FieldCache (Solr 7.1.0 API)

All Known Implementing Classes:

FieldCacheImpl
```
public interface FieldCache
```
Expert: Maintains caches of term values.
Created: May 19, 2004 11:13:14 AM

Since:

lucene 1.4

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

Nested Class Summary

Nested Classes
Modifier and Type	Interface and Description
`static class`	`FieldCache.CacheEntry` EXPERT: A unique Identifier/Description for each item in the FieldCache.
`static class`	`FieldCache.CreationPlaceholder` Placeholder indicating creation of this cache is currently in-progress.
`static interface`	`FieldCache.Parser` interface to all parsers.
`static class`	`FieldCache.PointParser` Base class for points parsers.

Field Summary

Fields
Modifier and Type	Field and Description
`static FieldCache`	`DEFAULT` Expert: The cache used internally by sorting and range query classes.
`static FieldCache.Parser`	`DOUBLE_POINT_PARSER` A parser instance for double values encoded by `NumericUtils`, e.g.
`static FieldCache.Parser`	`FLOAT_POINT_PARSER` A parser instance for float values encoded by `NumericUtils`, e.g.
`static FieldCache.Parser`	`INT_POINT_PARSER` A parser instance for int values encoded by `NumericUtils`, e.g.
`static BytesRef`	`INT32_TERM_PREFIX` Can be passed to `getDocTermOrds(org.apache.lucene.index.LeafReader, java.lang.String, org.apache.lucene.util.BytesRef)` to filter for 32-bit numeric terms
`static BytesRef`	`INT64_TERM_PREFIX` Can be passed to `getDocTermOrds(org.apache.lucene.index.LeafReader, java.lang.String, org.apache.lucene.util.BytesRef)` to filter for 64-bit numeric terms
`static FieldCache.Parser`	`LEGACY_DOUBLE_PARSER` Deprecated. Index with points and use `DOUBLE_POINT_PARSER` instead.
`static FieldCache.Parser`	`LEGACY_FLOAT_PARSER` Deprecated. Index with points and use `FLOAT_POINT_PARSER` instead.
`static FieldCache.Parser`	`LEGACY_INT_PARSER` Deprecated. Index with points and use `INT_POINT_PARSER` instead.
`static FieldCache.Parser`	`LEGACY_LONG_PARSER` Deprecated. Index with points and use `LONG_POINT_PARSER` instead.
`static FieldCache.Parser`	`LONG_POINT_PARSER` A parser instance for long values encoded by `NumericUtils`, e.g.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`FieldCache.CacheEntry[]`	`getCacheEntries()` EXPERT: Generates an array of CacheEntry objects representing all items currently in the FieldCache.
`Bits`	`getDocsWithField(LeafReader reader, String field, FieldCache.Parser parser)` Checks the internal cache for an appropriate entry, and if none is found, reads the terms/points in `field` and returns a bit set at the size of `reader.maxDoc()`, with turned on bits for each docid that does have a value for this field.
`SortedSetDocValues`	`getDocTermOrds(LeafReader reader, String field, BytesRef prefix)` Checks the internal cache for an appropriate entry, and if none is found, reads the term values in `field` and returns a `DocTermOrds` instance, providing a method to retrieve the terms (as ords) per document.
`NumericDocValues`	`getNumerics(LeafReader reader, String field, FieldCache.Parser parser)` Returns a `NumericDocValues` over the values found in documents in the given field.
`BinaryDocValues`	`getTerms(LeafReader reader, String field)` Checks the internal cache for an appropriate entry, and if none is found, reads the term values in `field` and returns a `BinaryDocValues` instance, providing a method to retrieve the term (as a BytesRef) per document.
`BinaryDocValues`	`getTerms(LeafReader reader, String field, float acceptableOverheadRatio)` Expert: just like `getTerms(org.apache.lucene.index.LeafReader,String)`, but you can specify whether more RAM should be consumed in exchange for faster lookups (default is "true").
`SortedDocValues`	`getTermsIndex(LeafReader reader, String field)` Checks the internal cache for an appropriate entry, and if none is found, reads the term values in `field` and returns a `SortedDocValues` instance, providing methods to retrieve sort ordinals and terms (as a ByteRef) per document.
`SortedDocValues`	`getTermsIndex(LeafReader reader, String field, float acceptableOverheadRatio)` Expert: just like `getTermsIndex(org.apache.lucene.index.LeafReader,String)`, but you can specify whether more RAM should be consumed in exchange for faster lookups (default is "true").
`void`	`purgeAllCaches()` EXPERT: Instructs the FieldCache to forcibly expunge all entries from the underlying caches.
`void`	`purgeByCacheKey(IndexReader.CacheKey coreCacheKey)` Expert: drops all cache entries associated with this reader `IndexReader.CacheHelper.getKey()`.

