Added a util class for durations

aksw-commons-utils-parent/aksw-commons-utils/src/main/java/org/aksw/commons/util/time/TimeAgo.java

@@ -0,0 +1,132 @@
+package org.aksw.commons.util.time;
+
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
+import java.util.AbstractMap.SimpleEntry;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map.Entry;
+import java.util.concurrent.TimeUnit;
+import java.util.function.BiFunction;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.HashBiMap;
+
+
+public class TimeAgo {
+
+    public static final List<Long> times = Arrays.asList(
+            TimeUnit.DAYS.toMillis(365),
+            TimeUnit.DAYS.toMillis(30),
+            TimeUnit.DAYS.toMillis(1),
+            TimeUnit.HOURS.toMillis(1),
+            TimeUnit.MINUTES.toMillis(1),
+            TimeUnit.SECONDS.toMillis(1));
+
+    public static final List<ChronoUnit> timesString = Arrays.asList(
+            ChronoUnit.YEARS,
+            ChronoUnit.MONTHS,
+            ChronoUnit.DAYS,
+            ChronoUnit.HOURS,
+            ChronoUnit.MINUTES,
+            ChronoUnit.SECONDS);
+
+    public static final BiMap<String, ChronoUnit> suffixToUnit = HashBiMap.create();
+
+    static {
+        suffixToUnit.put("ns", ChronoUnit.NANOS);
+        // suffixToUnit.put("mcs", ChronoUnit.MICROS);
+        suffixToUnit.put("ms", ChronoUnit.MILLIS);
+        suffixToUnit.put("s", ChronoUnit.SECONDS);
+        suffixToUnit.put("m", ChronoUnit.MINUTES);
+        suffixToUnit.put("h", ChronoUnit.HOURS);
+        suffixToUnit.put("d", ChronoUnit.DAYS);
+        suffixToUnit.put("M", ChronoUnit.MONTHS);
+        suffixToUnit.put("y", ChronoUnit.YEARS);
+    }
+
+    public static final Pattern parsePattern = Pattern.compile("(\\d+(\\.\\d*)?)([^\\d]*)");
+
+    public static Duration parse(String string) {
+        Matcher matcher = parsePattern.matcher(string);
+        Duration result = Duration.ZERO;
+        while (matcher.find()) {
+            String numberStr = matcher.group(1);
+            String unitStr = matcher.group(3);
+
+            Double number = Double.parseDouble(numberStr);
+            ChronoUnit chronoUnit = unitStr.isBlank() ? ChronoUnit.SECONDS : suffixToUnit.get(unitStr);
+
+            TimeUnit timeUnit = TimeUnit.of(chronoUnit);
+            long factor = TimeUnit.NANOSECONDS.convert(1, timeUnit);
+            long nanos = Math.multiplyExact(number.longValue(), factor);
+            Duration contrib = Duration.of(nanos, ChronoUnit.NANOS);
+
+            result = result == null ? contrib : result.plus(contrib);
+        }
+        return result;
+    }
+
+    public static String fmtLong(long value, ChronoUnit chronoUnit) {
+        return (value == 0 ? "moments" : value) + " " + chronoUnit.toString().toLowerCase() + " ago";
+    }
+
+    public static String fmtCompact(long value, ChronoUnit chronoUnit) {
+        String suffix = suffixToUnit.inverse().get(chronoUnit);
+        if (suffix == null) {
+            suffix = "(unknown time unit)";
+        }
+
+        return value == 0
+                ? "now"
+                : Long.toString(value) + suffix;
+    }
+
+    public static String toDuration(long duration, BiFunction<Long, ChronoUnit, String> formatter) {
+        Entry<Long, ChronoUnit> pair = toDuration(duration);
+        String result = formatter.apply(pair.getKey(), pair.getValue());
+        return result;
+    }
+
+    public static Entry<Long, ChronoUnit> toDuration(long duration) {
+
+        long value = 0;
+        ChronoUnit unit = null;
+        for (int i = 0; i < TimeAgo.times.size(); i++) {
+            Long current = TimeAgo.times.get(i);
+            long temp = duration / current;
+            if (temp > 0) {
+                value = temp;
+                unit = timesString.get(i);
+                break;
+            }
+        }
+        if (unit == null) {
+            unit = ChronoUnit.SECONDS;
+        }
+
+
+        return new SimpleEntry<>(value, unit);
+    }
+
+    public static void main(String args[]) {
+        Locale.setDefault(Locale.GERMAN);
+
+        System.out.println(parse("5m5m"));
+
+        BiFunction<Long, ChronoUnit, String> labelizer = TimeAgo::fmtCompact;
+        System.out.println(toDuration(123, labelizer));
+        System.out.println(toDuration(1230, labelizer));
+        System.out.println(toDuration(12300, labelizer));
+        System.out.println(toDuration(123000, labelizer));
+        System.out.println(toDuration(1230000, labelizer));
+        System.out.println(toDuration(12300000, labelizer));
+        System.out.println(toDuration(123000000, labelizer));
+        System.out.println(toDuration(1230000000, labelizer));
+        System.out.println(toDuration(12300000000L, labelizer));
+        System.out.println(toDuration(123000000000L, labelizer));
+    }
+}