Description

The DataStore API is missing a dispose() method that would allow the various datastores holding some kind of resource reference to release it. Notable examples are:

• ArcSDE and JDBC datastores, that hold onto a connection pool
• caching datastore wrappers, that hold onto a in memory or disk based cache

Status

This proposal is ready for discussion.

Voting:

• Andrea Aime +1
• Ian Turton +1
• Justin Deoliveira +1
• jgarnett +1
• Martin Desruisseaux +0
• Simone Giannecchini +1

Tasks

	no progress		done		impeded		lack mandate/funds/time		volunteer needed

API Changes

BEFORE

Before datastore users could only release the connection and hope the datastore would clean up after itself somehow (usually letting the garbage collector tear down whatever resource was held into memory):

   DataStore myDataStore = ...;
   // use datastore
   ...
   myDataStore = null;
   System.gc(); System.gc(); System.gc(); // clean up pretty please!!!

AFTER

The proposed change is:

public interface DataStore {
  ...
  /**
   * Releases all resources eventually held by this DataStore. The DataStore and all objects
   * generated out of it are not supposed to be working anymore after this method is called. 
   * This call provides no thread safety guarantees, making sure nothing else goes on while
   * closing the datastore is a responsibility of the client code.
   * Subsequent calls to this method will be treated as no-ops.
   */
  public void dispose();
}

Sample use:

   DataStore myDataStore = null;
   try {
      myDataStore = ...;
      // use data store
      ...
   } finally {
     if(myDataStore != null) 
       myDataStore.dipose();
   }

Documentation Changes

Please list the pages effected by this proposal.

Website:

• Update Upgrade to 2.4 instructions

User Guide:

• Update examples to reflect changes to the DataStore API

User Manual:

• Update examples to reflect changes to the DataStore API

Issue Tracker:

• check related issues to see of problems are affected