RexxHashTable.cpp

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/*----------------------------------------------------------------------------*/
/*                                                                            */
/* Copyright (c) 1995, 2004 IBM Corporation. All rights reserved.             */
/* Copyright (c) 2005-2009 Rexx Language Association. All rights reserved.    */
/*                                                                            */
/* This program and the accompanying materials are made available under       */
/* the terms of the Common Public License v1.0 which accompanies this         */
/* distribution. A copy is also available at the following address:           */
/* http://www.oorexx.org/license.html                          */
/*                                                                            */
/* Redistribution and use in source and binary forms, with or                 */
/* without modification, are permitted provided that the following            */
/* conditions are met:                                                        */
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/* notice, this list of conditions and the following disclaimer.              */
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/* the documentation and/or other materials provided with the distribution.   */
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/* Neither the name of Rexx Language Association nor the names                */
/* of its contributors may be used to endorse or promote products             */
/* derived from this software without specific prior written permission.      */
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/* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT   */
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/* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.               */
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/*----------------------------------------------------------------------------*/
/******************************************************************************/
/* REXX Kernel                                                                */
/*                                                                            */
/* Primitive Hash Table Class                                                 */
/*                                                                            */
/******************************************************************************/
#include "RexxCore.h"
#include "RexxHashTable.hpp"
#include "ArrayClass.hpp"
#include "SupplierClass.hpp"
#include "ProtectedObject.hpp"
 
/******************************************************************************/
/*                                                                            */
/* NOTE:  The following value for NO_MORE is based on the assumption that all */
/* hash table entry chaining proceeds upward from the lower section of the    */
/* table to the upper table.  That is, offset zero is never used for a next   */
/* element location.  This fact allows us to just issue a ClearObject call    */
/* to initialize the hash table rather than having to explicitly set each     */
/* index pointer to a value such as -1.                                       */
/*                                                                            */
/******************************************************************************/
 
// link terminator
const HashLink NO_MORE = 0;
// indicates not linked
const HashLink NO_LINK = ~((HashLink)0);
 
                                       /* compare a value item to the value */
                                       /* at the specified position         */
bool inline EQUAL_VALUE(RexxObject *value, RexxObject *other)
{
                                       /* true for either direct identity or*/
                                       /* real equality ("==")              */
  return (value == other) || value->isEqual(other);
}
 
RexxHashTable *RexxHashTable::newInstance(
  size_t entries )                     /* number of entries in the table    */
/******************************************************************************/
/* Function:  Create a new hash table                                         */
/******************************************************************************/
{
    RexxHashTable * newHash;             /* new hash table object             */
    size_t bytes;                        /* size of the allocated object      */
    size_t bucketSize;                   /* size of the bucket                */
 
    bucketSize = entries / 2;            /* get the size of the bucket from this capacity */
    if (bucketSize % 2 == 0)
    {           /* if this is even, increase it      */
        bucketSize++;
    }
 
    entries = bucketSize * 2;            /* double the bucket size for the overflow */
 
    bytes = sizeof(RexxHashTable) + (sizeof(TABENTRY) * (entries - 1));
    /* Get new object                    */
    newHash = (RexxHashTable *)new_object(bytes, T_HashTable);
    newHash->size = bucketSize;          /* record the size                   */
    newHash->free = entries - 1;         /* and the first free slot           */
    return newHash;                      /* and return it                     */
}
 
RexxTable *RexxHashTable::newInstance(
  size_t entries,                      /* number of entries in the table    */
  size_t companionSize,                /* size of companion "table" object  */
  size_t type)                         // type of collection we're creating
/******************************************************************************/
/* Function:  Create a hash table object and a "companion" table, vdict,      */
/*            directory, or relation object all in one shot.                  */
/*                                                                            */
/* Note:      It is necessary to make several assumptions about the           */
/*            "companion" object.  1)  The size specified is already a        */
/*            multiple of 4.  2)  The companion has an OREF pointing to the   */
/*            hashtab object in the same location as the table class.         */
/******************************************************************************/
{
    RexxHashTable *newHash;              /* new hash table object             */
    RexxTable     *newObj;               /* associated table object           */
    size_t bytes;                        /* size of the allocated object      */
    size_t bucketSize;                   /* size of the bucket                */
 
    bucketSize = entries / 2;            /* get the size of the bucket from this capacity */
    if (bucketSize % 2 == 0)
    {           /* if this is even, increase it      */
        bucketSize++;
    }
 
    entries = bucketSize * 2;            /* double the bucket size for the overflow */
                                         /* Compute size of hash tab object   */
    bytes = roundObjectBoundary(sizeof(RexxHashTable) + (sizeof(TABENTRY) * (entries - 1)));
    /* make sure we've got proper sizes for each of the object parts. */
    companionSize = roundObjectBoundary(companionSize);
    /* Get space for two objects         */
    newObj = (RexxTable *)new_object(bytes + companionSize, type);
                                         /* address the hash table            */
    newHash = (RexxHashTable *)(((char *)newObj) + companionSize);
    /* compute total size of the hash    */
    /* table (allowing for possible      */
    /* over allocation by the memory     */
    /* manager                           */
    bytes = newObj->getObjectSize() - companionSize;
 
    // initialize the hash table object
    ((RexxObject *)newHash)->initializeNewObject(bytes, memoryObject.markWord, RexxMemory::virtualFunctionTable[T_HashTable], TheHashTableBehaviour);
    /* reduce the companion size         */
    newObj->setObjectSize(companionSize);
    newHash->size = bucketSize;          /* record the size                   */
    newHash->free = entries - 1;         /* and the first free slot           */
                                         /* hook the hash into the companion  */
                                         /* OrefSet is not used, because the  */
                                         /* companion object is not fully set */
    newObj->contents = newHash;          /* up yet (no behaviour)             */
    return newObj;                       /* return the object                 */
}
 
void RexxHashTable::live(size_t liveMark)
/******************************************************************************/
/* Function:  Normal garbage collection live marking                          */
/******************************************************************************/
{
    TABENTRY *ep;                        /* table element pointer             */
    TABENTRY *endp;
    /* hash table size                   */
    size_t count = this->totalSlotsSize();
 
    /* loop through all of the entries   */
    for (ep = this->entries, endp = ep + count; ep < endp; ep++)
    {
        if (ep->index != OREF_NULL)        /* have a value here?                */
        {
            memory_mark(ep->index);          /* mark both the index and the       */
            memory_mark(ep->value);          /* value                             */
        }
    }
}
 
void RexxHashTable::liveGeneral(int reason)
/******************************************************************************/
/* Function:  Generalized object marking                                      */
/******************************************************************************/
{
    TABENTRY *ep;                        /* table element pointer             */
                                         /* hash table size                   */
    size_t count = this->totalSlotsSize();
 
