/*
 * Copyright (c) 1999, 2004, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.jndi.toolkit.ctx;

import java.util.Hashtable;

import javax.naming.*;
import javax.naming.spi.ResolveResult;

Provides implementation of p_* operations using
c_* operations provided by subclasses.
Clients: deal only with names for its own naming service.  Must
provide implementations for c_* methods, and for p_parseComponent()
and the c_*_nns methods if the defaults are not appropriate.
Author:
Rosanna Lee, Scott Seligman/**
  * Provides implementation of p_* operations using
  * c_* operations provided by subclasses.
  *
  * Clients: deal only with names for its own naming service.  Must
  * provide implementations for c_* methods, and for p_parseComponent()
  * and the c_*_nns methods if the defaults are not appropriate.
  *
  * @author Rosanna Lee
  * @author Scott Seligman
  */

public abstract class ComponentContext extends PartialCompositeContext {
    private static int debug = 0;

    protected ComponentContext() {
        _contextType = _COMPONENT;
    }

// ------ Abstract methods whose implementation are provided by subclass

    /* Equivalent methods in Context interface */
    protected abstract Object c_lookup(Name name, Continuation cont)
        throws NamingException;
    protected abstract Object c_lookupLink(Name name, Continuation cont)
        throws NamingException;

    protected abstract NamingEnumeration c_list(Name name,
        Continuation cont) throws NamingException;
    protected abstract NamingEnumeration c_listBindings(Name name,
        Continuation cont) throws NamingException;
    protected abstract void c_bind(Name name, Object obj, Continuation cont)
        throws NamingException;
    protected abstract void c_rebind(Name name, Object obj, Continuation cont)
        throws NamingException;
    protected abstract void c_unbind(Name name, Continuation cont)
        throws NamingException;
    protected abstract void c_destroySubcontext(Name name, Continuation cont)
        throws NamingException;
    protected abstract Context c_createSubcontext(Name name,
        Continuation cont) throws NamingException;
    protected abstract void c_rename(Name oldname, Name newname,
        Continuation cont) throws NamingException;
    protected abstract NameParser c_getNameParser(Name name, Continuation cont)
        throws NamingException;

// ------ Methods that may need to be overridden by subclass

    /* Parsing method */
    
Determines which of the first components of 'name' belong
to this naming system.
If no components belong to this naming system, return
the empty name (new CompositeName()) as the head,
and the entire name as the tail.
The default implementation supports strong separation.
If the name is empty or if the first component is empty,
head is the empty name and tail is the entire name.
(This means that this context does not have any name to work with).
Otherwise, it returns the first component as head, and the rest of
the components as tail.
Subclass should override this method according its own policies.
For example, a weakly separated system with dynamic boundary
determination would simply return as head 'name'.
A weakly separated with static boundary
determination would select the components in the front of 'name'
that conform to some syntax rules.  (e.g. in X.500 syntax, perhaps
select front components that have a equal sign).
If none conforms, return an empty name.
/**
      * Determines which of the first components of 'name' belong
      * to this naming system.
      * If no components belong to this naming system, return
      * the empty name (new CompositeName()) as the head,
      * and the entire name as the tail.
      *
      * The default implementation supports strong separation.
      * If the name is empty or if the first component is empty,
      * head is the empty name and tail is the entire name.
      * (This means that this context does not have any name to work with).
      * Otherwise, it returns the first component as head, and the rest of
      * the components as tail.
      *
      * Subclass should override this method according its own policies.
      *
      * For example, a weakly separated system with dynamic boundary
      * determination would simply return as head 'name'.
      * A weakly separated with static boundary
      * determination would select the components in the front of 'name'
      * that conform to some syntax rules.  (e.g. in X.500 syntax, perhaps
      * select front components that have a equal sign).
      * If none conforms, return an empty name.
      */
    protected HeadTail p_parseComponent(Name name, Continuation cont)
        throws NamingException {
        int separator;
        // if no name to parse, or if we're already at boundary
        if (name.isEmpty() ||  name.get(0).equals("")) {
            separator = 0;
        } else {
            separator = 1;
        }
        Name head, tail;

        if (name instanceof CompositeName) {
            head = name.getPrefix(separator);
            tail = name.getSuffix(separator);
        } else {
            // treat like compound name
            head = new CompositeName().add(name.toString());
            tail = null;
        }

        if (debug > 2) {
            System.err.println("ORIG: " + name);
            System.err.println("PREFIX: " + name);
            System.err.println("SUFFIX: " + null);
        }
        return new HeadTail(head, tail);
    }