- Field Detail
  - DEFAULT
```
static final FieldCache DEFAULT
```
    Expert: The cache used internally by sorting and range query classes.
  - INT_POINT_PARSER
```
static final FieldCache.Parser INT_POINT_PARSER
```
    A parser instance for int values encoded by NumericUtils, e.g. when indexed via IntPoint.
  - LONG_POINT_PARSER
```
static final FieldCache.Parser LONG_POINT_PARSER
```
    A parser instance for long values encoded by NumericUtils, e.g. when indexed via LongPoint.
  - FLOAT_POINT_PARSER
```
static final FieldCache.Parser FLOAT_POINT_PARSER
```
    A parser instance for float values encoded by NumericUtils, e.g. when indexed via FloatPoint.
  - DOUBLE_POINT_PARSER
```
static final FieldCache.Parser DOUBLE_POINT_PARSER
```
    A parser instance for double values encoded by NumericUtils, e.g. when indexed via DoublePoint.
  - LEGACY_INT_PARSER
```
@Deprecated
static final FieldCache.Parser LEGACY_INT_PARSER
```
    Deprecated. Index with points and use INT_POINT_PARSER instead.
    
    A parser instance for int values encoded by LegacyNumericUtils, e.g. when indexed via LegacyIntField/LegacyNumericTokenStream.
  - LEGACY_FLOAT_PARSER
```
@Deprecated
static final FieldCache.Parser LEGACY_FLOAT_PARSER
```
    Deprecated. Index with points and use FLOAT_POINT_PARSER instead.
    
    A parser instance for float values encoded with LegacyNumericUtils, e.g. when indexed via LegacyFloatField/LegacyNumericTokenStream.
  - LEGACY_LONG_PARSER
```
@Deprecated
static final FieldCache.Parser LEGACY_LONG_PARSER
```
    Deprecated. Index with points and use LONG_POINT_PARSER instead.
    
    A parser instance for long values encoded by LegacyNumericUtils, e.g. when indexed via LegacyLongField/LegacyNumericTokenStream.
  - LEGACY_DOUBLE_PARSER
```
@Deprecated
static final FieldCache.Parser LEGACY_DOUBLE_PARSER
```
    Deprecated. Index with points and use DOUBLE_POINT_PARSER instead.
    
    A parser instance for double values encoded with LegacyNumericUtils, e.g. when indexed via LegacyDoubleField/LegacyNumericTokenStream.
  - INT32_TERM_PREFIX
```
static final BytesRef INT32_TERM_PREFIX
```
    Can be passed to getDocTermOrds(org.apache.lucene.index.LeafReader, java.lang.String, org.apache.lucene.util.BytesRef) to filter for 32-bit numeric terms
  - INT64_TERM_PREFIX
```
static final BytesRef INT64_TERM_PREFIX
```
    Can be passed to getDocTermOrds(org.apache.lucene.index.LeafReader, java.lang.String, org.apache.lucene.util.BytesRef) to filter for 64-bit numeric terms
- Method Detail
  - getDocsWithField
```
Bits getDocsWithField(LeafReader reader,
                      String field,
                      FieldCache.Parser parser)
               throws IOException
```
    Checks the internal cache for an appropriate entry, and if none is found, reads the terms/points in field and returns a bit set at the size of reader.maxDoc(), with turned on bits for each docid that does have a value for this field.
    
    Parameters:
    
    parser - May be null if coming from the inverted index, otherwise can be a FieldCache.PointParser to compute from point values.
    
    Throws:
    
    IOException
  - getNumerics
```
NumericDocValues getNumerics(LeafReader reader,
                             String field,
                             FieldCache.Parser parser)
                      throws IOException
```
    Returns a NumericDocValues over the values found in documents in the given field. If the field was indexed as NumericDocValuesField, it simply uses LeafReader.getNumericDocValues(String) to read the values. Otherwise, it checks the internal cache for an appropriate entry, and if none is found, reads the terms/points in field as longs and returns an array of size reader.maxDoc() of the value each document has in the given field.
    
    Parameters:
    
    reader - Used to get field values.
    
    field - Which field contains the longs.
    
    parser - Computes long for string values. May be null if the requested field was indexed as NumericDocValuesField or LegacyLongField.
    
    Returns:
    
    The values in the given field for each document.
    