    /* loop through all of the entries   */
    for (ep = this->entries; ep < this->entries + count; ep++)
    {
        if (ep->index != OREF_NULL)        /* have a value here?                */
        {
            memory_mark_general(ep->index);  /* mark both the index and the       */
            memory_mark_general(ep->value);  /* value                             */
        }
    }
}
 
void RexxHashTable::flatten(RexxEnvelope *envelope)
/******************************************************************************/
/* Function:  Flatten an object                                               */
/******************************************************************************/
{
    setUpFlatten(RexxHashTable)
    size_t count = this->totalSlotsSize();  /* hash table size                   */
 
    for (size_t i=0; i < count ; i++)
    {
        if (this->entries[i].index != OREF_NULL)
        {
            flatten_reference(newThis->entries[i].index, envelope);
            flatten_reference(newThis->entries[i].value, envelope);
        }
    }
    cleanUpFlatten
}
 
RexxHashTable * RexxHashTable::add(
    RexxObject *_value,                 /* added element value               */
    RexxObject *_index)                 /* added index value                 */
/******************************************************************************/
/* Function:  Add an element to a hash table.  If the table needs to expand,  */
/*            the new table is returned.                                      */
/******************************************************************************/
{
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    /* if the hash slot is empty         */
    if (this->entries[position].index == OREF_NULL)
    {
        /* fill in both the value and index  */
        OrefSet(this,this->entries[position].value, _value);
        OrefSet(this,this->entries[position].index, _index);
        return OREF_NULL;                  /* successful  addition              */
    }
    /* go insert                         */
    return this->insert(_value, _index, position, FULL_TABLE);
}
 
RexxHashTable * RexxHashTable::primitiveAdd(
    RexxObject *_value,                 /* added element value               */
    RexxObject *_index)                 /* added index value                 */
/******************************************************************************/
/* Function:  Add an element to a hash table.  If the table needs to expand,  */
/*            the new table is returned.                                      */
/******************************************************************************/
{
    HashLink position = hashPrimitiveIndex(_index);   /* calculate the hash slot           */
    /* if the hash slot is empty         */
    if (this->entries[position].index == OREF_NULL)
    {
        /* fill in both the value and index  */
        OrefSet(this,this->entries[position].value, _value);
        OrefSet(this,this->entries[position].index, _index);
        return OREF_NULL;                  /* successful  addition              */
    }
    /* go insert                         */
    return this->insert(_value, _index, position, PRIMITIVE_TABLE);
}
 
 
RexxObject *RexxHashTable::remove(
            RexxObject *_index)         /* index to remove                   */
/******************************************************************************/
/* Function:  Remove an element from a hash table                             */
/******************************************************************************/
{
    HashLink _next;                      /* next hash position                */
    RexxObject *removed;                 /* removed item value                */
 
    HashLink position = hashIndex(_index);        /* calculate the hash slot           */
    HashLink previous = NO_LINK;                  /* no previous slot yet              */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get a match?                      */
            if (EQUAL_VALUE(_index, this->entries[position].index))
            {
                /* save the current value            */
                removed = this->entries[position].value;
                /* get the next pointer              */
                _next = this->entries[position].next;
                if (_next == NO_MORE)
                {        /* end of the chain?                 */
                         /* clear this slot entry             */
                    OrefSet(this,this->entries[position].index,OREF_NULL);
                    OrefSet(this,this->entries[position].value,OREF_NULL);
                    if (previous != NO_LINK)     /* if not the first of the chain     */
                    {
                        /* IH: In this special case we delete an item from the overhead and
                               therefore might have to increase the free counter, otherwise
                               hash table will be extended unnecessarily !!! */
                        if (position > this->free)
                        {
                            this->free = position;
                        }
                        /* break the link                    */
                        this->entries[previous].next = NO_MORE;
                    }
                }                              /* non-terminal chain element        */
                else
                {
                    /* close up the link                 */
                    this->entries[position].next = this->entries[_next].next;
                    /* copy value and index to current   */
                    OrefSet(this,this->entries[position].index,this->entries[_next].index);
                    OrefSet(this,this->entries[position].value,this->entries[_next].value);
                    /* clear the next entry              */
                    OrefSet(this,this->entries[_next].index,OREF_NULL);
                    OrefSet(this,this->entries[_next].value,OREF_NULL);
                    /* set to "pristine" condition       */
                    this->entries[_next].next = NO_MORE;
                    if (this->free < _next)       /* new-low water mark?               */
                    {
                        this->free = _next;         /* reset to this point               */
                    }
                }
                return removed;                /* return removed element value      */
            }
            else
            {
                previous = position;           /* remember previous member          */
            }
                                               /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return OREF_NULL;                    /* removed item not found            */
}
 
 
/**
 * Remove all elements with a given index from a hashtable,
 * returning an array of all items.
 *
 * @param _index The target index.
 *
 * @return An array of all matching items.
 */
RexxObject *RexxHashTable::removeAll(RexxObject *_index)
{
    // get a count of matching items
    size_t count = countAll(_index);
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    RexxArray *result = new_array(count);           /* get proper size result array      */
    // only copy if we have something to remove
    if (count > 0)
    {
        size_t i = 1;                               /* start at the first element        */
        HashLink previous = NO_LINK;                  /* no previous slot yet              */
        do
        {                                 /* while more items in chain         */
            /* copy the value into our array     */
            result->put(this->entries[position].value,i++);
                                          /* if got a match                    */
            if (EQUAL_VALUE(_index, this->entries[position].index))
            {
                /* get the next pointer              */
                HashLink _next = this->entries[position].next;
                if (_next == NO_MORE)
                {        /* end of the chain?                 */
                         /* clear this slot entry             */
                    OrefSet(this,this->entries[position].index,OREF_NULL);
                    OrefSet(this,this->entries[position].value,OREF_NULL);
                    if (previous != NO_LINK)     /* if not the first of the chain     */
                    {
                        /* IH: In this special case we delete an item from the overhead and
                               therefore might have to increase the free counter, otherwise
                               hash table will be extended unnecessarily !!! */
                        if (position > this->free)
                        {
                            this->free = position;
                        }
                        /* break the link                    */
                        this->entries[previous].next = NO_MORE;
                    }
                    return result;             // we've hit the end of the chain, we're done
                }                              /* non-terminal chain element        */
                else
                {
                    /* close up the link                 */
                    this->entries[position].next = this->entries[_next].next;
                    /* copy value and index to current   */
                    OrefSet(this,this->entries[position].index,this->entries[_next].index);
                    OrefSet(this,this->entries[position].value,this->entries[_next].value);
                    /* clear the next entry              */
                    OrefSet(this,this->entries[_next].index,OREF_NULL);
                    OrefSet(this,this->entries[_next].value,OREF_NULL);
                    /* set to "pristine" condition       */
                    this->entries[_next].next = NO_MORE;
                    if (this->free < _next)       /* new-low water mark?               */
                    {
                        this->free = _next;         /* reset to this point               */
                    }
 
