| /** |
| * Copyright The Apache Software Foundation |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.tajo.util; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| import java.lang.reflect.Field; |
| import java.lang.reflect.Modifier; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.ConcurrentSkipListMap; |
| |
| /** |
| * Class for determining the "size" of a class, an attempt to calculate the |
| * actual bytes that an object of this class will occupy in memory |
| * |
| * The core of this class is taken from the Derby project |
| */ |
| |
| public class ClassSize { |
| static final Log LOG = LogFactory.getLog(ClassSize.class); |
| |
| private static int nrOfRefsPerObj = 2; |
| |
| /** Array overhead */ |
| public static final int ARRAY; |
| |
| /** Overhead for ArrayList(0) */ |
| public static final int ARRAYLIST; |
| |
| /** Overhead for ByteBuffer */ |
| public static final int BYTE_BUFFER; |
| |
| /** Overhead for an Short */ |
| public static final int SHORT; |
| |
| /** Overhead for an Integer */ |
| public static final int INTEGER; |
| |
| /** Overhead for an Long */ |
| public static final int LONG; |
| |
| /** Overhead for an Float */ |
| public static final int FLOAT; |
| |
| /** Overhead for an Double */ |
| public static final int DOUBLE; |
| |
| /** Overhead for entry in map */ |
| public static final int MAP_ENTRY; |
| |
| /** Object overhead is minimum 2 * reference size (8 bytes on 64-bit) */ |
| public static final int OBJECT; |
| |
| /** Reference size is 8 bytes on 64-bit, 4 bytes on 32-bit */ |
| public static final int REFERENCE; |
| |
| /** String overhead */ |
| public static final int STRING; |
| |
| /** Overhead for TreeMap */ |
| public static final int TREEMAP; |
| |
| /** Overhead for ConcurrentHashMap */ |
| public static final int CONCURRENT_HASHMAP; |
| |
| /** Overhead for ConcurrentHashMap.Entry */ |
| public static final int CONCURRENT_HASHMAP_ENTRY; |
| |
| /** Overhead for ConcurrentHashMap.Segment */ |
| public static final int CONCURRENT_HASHMAP_SEGMENT; |
| |
| /** Overhead for ConcurrentSkipListMap */ |
| public static final int CONCURRENT_SKIPLISTMAP; |
| |
| /** Overhead for ConcurrentSkipListMap Entry */ |
| public static final int CONCURRENT_SKIPLISTMAP_ENTRY; |
| |
| /** Overhead for ReentrantReadWriteLock */ |
| public static final int REENTRANT_LOCK; |
| |
| /** Overhead for AtomicLong */ |
| public static final int ATOMIC_LONG; |
| |
| /** Overhead for AtomicInteger */ |
| public static final int ATOMIC_INTEGER; |
| |
| /** Overhead for AtomicBoolean */ |
| public static final int ATOMIC_BOOLEAN; |
| |
| /** Overhead for CopyOnWriteArraySet */ |
| public static final int COPYONWRITE_ARRAYSET; |
| |
| /** Overhead for CopyOnWriteArrayList */ |
| public static final int COPYONWRITE_ARRAYLIST; |
| |
| /** Overhead for timerange */ |
| public static final int TIMERANGE; |
| |
| /** Overhead for TimeRangeTracker */ |
| public static final int TIMERANGE_TRACKER; |
| |
| /** Overhead for KeyValueSkipListSet */ |
| public static final int KEYVALUE_SKIPLIST_SET; |
| |
| /* Are we running on jdk7? */ |
| private static final boolean JDK7; |
| static { |
| final String version = System.getProperty("java.version"); |
| // Verify String looks like this: 1.6.0_29 |
| if (!version.matches("\\d\\.\\d\\..*")) { |
| throw new RuntimeException("Unexpected version format: " + version); |
| } |
| // Convert char to int |
| int major = (int)(version.charAt(0) - '0'); |
| int minor = (int)(version.charAt(2) - '0'); |
| JDK7 = major == 1 && minor == 7; |
| } |
| |
| /** |
| * Method for reading the arc settings and setting overheads according |
| * to 32-bit or 64-bit architecture. |
