StandardMetadataTimingStatistic.java

package org.springframework.roo.metadata.internal;

import org.apache.commons.lang3.Validate;
import org.springframework.roo.metadata.MetadataTimingStatistic;

/**
 * Standard implementation of {@link MetadataTimingStatistic}.
 * 
 * @author Ben Alex
 */
public class StandardMetadataTimingStatistic implements MetadataTimingStatistic {

  // Chosen to match the maximum
  private static final int MAXIMUM_EXPECTED_INVOCATIONS = 5;

  private static final String INVOCATION_COUNT_FORMAT = "%" + MAXIMUM_EXPECTED_INVOCATIONS + "d";

  static final long NANOSECONDS_IN_MILLISECOND = 1000000L;
  private static final String TIME_FORMAT = "%"
      + (String.valueOf(NANOSECONDS_IN_MILLISECOND).length() - 1) + "d";

  private final long invocations;
  private final String name;
  private final long nanoseconds;

  /**
   * Constructor
   * 
   * @param name (required)
   * @param nanoseconds the elasped time in nanoseconds (zero or more)
   * @param invocations (zero or more)
   */
  public StandardMetadataTimingStatistic(final String name, final long nanoseconds,
      final long invocations) {
    Validate.notBlank(name, "Name required");
    Validate.isTrue(invocations >= 0, "Invocations must be zero or more");
    Validate.isTrue(nanoseconds >= 0, "Nanoseconds must be zero or more");
    this.invocations = invocations;
    this.name = name;
    this.nanoseconds = nanoseconds;
  }

  public int compareTo(final MetadataTimingStatistic o) {
    int result = Long.valueOf(nanoseconds).compareTo(o.getTime());
    if (result == 0) {
      result = Long.valueOf(invocations).compareTo(o.getInvocations());
    }
    if (result == 0) {
      result = name.compareTo(o.getName());
    }
    return result;
  }

  @Override
  public boolean equals(final Object obj) {
    return obj instanceof MetadataTimingStatistic && compareTo((MetadataTimingStatistic) obj) == 0;
  }

  public long getInvocations() {
    return invocations;
  }

  public String getName() {
    return name;
  }

  public long getTime() {
    return nanoseconds;
  }

  @Override
  public int hashCode() {
    return Long.valueOf(nanoseconds).hashCode() * Long.valueOf(invocations).hashCode()
        * name.hashCode();
  }

  @Override
  public String toString() {
    final StringBuilder sb = new StringBuilder();
    if (nanoseconds < NANOSECONDS_IN_MILLISECOND) {
      // Display as nanoseconds
      sb.append(String.format(TIME_FORMAT, nanoseconds)).append(" ns; ");
    } else {
      // Display as milliseconds
      sb.append(String.format(TIME_FORMAT, nanoseconds / 1000000)).append(" ms; ");
    }
    sb.append(String.format(INVOCATION_COUNT_FORMAT, invocations)).append(" call(s): ");
    sb.append(name);
    return sb.toString();
  }
}