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Cleanup quicksort code to preserve the original order of nodes when they
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are equal.

Fix mxmlIndexFind() implementation.

Add tests.
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@michaelrsweet
michaelrsweet committed May 16, 2004
1 parent 56d571d commit 934a9ae
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Showing 2 changed files with 293 additions and 31 deletions.
191 changes: 166 additions & 25 deletions mxml-index.c
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* "$Id: mxml-index.c,v 1.3 2004/05/16 13:45:56 mike Exp $"
* "$Id: mxml-index.c,v 1.4 2004/05/16 18:25:20 mike Exp $"
*
* Index support code for Mini-XML, a small XML-like file parsing library.
*
Expand Down Expand Up @@ -122,12 +122,24 @@ mxmlIndexFind(mxml_index_t *ind, /* I - Index to search */
last; /* Last entity in search */


#ifdef DEBUG
printf("mxmlIndexFind(ind=%p, element=\"%s\", value=\"%s\")\n",
ind, element ? element : "(null)", value ? value : "(null)");
#endif /* DEBUG */

/*
* Range check input...
*/

if (!ind || (!ind->attr && value))
{
#ifdef DEBUG
puts(" returning NULL...");
printf(" ind->attr=\"%s\"\n", ind->attr ? ind->attr : "(null)");
#endif /* DEBUG */

return (NULL);
}

/*
* If both element and value are NULL, just enumerate the nodes in the
Expand All @@ -142,7 +154,14 @@ mxmlIndexFind(mxml_index_t *ind, /* I - Index to search */
*/

if (!ind->num_nodes)
{
#ifdef DEBUG
puts(" returning NULL...");
puts(" no nodes!");
#endif /* DEBUG */

return (NULL);
}

/*
* If cur_node == 0, then find the first matching node...
Expand All @@ -157,20 +176,36 @@ mxmlIndexFind(mxml_index_t *ind, /* I - Index to search */
first = 0;
last = ind->num_nodes - 1;

while (last > first)
#ifdef DEBUG
printf(" find first time, num_nodes=%d...\n", ind->num_nodes);
#endif /* DEBUG */

while ((last - first) > 1)
{
current = (first + last) / 2;

#ifdef DEBUG
printf(" first=%d, last=%d, current=%d\n", first, last, current);
#endif /* DEBUG */

if ((diff = index_find(ind, element, value, ind->nodes[current])) == 0)
{
/*
* Found a match, move back to find the first...
*/

#ifdef DEBUG
puts(" match!");
#endif /* DEBUG */

while (current > 0 &&
!index_find(ind, element, value, ind->nodes[current - 1]))
current --;

#ifdef DEBUG
printf(" returning first match=%d\n", current);
#endif /* DEBUG */

/*
* Return the first match and save the index to the next...
*/
Expand All @@ -183,31 +218,43 @@ mxmlIndexFind(mxml_index_t *ind, /* I - Index to search */
last = current;
else
first = current;

#ifdef DEBUG
printf(" diff=%d\n", diff);
#endif /* DEBUG */
}

/*
* If we get this far, then we found exactly 0 or 1 matches...
*/

current = (first + last) / 2;
ind->cur_node = ind->num_nodes;
for (current = first; current <= last; current ++)
if (!index_find(ind, element, value, ind->nodes[current]))
{
/*
* Found exactly one (or possibly two) match...
*/

if (!index_find(ind, element, value, ind->nodes[current]))
{
/*
* Found exactly one match...
*/
#ifdef DEBUG
printf(" returning only match %d...\n", current);
#endif /* DEBUG */

return (ind->nodes[current]);
}
else
{
/*
* No matches...
*/
ind->cur_node = current + 1;

return (NULL);
}
return (ind->nodes[current]);
}

/*
* No matches...
*/

ind->cur_node = ind->num_nodes;

#ifdef DEBUG
puts(" returning NULL...");
#endif /* DEBUG */

return (NULL);
}
else if (ind->cur_node < ind->num_nodes &&
!index_find(ind, element, value, ind->nodes[ind->cur_node]))
Expand All @@ -216,6 +263,10 @@ mxmlIndexFind(mxml_index_t *ind, /* I - Index to search */
* Return the next matching node...
*/

#ifdef DEBUG
printf(" returning next match %d...\n", ind->cur_node);
#endif /* DEBUG */

return (ind->nodes[ind->cur_node ++]);
}

Expand All @@ -225,6 +276,10 @@ mxmlIndexFind(mxml_index_t *ind, /* I - Index to search */

ind->cur_node = ind->num_nodes;