| */ |
| static { |
| //Default value is set to 8, covering the case when arcModel is unknown |
| if (is32BitJVM()) { |
| REFERENCE = 4; |
| } else { |
| REFERENCE = 8; |
| } |
| |
| OBJECT = 2 * REFERENCE; |
| |
| ARRAY = align(3 * REFERENCE); |
| |
| ARRAYLIST = align(OBJECT + align(REFERENCE) + align(ARRAY) + |
| (2 * Bytes.SIZEOF_INT)); |
| |
| //noinspection PointlessArithmeticExpression |
| BYTE_BUFFER = align(OBJECT + align(REFERENCE) + align(ARRAY) + |
| (5 * Bytes.SIZEOF_INT) + |
| (3 * Bytes.SIZEOF_BOOLEAN) + Bytes.SIZEOF_LONG); |
| |
| SHORT = align(OBJECT + Bytes.SIZEOF_SHORT); |
| |
| INTEGER = align(OBJECT + Bytes.SIZEOF_INT); |
| |
| LONG = align(OBJECT + Bytes.SIZEOF_LONG); |
| |
| FLOAT = align(OBJECT + Bytes.SIZEOF_FLOAT); |
| |
| DOUBLE = align(OBJECT + Bytes.SIZEOF_DOUBLE); |
| |
| MAP_ENTRY = align(OBJECT + 5 * REFERENCE + Bytes.SIZEOF_BOOLEAN); |
| |
| TREEMAP = align(OBJECT + (2 * Bytes.SIZEOF_INT) + align(7 * REFERENCE)); |
| |
| // STRING is different size in jdk6 and jdk7. Just use what we estimate as size rather than |
| // have a conditional on whether jdk7. |
| STRING = (int) estimateBase(String.class, false); |
| |
| // CONCURRENT_HASHMAP is different size in jdk6 and jdk7; it looks like its different between |
| // 23.6-b03 and 23.0-b21. Just use what we estimate as size rather than have a conditional on |
| // whether jdk7. |
| CONCURRENT_HASHMAP = (int) estimateBase(ConcurrentHashMap.class, false); |
| |
| CONCURRENT_HASHMAP_ENTRY = align(REFERENCE + OBJECT + (3 * REFERENCE) + |
| (2 * Bytes.SIZEOF_INT)); |
| |
| CONCURRENT_HASHMAP_SEGMENT = align(REFERENCE + OBJECT + |
| (3 * Bytes.SIZEOF_INT) + Bytes.SIZEOF_FLOAT + ARRAY); |
| |
| // The size changes from jdk7 to jdk8, estimate the size rather than use a conditional |
| CONCURRENT_SKIPLISTMAP = (int) estimateBase(ConcurrentSkipListMap.class, false); |
| |
| CONCURRENT_SKIPLISTMAP_ENTRY = align( |
| align(OBJECT + (3 * REFERENCE)) + /* one node per entry */ |
| align((OBJECT + (3 * REFERENCE))/2)); /* one index per two entries */ |
| |
| REENTRANT_LOCK = align(OBJECT + (3 * REFERENCE)); |
| |
| ATOMIC_LONG = align(OBJECT + Bytes.SIZEOF_LONG); |
| |
| ATOMIC_INTEGER = align(OBJECT + Bytes.SIZEOF_INT); |
| |
| ATOMIC_BOOLEAN = align(OBJECT + Bytes.SIZEOF_BOOLEAN); |
| |
| COPYONWRITE_ARRAYSET = align(OBJECT + REFERENCE); |
| |
| COPYONWRITE_ARRAYLIST = align(OBJECT + (2 * REFERENCE) + ARRAY); |
| |
| TIMERANGE = align(ClassSize.OBJECT + Bytes.SIZEOF_LONG * 2 + Bytes.SIZEOF_BOOLEAN); |
| |
| TIMERANGE_TRACKER = align(ClassSize.OBJECT + Bytes.SIZEOF_LONG * 2); |
| |
| KEYVALUE_SKIPLIST_SET = align(OBJECT + REFERENCE); |
| } |
| |
| /** |
| * The estimate of the size of a class instance depends on whether the JVM |
| * uses 32 or 64 bit addresses, that is it depends on the size of an object |
| * reference. It is a linear function of the size of a reference, e.g. |
| * 24 + 5*r where r is the size of a reference (usually 4 or 8 bytes). |
| * |
| * This method returns the coefficients of the linear function, e.g. {24, 5} |
| * in the above example. |
| * |
| * @param cl A class whose instance size is to be estimated |
| * @param debug debug flag |
| * @return an array of 3 integers. The first integer is the size of the |
| * primitives, the second the number of arrays and the third the number of |
| * references. |
| */ |
| @SuppressWarnings("unchecked") |
| private static int [] getSizeCoefficients(Class cl, boolean debug) { |
| int primitives = 0; |
| int arrays = 0; |
| //The number of references that a new object takes |
| int references = nrOfRefsPerObj; |
| int index = 0; |
| |
| for ( ; null != cl; cl = cl.getSuperclass()) { |
