HiveUtils.java

package org.hivedb.util;

import org.hivedb.Hive;
import org.hivedb.meta.Node;
import org.hivedb.meta.directory.KeySemaphore;
import org.hivedb.util.functional.Transform;
import org.hivedb.util.functional.Unary;

import java.util.*;

public class HiveUtils {
  /**
   * This belongs in a utility class. Takes field values of an instance to generate a hash code
   *
   * @param objects
   * @return
   */
  public static int makeHashCode(Object... objects) {
    return makeHashCode(Arrays.asList(objects));
  }

  public static int makeHashCode(Collection<?> collection) {
    String result = "";
    for (Object object : collection)
      if (object != null)
        result += (object instanceof Collection ? new HashSet<Object>((Collection<?>) object).hashCode() : object.hashCode());
    return result.hashCode();
  }

  static int globalDeepFormatedStringTabLevel = 0;

  public static String toDeepFormatedString(Object target, Object... alteringKeyValues) {

    String tabs = makeTabs(globalDeepFormatedStringTabLevel);
    String formatString = "\n" + tabs + "%s (HashCode:%s)\n";
    Object[] values = new Object[2 + alteringKeyValues.length / 2];
    values[0] = target.getClass().getSimpleName();
    values[1] = target.hashCode();
    tabs = makeTabs(++globalDeepFormatedStringTabLevel);
    for (int i = 0; i < alteringKeyValues.length; i += 2) {
      formatString += "\n" + tabs + alteringKeyValues[i] + ":%s";
      values[i / 2 + 2] = alteringKeyValues[i + 1] instanceof Collection
        ? toDeepFormatedStringOfCollection(Arrays.asList(alteringKeyValues[i + 1]))
        : alteringKeyValues[i + 1];
    }
    globalDeepFormatedStringTabLevel--;
    return String.format(formatString, values);
  }

  public static String toDeepFormatedStringOfCollection(Collection<Object> collection) {
    String tabs = makeTabs(++globalDeepFormatedStringTabLevel);
    Set<Object> set = new TreeSet<Object>(collection);

    Object[] objects = new Object[1 + set.size()];
    String formatString = "[(Collection HashCode:%s)\n";
    objects[0] = set.hashCode();
    Iterator<?> iterator = set.iterator();
    for (int i = 1; i < objects.length; i++) {
      objects[i] = iterator.next();
      formatString += tabs + "%s" + (iterator.hasNext() ? ", " : "");
    }
    formatString += "]";
    globalDeepFormatedStringTabLevel--;
    return String.format(formatString, objects);
  }

  private static String makeTabs(int count) {
    String tabs = "";
    for (int i = 0; i < count; i++) tabs += "\t";
    return tabs;
  }

  public static Collection<Node> getNodesForSemaphores(Collection<KeySemaphore> semaphores, final Hive hive) {
    return Transform.map(new Unary<KeySemaphore, Node>() {
      public Node f(KeySemaphore item) {
        return hive.getNode(item.getNodeId());
      }
    }, semaphores);
  }

  public static <T> T defaultTo(T obj, T value) {
    return obj == null ? value : obj;
  }

  public static boolean empty(String s) {
    return s == null || "".equals(s);
  }
}