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/*
* Index support code for Mini-XML, a small XML file parsing library.
*
* https://www.msweet.org/mxml
*
* Copyright © 2003-2019 by Michael R Sweet.
*
* Licensed under Apache License v2.0. See the file "LICENSE" for more
* information.
*/
/*
* Include necessary headers...
*/
#include "config.h"
#include "mxml-private.h"
/*
* Sort functions...
*/
static int index_compare(mxml_index_t *ind, mxml_node_t *first,
mxml_node_t *second);
static int index_find(mxml_index_t *ind, const char *element,
const char *value, mxml_node_t *node);
static void index_sort(mxml_index_t *ind, int left, int right);
/*
* 'mxmlIndexDelete()' - Delete an index.
*/
void
mxmlIndexDelete(mxml_index_t *ind) /* I - Index to delete */
{
/*
* Range check input..
*/
if (!ind)
return;
/*
* Free memory...
*/
if (ind->attr)
free(ind->attr);
if (ind->alloc_nodes)
free(ind->nodes);
free(ind);
}
/*
* 'mxmlIndexEnum()' - Return the next node in the index.
*
* You should call @link mxmlIndexReset@ prior to using this function to get
* the first node in the index. Nodes are returned in the sorted order of the
* index.
*/
mxml_node_t * /* O - Next node or @code NULL@ if there is none */
mxmlIndexEnum(mxml_index_t *ind) /* I - Index to enumerate */
{
/*
* Range check input...
*/
if (!ind)
return (NULL);
/*
* Return the next node...
*/
if (ind->cur_node < ind->num_nodes)
return (ind->nodes[ind->cur_node ++]);
else
return (NULL);
}
/*
* 'mxmlIndexFind()' - Find the next matching node.
*
* You should call @link mxmlIndexReset@ prior to using this function for
* the first time with a particular set of "element" and "value"
* strings. Passing @code NULL@ for both "element" and "value" is equivalent
* to calling @link mxmlIndexEnum@.
*/
mxml_node_t * /* O - Node or @code NULL@ if none found */
mxmlIndexFind(mxml_index_t *ind, /* I - Index to search */
const char *element, /* I - Element name to find, if any */
const char *value) /* I - Attribute value, if any */
{
int diff, /* Difference between names */
current, /* Current entity in search */
first, /* First entity in 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...");
if (ind)
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
* index...
*/
if (!element && !value)
return (mxmlIndexEnum(ind));
/*
* If there are no nodes in the index, return NULL...
*/
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...
*/
if (ind->cur_node == 0)
{
/*
* Find the first node using a modified binary search algorithm...
*/
first = 0;
last = ind->num_nodes - 1;
#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...
*/
ind->cur_node = current + 1;
return (ind->nodes[current]);
}
else if (diff < 0)
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...
*/
for (current = first; current <= last; current ++)
if (!index_find(ind, element, value, ind->nodes[current]))
{
/*
* Found exactly one (or possibly two) match...
*/
#ifdef DEBUG
printf(" returning only match %d...\n", current);
#endif /* DEBUG */
ind->cur_node = current + 1;
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]))
{
/*
* Return the next matching node...
*/
#ifdef DEBUG
printf(" returning next match %d...\n", ind->cur_node);
#endif /* DEBUG */
return (ind->nodes[ind->cur_node ++]);
}
/*
* If we get this far, then we have no matches...
*/
ind->cur_node = ind->num_nodes;
#ifdef DEBUG
puts(" returning NULL...");
#endif /* DEBUG */
return (NULL);
}
/*
* 'mxmlIndexGetCount()' - Get the number of nodes in an index.
*
* @since Mini-XML 2.7@
*/
int /* I - Number of nodes in index */
mxmlIndexGetCount(mxml_index_t *ind) /* I - Index of nodes */
{
/*
* Range check input...
*/
if (!ind)
return (0);
/*
* Return the number of nodes in the index...
*/
return (ind->num_nodes);
}
/*
* 'mxmlIndexNew()' - Create a new index.
*
* The index will contain all nodes that contain the named element and/or
* attribute. If both "element" and "attr" are @code NULL@, then the index will
* contain a sorted list of the elements in the node tree. Nodes are
* sorted by element name and optionally by attribute value if the "attr"
* argument is not NULL.