    /* Resolution method for supporting federation */

    
Resolves the nns for 'name' when the named context is acting
as an intermediate context.
For a system that supports only junctions, this would be
equilvalent to
        c_lookup(name, cont);
because for junctions, an intermediate slash simply signifies
a syntactic separator.
For a system that supports only implicit nns, this would be
equivalent to
        c_lookup_nns(name, cont);
because for implicit nns, a slash always signifies the implicit nns,
regardless of whether it is intermediate or trailing.
By default this method supports junctions, and also allows for an
implicit nns to be dynamically determined through the use of the
"nns" reference (see c_processJunction_nns()).
Contexts that implement implicit nns directly should provide an
appropriate override.
A junction, by definition, is a binding of a name in one
namespace to an object in another.  The default implementation
of this method detects the crossover into another namespace
using the following heuristic:  there is a junction when "name"
resolves to a context that is not an instance of
this.getClass().  Contexts supporting junctions for which this
heuristic is inappropriate should override this method.
/**
      * Resolves the nns for 'name' when the named context is acting
      * as an intermediate context.
      *
      * For a system that supports only junctions, this would be
      * equilvalent to
      *         c_lookup(name, cont);
      * because for junctions, an intermediate slash simply signifies
      * a syntactic separator.
      *
      * For a system that supports only implicit nns, this would be
      * equivalent to
      *         c_lookup_nns(name, cont);
      * because for implicit nns, a slash always signifies the implicit nns,
      * regardless of whether it is intermediate or trailing.
      *
      * By default this method supports junctions, and also allows for an
      * implicit nns to be dynamically determined through the use of the
      * "nns" reference (see c_processJunction_nns()).
      * Contexts that implement implicit nns directly should provide an
      * appropriate override.
      *
      * A junction, by definition, is a binding of a name in one
      * namespace to an object in another.  The default implementation
      * of this method detects the crossover into another namespace
      * using the following heuristic:  there is a junction when "name"
      * resolves to a context that is not an instance of
      * this.getClass().  Contexts supporting junctions for which this
      * heuristic is inappropriate should override this method.
      */
    protected Object c_resolveIntermediate_nns(Name name, Continuation cont)
        throws NamingException {
            try {
                final Object obj = c_lookup(name, cont);

                // Do not append "" to Continuation 'cont' even if set
                // because the intention is to ignore the nns

                if (obj != null && getClass().isInstance(obj)) {
                    // If "obj" is in the same type as this object, it must
                    // not be a junction. Continue the lookup with "/".

                    cont.setContinueNNS(obj, name, this);
                    return null;

                } else if (obj != null && !(obj instanceof Context)) {
                    // obj is not even a context, so try to find its nns
                    // dynamically by constructing a Reference containing obj.
                    RefAddr addr = new RefAddr("nns") {
                        public Object getContent() {
                            return obj;
                        }
                        private static final long serialVersionUID =
                            -8831204798861786362L;
                    };
                    Reference ref = new Reference("java.lang.Object", addr);

                    // Resolved name has trailing slash to indicate nns
                    CompositeName resName = (CompositeName)name.clone();
                    resName.add(""); // add trailing slash

                    // Set continuation leave it to
                    // PartialCompositeContext.getPCContext() to throw CPE.
                    // Do not use setContinueNNS() because we've already
                    // consumed "/" (i.e., moved it to resName).

                    cont.setContinue(ref, resName, this);
                    return null;
                } else {
                    // Consume "/" and continue
                    return obj;
                }

            } catch (NamingException e) {
                e.appendRemainingComponent(""); // add nns back
                throw e;
            }
        }

