HADOOP-8608. Add Configuration API for parsing time durations.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1494825 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -138,6 +138,8 @@ Release 2.1.0-beta - UNRELEASED
     HADOOP-9517. Documented various aspects of compatibility for Apache
     Hadoop. (Karthik Kambatla via acmurthy)
 
+    HADOOP-8608. Add Configuration API for parsing time durations. (cdouglas)
+
   OPTIMIZATIONS
 
     HADOOP-9150. Avoid unnecessary DNS resolution attempts for logical URIs

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java

@@ -54,6 +54,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
+import java.util.concurrent.TimeUnit;
 
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
@@ -1139,6 +1140,93 @@ public class Configuration implements Iterable<Map.Entry<String,String>>,
       : Enum.valueOf(defaultValue.getDeclaringClass(), val);
   }
 
+  enum ParsedTimeDuration {
+    NS {
+      TimeUnit unit() { return TimeUnit.NANOSECONDS; }
+      String suffix() { return "ns"; }
+    },
+    US {
+      TimeUnit unit() { return TimeUnit.MICROSECONDS; }
+      String suffix() { return "us"; }
+    },
+    MS {
+      TimeUnit unit() { return TimeUnit.MILLISECONDS; }
+      String suffix() { return "ms"; }
+    },
+    S {
+      TimeUnit unit() { return TimeUnit.SECONDS; }
+      String suffix() { return "s"; }
+    },
+    M {
+      TimeUnit unit() { return TimeUnit.MINUTES; }
+      String suffix() { return "m"; }
+    },
+    H {
+      TimeUnit unit() { return TimeUnit.HOURS; }
+      String suffix() { return "h"; }
+    },
+    D {
+      TimeUnit unit() { return TimeUnit.DAYS; }
+      String suffix() { return "d"; }
+    };
+    abstract TimeUnit unit();
+    abstract String suffix();
+    static ParsedTimeDuration unitFor(String s) {
+      for (ParsedTimeDuration ptd : values()) {
+        // iteration order is in decl order, so SECONDS matched last
+        if (s.endsWith(ptd.suffix())) {
+          return ptd;
+        }
+      }
+      return null;
+    }
+    static ParsedTimeDuration unitFor(TimeUnit unit) {
+      for (ParsedTimeDuration ptd : values()) {
+        if (ptd.unit() == unit) {
+          return ptd;
+        }
+      }
+      return null;
+    }
+  }
+
+  /**
+   * Set the value of <code>name</code> to the given time duration. This
+   * is equivalent to <code>set(&lt;name&gt;, value + &lt;time suffix&gt;)</code>.
+   * @param name Property name
+   * @param value Time duration
+   * @param unit Unit of time
+   */
+  public void setTimeDuration(String name, long value, TimeUnit unit) {
+    set(name, value + ParsedTimeDuration.unitFor(unit).suffix());
+  }
+
+  /**
+   * Return time duration in the given time unit. Valid units are encoded in
+   * properties as suffixes: nanoseconds (ns), microseconds (us), milliseconds
+   * (ms), seconds (s), minutes (m), hours (h), and days (d).
+   * @param name Property name
+   * @param defaultValue Value returned if no mapping exists.
+   * @param unit Unit to convert the stored property, if it exists.
+   * @throws NumberFormatException If the property stripped of its unit is not
+   *         a number
+   */
+  public long getTimeDuration(String name, long defaultValue, TimeUnit unit) {
+    String vStr = get(name);
+    if (null == vStr) {
+      return defaultValue;
+    }
+    vStr = vStr.trim();
+    ParsedTimeDuration vUnit = ParsedTimeDuration.unitFor(vStr);
+    if (null == vUnit) {
+      LOG.warn("No unit for " + name + "(" + vStr + ") assuming " + unit);
+      vUnit = ParsedTimeDuration.unitFor(unit);
+    } else {
+      vStr = vStr.substring(0, vStr.lastIndexOf(vUnit.suffix()));
+    }
+    return unit.convert(Long.parseLong(vStr), vUnit.unit());
+  }
+
   /**
    * Get the value of the <code>name</code> property as a <code>Pattern</code>.
    * If no such property is specified, or if the specified value is not a valid

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/conf/TestConfiguration.java

@@ -36,6 +36,7 @@ import java.util.Map;
 import java.util.Random;
 import java.util.Set;
 import java.util.regex.Pattern;
+import static java.util.concurrent.TimeUnit.*;
 
 import junit.framework.TestCase;
 import static org.junit.Assert.assertArrayEquals;
@@ -694,6 +695,37 @@ public class TestConfiguration extends TestCase {
     assertTrue(fail);
   }
 
+  public void testTimeDuration() {
+    Configuration conf = new Configuration(false);
+    conf.setTimeDuration("test.time.a", 7L, SECONDS);
+    assertEquals("7s", conf.get("test.time.a"));
+    assertEquals(0L, conf.getTimeDuration("test.time.a", 30, MINUTES));
+    assertEquals(7L, conf.getTimeDuration("test.time.a", 30, SECONDS));
+    assertEquals(7000L, conf.getTimeDuration("test.time.a", 30, MILLISECONDS));
+    assertEquals(7000000L,
+        conf.getTimeDuration("test.time.a", 30, MICROSECONDS));
+    assertEquals(7000000000L,
+        conf.getTimeDuration("test.time.a", 30, NANOSECONDS));
+    conf.setTimeDuration("test.time.b", 1, DAYS);
+    assertEquals("1d", conf.get("test.time.b"));
+    assertEquals(1, conf.getTimeDuration("test.time.b", 1, DAYS));
+    assertEquals(24, conf.getTimeDuration("test.time.b", 1, HOURS));
+    assertEquals(MINUTES.convert(1, DAYS),
+        conf.getTimeDuration("test.time.b", 1, MINUTES));
+
+    // check default
+    assertEquals(30L, conf.getTimeDuration("test.time.X", 30, SECONDS));
+    conf.set("test.time.X", "30");
+    assertEquals(30L, conf.getTimeDuration("test.time.X", 40, SECONDS));
+
+    for (Configuration.ParsedTimeDuration ptd :
+         Configuration.ParsedTimeDuration.values()) {
+      conf.setTimeDuration("test.time.unit", 1, ptd.unit());
+      assertEquals(1 + ptd.suffix(), conf.get("test.time.unit"));
+      assertEquals(1, conf.getTimeDuration("test.time.unit", 2, ptd.unit()));
+    }
+  }
+
   public void testPattern() throws IOException {
     out = new BufferedWriter(new FileWriter(CONFIG));
     startConfig();