Move memory parsing to utility class.

org.jdrupes.vmoperator.util/src/org/jdrupes/vmoperator/util/ParseUtils.java

@@ -0,0 +1,95 @@
+/*
+ * VM-Operator
+ * Copyright (C) 2023 Michael N. Lipp
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.jdrupes.vmoperator.util;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
+
+/**
+ * Provides methods for parsing.
+ */
+@SuppressWarnings("PMD.UseUtilityClass")
+public class ParseUtils {
+
+    @SuppressWarnings({ "PMD.UseConcurrentHashMap",
+        "PMD.FieldNamingConventions", "PMD.VariableNamingConventions" })
+    private static final Map<String, BigInteger> unitMap = new HashMap<>();
+    @SuppressWarnings({ "PMD.FieldNamingConventions",
+        "PMD.VariableNamingConventions" })
+    private static final Pattern memorySize
+        = Pattern.compile("^\\s*(\\d+(\\.\\d+)?)\\s*([A-Za-z]*)\\s*");
+
+    static {
+        // SI units and common abbreviations
+        BigInteger factor = BigInteger.ONE;
+        unitMap.put("", factor);
+        BigInteger scale = BigInteger.valueOf(1000);
+        for (var unit : List.of("B", "kB", "MB", "GB", "TB", "PB", "EB")) {
+            unitMap.put(unit, factor);
+            factor = factor.multiply(scale);
+        }
+        // Binary units
+        factor = BigInteger.valueOf(1024);
+        scale = BigInteger.valueOf(1024);
+        for (var unit : List.of("KiB", "MiB", "GiB", "TiB", "PiB", "EiB")) {
+            unitMap.put(unit, factor);
+            unitMap.put(unit.substring(0, 2), factor);
+            factor = factor.multiply(scale);
+        }
+    }
+
+    /**
+     * Parses a memory size specification.
+     *
+     * @param amount the amount
+     * @return the big integer
+     */
+    @SuppressWarnings("PMD.DataflowAnomalyAnalysis")
+    public static BigInteger parseMemory(Object amount) {
+        if (amount == null) {
+            return (BigInteger) amount;
+        }
+        if (amount instanceof BigInteger number) {
+            return number;
+        }
+        if (amount instanceof Number number) {
+            return BigInteger.valueOf(number.longValue());
+        }
+        var matcher = memorySize.matcher(amount.toString());
+        if (!matcher.matches()) {
+            throw new NumberFormatException(amount.toString());
+        }
+        var unit = BigInteger.ONE;
+        if (matcher.group(3) != null) {
+            unit = unitMap.get(matcher.group(3));
+            if (unit == null) {
+                throw new NumberFormatException("Illegal unit \""
+                    + matcher.group(3) + "\" in \"" + amount.toString() + "\"");
+            }
+        }
+        var number = matcher.group(1);
+        return new BigDecimal(number).multiply(new BigDecimal(unit))
+            .toBigInteger();
+    }
+
+}