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HBASE-1188 Memory size of Java Objects - Make cacheable objects implement HeapSize 

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@748259 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Michael Stack 2009-02-26 18:21:49 +00:00
parent e52b1ac411
commit 2ec433e990
2 changed files with 36 additions and 2 deletions
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2
CHANGES.txt
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@ -63,6 +63,8 @@ Release 0.20.0 - Unreleased
options show up (Erik Holstad via Stack)
HBASE-1189 Changing the map type used internally for HbaseMapWritable
(Erik Holstad via Stack)
HBASE-1188 Memory size of Java Objects - Make cacheable objects implement
HeapSize (Erik Holstad via Stack)
Release 0.19.0 - 01/21/2009
INCOMPATIBLE CHANGES

32
src/java/org/apache/hadoop/hbase/io/HeapSize.java
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@ -25,6 +25,38 @@ package org.apache.hadoop.hbase.io;
* probably do not account for 32 vs 64 bit nor for different VM implemenations.
*/
public interface HeapSize {
/** Reference size is 8 bytes on 64-bit, 4 bytes on 32-bit */
static final int REFERENCE = 8;
/** Object overhead is minimum 2 * reference size (8 bytes on 64-bit) */
static final int OBJECT = 2 * REFERENCE;
/**
* The following types are always allocated in blocks of 8 bytes (on 64bit)
* For example, if you have two ints in a class, it will use 8 bytes.
* If you have three ints in a class, it will use 16 bytes.
*/
static final int SHORT = 4;
static final int INT = 4;
static final int FLOAT = 4;
static final int BOOLEAN = 4;
static final int CHAR = 4;
static final int BYTE = 1;
/** These types are always 8 bytes */
static final int DOUBLE = 8;
static final int LONG = 8;
/** Array overhead */
static final int BYTE_ARRAY = REFERENCE;
static final int ARRAY = 3 * REFERENCE;
static final int MULTI_ARRAY = (4 * REFERENCE) + ARRAY;
static final int BLOCK_SIZE_TAX = 8;
/**
* @return Approximate 'exclusive deep size' of implementing object. Includes
* count of payload and hosting object sizings.