The Instance Provider Interface (InstanceProvider) (WBEMfor Solaris on Sun Developer's Guide)

WBEMfor Solaris on Sun Developer's Guide

The Instance Provider Interface (`InstanceProvider`)

The following table describes the methods in the instance provider interface in the Provider package (com.sun.wbem.provider).

These methods each take the op argument, the CIM object path of the specified CIM class or CIM instance. The object path includes the namespace, class name, and keys (if the object is an instance). The namespace is a directory that can contain other namespaces, classes, instances, and qualifier types. A key is a property that uniquely identifies an instance of a class. Key properties have a KEY qualifier.

For example, the following object path has two parts:

\\myserver\root\cimv2\Solaris_ComputerSystem:Name=mycomputer:
   CreationClassName=Solaris_ComputerSystem

\\myserver\root\cimv2

The default CIM namespace on host myserver.
Solaris_ComputerSystem:Name=mycomputer: CreationClassName=Solaris_ComputerSystem

A specific Solaris Computer System object in the default namespace on host myserver. This Solaris computer system is uniquely identified by two key property values in the format (property=value):
- Name=mycomputer
- CreationClassName=Solaris_ComputerSystem

Table 7-2 InstanceProvider Interface Methods


Method	Description
`enumInstances`	Enumerates all instances of the class specified in the object path. You can do deep or shallow enumeration, but currently the CIM Object Manager only requests shallow enumeration.
`getInstance`	Returns the instance specified in the object path (`op`).
`setInstance`	Sets the instance specified in the object path (`op`). If the instance does not exist, it must be added.
`deleteInstance`	Deletes the instance specified in the object path (`op`).

Example -- Implementing an Instance Provider

The code segment in Example 7-1, creates a Solaris instance provider class that routes requests for instance data from the CIM Object Manager to one or more specialized providers. These specialized providers service requests for dynamic data for a particular type of Solaris object. For example, the Solaris_Package provider services requests for instances of the Solaris_Package class.

An instance provider must implement all methods in the InstanceProvider interface. The code segment in Example 7-1 shows only two methods:

enumInstances - Calls the appropriate provider to enumerate Solaris packages and patches. This method does a deep enumeration, which returns the class instances and all instances of its subclasses.
getInstances - Calls the appropriate provider to get instances of Solaris packages and patches.

Example 7-1 Implementing an Instance Provider

public class Solaris implements InstanceProvider
{
   /**
    * Top-level provider class routes requests from the CIM
    * Object Manager to the appropriate provider.
    */
 
    public void initialize(CIMONHandle, ch) 
    throws CIMException {
    }
 
    public void cleanup() 
    throws CIMException {
    }
 
    /* This class returns a vector of enumerated instances of the 
    specified object in the specified class. If the object is a 
    Solaris package, it calls the Solaris_Package provider to return 
    a list of the Solaris packages on the system. If the object is a 
    Solaris patch, it calls the Solaris_Patch provider to return a 
    list of the Solaris patches on the system. */
 
    public Vector enumInstances(CIMObjectPath op, CIMClient.DEEP, CIMClass cc)
    throws CIMException {
        if (op.getObjectName().equalsIgnoreCase("solaris_package")) {
            Solaris_Package sp = new Solaris_Package();
            return sp.enumerateInstances(op);
        }
        if (op.getObjectName().equalsIgnoreCase("solaris_patch")) {
            Solaris_Patch sp = new Solaris_Patch();
            return sp.enumerateInstances(op);
        }
       return new Vector();
    }
 
 
    /* This class returns an instance of the specified object in the 
    specified class. If the object is a Solaris package, it
    calls the Solaris_Package provider to return the data for the
    specified Solaris package. If the object is a Solaris patch, it 
    calls the Solaris_Patch provider to return the data for the 
    specified Solaris patch. */
 
    public CIMInstance getInstance(CIMObjectPath op, CIMClass cc) 
    throws CIMException {
        if (op.getObjectName().equalsIgnoreCase("solaris_package")) {
            Solaris_Package sp = new Solaris_Package();     
            return sp.getInstance(op,cc);
        }
        if (op.getObjectName().equalsIgnoreCase("solaris_patch")) {
            Solaris_Patch sp = new Solaris_Patch();         
            return sp.getInstance(op,cc);
        } 
}

The specialized Solaris instance providers use the API to get and set instances of objects. These providers also declare native methods that call C functions to get Solaris-specific values, such as host name, serial number, release, machine, architecture, and manufacturer.

The code segment in Example 7-2 shows the solaris_package class, which is called in Example 7-1. This code segment implements the getInstance method. This method creates a new instance of the specified class and then fills it with properties returned from native C functions, such as GetPkgArchitecture().

Example 7-2 Solaris Package Provider

public class Solaris_Package 
{
    public CIMInstance getInstance(CIMObjectPath op, CIMClass cc) {
        String pkgName = "";
 
        for (Enumeration e = op.getKeys().elements(); e.hasMoreElements();) {
            CIMProperty cp = (CIMProperty)e.nextElement();
            if (cp.getName().equalsIgnoreCase("name")) {
                pkgName = (String) ((CIMValue)(cp.getValue())).getValue();
            }
        }
 
 
        CIMInstance ci = cc.newInstance();
        ci.setProperty("Name", new CIMValue(pkgName));
        ci.setProperty("TargetOperatingSystem", 
                          new CIMValue(new UnsignedInt16(29)));
 
        ci.setProperty("Status", 
                     new CIMValue(GetPkgStatus(pkgName)));
  			 ci.setProperty("Architecture", 
                          new CIMValue(GetPkgArchitecture(pkgName)));
        ci.setProperty("Description", new CIMValue(GetPkgDescription(pkgName)));
        ci.setProperty("Caption", new CIMValue(GetPkgDescription(pkgName)));
        ci.setProperty("Manufacturer", new CIMValue(GetPkgVendor(pkgName)));
        ci.setProperty("Category", new CIMValue(GetPkgCategory(pkgName)));
        ci.setProperty("Basedir", new CIMValue(GetPkgBasedir(pkgName)));
       return ci;
    }
 
    native String GetPkgDescription(String pkgName);
    native String GetPkgArchitecture(String pkgName);
    native String GetPkgVersion(String pkgName);
    native String GetPkgVendor(String pkgName);
    native String GetPkgBasedir(String pkgName);
    native String GetPkgCategory(String pkgName);
    native String GetPkgStatus(String pkgName);
 
 
   static {
       System.loadLibrary("NativeUnix");
   
    }
 
}