org.apache.lucene.index

Interface TermDocs

All Known Subinterfaces:

TermPositions

All Known Implementing Classes:

FilterIndexReader.FilterTermDocs, FilterIndexReader.FilterTermPositions, MultipleTermPositions

public interface TermDocs

TermDocs provides an interface for enumerating <document, frequency> pairs for a term.

The document portion names each document containing the term. Documents are indicated by number. The frequency portion gives the number of times the term occurred in each document.

The pairs are ordered by document number.

See Also:

IndexReader.termDocs()

Method Summary

Modifier and Type	Method and Description
void	close() Frees associated resources.
int	doc() Returns the current document number.
int	freq() Returns the frequency of the term within the current document.
boolean	next() Moves to the next pair in the enumeration.
int	read(int[] docs, int[] freqs) Attempts to read multiple entries from the enumeration, up to length of docs.
void	seek(Term term) Sets this to the data for a term.
void	seek(TermEnum termEnum) Sets this to the data for the current term in a TermEnum.
boolean	skipTo(int target) Skips entries to the first beyond the current whose document number is greater than or equal to target.

Method Detail

seek

void seek(Term term)
   throws java.io.IOException

Sets this to the data for a term. The enumeration is reset to the start of the data for this term.

Throws:

java.io.IOException

seek

void seek(TermEnum termEnum)
   throws java.io.IOException

Sets this to the data for the current term in a TermEnum. This may be optimized in some implementations.

Throws:

java.io.IOException

doc

int doc()

Returns the current document number.

This is invalid until next() is called for the first time.

freq

int freq()

Returns the frequency of the term within the current document.

This is invalid until next() is called for the first time.

next

boolean next()
      throws java.io.IOException

Moves to the next pair in the enumeration.

Returns true iff there is such a next pair in the enumeration.

Throws:

java.io.IOException

read

int read(int[] docs,
         int[] freqs)
  throws java.io.IOException

Attempts to read multiple entries from the enumeration, up to length of docs. Document numbers are stored in docs, and term frequencies are stored in freqs. The freqs array must be as long as the docs array.

Returns the number of entries read. Zero is only returned when the stream has been exhausted.

Throws:

java.io.IOException

skipTo

boolean skipTo(int target)
        throws java.io.IOException

Skips entries to the first beyond the current whose document number is greater than or equal to target.

Returns true iff there is such an entry.

Behaves as if written:

   boolean skipTo(int target) {
     do {
       if (!next())
             return false;
     } while (target > doc());
     return true;
   }
 

Some implementations are considerably more efficient than that.

Throws:

java.io.IOException

close

void close()
    throws java.io.IOException

Frees associated resources.

Throws:

java.io.IOException