                    // NOTE:  We don't update either previous or position because we'll
                    // be looking at the same link again
                }
            }
            else
            {
                // remember the previous position and step to the next one
                previous = position;
                position = this->entries[position].next;
            }
            /* step to the next link             */
        } while (position != NO_MORE);
    }
    return result;                       /* return the result array           */
}
 
RexxObject *RexxHashTable::primitiveRemove(
            RexxObject *_index)        /* index to remove                   */
/******************************************************************************/
/* Function:  Remove an element from a hash table                             */
/******************************************************************************/
{
    HashLink _next;                      /* next hash position                */
    RexxObject *removed;                 /* removed item value                */
 
    HashLink position = hashPrimitiveIndex(_index); /* calculate the hash slot           */
 
    HashLink previous = NO_LINK;                  /* no previous slot yet              */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get a match?                      */
            if (_index == this->entries[position].index)
            {
                /* save the current value            */
                removed = this->entries[position].value;
                /* get the next pointer              */
                _next = this->entries[position].next;
                if (_next == NO_MORE)
                {         /* end of the chain?                 */
                    /* clear this slot entry             */
                    OrefSet(this,this->entries[position].index,OREF_NULL);
                    OrefSet(this,this->entries[position].value,OREF_NULL);
                    if (previous != NO_LINK)     /* if not the first of the chain     */
                    {
                        /* IH: In this special case we delete an item from the overhead and
                               therefore might have to increase the free counter, otherwise
                               hash table will be extended unnecessarily !!! */
                        if (position > this->free)
                        {
                            this->free = position;
                        }
                        /* break the link                    */
                        this->entries[previous].next = NO_MORE;
                    }
                }                              /* non-terminal chain element        */
                else
                {
                    /* close up the link                 */
                    this->entries[position].next = this->entries[_next].next;
                    /* copy value and index to current   */
                    OrefSet(this,this->entries[position].index,this->entries[_next].index);
                    OrefSet(this,this->entries[position].value,this->entries[_next].value);
                    /* clear the next entry              */
                    OrefSet(this,this->entries[_next].index,OREF_NULL);
                    OrefSet(this,this->entries[_next].value,OREF_NULL);
                    /* set to "pristine" condition       */
                    this->entries[_next].next = NO_MORE;
                    if (this->free < _next)      /* new-low water mark?               */
                    {
                        this->free = _next;         /* reset to this point               */
                    }
                }
                return removed;                /* return removed element value      */
            }
            else
            {
                previous = position;           /* remember previous member          */
            }
                                               /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return OREF_NULL;                    /* removed item not found            */
}
 
RexxObject *RexxHashTable::removeItem(
    RexxObject *_value,                 /* item to remove                    */
    RexxObject *_index )                /* index to remove                   */
/******************************************************************************/
/* Function:  Remove the tuple (value, item) from the hash table.  If         */
/*            the item is not found, .nil is returned.                        */
/******************************************************************************/
{
    HashLink _next;                      /* next hash position                */
    RexxObject * removed;                /* removed item value                */
 
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    HashLink previous = NO_LINK;                  /* no previous slot yet              */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get a match?                      */
            if (EQUAL_VALUE(_index, this->entries[position].index) &&
                EQUAL_VALUE(_value, this->entries[position].value))
            {
                /* save the current value            */
                removed = this->entries[position].value;
                /* get the next pointer              */
                _next = this->entries[position].next;
                if (_next == NO_MORE)
                {         /* end of the chain?                 */
                    /* clear this slot entry             */
                    OrefSet(this,this->entries[position].index,OREF_NULL);
                    OrefSet(this,this->entries[position].value,OREF_NULL);
                    if (previous != NO_LINK)     /* if not the first of the chain     */
                    {
                        /* break the link                    */
                        this->entries[previous].next = NO_MORE;
                    }
                }                              /* non-terminal chain element        */
                else
                {
                    /* close up the link                 */
                    this->entries[position].next = this->entries[_next].next;
                    /* copy value and index to current   */
                    OrefSet(this,this->entries[position].index,this->entries[_next].index);
                    OrefSet(this,this->entries[position].value,this->entries[_next].value);
                    /* clear the next entry              */
                    OrefSet(this,this->entries[_next].index,OREF_NULL);
                    OrefSet(this,this->entries[_next].value,OREF_NULL);
                    /* set to "pristine" condition       */
                    this->entries[_next].next = NO_MORE;
                    if (this->free < _next)       /* new-low water mark?               */
                    {
                        this->free = _next;         /* reset to this point               */
                    }
                }
                return removed;                /* return removed element value      */
            }
            else
            {
                previous = position;           /* remember previous member          */
            }
                                               /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return OREF_NULL;                    /* removed item not found            */
}
 
 
RexxObject *RexxHashTable::primitiveRemoveItem(
    RexxObject *_value,                 /* item to remove                    */
    RexxObject *_index )                /* index to remove                   */
/******************************************************************************/
/* Function:  Remove the tuple (value, item) from the hash table.  If         */
/*            the item is not found, .nil is returned.                        */
/******************************************************************************/
{
    HashLink _next;                      /* next hash position                */
    RexxObject * removed;                /* removed item value                */
 
    HashLink position = hashPrimitiveIndex(_index);  /* calculate the hash slot           */
    HashLink previous = NO_LINK;                  /* no previous slot yet              */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get a match?                      */
            if (_index == this->entries[position].index && _value == this->entries[position].value)
            {
                /* save the current value            */
                removed = this->entries[position].value;
                /* get the next pointer              */
                _next = this->entries[position].next;
                if (_next == NO_MORE)
                {        /* end of the chain?                 */
                         /* clear this slot entry             */
                    OrefSet(this,this->entries[position].index,OREF_NULL);
                    OrefSet(this,this->entries[position].value,OREF_NULL);
                    if (previous != NO_LINK)     /* if not the first of the chain     */
                    {
                        /* break the link                    */
                        this->entries[previous].next = NO_MORE;
                    }
                }                              /* non-terminal chain element        */
                else
                {
                    /* close up the link                 */
                    this->entries[position].next = this->entries[_next].next;
                    /* copy value and index to current   */
                    OrefSet(this,this->entries[position].index,this->entries[_next].index);
                    OrefSet(this,this->entries[position].value,this->entries[_next].value);
                    /* clear the next entry              */
                    OrefSet(this,this->entries[_next].index,OREF_NULL);
                    OrefSet(this,this->entries[_next].value,OREF_NULL);
                    /* set to "pristine" condition       */
                    this->entries[_next].next = NO_MORE;
                    if (this->free < _next)       /* new-low water mark?               */
                    {
                        this->free = _next;         /* reset to this point               */
                    }
                }
                return removed;                /* return removed element value      */
            }
            else
            {
                previous = position;           /* remember previous member          */
            }
                                               /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return OREF_NULL;                    /* removed item not found            */
}
 
