ObjectSizes.java
/*
* 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.cassandra.utils;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import org.github.jamm.MemoryMeter;
import org.github.jamm.MemoryMeter.ByteBufferMode;
import org.github.jamm.MemoryMeter.Guess;
import static org.github.jamm.MemoryMeterStrategy.MEMORY_LAYOUT;
import static org.github.jamm.utils.ArrayMeasurementUtils.computeArraySize;
/**
* A convenience class for wrapping access to MemoryMeter. Should be used instead of using a {@code MemoryMeter} directly.
* {@code MemoryMeter} can be used directly for testing as it allow a more fine tuned configuration for comparison.
*/
public class ObjectSizes
{
private static final MemoryMeter meter = MemoryMeter.builder().withGuessing(Guess.INSTRUMENTATION_AND_SPECIFICATION,
Guess.UNSAFE)
.build();
private static final long HEAP_BUFFER_SHALLOW_SIZE = measure(ByteBufferUtil.EMPTY_BYTE_BUFFER);
private static final long DIRECT_BUFFER_SHALLOW_SIZE = measure(ByteBuffer.allocateDirect(0));
private static final long DIRECT_BUFFER_DEEP_SIZE = measureDeep(ByteBuffer.allocateDirect(0));
public static final long IPV6_SOCKET_ADDRESS_SIZE = ObjectSizes.measureDeep(new InetSocketAddress(getIpvAddress(16), 42));
/**
* Memory a byte array consumes
*
* @param bytes byte array to get memory size
* @return heap-size of the array
*/
public static long sizeOfArray(byte[] bytes)
{
return meter.measureArray(bytes);
}
/**
* Memory a long array consumes
*
* @param longs byte array to get memory size
* @return heap-size of the array
*/
public static long sizeOfArray(long[] longs)
{
return meter.measureArray(longs);
}
/**
* Memory an int array consumes
*
* @param ints byte array to get memory size
* @return heap-size of the array
*/
public static long sizeOfArray(int[] ints)
{
return meter.measureArray(ints);
}
/**
* Memory a reference array consumes
*
* @param length the length of the reference array
* @return heap-size of the array
*/
public static long sizeOfReferenceArray(int length)
{
return sizeOfArray(length, MEMORY_LAYOUT.getReferenceSize());
}
/**
* Memory a reference array consumes itself only
*
* @param objects the array to size
* @return heap-size of the array (excluding memory retained by referenced objects)
*/
public static long sizeOfArray(Object[] objects)
{
return meter.measureArray(objects);
}
private static long sizeOfArray(int length, int elementSize)
{
return computeArraySize(MEMORY_LAYOUT.getArrayHeaderSize(), length, elementSize, MEMORY_LAYOUT.getObjectAlignment());
}
/**
* Amount of heap memory consumed by the array of byte buffers. It sums memory consumed by the array itself
* and for each included byte buffer using {@link #sizeOnHeapOf(ByteBuffer)}.
*/
public static long sizeOnHeapOf(ByteBuffer[] array)
{
if (array == null)
return 0;
long sum = sizeOfArray(array);
for (ByteBuffer buffer : array)
sum += sizeOnHeapOf(buffer);
return sum;
}
/**
* Amount of non-data heap memory consumed by the array of byte buffers. It sums memory consumed
* by the array itself and for each included byte buffer using {@link #sizeOnHeapExcludingDataOf(ByteBuffer)}.
*/
public static long sizeOnHeapExcludingDataOf(ByteBuffer[] array)
{
if (array == null)
return 0;
long sum = sizeOfArray(array);
for (ByteBuffer b : array)
sum += sizeOnHeapExcludingDataOf(b);
return sum;
}
/**
* Measures the heap memory used by the specified byte buffer. If the buffer is a slab only the data size will be
* counted but not the internal overhead. A SLAB is assumed to be created by: {@code buffer.duplicate().position(start).limit(end)} without the use of {@code slice()}.
* <p>This method makes a certain amount of assumptions:
* <ul>
* <li>That slabs are always created using: {@code buffer.duplicate().position(start).limit(end)} and not through slice</li>
* <li>That the input buffers are not read-only buffers</li>
* <li>That the direct buffers that are not slab are not duplicates</li>
* </ul>
* Non-respect of those assumptions can lead to an invalid value being returned.