    /* Equivalent of Context Methods for supporting nns */

    // The following methods are called when the Context methods
    // are invoked with a name that has a trailing slash.
    // For naming systems that support implicit nns,
    // the trailing slash signifies the implicit nns.
    // For such naming systems, override these c_*_nns methods.
    //
    // For naming systems that do not support implicit nns, the
    // default implementations here throw an exception.  See
    // c_processJunction_nns() for details.

    protected Object c_lookup_nns(Name name, Continuation cont)
        throws NamingException {
            c_processJunction_nns(name, cont);
            return null;
        }

    protected Object c_lookupLink_nns(Name name, Continuation cont)
        throws NamingException {
            c_processJunction_nns(name, cont);
            return null;
        }

    protected NamingEnumeration c_list_nns(Name name,
        Continuation cont) throws NamingException {
            c_processJunction_nns(name, cont);
            return null;
        }

    protected NamingEnumeration c_listBindings_nns(Name name,
        Continuation cont) throws NamingException {
            c_processJunction_nns(name, cont);
            return null;
        }

    protected void c_bind_nns(Name name, Object obj, Continuation cont)
        throws NamingException {
            c_processJunction_nns(name, cont);
        }

    protected void c_rebind_nns(Name name, Object obj, Continuation cont)
        throws NamingException {
            c_processJunction_nns(name, cont);
        }

    protected void c_unbind_nns(Name name, Continuation cont)
        throws NamingException {
            c_processJunction_nns(name, cont);
        }

    protected Context c_createSubcontext_nns(Name name,
        Continuation cont) throws NamingException {
            c_processJunction_nns(name, cont);
            return null;
        }

    protected void c_destroySubcontext_nns(Name name, Continuation cont)
        throws NamingException {
            c_processJunction_nns(name, cont);
        }


    protected void c_rename_nns(Name oldname, Name newname, Continuation cont)
        throws NamingException {
            c_processJunction_nns(oldname, cont);
        }

    protected NameParser c_getNameParser_nns(Name name, Continuation cont)
        throws NamingException {
            c_processJunction_nns(name, cont);
            return null;
        }

// ------ internal method used by ComponentContext

    
Locates the nns using the default policy.  This policy fully
handles junctions, but otherwise throws an exception when an
attempt is made to resolve an implicit nns.
The default policy is as follows:  If there is a junction in
the namespace, then resolve to the junction and continue the
operation there (thus deferring to that context to find its own
nns).  Otherwise, resolve as far as possible and then throw
CannotProceedException with the resolved object being a reference:
the address type is "nns", and the address contents is this
context.
For example, when c_bind_nns(name, obj, ...) is invoked, the
caller is attempting to bind the object "obj" to the nns of
"name".  If "name" is a junction, it names an object in another
naming system that (presumably) has an nns.  c_bind_nns() will
first resolve "name" to a context and then attempt to continue
the bind operation there, (thus binding to the nns of the
context named by "name").  If "name" is empty then throw an
exception, since this context does not by default support an
implicit nns.
To implement a context that does support an implicit nns, it is
necessary to override this default policy.  This is done by
overriding the c_*_nns() methods (which each call this method
by default).
/**
     * Locates the nns using the default policy.  This policy fully
     * handles junctions, but otherwise throws an exception when an
     * attempt is made to resolve an implicit nns.
     *
     * The default policy is as follows:  If there is a junction in
     * the namespace, then resolve to the junction and continue the
     * operation there (thus deferring to that context to find its own
     * nns).  Otherwise, resolve as far as possible and then throw
     * CannotProceedException with the resolved object being a reference:
     * the address type is "nns", and the address contents is this
     * context.
     *
     * For example, when c_bind_nns(name, obj, ...) is invoked, the
     * caller is attempting to bind the object "obj" to the nns of
     * "name".  If "name" is a junction, it names an object in another
     * naming system that (presumably) has an nns.  c_bind_nns() will
     * first resolve "name" to a context and then attempt to continue
     * the bind operation there, (thus binding to the nns of the
     * context named by "name").  If "name" is empty then throw an
     * exception, since this context does not by default support an
     * implicit nns.
     *
     * To implement a context that does support an implicit nns, it is
     * necessary to override this default policy.  This is done by
     * overriding the c_*_nns() methods (which each call this method
     * by default).
     */
    protected void c_processJunction_nns(Name name, Continuation cont)
            throws NamingException
    {
        if (name.isEmpty()) {
            // Construct a new Reference that contains this context.
            RefAddr addr = new RefAddr("nns") {
                public Object getContent() {
                    return ComponentContext.this;
                }
                private static final long serialVersionUID =
                    -1389472957988053402L;
            };
            Reference ref = new Reference("java.lang.Object", addr);