RexxObject *RexxHashTable::primitiveHasItem(
    RexxObject *_value,                 /* item to locate                    */
    RexxObject *_index )                /* index to locate                   */
/******************************************************************************/
/* Function:  Determine if a tuple (value, item) pair exists in the hash      */
/*            table.  Return true if found, false other wise.                 */
/******************************************************************************/
{
    HashLink position = hashPrimitiveIndex(_index);    /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get a match?                      */
            if (_index == this->entries[position].index && _value == this->entries[position].value)
            {
                /* got the one we want               */
                return(RexxObject *)TheTrueObject;
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return(RexxObject *)TheFalseObject; /* item was not found                */
}
 
 
RexxObject *RexxHashTable::primitiveHasItem(
    RexxObject *_value)                 /* item to locate                    */
/******************************************************************************/
/* Function:  Determine if a tuple (value, item) pair exists in the hash      */
/*            table.  Return true if found, false other wise.                 */
/******************************************************************************/
{
    return primitiveGetIndex(_value) == OREF_NULL ? TheFalseObject : TheTrueObject;
}
 
 
RexxObject *RexxHashTable::hasItem(
    RexxObject *_value,                 /* item to locate                    */
    RexxObject *_index )                /* index to locate                   */
/******************************************************************************/
/* Function:  Determine if a tuple (value, item) pair exists in the hash      */
/*            table.  Return true if found, false other wise.                 */
/******************************************************************************/
{
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get a match?                      */
            if (EQUAL_VALUE(_index, this->entries[position].index) &&
                EQUAL_VALUE(_value, this->entries[position].value))
            {
                /* got the one we want               */
                return(RexxObject *)TheTrueObject;
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return(RexxObject *)TheFalseObject; /* item was not found                */
}
 
 
/**
 * Test if an item exists in the hash collection.
 *
 * @param value  The test value.
 *
 * @return .true if it exists, .false otherwise.
 */
RexxObject *RexxHashTable::hasItem(RexxObject *_value)
{
    // our size
    size_t count = this->totalSlotsSize();
 
    TABENTRY *ep = this->entries;
    TABENTRY *endp = ep + count;
                                         /* loop through all of the entries   */
    for (; ep < endp; ep++)
    {
        // if we have an item, see if it's the one we're looking for.
        if (ep->index != OREF_NULL)
        {
            if (EQUAL_VALUE(_value, ep->value))
            {
                return TheTrueObject;    // return the index value
 
            }
        }
    }
    return TheFalseObject;
}
 
 
/**
 * Removes an item from the hash table.
 *
 * @param value  The test value.
 *
 * @return .true if it exists, .false otherwise.
 */
RexxObject *RexxHashTable::removeItem(RexxObject *_value)
{
    // our size
    size_t count = this->totalSlotsSize();
 
    TABENTRY *ep = this->entries;
    TABENTRY *endp = ep + count;
                                         /* loop through all of the entries   */
    for (; ep < endp; ep++)
    {
        // if we have an item, see if it's the one we're looking for.
        if (ep->index != OREF_NULL)
        {
            if (EQUAL_VALUE(_value, ep->value))
            {
                // this is complicated, so it's easier to just remove
                // this using the fully qualified tuple.
                return removeItem(_value, ep->index);
            }
        }
    }
    return TheNilObject;
}
 
 
/**
 * Removes an item from the hash table.
 *
 * @param value  The test value.
 *
 * @return .true if it exists, .false otherwise.
 */
RexxObject *RexxHashTable::primitiveRemoveItem(RexxObject *_value)
{
    // our size
    size_t count = this->totalSlotsSize();
 
    TABENTRY *ep = this->entries;
    TABENTRY *endp = ep + count;
                                         /* loop through all of the entries   */
    for (; ep < endp; ep++)
    {
        // if we have an item, see if it's the one we're looking for.
        if (ep->index != OREF_NULL)
        {
            if (_value == ep->value)
            {
                // this is complicated, so it's easier to just remove
                // this using the fully qualified tuple.
                return primitiveRemoveItem(_value, ep->index);
            }
        }
    }
    return TheNilObject;
}
 
 
RexxObject *RexxHashTable::nextItem(
  RexxObject *_value,                   /* item to locate                    */
  RexxObject *_index )                  /* index to locate                   */
/******************************************************************************/
/* Function:  Return the next item with the key index that follows the        */
/*            given (value index) pair.  Used only for superscope lookup.     */
/*            Note:  This routine does the comparisons in as fast as way      */
/*            as possible, relying solely on object identify for a match.     */
/******************************************************************************/
{
    RexxObject *scope;                   /* returned scope                    */
 
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get a match?                      */
            if (this->entries[position].index == _index && this->entries[position].value == _value)
            {
                while ((position = this->entries[position].next) != NO_MORE)
                {
                    /* same index value?                 */
                    if (this->entries[position].index == _index)
                    {
                        /* this is the value we want         */
                        return this->entries[position].value;
                    }
                }
                return TheNilObject;           /* didn't find what we wanted        */
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
        /* must be added via setmethod, so   */
        scope = this->primitiveGet(_index);/* return first one for this index   */
                                           /* truely not there?                 */
        if (scope == (RexxObject *)OREF_NULL)
        {
            return TheNilObject;             /* return a failure                  */
        }
        return scope;                      /* return the first scope            */
    }
    return TheNilObject;                 /* item was not found                */
}
 
 
RexxObject *RexxHashTable::primitiveNextItem(
  RexxObject *_value,                   /* item to locate                    */
  RexxObject *_index )                  /* index to locate                   */
/******************************************************************************/
/* Function:  Return the next item with the key index that follows the        */
/*            given (value index) pair.  Used only for superscope lookup.     */
/*            Note:  This routine does the comparisons in as fast as way      */
/*            as possible, relying solely on object identify for a match.     */
/******************************************************************************/
{
    RexxObject *scope;                   /* returned scope                    */
 
    HashLink position = hashPrimitiveIndex(_index); /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get a match?                      */
            if (this->entries[position].index == _index && this->entries[position].value == _value)
            {
                while ((position = this->entries[position].next) != NO_MORE)
                {
                    /* same index value?                 */
                    if (this->entries[position].index == _index)
                    {
                        /* this is the value we want         */
                        return this->entries[position].value;
                    }
                }
                return TheNilObject;           /* didn't find what we wanted        */
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
        /* must be added via setmethod, so   */
        scope = this->primitiveGet(_index); /* return first one for this index   */
        /* truely not there?                 */
        if (scope == (RexxObject *)OREF_NULL)
        {
            return TheNilObject;             /* return a failure                  */
        }
        return scope;                      /* return the first scope            */
    }
    return TheNilObject;                 /* item was not found                */
}
 