| Field[] field = cl.getDeclaredFields(); |
| if (null != field) { |
| for (Field aField : field) { |
| if (Modifier.isStatic(aField.getModifiers())) continue; |
| Class fieldClass = aField.getType(); |
| if (fieldClass.isArray()) { |
| arrays++; |
| references++; |
| } else if (!fieldClass.isPrimitive()) { |
| references++; |
| } else {// Is simple primitive |
| String name = fieldClass.getName(); |
| |
| if (name.equals("int") || name.equals("I")) |
| primitives += Bytes.SIZEOF_INT; |
| else if (name.equals("long") || name.equals("J")) |
| primitives += Bytes.SIZEOF_LONG; |
| else if (name.equals("boolean") || name.equals("Z")) |
| primitives += Bytes.SIZEOF_BOOLEAN; |
| else if (name.equals("short") || name.equals("S")) |
| primitives += Bytes.SIZEOF_SHORT; |
| else if (name.equals("byte") || name.equals("B")) |
| primitives += Bytes.SIZEOF_BYTE; |
| else if (name.equals("char") || name.equals("C")) |
| primitives += Bytes.SIZEOF_CHAR; |
| else if (name.equals("float") || name.equals("F")) |
| primitives += Bytes.SIZEOF_FLOAT; |
| else if (name.equals("double") || name.equals("D")) |
| primitives += Bytes.SIZEOF_DOUBLE; |
| } |
| if (debug) { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("" + index + " " + aField.getName() + " " + aField.getType()); |
| } |
| } |
| index++; |
| } |
| } |
| } |
| return new int [] {primitives, arrays, references}; |
| } |
| |
| /** |
| * Estimate the static space taken up by a class instance given the |
| * coefficients returned by getSizeCoefficients. |
| * |
| * @param coeff the coefficients |
| * |
| * @param debug debug flag |
| * @return the size estimate, in bytes |
| */ |
| private static long estimateBaseFromCoefficients(int [] coeff, boolean debug) { |
| long prealign_size = coeff[0] + align(coeff[1] * ARRAY) + coeff[2] * REFERENCE; |
| |
| // Round up to a multiple of 8 |
| long size = align(prealign_size); |
| if(debug) { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Primitives=" + coeff[0] + ", arrays=" + coeff[1] + |
| ", references(includes " + nrOfRefsPerObj + |
| " for object overhead)=" + coeff[2] + ", refSize " + REFERENCE + |
| ", size=" + size + ", prealign_size=" + prealign_size); |
| } |
| } |
| return size; |
| } |
| |
| /** |
| * Estimate the static space taken up by the fields of a class. This includes |
| * the space taken up by by references (the pointer) but not by the referenced |
| * object. So the estimated size of an array field does not depend on the size |
| * of the array. Similarly the size of an object (reference) field does not |
| * depend on the object. |
| * |
| * @param cl class |
| * @param debug debug flag |
| * @return the size estimate in bytes. |
| */ |
| @SuppressWarnings("unchecked") |
| public static long estimateBase(Class cl, boolean debug) { |
| return estimateBaseFromCoefficients( getSizeCoefficients(cl, debug), debug); |
| } |
| |
| /** |
| * Aligns a number to 8. |
| * @param num number to align to 8 |
| * @return smallest number >= input that is a multiple of 8 |
| */ |
| public static int align(int num) { |
| return (int)(align((long)num)); |
| } |
| |
| /** |
| * Aligns a number to 8. |
| * @param num number to align to 8 |
| * @return smallest number >= input that is a multiple of 8 |
| */ |
| public static long align(long num) { |
| //The 7 comes from that the alignSize is 8 which is the number of bytes |
| //stored and sent together |
| return ((num + 7) >> 3) << 3; |
| } |
| |
| /** |
| * Determines if we are running in a 32-bit JVM. Some unit tests need to |
| * know this too. |
| */ |
| public static boolean is32BitJVM() { |
| return System.getProperty("sun.arch.data.model").equals("32"); |
| } |
| |
| } |
| |