            // Set continuation leave it to PartialCompositeContext.getPCContext()
            // to throw the exception.
            // Do not use setContinueNNS() because we've are
            // setting relativeResolvedName to "/".
            cont.setContinue(ref, _NNS_NAME, this);
            return;
        }

        try {
            // lookup name to continue operation in nns
            Object target = c_lookup(name, cont);
            if (cont.isContinue())
                cont.appendRemainingComponent("");
            else {
                cont.setContinueNNS(target, name, this);
            }
        } catch (NamingException e) {
            e.appendRemainingComponent(""); // add nns back
            throw e;
        }
    }

    protected static final byte USE_CONTINUATION = 1;
    protected static final byte TERMINAL_COMPONENT = 2;
    protected static final byte TERMINAL_NNS_COMPONENT = 3;

    
Determine whether 'name' is a terminal component in
this naming system.
If so, return status indicating so, so that caller
can perform context operation on this name.
If not, then the first component(s) of 'name' names
an intermediate context.  In that case, resolve these components
and set Continuation to be the object named.
see test cases at bottom of file.
/**
      * Determine whether 'name' is a terminal component in
      * this naming system.
      * If so, return status indicating so, so that caller
      * can perform context operation on this name.
      *
      * If not, then the first component(s) of 'name' names
      * an intermediate context.  In that case, resolve these components
      * and set Continuation to be the object named.
      *
      * see test cases at bottom of file.
      */

    protected HeadTail p_resolveIntermediate(Name name, Continuation cont)
        throws NamingException {
        int ret = USE_CONTINUATION;
        cont.setSuccess();      // initialize
        HeadTail p = p_parseComponent(name, cont);
        Name tail = p.getTail();
        Name head = p.getHead();

        if (tail == null || tail.isEmpty()) {
//System.out.println("terminal : " + head);
            ret = TERMINAL_COMPONENT;
        } else if (!tail.get(0).equals("")) {
            // tail does not begin with "/"
/*
            if (head.isEmpty()) {
                // Context could not find name that it can use
                // illegal syntax error or name not found
//System.out.println("nnf exception : " + head);
                NamingException e = new NameNotFoundException();
                cont.setError(this, name);
                throw cont.fillInException(e);
            } else  {
*/
                // head is being used as intermediate context,
                // resolve head and set Continuation with tail
                try {
                    Object obj = c_resolveIntermediate_nns(head, cont);
//System.out.println("resInter : " + head + "=" + obj);
                    if (obj != null)
                        cont.setContinue(obj, head, this, tail);
                    else if (cont.isContinue()) {
                        checkAndAdjustRemainingName(cont.getRemainingName());
                        cont.appendRemainingName(tail);
                    }
                } catch (NamingException e) {
                    checkAndAdjustRemainingName(e.getRemainingName());
                    e.appendRemainingName(tail);
                    throw e;
                }
/*
            }
*/
        } else {
            // tail begins with "/"
            if (tail.size() == 1) {
                ret = TERMINAL_NNS_COMPONENT;
//System.out.println("terminal_nns : " + head);
            } else if (head.isEmpty() || isAllEmpty(tail)) {
                // resolve nns of head and continue with tail.getSuffix(1)
                Name newTail = tail.getSuffix(1);
                try {
                    Object obj = c_lookup_nns(head, cont);
//System.out.println("lookup_nns : " + head + "=" + obj);
                    if (obj != null)
                        cont.setContinue(obj, head, this, newTail);
                    else if (cont.isContinue()) {
                        cont.appendRemainingName(newTail);
//                      Name rname = cont.getRemainingName();
//System.out.println("cont.rname" + rname);
                    }
                } catch (NamingException e) {
                    e.appendRemainingName(newTail);
                    throw e;
                }
            } else {
                // head is being used as intermediate context
                // resolve and set continuation to tail
                try {
                    Object obj = c_resolveIntermediate_nns(head, cont);
//System.out.println("resInter2 : " + head + "=" + obj);
                    if (obj != null)
                        cont.setContinue(obj, head, this, tail);
                    else if (cont.isContinue()) {
                        checkAndAdjustRemainingName(cont.getRemainingName());
                        cont.appendRemainingName(tail);
                    }
                } catch (NamingException e) {
                    checkAndAdjustRemainingName(e.getRemainingName());
                    e.appendRemainingName(tail);
                    throw e;
                }
            }
        }