RexxArray  *RexxHashTable::getAll(
    RexxObject *_index)                 /* target index                      */
/******************************************************************************/
/* Function:  Get all elements with a specified index as an array             */
/******************************************************************************/
{
    // get a count of matching items
    size_t count = countAll(_index);
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    RexxArray *result = new_array(count);           /* get proper size result array      */
    // only copy if we have something to copy
    if (count > 0)
    {
        size_t i = 1;                               /* start at the first element        */
        position = hashIndex(_index);         /* calculate the hash slot           */
        do
        {                                 /* while more items in chain         */
                                          /* if got a match                    */
            if (EQUAL_VALUE(_index, this->entries[position].index))
            {
                /* copy the value into our array     */
                result->put(this->entries[position].value,i++);
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return result;                       /* return the result array           */
}
 
/**
 * Return a count of all items with a given index.
 *
 * @param _index The target index
 *
 * @return The count of matching items.
 */
size_t RexxHashTable::countAll(RexxObject *_index)
{
    size_t count = 0;                           /* no items found yet                */
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* if got a match                    */
            if (EQUAL_VALUE(_index, this->entries[position].index))
            {
                count++;                       /* bump our counter                  */
            }
                                               /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
        return count;
    }
    else
    {
        /* no elements found                 */
        return 0;
    }
}
 
RexxArray  *RexxHashTable::primitiveGetAll(
    RexxObject *_index)                 /* target index                      */
/******************************************************************************/
/* Function:  Get all elements with a specified index as an array             */
/******************************************************************************/
{
    size_t count = 0;                           /* no items found yet                */
    HashLink position = hashPrimitiveIndex(_index);  /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* if got a match                    */
            if (_index == this->entries[position].index)
            {
                count++;                       /* bump our counter                  */
            }
                                               /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    else
    {
        /* no elements found                 */
        return(RexxArray *)TheNullArray->copy();
    }
 
    RexxArray *result = new_array(count);           /* get proper size result array      */
    size_t i = 1;                               /* start at the first element        */
    position = hashPrimitiveIndex(_index);  /* calculate the hash slot           */
    do
    {                                 /* while more items in chain         */
                                      /* if got a match                    */
        if (_index == this->entries[position].index)
        {
            /* copy the value into our array     */
            result->put(this->entries[position].value,i++);
        }
        /* step to the next link             */
    } while ((position = this->entries[position].next) != NO_MORE);
    return result;                       /* return the result array           */
}
 
RexxArray *RexxHashTable::stringGetAll(
    RexxString *_index)                 /* target index                      */
/******************************************************************************/
/* Function:  Return an array of all value with the same index (using string  */
/*            lookup semantics)                                               */
/******************************************************************************/
{
    const char *data = _index->getStringData();      /* get the string data               */
    sizeB_t length = _index->getBLength();        /* and the length also               */
    size_t count = 0;                           /* no items found yet                */
    HashLink position = hashStringIndex(_index);   /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get the entry                     */
            RexxString *entry = (RexxString *)this->entries[position].index;
            /* if got a match                    */
            if (_index == entry || entry->memCompare(data, length)) // todo m17n
            {
                count++;                       /* bump our counter                  */
            }
                                               /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    else
    {
        /* no elements found                 */
        return(RexxArray *)TheNullArray->copy();
    }
 
    RexxArray *result = new_array(count);           /* get proper size result array      */
    size_t i = 1;                               /* start at the first element        */
    position = hashIndex(_index);        /* calculate the hash slot           */
    do
    {                                 /* while more items in chain         */
                                      /* get the entry                     */
        RexxString *entry = (RexxString *)this->entries[position].index;
        /* if got a match                    */
        if (_index == entry || entry->memCompare(data, length)) // todo m17n
        {
            /* copy the value into our array     */
            result->put(this->entries[position].value,i++);
        }
        /* step to the next link             */
    } while ((position = this->entries[position].next) != NO_MORE);
    return result;                       /* return the result array           */
}
 
RexxArray  *RexxHashTable::allIndex(
    RexxObject *_value)                 /* target value item                 */
/******************************************************************************/
/* Function:  Return all index items that match the associated value          */
/*            item.                                                           */
/******************************************************************************/
{
    size_t count = 0;                           /* no items found yet                */
    size_t i;
    /* loop through them all             */
    for (i = this->totalSlotsSize(); i > 0; i--)
    {
        /* real entry?                       */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            /* is this the item we want?         */
            if (EQUAL_VALUE(_value, this->entries[i - 1].value))
            {
                count++;                       /* bump our counter                  */
            }
        }
    }
 
    RexxArray *result = new_array(count);           /* get proper size result array      */
    size_t j = 1;                               /* start at the first element        */
    /* loop through them all             */
    for (i = this->totalSlotsSize(); i > 0; i--)
    {
        /* real entry?                       */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            /* is this the item we want?         */
            if (EQUAL_VALUE(_value, this->entries[i - 1].value))
            {
                /* copy the value into our array     */
                result->put(this->entries[i - 1].index, j++);
            }
        }
    }
    return result;                       /* return the result array           */
}
 
 
RexxObject *RexxHashTable::getIndex(
    RexxObject *_value)                 /* target object                     */
/******************************************************************************/
/* Function:  Return an index associated with the supplied item.  The result  */
/*            is undefined for items that are referenced by multiple          */
/*            indices.                                                        */
/******************************************************************************/
{
    RexxObject *result = OREF_NULL;                  /* no item yet                       */
    /* loop through them all             */
    for (size_t i = this->totalSlotsSize(); i > 0; i--)
    {
        /* real entry?                       */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            /* is this the item we want?         */
            if (EQUAL_VALUE(_value, this->entries[i - 1].value))
            {
                /* get the index                     */
                result = this->entries[i - 1].index;
                break;                         /* finished                          */
            }
        }
    }
    return result;                       /* return the count                  */
}
 
 
RexxObject *RexxHashTable::primitiveGetIndex(
    RexxObject *_value)                 /* target object                     */
/******************************************************************************/
/* Function:  Return an index associated with the supplied item.  The result  */
/*            is undefined for items that are referenced by multiple          */
/*            indices.                                                        */
/******************************************************************************/
{
    RexxObject *result = OREF_NULL;                  /* no item yet                       */
    /* loop through them all             */
    for (size_t i = this->totalSlotsSize(); i > 0; i--)
    {
        /* real entry?                       */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            /* is this the item we want?         */
            if (_value == this->entries[i - 1].value)
            {
                /* get the index                     */
                result = this->entries[i - 1].index;
                break;                         /* finished                          */
            }
        }
    }
    return result;                       /* return the count                  */
}
 
 
RexxObject *RexxHashTable::get(
    RexxObject *_index)                 /* index of target item              */
/******************************************************************************/
/* Function:  Get an item from a hash table                                   */
/******************************************************************************/
{
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* if got a match                    */
            if (EQUAL_VALUE(_index, this->entries[position].index))
            {
                /* return this item's value          */
                return this->entries[position].value;
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return OREF_NULL;                    /* no value found                    */
}
 