#ifdef DEBUG
puts(" returning NULL...");
#endif /* DEBUG */

return (NULL);
}

Expand Down Expand Up @@ -253,19 +308,34 @@ mxmlIndexNew(mxml_node_t *node, /* I - XML node tree */
* Range check input...
*/

#ifdef DEBUG
printf("mxmlIndexNew(node=%p, element=\"%s\", attr=\"%s\")\n",
node, element ? element : "(null)", attr ? attr : "(null)");
#endif /* DEBUG */

if (!node)
return (NULL);

/*
* Create a new index...
*/

if ((ind = calloc(1, sizeof(mxml_index_t))) != NULL)
if ((ind = calloc(1, sizeof(mxml_index_t))) == NULL)
{
mxml_error("Unable to allocate %d bytes for index - %s",
sizeof(mxml_index_t), strerror(errno));
return (NULL);
}

for (current = mxmlFindElement(node, node, element, attr, NULL, MXML_DESCEND);
current;
current = mxmlFindElement(current, node, element, attr, NULL, MXML_DESCEND))
if (attr)
ind->attr = strdup(attr);

if (!element && !attr)
current = node;
else
current = mxmlFindElement(node, node, element, attr, NULL, MXML_DESCEND);

while (current)
{
if (ind->num_nodes >= ind->alloc_nodes)
{
Expand Down Expand Up @@ -293,15 +363,79 @@ mxmlIndexNew(mxml_node_t *node, /* I - XML node tree */
}

ind->nodes[ind->num_nodes ++] = current;

current = mxmlFindElement(current, node, element, attr, NULL, MXML_DESCEND);
}

/*
* Sort nodes based upon the search criteria...
*/

#ifdef DEBUG
{
int i; /* Looping var */


printf("%d node(s) in index.\n\n", ind->num_nodes);

if (attr)
{
printf("Node Address Element %s\n", attr);
puts("-------- -------- -------------- ------------------------------");

for (i = 0; i < ind->num_nodes; i ++)
printf("%8d %-8p %-14.14s %s\n", i, ind->nodes[i],
ind->nodes[i]->value.element.name,
mxmlElementGetAttr(ind->nodes[i], attr));
}
else
{
puts("Node Address Element");
puts("-------- -------- --------------");

for (i = 0; i < ind->num_nodes; i ++)
printf("%8d %-8p %s\n", i, ind->nodes[i],
ind->nodes[i]->value.element.name);
}

putchar('\n');
}
#endif /* DEBUG */

if (ind->num_nodes > 1)
index_sort(ind, 0, ind->num_nodes - 1);

#ifdef DEBUG
{
int i; /* Looping var */


puts("After sorting:\n");

if (attr)
{
printf("Node Address Element %s\n", attr);
puts("-------- -------- -------------- ------------------------------");

for (i = 0; i < ind->num_nodes; i ++)
printf("%8d %-8p %-14.14s %s\n", i, ind->nodes[i],
ind->nodes[i]->value.element.name,
mxmlElementGetAttr(ind->nodes[i], attr));
}
else
{
puts("Node Address Element");
puts("-------- -------- --------------");

for (i = 0; i < ind->num_nodes; i ++)
printf("%8d %-8p %s\n", i, ind->nodes[i],
ind->nodes[i]->value.element.name);
}

putchar('\n');
}
#endif /* DEBUG */

/*
* Return the new index...
*/
Expand All @@ -321,6 +455,10 @@ mxmlIndexNew(mxml_node_t *node, /* I - XML node tree */
mxml_node_t * /* O - First node or NULL if there is none */
mxmlIndexReset(mxml_index_t *ind) /* I - Index to reset */
{
#ifdef DEBUG
printf("mxmlIndexReset(ind=%p)\n", ind);
#endif /* DEBUG */

/*
* Range check input...
*/
Expand Down Expand Up @@ -483,8 +621,11 @@ index_sort(mxml_index_t *ind, /* I - Index to sort */
* pivot node...
*/

ind->nodes[left] = ind->nodes[tempr];
ind->nodes[tempr] = pivot;
if (index_compare(ind, pivot, ind->nodes[tempr]) > 0)
{
ind->nodes[left] = ind->nodes[tempr];
ind->nodes[tempr] = pivot;
}

/*
* Recursively sort the left and right partitions as needed...
Expand All @@ -499,5 +640,5 @@ index_sort(mxml_index_t *ind, /* I - Index to sort */


/*
* End of "$Id: mxml-index.c,v 1.3 2004/05/16 13:45:56 mike Exp $".
* End of "$Id: mxml-index.c,v 1.4 2004/05/16 18:25:20 mike Exp $".
*/
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