        p.setStatus(ret);
        return p;
    }

    // When c_resolveIntermediate_nns() or c_lookup_nns() sets up
    // its continuation, to indicate "nns", it appends an empty
    // component to the remaining name (e.g. "eng/"). If last
    // component of remaining name is empty; delete empty component
    // before appending tail so that composition of the names work
    // correctly. For example, when merging "eng/" and "c.b.a", we want
    // the result to be "eng/c.b.a" because the trailing slash in eng
    // is extraneous.  When merging "" and "c.b.a", we want the result
    // to be "/c.b.a" and so must keep the trailing slash (empty name).
    void checkAndAdjustRemainingName(Name rname) throws InvalidNameException {
        int count;
        if (rname != null && (count=rname.size()) > 1 &&
            rname.get(count-1).equals("")) {
            rname.remove(count-1);
        }
    }

    // Returns true if n contains only empty components
    protected boolean isAllEmpty(Name n) {
        int count = n.size();
        for (int i =0; i < count; i++ ) {
            if (!n.get(i).equals("")) {
                return false;
            }
        }
        return true;
    }



// ------ implementations of p_ Resolver and Context methods using
// ------ corresponding c_ and c_*_nns methods


    /* implementation for Resolver method */

    protected ResolveResult p_resolveToClass(Name name,
                                             Class contextType,
                                             Continuation cont)
            throws NamingException {

        if (contextType.isInstance(this)) {
            cont.setSuccess();
            return (new ResolveResult(this, name));
        }

        ResolveResult ret = null;
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
        case TERMINAL_NNS_COMPONENT:
            Object obj = p_lookup(name, cont);
            if (!cont.isContinue() && contextType.isInstance(obj)) {
                ret = new ResolveResult(obj, _EMPTY_NAME);
            }
            break;

        case TERMINAL_COMPONENT:
            cont.setSuccess();  // no contextType found; return null
            break;

        default:
            /* USE_CONTINUATION */
            /* pcont already set or exception thrown */
            break;
        }
        return ret;
    }

    /* implementations of p_ Context methods */

    protected Object p_lookup(Name name, Continuation cont) throws NamingException {
        Object ret = null;
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                ret = c_lookup_nns(res.getHead(), cont);
                if (ret instanceof LinkRef) {
                    cont.setContinue(ret, res.getHead(), this);
                    ret = null;
                }
                break;

            case TERMINAL_COMPONENT:
                ret = c_lookup(res.getHead(), cont);
                if (ret instanceof LinkRef) {
                    cont.setContinue(ret, res.getHead(), this);
                    ret = null;
                }
                break;

            default:
                /* USE_CONTINUATION */
                /* pcont already set or exception thrown */
                break;
        }
        return ret;
    }

    protected NamingEnumeration p_list(Name name, Continuation cont)
        throws NamingException {
        NamingEnumeration ret = null;
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                if (debug > 0)
                    System.out.println("c_list_nns(" + res.getHead() + ")");
                ret = c_list_nns(res.getHead(), cont);
                break;

