Package org.apache.lucene.codecs

Class TermVectorsWriter

java.lang.Object
org.apache.lucene.codecs.TermVectorsWriter
All Implemented Interfaces:
Closeable, AutoCloseable, Accountable
Direct Known Subclasses:
Lucene90CompressingTermVectorsWriter
public abstract class TermVectorsWriter extends Object implements Closeable, Accountable
Codec API for writing term vectors:
  1. For every document, startDocument(int) is called, informing the Codec how many fields will be written.
  2. startField(FieldInfo, int, boolean, boolean, boolean) is called for each field in the document, informing the codec how many terms will be written for that field, and whether or not positions, offsets, or payloads are enabled.
  3. Within each field, startTerm(BytesRef, int) is called for each term.
  4. If offsets and/or positions are enabled, then addPosition(int, int, int, BytesRef) will be called for each term occurrence.
  5. After all documents have been written, finish(int) is called for verification/sanity-checks.
  6. Finally the writer is closed (close())
WARNING: This API is experimental and might change in incompatible ways in the next release.

  • Field Summary

    Fields inherited from interface org.apache.lucene.util.Accountable

    NULL_ACCOUNTABLE

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    TermVectorsWriter()
    Sole constructor.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected final void
    addAllDocVectors(Fields vectors, MergeState mergeState)
    Safe (but, slowish) default method to write every vector field in the document.
    abstract void
    addPosition(int position, int startOffset, int endOffset, BytesRef payload)
    Adds a term position and offsets
    void
    addProx(int numProx, DataInput positions, DataInput offsets)
    Called by IndexWriter when writing new segments.
    abstract void
    close()
     
    abstract void
    finish(int numDocs)
    Called before close(), passing in the number of documents that were written.
    void
    finishDocument()
    Called after a doc and all its fields have been added.
    void
    finishField()
    Called after a field and all its terms have been added.
    void
    finishTerm()
    Called after a term and all its positions have been added.
    int
    merge(MergeState mergeState)
    Merges in the term vectors from the readers in mergeState.
    abstract void
    startDocument(int numVectorFields)
    Called before writing the term vectors of the document.
    abstract void
    startField(FieldInfo info, int numTerms, boolean positions, boolean offsets, boolean payloads)
    Called before writing the terms of the field.
    abstract void
    startTerm(BytesRef term, int freq)
    Adds a term and its term frequency freq.

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface org.apache.lucene.util.Accountable

    getChildResources, ramBytesUsed

  • Constructor Details

    • TermVectorsWriter

      protected TermVectorsWriter()
      Sole constructor. (For invocation by subclass constructors, typically implicit.)

  • Method Details

    • startDocument

      public abstract void startDocument(int numVectorFields) throws IOException
      Called before writing the term vectors of the document. startField(FieldInfo, int, boolean, boolean, boolean) will be called numVectorFields times. Note that if term vectors are enabled, this is called even if the document has no vector fields, in this case numVectorFields will be zero.
      Throws:
      IOException

    • finishDocument

      public void finishDocument() throws IOException
      Called after a doc and all its fields have been added.
      Throws:
      IOException

    • startField

      public abstract void startField(FieldInfo info, int numTerms, boolean positions, boolean offsets, boolean payloads) throws IOException
      Called before writing the terms of the field. startTerm(BytesRef, int) will be called numTerms times.
      Throws:
      IOException

    • finishField

      public void finishField() throws IOException
      Called after a field and all its terms have been added.
      Throws:
      IOException

    • startTerm

      public abstract void startTerm(BytesRef term, int freq) throws IOException
      Adds a term and its term frequency freq. If this field has positions and/or offsets enabled, then addPosition(int, int, int, BytesRef) will be called freq times respectively.
      Throws:
      IOException

    • finishTerm

      public void finishTerm() throws IOException
      Called after a term and all its positions have been added.
      Throws:
      IOException

    • addPosition

      public abstract void addPosition(int position, int startOffset, int endOffset, BytesRef payload) throws IOException
      Adds a term position and offsets
      Throws:
      IOException

    • finish

      public abstract void finish(int numDocs) throws IOException
      Called before close(), passing in the number of documents that were written. Note that this is intentionally redundant (equivalent to the number of calls to startDocument(int), but a Codec should check that this is the case to detect the JRE bug described in LUCENE-1282.
      Throws:
      IOException

    • addProx

      public void addProx(int numProx, DataInput positions, DataInput offsets) throws IOException
      Called by IndexWriter when writing new segments.

      This is an expert API that allows the codec to consume positions and offsets directly from the indexer.

      The default implementation calls addPosition(int, int, int, BytesRef), but subclasses can override this if they want to efficiently write all the positions, then all the offsets, for example.

      NOTE: This API is extremely expert and subject to change or removal!!!

      Throws:
      IOException
      NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

    • merge

      public int merge(MergeState mergeState) throws IOException
      Merges in the term vectors from the readers in mergeState. The default implementation skips over deleted documents, and uses startDocument(int), startField(FieldInfo, int, boolean, boolean, boolean), startTerm(BytesRef, int), addPosition(int, int, int, BytesRef), and finish(int), returning the number of documents that were written. Implementations can override this method for more sophisticated merging (bulk-byte copying, etc).
      Throws:
      IOException

    • addAllDocVectors

      protected final void addAllDocVectors(Fields vectors, MergeState mergeState) throws IOException
      Safe (but, slowish) default method to write every vector field in the document.
      Throws:
      IOException

    • close

      public abstract void close() throws IOException
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Throws:
      IOException