| /** |
| * 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 |
| * <p> |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * <p> |
| * 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.hadoop.hdds.scm.container.placement.metrics; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.base.Preconditions; |
| |
| /** |
| * SCM Node Metric that is used in the placement classes. |
| */ |
| public class SCMNodeMetric implements DatanodeMetric<SCMNodeStat, Long> { |
| private SCMNodeStat stat; |
| |
| /** |
| * Constructs an SCMNode Metric. |
| * |
| * @param stat - SCMNodeStat. |
| */ |
| public SCMNodeMetric(SCMNodeStat stat) { |
| this.stat = stat; |
| } |
| |
| /** |
| * Set the capacity, used and remaining space on a datanode. |
| * |
| * @param capacity in bytes |
| * @param used in bytes |
| * @param remaining in bytes |
| */ |
| @VisibleForTesting |
| public SCMNodeMetric(long capacity, long used, long remaining) { |
| this.stat = new SCMNodeStat(); |
| this.stat.set(capacity, used, remaining); |
| } |
| |
| /** |
| * |
| * @param o - Other Object |
| * @return - True if *this* object is greater than argument. |
| */ |
| @Override |
| public boolean isGreater(SCMNodeStat o) { |
| Preconditions.checkNotNull(this.stat, "Argument cannot be null"); |
| Preconditions.checkNotNull(o, "Argument cannot be null"); |
| |
| // if zero, replace with 1 for the division to work. |
| long thisDenominator = (this.stat.getCapacity().get() == 0) |
| ? 1 : this.stat.getCapacity().get(); |
| long otherDenominator = (o.getCapacity().get() == 0) |
| ? 1 : o.getCapacity().get(); |
| |
| float thisNodeWeight = |
| stat.getScmUsed().get() / (float) thisDenominator; |
| |
| float oNodeWeight = |
| o.getScmUsed().get() / (float) otherDenominator; |
| |
| if (Math.abs(thisNodeWeight - oNodeWeight) > 0.000001) { |
| return thisNodeWeight > oNodeWeight; |
| } |
| // if these nodes are have similar weight then return the node with more |
| // free space as the greater node. |
| return stat.getRemaining().isGreater(o.getRemaining().get()); |
| } |
| |
| /** |
| * Inverse of isGreater. |
| * |
| * @param o - other object. |
| * @return True if *this* object is Lesser than argument. |
| */ |
| @Override |
| public boolean isLess(SCMNodeStat o) { |
| Preconditions.checkNotNull(o, "Argument cannot be null"); |
| |
| // if zero, replace with 1 for the division to work. |
| long thisDenominator = (this.stat.getCapacity().get() == 0) |
| ? 1 : this.stat.getCapacity().get(); |
| long otherDenominator = (o.getCapacity().get() == 0) |
| ? 1 : o.getCapacity().get(); |
| |
| float thisNodeWeight = |
| stat.getScmUsed().get() / (float) thisDenominator; |
| |
| float oNodeWeight = |
| o.getScmUsed().get() / (float) otherDenominator; |
| |
| if (Math.abs(thisNodeWeight - oNodeWeight) > 0.000001) { |
| return thisNodeWeight < oNodeWeight; |
| } |
| |
| // if these nodes are have similar weight then return the node with less |
| // free space as the lesser node. |
| return stat.getRemaining().isLess(o.getRemaining().get()); |
| } |
| |
| /** |
| * Returns true if the object has same values. Because of issues with |
| * equals, and loss of type information this interface supports isEqual. |
| * |
| * @param o object to compare. |
| * @return True, if the values match. |
| * TODO : Consider if it makes sense to add remaining to this equation. |
| */ |
| @Override |
| public boolean isEqual(SCMNodeStat o) { |
| float thisNodeWeight = stat.getScmUsed().get() / (float) |
| stat.getCapacity().get(); |
| float oNodeWeight = o.getScmUsed().get() / (float) o.getCapacity().get(); |
| return Math.abs(thisNodeWeight - oNodeWeight) < 0.000001; |
| } |
| |
| /** |
| * A resourceCheck, defined by resourceNeeded. |
| * For example, S could be bytes required |
| * and DatanodeMetric can reply by saying it can be met or not. |
| * |
| * @param resourceNeeded - ResourceNeeded in its own metric. |
| * @return boolean, True if this resource requirement can be met. |
| */ |
| @Override |
| public boolean hasResources(Long resourceNeeded) { |
| return false; |
| } |
| |
| /** |
| * Returns the metric. |
| * |
| * @return T, the object that represents this metric. |
| */ |
| @Override |
| public SCMNodeStat get() { |
| return stat; |
| } |
| |
| /** |
| * Sets the value of this metric. |
| * |
| * @param value - value of the metric. |
| */ |
| @Override |
| public void set(SCMNodeStat value) { |
| stat.set(value.getCapacity().get(), value.getScmUsed().get(), |
| value.getRemaining().get()); |
| } |
| |
| /** |
| * Adds a value of to the base. |
| * |
| * @param value - value |
| */ |
| @Override |
| public void add(SCMNodeStat value) { |
| stat.add(value); |
| } |
| |
| /** |
| * subtract a value. |
| * |
| * @param value value |
| */ |
| @Override |
| public void subtract(SCMNodeStat value) { |
| stat.subtract(value); |
| } |
| |
| /** |
| * Compares this object with the specified object for order. Returns a |
| * negative integer, zero, or a positive integer as this object is less |
| * than, equal to, or greater than the specified object. |
| * |
| * @param o the object to be compared. |
| * @return a negative integer, zero, or a positive integer as this object is |
| * less than, equal to, or greater than the specified object. |
| * @throws NullPointerException if the specified object is null |
| * @throws ClassCastException if the specified object's type prevents it |
| * from being compared to this object. |
| */ |
| //@Override |
| public int compareTo(SCMNodeStat o) { |
| if (isEqual(o)) { |
| return 0; |
| } |
| if (isGreater(o)) { |
| return 1; |
| } else { |
| return -1; |
| } |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| |
| SCMNodeMetric that = (SCMNodeMetric) o; |
| |
| return stat != null ? stat.equals(that.stat) : that.stat == null; |
| } |
| |
| @Override |
| public int hashCode() { |
| return stat != null ? stat.hashCode() : 0; |
| } |
| } |