    Throws:
    
    IOException - If any error occurs.
  - getTerms
```
BinaryDocValues getTerms(LeafReader reader,
                         String field)
                  throws IOException
```
    Checks the internal cache for an appropriate entry, and if none is found, reads the term values in field and returns a BinaryDocValues instance, providing a method to retrieve the term (as a BytesRef) per document.
    
    Parameters:
    
    reader - Used to get field values.
    
    field - Which field contains the strings.
    
    Returns:
    
    The values in the given field for each document.
    
    Throws:
    
    IOException - If any error occurs.
  - getTerms
```
BinaryDocValues getTerms(LeafReader reader,
                         String field,
                         float acceptableOverheadRatio)
                  throws IOException
```
    Expert: just like getTerms(org.apache.lucene.index.LeafReader,String), but you can specify whether more RAM should be consumed in exchange for faster lookups (default is "true"). Note that the first call for a given reader and field "wins", subsequent calls will share the same cache entry.
    
    Throws:
    
    IOException
  - getTermsIndex
```
SortedDocValues getTermsIndex(LeafReader reader,
                              String field)
                       throws IOException
```
    Checks the internal cache for an appropriate entry, and if none is found, reads the term values in field and returns a SortedDocValues instance, providing methods to retrieve sort ordinals and terms (as a ByteRef) per document.
    
    Parameters:
    
    reader - Used to get field values.
    
    field - Which field contains the strings.
    
    Returns:
    
    The values in the given field for each document.
    
    Throws:
    
    IOException - If any error occurs.
  - getTermsIndex
```
SortedDocValues getTermsIndex(LeafReader reader,
                              String field,
                              float acceptableOverheadRatio)
                       throws IOException
```
    Expert: just like getTermsIndex(org.apache.lucene.index.LeafReader,String), but you can specify whether more RAM should be consumed in exchange for faster lookups (default is "true"). Note that the first call for a given reader and field "wins", subsequent calls will share the same cache entry.
    
    Throws:
    
    IOException
  - getDocTermOrds
```
SortedSetDocValues getDocTermOrds(LeafReader reader,
                                  String field,
                                  BytesRef prefix)
                           throws IOException
```
    Checks the internal cache for an appropriate entry, and if none is found, reads the term values in field and returns a DocTermOrds instance, providing a method to retrieve the terms (as ords) per document.
    
    Parameters:
    
    reader - Used to build a DocTermOrds instance
    
    field - Which field contains the strings.
    
    prefix - prefix for a subset of the terms which should be uninverted. Can be null or INT32_TERM_PREFIX or INT64_TERM_PREFIX
    
    Returns:
    
    a DocTermOrds instance
    
    Throws:
    
    IOException - If any error occurs.
  - getCacheEntries
```
FieldCache.CacheEntry[] getCacheEntries()
```
    EXPERT: Generates an array of CacheEntry objects representing all items currently in the FieldCache.
    NOTE: These CacheEntry objects maintain a strong reference to the Cached Values. Maintaining references to a CacheEntry the AtomicIndexReader associated with it has garbage collected will prevent the Value itself from being garbage collected when the Cache drops the WeakReference.
    
    WARNING: This API is experimental and might change in incompatible ways in the next release.
  - purgeAllCaches
```
void purgeAllCaches()
```
    EXPERT: Instructs the FieldCache to forcibly expunge all entries from the underlying caches. This is intended only to be used for test methods as a way to ensure a known base state of the Cache (with out needing to rely on GC to free WeakReferences). It should not be relied on for "Cache maintenance" in general application code.
    
    WARNING: This API is experimental and might change in incompatible ways in the next release.
  - purgeByCacheKey
```
void purgeByCacheKey(IndexReader.CacheKey coreCacheKey)
```
    Expert: drops all cache entries associated with this reader IndexReader.CacheHelper.getKey(). NOTE: this cache key must precisely match the reader that the cache entry is keyed on. If you pass a top-level reader, it usually will have no effect as Lucene now caches at the segment reader level.

Interface FieldCache

Nested Class Summary

Field Summary

Method Summary

Field Detail

DEFAULT

INT_POINT_PARSER

LONG_POINT_PARSER

FLOAT_POINT_PARSER

DOUBLE_POINT_PARSER

LEGACY_INT_PARSER

LEGACY_FLOAT_PARSER

LEGACY_LONG_PARSER

LEGACY_DOUBLE_PARSER

INT32_TERM_PREFIX

INT64_TERM_PREFIX

Method Detail

getDocsWithField

getNumerics

getTerms

getTerms

getTermsIndex

getTermsIndex

getDocTermOrds

getCacheEntries

purgeAllCaches

purgeByCacheKey