HBASE-28600 Introduce StorageSize, StorageUnit from hadoop 3

Author: jinhyukify

hbase-common/src/main/java/org/apache/hadoop/hbase/StorageSize.java

@@ -0,0 +1,123 @@
+/*
+ * 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.hadoop.hbase;
+
+import static org.apache.commons.lang3.StringUtils.isBlank;
+import static org.apache.commons.lang3.StringUtils.isNotBlank;
+
+import java.util.Locale;
+import org.apache.yetus.audience.InterfaceAudience;
+
+import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
+
+/**
+ * This class is adapted from the Hadoop 3.x source code to HBase as part of a backporting effort to
+ * support storage size parsing functionality in older versions of HBase.
+ * <p>
+ * Source: <a href=
+ * "https://github.com/apache/hadoop/blob/branch-3.1.0/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/StorageSize.java">
+ * Hadoop 3.1.0 StorageSize.java </a>
+ * </p>
+ */
+@InterfaceAudience.Private
+public class StorageSize {
+  private final StorageUnit unit;
+  private final double value;
+
+  /**
+   * Constucts a Storage Measure, which contains the value and the unit of measure.
+   * @param unit  - Unit of Measure
+   * @param value - Numeric value.
+   */
+  public StorageSize(StorageUnit unit, double value) {
+    this.unit = unit;
+    this.value = value;
+  }
+
+  private static void checkState(boolean state, String errorString) {
+    if (!state) {
+      throw new IllegalStateException(errorString);
+    }
+  }
+
+  public static double getStorageSize(String value, double defaultValue, StorageUnit targetUnit) {
+    Preconditions.checkNotNull(targetUnit, "Conversion unit cannot be null.");
+
+    if (isBlank(value)) {
+      return targetUnit.getDefault(defaultValue);
+    }
+
+    final StorageSize measure = parse(value);
+    double byteValue = measure.getUnit().toBytes(measure.getValue());
+    return targetUnit.fromBytes(byteValue);
+  }
+
+  public static StorageSize parse(String value) {
+    checkState(isNotBlank(value), "value cannot be blank");
+    String sanitizedValue = value.trim().toLowerCase(Locale.ENGLISH);
+    StorageUnit parsedUnit = null;
+    for (StorageUnit unit : StorageUnit.values()) {
+      if (
+        sanitizedValue.endsWith(unit.getShortName()) || sanitizedValue.endsWith(unit.getLongName())
+          || sanitizedValue.endsWith(unit.getSuffixChar())
+      ) {
+        parsedUnit = unit;
+        break;
+      }
+    }
+
+    if (parsedUnit == null) {
+      throw new IllegalArgumentException(
+        value + " is not in expected format." + "Expected format is <number><unit>. e.g. 1000MB");
+    }
+
+    String suffix = "";
+    boolean found = false;
+
+    // We are trying to get the longest match first, so the order of
+    // matching is getLongName, getShortName and then getSuffixChar.
+    if (!found && sanitizedValue.endsWith(parsedUnit.getLongName())) {
+      found = true;
+      suffix = parsedUnit.getLongName();
+    }
+
+    if (!found && sanitizedValue.endsWith(parsedUnit.getShortName())) {
+      found = true;
+      suffix = parsedUnit.getShortName();
+    }
+
+    if (!found && sanitizedValue.endsWith(parsedUnit.getSuffixChar())) {
+      found = true;
+      suffix = parsedUnit.getSuffixChar();
+    }
+
+    checkState(found, "Something is wrong, we have to find a " + "match. Internal error.");
+
+    String valString = sanitizedValue.substring(0, value.length() - suffix.length());
+    return new StorageSize(parsedUnit, Double.parseDouble(valString));
+
+  }
+
+  public StorageUnit getUnit() {
+    return unit;
+  }
+
+  public double getValue() {
+    return value;
+  }
+}