RexxObject *RexxHashTable::primitiveGet(
    RexxObject *_index)                 /* index of target item              */
/******************************************************************************/
/* Function:  Get an item from a hash table                                   */
/******************************************************************************/
{
    HashLink position = hashPrimitiveIndex(_index);  /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* if got a match                    */
            if (_index == this->entries[position].index)
            {
                /* return this item's value          */
                return this->entries[position].value;
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return OREF_NULL;                    /* no value found                    */
}
 
RexxHashTable *RexxHashTable::insert(
    RexxObject *_value,                 /* value to insert                   */
    RexxObject * _index,                /* index to insert                   */
    HashLink position,                  /* insertion position                */
    int    type )                       /* string type insertion             */
/******************************************************************************/
/* Function:  Insert an element into an overflow location of a hash table     */
/******************************************************************************/
{
    HashLink over;                       /* overflow slot location            */
    RexxHashTable *newHash;              /* newly created hash table          */
    TABENTRY *primeEntry = &(this->entries[position]);
 
    HashLink low = this->mainSlotsSize();         /* get low free bound                */
    for (over = this->free;              /* look for overflow slot            */
        over >= low;
        over--)
    {
        TABENTRY *entry = &(this->entries[over]);
        /* find an empty slot?               */
        if (entry->index == OREF_NULL)
        {
            /* insert after hash slot            */
            entry->next = primeEntry->next;
            /* copy current index and value      */
            /* to the overflow slot              */
            OrefSet(this, entry->value, primeEntry->value);
            OrefSet(this, entry->index, primeEntry->index);
            /* set the new values in the first   */
            /* chain entry                       */
            OrefSet(this, primeEntry->value, _value);
            OrefSet(this, primeEntry->index, _index);
            /* set the overflow location         */
            primeEntry->next = over;
            this->free = over-1;             /* update free pointer               */
            return OREF_NULL;                /* this was a successful addition    */
        }
    }
    /* allocate a larger hash table      */
    newHash = new_hashtab(this->totalSlotsSize() * 2);
    ProtectedObject p(newHash);
    switch (type)
    {                      /* remerge based on the type         */
 
        case STRING_TABLE:                 /* string based table                */
            this->stringMerge(newHash);      /* do a string merge                 */
            break;
 
        case PRIMITIVE_TABLE:              /* primitive object table            */
            this->primitiveMerge(newHash);   /* do a primitive merge              */
            break;
 
        case FULL_TABLE:                   /* full table look ups               */
            this->reMerge(newHash);          /* do a normal merge                 */
            break;
    }
 
    // primitive tables require a primitive index.
    if (type == PRIMITIVE_TABLE)
    {
        position = newHash->hashPrimitiveIndex(_index);/* calculate the hash slot           */
    }
    else
    {
 
        position = newHash->hashIndex(_index);/* calculate the hash slot           */
    }
    /* if the hash slot is empty         */
    if (newHash->entries[position].index == OREF_NULL)
    {
        /* fill in both the value and index  */
        OrefSet(newHash, newHash->entries[position].value, _value);
        OrefSet(newHash, newHash->entries[position].index, _index);
    }
    else
    {
        /* try to insert again               */
        newHash->insert(_value, _index, position, type);
    }
    return newHash;                     /* return the new hash               */
}
 
RexxHashTable *RexxHashTable::stringAdd(
    RexxObject *_value,                 /* added element value               */
    RexxString *_index)                 /* added index value                 */
/******************************************************************************/
/* Function:  Add an element to a hash table, using only string searches      */
/******************************************************************************/
{
    HashLink position = hashStringIndex(_index);   /* calculate the hash slot           */
    /* if the hash slot is empty         */
    if (this->entries[position].index == OREF_NULL)
    {
        /* fill in both the value and index  */
        OrefSet(this, this->entries[position].value, _value);
        OrefSet(this, this->entries[position].index, _index);
        return OREF_NULL;                  /* successful  addition              */
    }
    else                                 /* hash slot is full                 */
    {
        /* go insert                         */
        return this->insert(_value, _index, position, STRING_TABLE);
    }
}
 
RexxObject *RexxHashTable::stringGet(
    RexxString *_index)                 /* index of target item              */
/******************************************************************************/
/* Function:  Search a hash table, restricting the search to string items.    */
/******************************************************************************/
{
    const char *data = _index->getStringData();            /* get the string data               */
    sizeB_t length = _index->getBLength();              /* and the length also               */
 
    HashLink position = hashStringIndex(_index);  /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        do
        {                               /* while more items in chain         */
                                        /* get the entry                     */
            RexxString *entry = (RexxString *)this->entries[position].index;
            /* if got a match                    */
            if (_index == entry || entry->memCompare(data, size_v(length))) // todo m17n
            {
                /* return this item's value          */
                return this->entries[position].value;
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
    }
    return OREF_NULL;                    /* no value found                    */
}
 
RexxHashTable *RexxHashTable::stringPut(
    RexxObject *_value,                 /* value of the item                 */
    RexxString *_index)                 /* target index                      */
/******************************************************************************/
/* Function:  Add a value to a table, searching only for character string     */
/*            matches.                                                        */
/******************************************************************************/
{
    const char *data = _index->getStringData();            /* get the string data               */
    sizeB_t length = _index->getBLength();              /* and the length also               */
 
    HashLink position = hashStringIndex(_index);   /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        HashLink front = position;                  /* save the starting location        */
        do
        {                               /* while more items in chain         */
                                        /* get the entry                     */
            RexxString *entry = (RexxString *)this->entries[position].index;
            /* if got a match                    */
            if (_index == entry || entry->memCompare(data, size_v(length))) // todo m17n
            {
                /* set a new value                   */
                OrefSet(this, this->entries[position].value, _value);
                return OREF_NULL;              /* indicate success                  */
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
        /* go insert                         */
        return this->insert(_value, _index, front, STRING_TABLE);
    }
    else
    {                               /* empty at this slot                */
                                    /* fill in both the value and index  */
        OrefSet(this,this->entries[position].value, _value);
        OrefSet(this,this->entries[position].index, _index);
        return OREF_NULL;                  /* successful  addition              */
    }
}
 
RexxHashTable *RexxHashTable::put(
    RexxObject *_value,                 /* value of the item                 */
    RexxObject *_index)                 /* target index                      */
/******************************************************************************/
/* Function:  Add or replace an entry in the hash table.  This will return    */
/*            a new hash table if there is an overflow situation.             */
/******************************************************************************/
{
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        HashLink front = position;                  /* save the starting position        */
        do
        {                               /* while more items in chain         */
                                        /* if got a match                    */
            if (EQUAL_VALUE(_index, this->entries[position].index))
            {
                /* set a new value                   */
                OrefSet(this,this->entries[position].value, _value);
                return OREF_NULL;              /* indicate success                  */
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
        /* go insert                         */
        return this->insert(_value, _index, front, FULL_TABLE);
    }
    else
    {                               /* empty at this slot                */
                                    /* fill in both the value and index  */
        OrefSet(this,this->entries[position].value, _value);
        OrefSet(this,this->entries[position].index, _index);
        return OREF_NULL;                  /* successful  addition              */
    }
}
 