* @param buffer the buffer to measure
* @return the heap memory used by the specified byte buffer.
*/
public static long sizeOnHeapOf(ByteBuffer buffer)
{
if (buffer == null)
return 0;
assert !buffer.isReadOnly();
// We assume here that slabs are always created using: buffer.duplicate().position(start).limit(end) and not through slice
if (ByteBufferMode.SLAB_ALLOCATION_NO_SLICE.isSlab(buffer))
{
if (buffer.isDirect())
return DIRECT_BUFFER_SHALLOW_SIZE; // We ignore the underlying buffer
return HEAP_BUFFER_SHALLOW_SIZE + buffer.remaining(); // We ignore the array overhead
}
if (buffer.isDirect())
return DIRECT_BUFFER_DEEP_SIZE; // That might not be true if the buffer is a view of another buffer so we could undercount
return HEAP_BUFFER_SHALLOW_SIZE + meter.measureArray(buffer.array());
}
/**
* Measures the heap memory used by the specified byte buffer excluding the data. If the buffer shallow size will be counted.
* A SLAB is assumed to be created by: {@code buffer.duplicate().position(start).limit(end)} without the use of {@code slice()}.
* <p>This method makes a certain amount of assumptions:
* <ul>
* <li>That slabs are always created using: {@code buffer.duplicate().position(start).limit(end)} and not through slice</li>
* <li>That the input buffers are not read-only buffers</li>
* <li>That the direct buffers that are not slab are not duplicates</li>
* </ul>
* Non-respect of those assumptions can lead to an invalid value being returned. T
* @param buffer the buffer to measure
* @return the heap memory used by the specified byte buffer excluding the data..
*/
public static long sizeOnHeapExcludingDataOf(ByteBuffer buffer)
{
if (buffer == null)
return 0;
assert !buffer.isReadOnly();
// We assume here that slabs are always created using: buffer.duplicate().position(start).limit(end) and not through slice
if (ByteBufferMode.SLAB_ALLOCATION_NO_SLICE.isSlab(buffer))
{
if (buffer.isDirect())
return DIRECT_BUFFER_SHALLOW_SIZE; // We ignore the underlying buffer
return HEAP_BUFFER_SHALLOW_SIZE; // We ignore the array overhead
}
if (buffer.isDirect())
return DIRECT_BUFFER_DEEP_SIZE; // That might not be true if the buffer is a view of another buffer so we could undercount
byte[] bytes = buffer.array();
return HEAP_BUFFER_SHALLOW_SIZE + meter.measureArray(bytes) - bytes.length;
}
/**
* Memory a String consumes
*
* @param str String to calculate memory size of
* @return Total in-memory size of the String
*/
public static long sizeOf(String str)
{
return meter.measureStringDeep(str);
}
/**
* @param pojo the object to measure
* @return the size on the heap of the instance and all retained heap referenced by it, excluding portions of
* ByteBuffer that are not directly referenced by it but including any other referenced that may also be retained
* by other objects.
*/
public static long measureDeep(Object pojo)
{
return meter.measureDeep(pojo);
}
/**
* @param pojo the object to measure
* @return The size on the heap of the instance and all retained heap referenced by it, excluding portions of
* ByteBuffer that are not directly referenced by it but including any other referenced that may also be retained
* by other objects. This also includes bytes referenced in direct byte buffers, and may double-count memory if
* it is referenced by multiple ByteBuffer copies.
*/
public static long measureDeepOmitShared(Object pojo)
{
return meter.measureDeep(pojo, ByteBufferMode.SLAB_ALLOCATION_NO_SLICE);
}
/**
* @param pojo the object to measure
* @return the size on the heap of the instance only, excluding any referenced objects
*/
public static long measure(Object pojo)
{
return meter.measure(pojo);
}
private static InetAddress getIpvAddress(int size)
{
if (size == 16 || size ==4)
{
try
{
return InetAddress.getByAddress(new byte[size]);
}
catch (UnknownHostException e)
{
throw new IllegalArgumentException("Invalid size of a byte array when getting and ipv address: " + size);
}
}
else throw new IllegalArgumentException("Excpected a byte array size of 4 or 16 for an ipv address but got: " + size);
}
}