com.hazelcast.internal.memory.MemoryStatsSupport Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2020, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.internal.memory;
import static com.hazelcast.internal.util.OperatingSystemMXBeanSupport.readLongAttribute;
/**
* This class provides heap usage statistics
*/
public final class MemoryStatsSupport {
private static final long TOTAL_PHYSICAL_MEMORY = readLongAttribute("TotalPhysicalMemorySize", -1L);
private static final long TOTAL_SWAP_SPACE = readLongAttribute("TotalSwapSpaceSize", -1L);
/**
* No public constructor is needed for utility classes
*/
private MemoryStatsSupport() {
}
/**
* Returns the total available physical memory on the system in bytes or -1 if not available.
*
* @return physical memory in bytes or -1 if not available
*/
public static long totalPhysicalMemory() {
return TOTAL_PHYSICAL_MEMORY;
}
/**
* Returns the amount of physical memory that is available on the system in bytes or -1 if not available.
*
* @return free physical memory in bytes or -1 if not available
*/
public static long freePhysicalMemory() {
return readLongAttribute("FreePhysicalMemorySize", -1L);
}
/**
* Returns the total amount of swap space in bytes or -1 if not available.
*
* @return total amount of swap space in bytes or -1 if not available
*/
public static long totalSwapSpace() {
return TOTAL_SWAP_SPACE;
}
/**
* Returns the amount of free swap space in bytes or -1 if not available.
*
* @return amount of free swap space in bytes or -1 if not available
*/
public static long freeSwapSpace() {
return readLongAttribute("FreeSwapSpaceSize", -1L);
}
}