org.apache.lucene.util
Class RamUsageEstimator
java.lang.Object
org.apache.lucene.util.RamUsageEstimator
public final class RamUsageEstimator
- extends Object
Estimates the size of a given Object using a given MemoryModel for primitive
size information.
Resource Usage:
Internally uses a Map to temporally hold a reference to every
object seen.
If checkInterned, all Strings checked will be interned, but those
that were not already interned will be released for GC when the
estimate is complete.
- NOTE: This API is for Lucene internal purposes only and might change in incompatible ways in the next release.
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
NUM_BYTES_SHORT
public static final int NUM_BYTES_SHORT
- See Also:
- Constant Field Values
NUM_BYTES_INT
public static final int NUM_BYTES_INT
- See Also:
- Constant Field Values
NUM_BYTES_LONG
public static final int NUM_BYTES_LONG
- See Also:
- Constant Field Values
NUM_BYTES_FLOAT
public static final int NUM_BYTES_FLOAT
- See Also:
- Constant Field Values
NUM_BYTES_DOUBLE
public static final int NUM_BYTES_DOUBLE
- See Also:
- Constant Field Values
NUM_BYTES_CHAR
public static final int NUM_BYTES_CHAR
- See Also:
- Constant Field Values
NUM_BYTES_OBJECT_HEADER
public static final int NUM_BYTES_OBJECT_HEADER
- See Also:
- Constant Field Values
NUM_BYTES_OBJECT_REF
public static final int NUM_BYTES_OBJECT_REF
NUM_BYTES_ARRAY_HEADER
public static final int NUM_BYTES_ARRAY_HEADER
RamUsageEstimator
public RamUsageEstimator()
- Constructs this object with an AverageGuessMemoryModel and
checkInterned = true.
RamUsageEstimator
public RamUsageEstimator(boolean checkInterned)
- Parameters:
checkInterned
- check if Strings are interned and don't add to size
if they are. Defaults to true but if you know the objects you are checking
won't likely contain many interned Strings, it will be faster to turn off
intern checking.
RamUsageEstimator
public RamUsageEstimator(MemoryModel memoryModel)
- Parameters:
memoryModel
- MemoryModel to use for primitive object sizes.
RamUsageEstimator
public RamUsageEstimator(MemoryModel memoryModel,
boolean checkInterned)
- Parameters:
memoryModel
- MemoryModel to use for primitive object sizes.checkInterned
- check if Strings are interned and don't add to size
if they are. Defaults to true but if you know the objects you are checking
won't likely contain many interned Strings, it will be faster to turn off
intern checking.
estimateRamUsage
public long estimateRamUsage(Object obj)
humanReadableUnits
public static String humanReadableUnits(long bytes,
DecimalFormat df)
- Return good default units based on byte size.
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