            case TERMINAL_COMPONENT:
                if (debug > 0)
                    System.out.println("c_list(" + res.getHead() + ")");
                ret = c_list(res.getHead(), cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
        return ret;
    }

    protected NamingEnumeration p_listBindings(Name name, Continuation cont) throws
        NamingException {
        NamingEnumeration ret = null;
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                ret = c_listBindings_nns(res.getHead(), cont);
                break;

            case TERMINAL_COMPONENT:
                ret = c_listBindings(res.getHead(), cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
        return ret;
    }

    protected void p_bind(Name name, Object obj, Continuation cont) throws
        NamingException {
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                c_bind_nns(res.getHead(), obj, cont);
                break;

            case TERMINAL_COMPONENT:
                c_bind(res.getHead(), obj, cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
    }

    protected void p_rebind(Name name, Object obj, Continuation cont) throws
        NamingException {
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                c_rebind_nns(res.getHead(), obj, cont);
                break;

            case TERMINAL_COMPONENT:
                c_rebind(res.getHead(), obj, cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
    }

    protected void p_unbind(Name name, Continuation cont) throws
        NamingException {
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                c_unbind_nns(res.getHead(), cont);
                break;

            case TERMINAL_COMPONENT:
                c_unbind(res.getHead(), cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
    }

    protected void p_destroySubcontext(Name name, Continuation cont) throws
        NamingException {
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                c_destroySubcontext_nns(res.getHead(), cont);
                break;

            case TERMINAL_COMPONENT:
                c_destroySubcontext(res.getHead(), cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
    }

    protected Context p_createSubcontext(Name name, Continuation cont) throws
        NamingException {
            Context ret = null;
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                ret = c_createSubcontext_nns(res.getHead(), cont);
                break;

            case TERMINAL_COMPONENT:
                ret = c_createSubcontext(res.getHead(), cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
        return ret;
    }

    protected void p_rename(Name oldName, Name newName, Continuation cont) throws
        NamingException {
        HeadTail res = p_resolveIntermediate(oldName, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                c_rename_nns(res.getHead(), newName, cont);
                break;

            case TERMINAL_COMPONENT:
                c_rename(res.getHead(), newName, cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
    }

    protected NameParser p_getNameParser(Name name, Continuation cont) throws
        NamingException {
        NameParser ret = null;
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                ret = c_getNameParser_nns(res.getHead(), cont);
                break;

            case TERMINAL_COMPONENT:
                ret = c_getNameParser(res.getHead(), cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
        return ret;
    }

    protected Object p_lookupLink(Name name, Continuation cont)
        throws NamingException {
        Object ret = null;
        HeadTail res = p_resolveIntermediate(name, cont);
        switch (res.getStatus()) {
            case TERMINAL_NNS_COMPONENT:
                ret = c_lookupLink_nns(res.getHead(), cont);
                break;

            case TERMINAL_COMPONENT:
                ret = c_lookupLink(res.getHead(), cont);
                break;

            default:
                /* USE_CONTINUATION */
                /* cont already set or exception thrown */
                break;
        }
        return ret;
    }
}

/*
 *      How p_resolveIntermediate() should behave for various test cases

a.b/x   {a.b, x}
        c_resolveIntermediate_nns(a.b)
        continue(x)
        {x,}
        terminal(x)

a.b/    {a.b, ""}
        terminal_nns(a.b);

a.b//
        {a.b, ("", "")}
        c_lookup_nns(a.b)
        continue({""})
        {,""}
        terminal_nns({})

/x      {{}, {"", x}}
        c_lookup_nns({})
        continue(x)
        {x,}
        terminal(x)

//y     {{}, {"", "", y}}
        c_lookup_nns({})
        continue({"", y})
        {{}, {"", y}}
        c_lookup_nns({})
        continue(y)
        {y,}
        terminal(y)

a.b//y  {a.b, {"", y}}
        c_resolveIntermediate_nns(a.b)
        continue({"", y})
        {{}, {"",y}}
        c_lookup_nns({});
        continue(y)
        {y,}
        terminal(y);
 *
 */