RexxHashTable *RexxHashTable::primitivePut(
    RexxObject *_value,                 /* value of the item                 */
    RexxObject *_index)                 /* target index                      */
/******************************************************************************/
/* Function:  Add or replace an entry in the hash table.  This will return    */
/*            a new hash table if there is an overflow situation.             */
/******************************************************************************/
{
    HashLink position = hashPrimitiveIndex(_index);  /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        HashLink front = position;                  /* save the starting position        */
        do
        {                               /* while more items in chain         */
                                        /* if got a match                    */
            if (_index == this->entries[position].index)
            {
                /* set a new value                   */
                OrefSet(this,this->entries[position].value, _value);
                return OREF_NULL;              /* indicate success                  */
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
        /* go insert                         */
        return this->insert(_value, _index, front, PRIMITIVE_TABLE);
    }
    else
    {                               /* empty at this slot                */
                                    /* fill in both the value and index  */
        OrefSet(this,this->entries[position].value, _value);
        OrefSet(this,this->entries[position].index, _index);
        return OREF_NULL;                  /* successful  addition              */
    }
}
 
RexxHashTable *RexxHashTable::putNodupe(
    RexxObject *_value,                 /* value of the item                 */
    RexxObject *_index)                 /* target index                      */
/******************************************************************************/
/* Function:  Add an entry to a hash table, making sure there are no          */
/*            duplicate entries.                                              */
/******************************************************************************/
{
    HashLink position = hashIndex(_index);         /* calculate the hash slot           */
    /* have an entry at this slot        */
    if (this->entries[position].index != OREF_NULL)
    {
        HashLink front = position;                  /* save the starting point           */
        do
        {                               /* while more items in chain         */
                                        /* if got match on index and value   */
            if (EQUAL_VALUE(_index, this->entries[position].index) && this->entries[position].value == _value)
            {
                return OREF_NULL;              /* indicate success                  */
            }
            /* step to the next link             */
        } while ((position = this->entries[position].next) != NO_MORE);
        /* go insert                         */
        return this->insert(_value, _index, front, FULL_TABLE);
    }
    else
    {                               /* empty at this slot                */
                                    /* fill in both the value and index  */
        OrefSet(this,this->entries[position].value, _value);
        OrefSet(this,this->entries[position].index, _index);
        return OREF_NULL;                  /* successful  addition              */
    }
}
 
RexxObject *RexxHashTable::value(
  HashLink position)                   /* target position                   */
/******************************************************************************/
/* Function:  Return the value associated with a numeric index.               */
/******************************************************************************/
{
    /* within the bounds?                */
    if (position < this->totalSlotsSize())
    {
        /* return the entry value            */
        return this->entries[position].value;
    }
    else
    {
        return OREF_NULL;                  /* return nothing                    */
    }
}
 
size_t RexxHashTable::totalEntries(void)
/******************************************************************************/
/* Function:  Return the count of entries in a hash table.                    */
/******************************************************************************/
{
    size_t result = 0;                          /* no items yet                      */
    /* loop through them all             */
    for (size_t i = this->totalSlotsSize(); i > 0; i--)
    {
        /* real entry?                       */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            result++;                        /* count it!                         */
        }
    }
    return result;                       /* return the count                  */
}
 
 
RexxObject *RexxHashTable::merge(
    RexxHashTableCollection *target)   /* target other collection           */
/******************************************************************************/
/* Function:  Merge a hash table into another collection target.              */
/******************************************************************************/
{
    /* loop through them all             */
    for (size_t i = this->totalSlotsSize(); i > 0; i--)
    {
        /* is this a real entry?             */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            /* merge into the target collection  */
            target->mergeItem(this->entries[i - 1].value,this->entries[i - 1].index);
        }
    }
    return OREF_NULL;                    /* always returns nothing            */
}
 
 
void RexxHashTable::reMerge(
  RexxHashTable *newHash)              /* target other collection           */
/******************************************************************************/
/* Function:   Merge a hash table into another hash table after a table       */
/*             expansion.                                                     */
/******************************************************************************/
{
    /* loop through them all             */
    for (size_t i = this->totalSlotsSize(); i > 0; i--)
    {
        /* is this a real entry?             */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            /* add this item to the new hash     */
            newHash->add(this->entries[i - 1].value, this->entries[i - 1].index);
        }
    }
}
 
void RexxHashTable::primitiveMerge(
  RexxHashTable *newHash)              /* target other collection           */
/******************************************************************************/
/* Function:   Merge a hash table into another hash table after a table       */
/*             expansion.                                                     */
/******************************************************************************/
{
    /* loop through them all             */
    for (size_t i = this->totalSlotsSize(); i > 0; i--)
    {
        /* is this a real entry?             */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            /* add this item to the new hash     */
            newHash->primitiveAdd(this->entries[i - 1].value, this->entries[i - 1].index);
        }
    }
}
 
RexxObject *RexxHashTable::stringMerge(
  RexxHashTable *target)               /* target other collection           */
/******************************************************************************/
/* Function:  Merge a string based hash table into another                    */
/******************************************************************************/
{
    /* loop through them all             */
    for (size_t i = this->totalSlotsSize(); i > 0; i--)
    {
        /* is this a real entry?             */
        if (this->entries[i - 1].index != OREF_NULL)
        {
            /* merge into the target collection  */
            target->stringAdd(this->entries[i - 1].value, (RexxString *)this->entries[i - 1].index);
        }
    }
    return OREF_NULL;                    /* always returns nothing            */
}
 
HashLink RexxHashTable::first(void)
/******************************************************************************/
/* Function:  Return the index of the first item in the hash table            */
/******************************************************************************/
{
    /* loop until first item is found or */
    /* we reach the end of the table     */
    HashLink i;
    for (i = 0; i < this->totalSlotsSize() && this->entries[i].index == OREF_NULL; i++) ;
    return i;                            /* return the position               */
}
 
HashLink RexxHashTable::next(
  HashLink position)                   /* current index position            */
/******************************************************************************/
/* Function:  Return the index of the "next" item after an index              */
/******************************************************************************/
{
    /* loop until first item is found or */
    /* we reach the end of the table     */
    HashLink i;
    for (i = position+1; i < this->totalSlotsSize() && this->entries[i].index == OREF_NULL; i++) ;
    return i;                            /* return the position               */
}
 
RexxObject *RexxHashTable::mergeItem(
    RexxObject *_value,                 /* value to add                      */
    RexxObject *_index)                 /* index location                    */
/******************************************************************************/
/* Function:  Merge an individual item into this hash table                   */
/******************************************************************************/
{
    this->putNodupe(_value, _index);       /* add without duplicating           */
    return OREF_NULL;                    /* always return nothing             */
}
 
