core/index.c

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#include <stdlib.h>
#include <memory.h>
#include <string.h>
#include <errno.h>
#include "output.h"
#include "index.h"

static unsigned int next_index_id = 0;

INDEX *index_create(int first_ordinal, 
                    int last_ordinal) 
{
    int size = (unsigned int)(last_ordinal - first_ordinal + 1);
    INDEX *index = malloc(sizeof(INDEX));
    if (index!=NULL)
    {
        if (size<1)
        {
            errno = EINVAL;
            goto Undo;
        }
        index->ordinal = malloc(sizeof(LIST*)*size);
        if (index->ordinal==NULL)
        {
            errno = ENOMEM;
            goto Undo;
        }
        index->id = next_index_id++;
        index->first_ordinal = first_ordinal;
        index->last_ordinal = last_ordinal;
        memset(index->ordinal,0,sizeof(LIST*)*size);
        output_verbose("creating index %d", index->id);
    }
    else
    {
        errno = ENOMEM;
        return NULL;
    }

    /* reversal forces adjustment when first item is received */
    index->first_used=last_ordinal;
    index->last_used=first_ordinal;
    return index;
Undo:
    free(index);
    return NULL;
}

STATUS index_insert(INDEX *index,   
                    void *data,     
                    int ordinal)    
{
    int pos = ordinal - index->first_ordinal;

    if (ordinal<index->first_ordinal) /* grow on bottom end */
    {
        /* (this is very unusual and shouldn't happen the way things are now) */
        output_fatal("ordinal %d is too small (first is %d)",ordinal, index->first_ordinal);
        /*  TROUBLESHOOT
            This is an internal error caused by an attempt to index something improperly.
            Because the indexing system start at index 0, this means a negative index
            number was attempting, which is most likely a bug.  This usually occurs
            during object initialization and might be caused by invalid object numbers,
            either negative or greater than about 2 billion.  If your model is using a
            the <b><i>class</i>:<i>id</i></b> naming convention, check the object id numbers
            to make sure they are correct.
        */
        errno = EINVAL;
        return FAILED;
    }
    else if (ordinal>=index->last_ordinal) /* grow on to end */
    {   
        int oldsize = index->last_ordinal - index->first_ordinal;
        int newsize = oldsize;
        LIST **newblock = NULL;
        while (ordinal >= index->first_ordinal + newsize)
            newsize *= 2;   /* double until it fits */
        newblock = malloc(sizeof(LIST*)*newsize);
        if (newblock==NULL)
        {
            output_fatal("unable to grow index %d: %s",index->id, strerror(errno));
            /*  TROUBLESHOOT
                An internal memory allocation error cause an index operation to fail.
                The message will usually include some explanation as to what cause
                the failure.  Remedy the indicated memory problem to fix the indexing problem.
            */
            return FAILED;
        }
        output_verbose("growing index %d to %d ordinals", index->id, newsize);
        memset(newblock,0,sizeof(LIST*)*newsize);
        memcpy(newblock,index->ordinal,sizeof(LIST*)*oldsize);
        free(index->ordinal);
        index->ordinal = newblock;
        index->last_ordinal = index->first_ordinal + newsize;
    
    }
    if (index->ordinal[pos]==NULL) /* new list at ordinal */
    {
        index->ordinal[pos] = list_create();
        if (index->ordinal[pos]==NULL)
            return FAILED;
    }
    if (list_append(index->ordinal[pos],data)==NULL)
        return FAILED;
    if (ordinal<index->first_used) index->first_used=ordinal;
    if (ordinal>index->last_used) index->last_used=ordinal;
    return SUCCESS;
}

void index_shuffle(INDEX *index)    
{
    int i, size = index->last_used - index->first_used;
    for (i=0; i<size; i++)
        list_shuffle(index->ordinal[i]);
    output_verbose("shuffled %d lists in index %d", size, index->id);
}

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GridLAB-D^TM Version 2.0

An open-source project initiated by the US Department of Energy