Package org.apache.solr.legacy

Class LegacyNumericUtils

java.lang.Object
org.apache.solr.legacy.LegacyNumericUtils
@Deprecated public final class LegacyNumericUtils extends Object
Deprecated.
Please use PointValues instead.
This is a helper class to generate prefix-encoded representations for numerical values and supplies converters to represent float/double values as sortable integers/longs.

To quickly execute range queries in Apache Lucene, a range is divided recursively into multiple intervals for searching: The center of the range is searched only with the lowest possible precision in the trie, while the boundaries are matched more exactly. This reduces the number of terms dramatically.

This class generates terms to achieve this: First the numerical integer values need to be converted to bytes. For that integer values (32 bit or 64 bit) are made unsigned and the bits are converted to ASCII chars with each 7 bit. The resulting byte[] is sortable like the original integer value (even using UTF-8 sort order). Each value is also prefixed (in the first char) by the shift value (number of bits removed) used during encoding.

For easy usage, the trie algorithm is implemented for indexing inside LegacyNumericTokenStream that can index int, long , float, and double. For querying, LegacyNumericRangeQuery implements the query part for the same data types.

Since:
2.9, API changed non backwards-compliant in 4.0
NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

  • Field Details

  • Method Details

    • longToPrefixCoded

      public static void longToPrefixCoded(long val, int shift, org.apache.lucene.util.BytesRefBuilder bytes)
      Deprecated.
      Returns prefix coded bits after reducing the precision by shift bits. This is method is used by LegacyNumericTokenStream. After encoding, bytes.offset will always be 0.
      Parameters:
      val - the numeric value
      shift - how many bits to strip from the right
      bytes - will contain the encoded value

    • intToPrefixCoded

      public static void intToPrefixCoded(int val, int shift, org.apache.lucene.util.BytesRefBuilder bytes)
      Deprecated.
      Returns prefix coded bits after reducing the precision by shift bits. This is method is used by LegacyNumericTokenStream. After encoding, bytes.offset will always be 0.
      Parameters:
      val - the numeric value
      shift - how many bits to strip from the right
      bytes - will contain the encoded value

    • getPrefixCodedLongShift

      public static int getPrefixCodedLongShift(org.apache.lucene.util.BytesRef val)
      Deprecated.
      Returns the shift value from a prefix encoded long.
      Throws:
      NumberFormatException - if the supplied BytesRef is not correctly prefix encoded.

    • getPrefixCodedIntShift

      public static int getPrefixCodedIntShift(org.apache.lucene.util.BytesRef val)
      Deprecated.
      Returns the shift value from a prefix encoded int.
      Throws:
      NumberFormatException - if the supplied BytesRef is not correctly prefix encoded.

    • prefixCodedToLong

      public static long prefixCodedToLong(org.apache.lucene.util.BytesRef val)
      Deprecated.
      Returns a long from prefixCoded bytes. Rightmost bits will be zero for lower precision codes. This method can be used to decode a term's value.
      Throws:
      NumberFormatException - if the supplied BytesRef is not correctly prefix encoded.
      See Also:

    • prefixCodedToInt

      public static int prefixCodedToInt(org.apache.lucene.util.BytesRef val)
      Deprecated.
      Returns an int from prefixCoded bytes. Rightmost bits will be zero for lower precision codes. This method can be used to decode a term's value.
      Throws:
      NumberFormatException - if the supplied BytesRef is not correctly prefix encoded.
      See Also:

    • splitLongRange

      public static void splitLongRange(LegacyNumericUtils.LongRangeBuilder builder, int precisionStep, long minBound, long maxBound)
      Deprecated.
      Splits a long range recursively. You may implement a builder that adds clauses to a BooleanQuery for each call to its LegacyNumericUtils.LongRangeBuilder.addRange(BytesRef,BytesRef) method.

      This method is used by LegacyNumericRangeQuery.

    • splitIntRange

      public static void splitIntRange(LegacyNumericUtils.IntRangeBuilder builder, int precisionStep, int minBound, int maxBound)
      Deprecated.
      Splits an int range recursively. You may implement a builder that adds clauses to a BooleanQuery for each call to its LegacyNumericUtils.IntRangeBuilder.addRange(BytesRef,BytesRef) method.

      This method is used by LegacyNumericRangeQuery.

    • filterPrefixCodedLongs

      public static org.apache.lucene.index.TermsEnum filterPrefixCodedLongs(org.apache.lucene.index.TermsEnum termsEnum)
      Deprecated.
      Filters the given TermsEnum by accepting only prefix coded 64 bit terms with a shift value of 0.
      Parameters:
      termsEnum - the terms enum to filter
      Returns:
      a filtered TermsEnum that only returns prefix coded 64 bit terms with a shift value of 0.

    • filterPrefixCodedInts

      public static org.apache.lucene.index.TermsEnum filterPrefixCodedInts(org.apache.lucene.index.TermsEnum termsEnum)
      Deprecated.
      Filters the given TermsEnum by accepting only prefix coded 32 bit terms with a shift value of 0.
      Parameters:
      termsEnum - the terms enum to filter
      Returns:
      a filtered TermsEnum that only returns prefix coded 32 bit terms with a shift value of 0.

    • getMinInt

      public static Integer getMinInt(org.apache.lucene.index.Terms terms) throws IOException
      Deprecated.
      Returns the minimum int value indexed into this numeric field or null if no terms exist.
      Throws:
      IOException

    • getMaxInt

      public static Integer getMaxInt(org.apache.lucene.index.Terms terms) throws IOException
      Deprecated.
      Returns the maximum int value indexed into this numeric field or null if no terms exist.
      Throws:
      IOException

    • getMinLong

      public static Long getMinLong(org.apache.lucene.index.Terms terms) throws IOException
      Deprecated.
      Returns the minimum long value indexed into this numeric field or null if no terms exist.
      Throws:
      IOException

    • getMaxLong

      public static Long getMaxLong(org.apache.lucene.index.Terms terms) throws IOException
      Deprecated.
      Returns the maximum long value indexed into this numeric field or null if no terms exist.
      Throws:
      IOException