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java.lang.Object org.apache.lucene.facet.taxonomy.writercache.cl2o.Cl2oTaxonomyWriterCache
public class Cl2oTaxonomyWriterCache
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.
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 |
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public Cl2oTaxonomyWriterCache(int initialCapcity, float loadFactor, int numHashArrays)
Method Detail |
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public void clear()
TaxonomyWriterCache
TaxonomyWriterCache.close()
, the caller can
assume that the cache is still operable after this method returns.
clear
in interface TaxonomyWriterCache
public void close()
TaxonomyWriterCache
close
in interface TaxonomyWriterCache
public boolean isFull()
TaxonomyWriterCache
TaxonomyWriterCache.put(org.apache.lucene.facet.taxonomy.CategoryPath, int)
will
evict entries from it, false otherwise.
isFull
in interface TaxonomyWriterCache
public int get(CategoryPath categoryPath)
TaxonomyWriterCache
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.
get
in interface TaxonomyWriterCache
public boolean put(CategoryPath categoryPath, int ordinal)
TaxonomyWriterCache
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.
put
in interface TaxonomyWriterCache
public int getMemoryUsage()
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