[HBASE-17512] Optimize ServerName.parsePort() to reduce objects creation

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.2.4
• Labels: beginner
• Assignee: Samuel David Glover
• Reporter: Jean-Marc Spaggiari
• Created: 23/Jan/17 16:42
• Updated: 02/Feb/23 08:55

Description

ServerName.parsePort() calls the split method on a string. This string format is like "www.example.org,1234,1212121212" where we try to get only 1234. Each time the split() method is called, it creates 4 objets. 3 strings and an array. And we just us one of those strings.

This this method is called in a single place. In the constructor:

  private ServerName(final String serverName) {
    this(parseHostname(serverName), parsePort(serverName),
      parseStartcode(serverName));
  }

So parsePort creates 3 string. Te hostname, the port, the startcode, but returns only the port, while we call 2 other methods to redo the exact same work.

This constructor is called only there:

  /**
   * Retrieve an instance of ServerName.
   * Callers should use the equals method to compare returned instances, though we may return
   * a shared immutable object as an internal optimization.
   */
  public static ServerName valueOf(final String serverName) {
    return new ServerName(serverName);
  }

and this is called here and there. Not intensively, but still, should be cleaned.

Instead of using split, something like this might do better:

  public static int parsePort(final String serverName) {
    int indexStart = serverName.indexOf(SERVERNAME_SEPARATOR);
    int indexStop = serverName.lastIndexOf(SERVERNAME_SEPARATOR);
    return Integer.parseInt(serverName.substring(indexStart + 1, indexStop));
  }