAddress in interface FieldVector
      Returns:
      buffer address

    • getOffsetBufferAddress

      public long getOffsetBufferAddress()
      Description copied from interface: FieldVector
      Gets the starting address of the underlying buffer associated with offset vector.
      Specified by:
      getOffsetBufferAddress in interface FieldVector
      Returns:
      buffer address

    • getValidityBuffer

      public ArrowBuf getValidityBuffer()
      Description copied from interface: ValueVector
      Gets the underlying buffer associated with validity vector.
      Specified by:
      getValidityBuffer in interface ValueVector
      Returns:
      buffer

    • getDataBuffer

      public ArrowBuf getDataBuffer()
      Description copied from interface: ValueVector
      Gets the underlying buffer associated with data vector.
      Specified by:
      getDataBuffer in interface ValueVector
      Returns:
      buffer

    • getOffsetBuffer

      public ArrowBuf getOffsetBuffer()
      Description copied from interface: ValueVector
      Gets the underlying buffer associated with offset vector.
      Specified by:
      getOffsetBuffer in interface ValueVector
      Returns:
      buffer

    • getValueCount

      public int getValueCount()
      Description copied from interface: ValueVector
      Gets the number of values.
      Specified by:
      getValueCount in interface ValueVector
      Returns:
      number of values in the vector

    • setValueCount

      public void setValueCount(int valueCount)
      Description copied from interface: ValueVector
      Set number of values in the vector.
      Specified by:
      setValueCount in interface ValueVector

    • getObject

      public Object getObject(int index)
      Description copied from interface: ValueVector
      Get friendly type object from the vector.
      Specified by:
      getObject in interface ValueVector
      Parameters:
      index - index of object to get
      Returns:
      friendly type object, null if value is unset

    • getNullCount

      public int getNullCount()
      Description copied from interface: ValueVector
      Returns number of null elements in the vector.
      Specified by:
      getNullCount in interface ValueVector
      Returns:
      number of null elements

    • setNull

      public void setNull(int index)
      Set the element at the given index to null. In a NullVector, this is a no-op.
      Specified by:
      setNull in interface FieldVector
      Parameters:
      index - position of element

    • isNull

      public boolean isNull(int index)
      Description copied from interface: ValueVector
      Check whether an element in the vector is null.
      Specified by:
      isNull in interface ValueVector
      Parameters:
      index - index to check for null
      Returns:
      true if element is null

    • hashCode

      public int hashCode(int index)
      Description copied from interface: ValueVector
      Returns hashCode of element in index with the default hasher.
      Specified by:
      hashCode in interface ValueVector

    • hashCode

      public int hashCode(int index, ArrowBufHasher hasher)
      Description copied from interface: ValueVector
      Returns hashCode of element in index with the given hasher.
      Specified by:
      hashCode in interface ValueVector

    • accept

      public <OUT, IN> OUT accept(VectorVisitor<OUT,IN> visitor, IN value)
      Description copied from interface: ValueVector
      Accept a generic VectorVisitor and return the result.
      Specified by:
      accept in interface ValueVector
      Type Parameters:
      OUT - the output result type.
      IN - the input data together with visitor.

    • copyFrom

      public void copyFrom(int fromIndex, int thisIndex, ValueVector from)
      Description copied from interface: ValueVector
      Copy a cell value from a particular index in source vector to a particular position in this vector.
      Specified by:
      copyFrom in interface ValueVector
      Parameters:
      fromIndex - position to copy from in source vector
      thisIndex - position to copy to in this vector
      from - source vector

    • copyFromSafe

      public void copyFromSafe(int fromIndex, int thisIndex, ValueVector from)
      Description copied from interface: ValueVector
      Same as ValueVector.copyFrom(int, int, ValueVector) except that it handles the case when the capacity of the vector needs to be expanded before copy.
      Specified by:
      copyFromSafe in interface ValueVector
      Parameters:
      fromIndex - position to copy from in source vector
      thisIndex - position to copy to in this vector
      from - source vector

    • getName

      public String getName()
      Description copied from interface: ValueVector
      Gets the name of the vector.
      Specified by:
      getName in interface ValueVector
      Returns:
      the name of the vector.