## org.apache.lucene.facet.taxonomy.writercache.cl2o
Class Cl2oTaxonomyWriterCache

    java.lang.Object
      org.apache.lucene.facet.taxonomy.writercache.cl2o.Cl2oTaxonomyWriterCache

All Implemented Interfaces:
  TaxonomyWriterCache

    public class Cl2oTaxonomyWriterCache

extends Object
implements TaxonomyWriterCache

`TaxonomyWriterCache` using `CompactLabelToOrdinal`. Although called cache, it maintains in memory all the mappings from category to ordinal, relying on that `CompactLabelToOrdinal` is an efficient mapping for this purpose.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Constructor Summary
`Cl2oTaxonomyWriterCache(int initialCapcity, float loadFactor, int numHashArrays)`

Method Summary
`void` `clear()` Clears the content of the cache.
`void` `close()` Let go of whatever resources the cache is holding.
`int` `get(CategoryPath categoryPath)` Lookup a category in the cache, returning its ordinal, or a negative number if the category is not in the cache.
`int` `getMemoryUsage()` Returns the number of bytes in memory used by this object.
`boolean` `isFull()` Returns true if the cache is full, such that the next `TaxonomyWriterCache.put(org.apache.lucene.facet.taxonomy.CategoryPath, int)` will evict entries from it, false otherwise.
`boolean` `put(CategoryPath categoryPath, int ordinal)` Add a category to the cache, with the given ordinal as the value.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### Cl2oTaxonomyWriterCache

    public Cl2oTaxonomyWriterCache(int initialCapcity,
                                   float loadFactor,
                                   int numHashArrays)

Method Detail

### clear

    public void clear()

  Description copied from interface: `TaxonomyWriterCache`
  Clears the content of the cache. Unlike `TaxonomyWriterCache.close()`, the caller can assume that the cache is still operable after this method returns.

  Specified by:
    `clear` in interface `TaxonomyWriterCache`

### close

    public void close()

  Description copied from interface: `TaxonomyWriterCache`
  Let go of whatever resources the cache is holding. After a close(), this object can no longer be used.

  Specified by:
    `close` in interface `TaxonomyWriterCache`

### isFull

    public boolean isFull()

  Description copied from interface: `TaxonomyWriterCache`
  Returns true if the cache is full, such that the next `TaxonomyWriterCache.put(org.apache.lucene.facet.taxonomy.CategoryPath, int)` will evict entries from it, false otherwise.

  Specified by:
    `isFull` in interface `TaxonomyWriterCache`

### get

    public int get(CategoryPath categoryPath)

  Description copied from interface: `TaxonomyWriterCache`
  Lookup a category in the cache, returning its ordinal, or a negative number if the category is not in the cache.

  It is up to the caller to remember what a negative response means: If the caller knows the cache is complete (it was initially fed with all the categories, and since then put() never returned true) it means the category does not exist. Otherwise, the category might still exist, but just be missing from the cache.

  Specified by:
    `get` in interface `TaxonomyWriterCache`

### put

    public boolean put(CategoryPath categoryPath,
                       int ordinal)

  Description copied from interface: `TaxonomyWriterCache`
  Add a category to the cache, with the given ordinal as the value.

  If the implementation keeps only a partial cache (e.g., an LRU cache) and finds that its cache is full, it should clear up part of the cache and return `true`. Otherwise, it should return `false`.

  The reason why the caller needs to know if part of the cache was cleared is that in that case it will have to commit its on-disk index (so that all the latest category additions can be searched on disk, if we can't rely on the cache to contain them).

  Ordinals should be non-negative. Currently there is no defined way to specify that a cache should remember a category does NOT exist. It doesn't really matter, because normally the next thing we do after finding that a category does not exist is to add it.

  Specified by:
    `put` in interface `TaxonomyWriterCache`

### getMemoryUsage

    public int getMemoryUsage()

  Returns the number of bytes in memory used by this object.

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