RexxObject *RexxHashTable::replace(
    RexxObject *_value,                 /* value to replace                  */
    HashLink  position)                /* position to replace               */
/******************************************************************************/
/* Function:  Replace an item with a new value                                */
/******************************************************************************/
{
                                       /* just set the new value            */
    OrefSet(this,this->entries[position].value, _value);
    return OREF_NULL;                    /* always return nothing             */
}
 
RexxArray  *RexxHashTable::allItems()
/******************************************************************************/
/* Function:  Create an array containing the hash table values                */
/******************************************************************************/
{
    RexxArray *result = new_array(items());         /* get a new array                   */
    size_t j = 0;                               /* set the insertion point           */
    /* loop through all of the items     */
    for (size_t i = 0; i < this->totalSlotsSize(); i++)
    {
        /* real entry?                       */
        if (this->entries[i].index != OREF_NULL)
        {
            /* copy the value into the array     */
            result->put(this->entries[i].value, ++j);
        }
    }
    return result;                       /* return the result array           */
}
 
 
/**
 * count the number of items in the hash table.
 *
 * @return The item count.
 */
size_t RexxHashTable::items()
{
    size_t count = 0;
 
    for (size_t i = 0; i < this->totalSlotsSize(); i++)
    {
 
        if (this->entries[i].index != OREF_NULL)
        {
            count++;
        }
    }
    return count;
}
 
 
/**
 * Empty an individual hashtable bucket.  This will clear
 * the entire chain.
 *
 * @param position The hash table bucket to clear.
 */
void RexxHashTable::emptySlot(HashLink position)
{
    if (this->entries[position].index != OREF_NULL)
    {
        // we have an initial link, so clear those entries out
        OrefSet(this,this->entries[position].index,OREF_NULL);
        OrefSet(this,this->entries[position].value,OREF_NULL);
        // we have at least a head element, so run the chain
        // clearing everything out
 
        // step to the next link.  The remainder are cleared out and
        // returned to the free pool.
        HashLink _next = entries[position].next;
        // and make sure the link is severed.
        entries[position].next = NO_MORE;
        while (_next != NO_MORE)
        {
            position = _next;
            // clear the entries out
            OrefSet(this,this->entries[position].index,OREF_NULL);
            OrefSet(this,this->entries[position].value,OREF_NULL);
 
            // get the next link, and clear the link info in the current
            _next = entries[position].next;
            entries[position].next = NO_MORE;
            // if this creates a new highwater mark, move the free pointer.
            if (position > this->free)
            {
                this->free = position;
            }
 
        }
    }
}
 
 
/**
 * Empty a HashTable.
 */
void RexxHashTable::empty()
{
    // run the main hash bucket clearing the links
    for (HashLink i = 0; i < mainSlotsSize(); i++)
    {
        emptySlot(i);
    }
}
 
 
/**
 * Test if the hash table is empty.
 *
 * @return
 */
bool RexxHashTable::isEmpty()
{
    return items() == 0;
}
 
 
 
 
RexxArray *RexxHashTable::makeArray(void)
/******************************************************************************/
/* Function:  Create an array containing the hash table indexes.              */
/******************************************************************************/
{
    // this just returns the index values
    return this->allIndexes();
}
 
 
RexxArray *RexxHashTable::allIndexes()
/******************************************************************************/
/* Function:  Create an array containing the hash table indexes.              */
/******************************************************************************/
{
    RexxArray *result = new_array(items());         /* get a new array                   */
    size_t j = 0;                               /* set the insertion point           */
    /* loop through all of the items     */
    for (size_t i = 0; i < this->totalSlotsSize(); i++)
    {
        /* real entry?                       */
        if (this->entries[i].index != OREF_NULL)
        {
            /* copy the index into the array     */
            result->put(this->entries[i].index, ++j);
        }
    }
    return result;                       /* return the result array           */
}
 
/**
 * Return an array containing the unique indexes of a
 * Relation object.
 *
 * @return An array with the set of unique index values
 */
RexxArray *RexxHashTable::uniqueIndexes()
{
    RexxTable *indexSet = new_table();
    ProtectedObject p(indexSet);
    size_t j = 0;                               /* set the insertion point           */
    // loop through all of the items
    for (size_t i = 0; i < this->totalSlotsSize(); i++)
    {
        // add the index for every entry to the accumulator
        if (this->entries[i].index != OREF_NULL)
        {
            indexSet->put(TheNilObject, this->entries[i].index);
        }
    }
    // now return the reduced index set
    return indexSet->allIndexes();
}
 
 
RexxSupplier *RexxHashTable::supplier(void)
/******************************************************************************/
/* Function:  create a supplier from a hash table                             */
/******************************************************************************/
{
    size_t count = items();                     /* no items yet                      */
 
    RexxArray *values = new_array(count);           /* get a new array                   */
    RexxArray *indexes = new_array(count);          /* and an index array                */
    size_t j = 1;                               /* set the insertion point           */
    /* loop through all of the items     */
    for (size_t i = 0; i < this->totalSlotsSize(); i++)
    {
        /* real entry?                       */
        if (this->entries[i].index != OREF_NULL)
        {
            /* copy the index into the array     */
            indexes->put(this->entries[i].index, j);
            /* and the value                     */
            values->put(this->entries[i].value, j);
            j++;                             /* step the array location           */
        }
    }
    /* return the supplier               */
    return(RexxSupplier *)new_supplier(values, indexes);
}
 
RexxObject *RexxHashTable::index(
  HashLink position)                   /* return an index item for position */
/******************************************************************************/
/* Function:  Return the item associated with a numeric hash table index      */
/******************************************************************************/
{
    /* if within bounds                  */
    if (position < this->totalSlotsSize())
    {
        /* return the index item             */
        return this->entries[position].index;
    }
    else
    {
        return OREF_NULL;                  /* otherwise, no item for this       */
    }
}
 
RexxHashTable *RexxHashTable::reHash(void)
/******************************************************************************/
/* Function:  Rehash the elements of a hash table because of a restore        */
/******************************************************************************/
{
    /* Assume the same size will work,   */
    RexxHashTable *newHash = new_hashtab(this->totalSlotsSize());
    /* should in MOST cases....          */
    for (size_t i = this->totalSlotsSize(); i > 0; i--)
    {
        if (this->entries[i - 1].index != OREF_NULL)
        {
            RexxHashTable *expandHash = newHash->add(this->entries[i - 1].value, this->entries[i - 1].index);
            if (expandHash != OREF_NULL)     /* have a reallocation occur?        */
            {
                newHash = expandHash;          /* finish up with the new table      */
            }
        }
    }
    return newHash;                      /* Return the updated(rehashed) hashtable*/
}