*/
mxml_index_t * /* O - New index */
mxmlIndexNew(mxml_node_t *node, /* I - XML node tree */
const char *element, /* I - Element to index or @code NULL@ for all */
const char *attr) /* I - Attribute to index or @code NULL@ for none */
{
mxml_index_t *ind; /* New index */
mxml_node_t *current, /* Current node in index */
**temp; /* Temporary node pointer array */
/*
* 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)
{
mxml_error("Unable to allocate %d bytes for index - %s", (int)sizeof(mxml_index_t), strerror(errno));
return (NULL);
}
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)
{
if (!ind->alloc_nodes)
temp = malloc(64 * sizeof(mxml_node_t *));
else
temp = realloc(ind->nodes, (ind->alloc_nodes + 64) * sizeof(mxml_node_t *));
if (!temp)
{
/*
* Unable to allocate memory for the index, so abort...
*/
mxml_error("Unable to allocate %d bytes for index: %s", (int)((ind->alloc_nodes + 64) * sizeof(mxml_node_t *)), strerror(errno));
mxmlIndexDelete(ind);
return (NULL);
}
ind->nodes = temp;
ind->alloc_nodes += 64;
}
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...
*/
return (ind);
}
/*
* 'mxmlIndexReset()' - Reset the enumeration/find pointer in the index and
* return the first node in the index.
*
* This function should be called prior to using @link mxmlIndexEnum@ or
* @link mxmlIndexFind@ for the first time.
*/
mxml_node_t * /* O - First node or @code 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...
*/
if (!ind)
return (NULL);
/*
* Set the index to the first element...
*/
ind->cur_node = 0;
/*
* Return the first node...
*/
if (ind->num_nodes)
return (ind->nodes[0]);
else
return (NULL);
}
/*
* 'index_compare()' - Compare two nodes.
*/
static int /* O - Result of comparison */
index_compare(mxml_index_t *ind, /* I - Index */
mxml_node_t *first, /* I - First node */
mxml_node_t *second) /* I - Second node */
{
int diff; /* Difference */
/*
* Check the element name...
*/
if ((diff = strcmp(first->value.element.name,
second->value.element.name)) != 0)
return (diff);
/*
* Check the attribute value...
*/
if (ind->attr)
{
if ((diff = strcmp(mxmlElementGetAttr(first, ind->attr),
mxmlElementGetAttr(second, ind->attr))) != 0)
return (diff);
}
/*
* No difference, return 0...
*/
return (0);
}
/*
* 'index_find()' - Compare a node with index values.
*/
static int /* O - Result of comparison */
index_find(mxml_index_t *ind, /* I - Index */
const char *element, /* I - Element name or @code NULL@ */
const char *value, /* I - Attribute value or @code NULL@ */
mxml_node_t *node) /* I - Node */
{
int diff; /* Difference */
/*
* Check the element name...
*/
if (element)
{
if ((diff = strcmp(element, node->value.element.name)) != 0)
return (diff);
}
/*
* Check the attribute value...
*/
if (value)
{
if ((diff = strcmp(value, mxmlElementGetAttr(node, ind->attr))) != 0)
return (diff);
}
/*
* No difference, return 0...
*/
return (0);
}
/*
* 'index_sort()' - Sort the nodes in the index...
*
* This function implements the classic quicksort algorithm...
*/
static void
index_sort(mxml_index_t *ind, /* I - Index to sort */
int left, /* I - Left node in partition */
int right) /* I - Right node in partition */
{
mxml_node_t *pivot, /* Pivot node */
*temp; /* Swap node */
int templ, /* Temporary left node */
tempr; /* Temporary right node */
/*
* Loop until we have sorted all the way to the right...
*/
do
{
/*
* Sort the pivot in the current partition...
*/
pivot = ind->nodes[left];
for (templ = left, tempr = right; templ < tempr;)
{
/*
* Move left while left node <= pivot node...
*/
while ((templ < right) &&
index_compare(ind, ind->nodes[templ], pivot) <= 0)
templ ++;
/*
* Move right while right node > pivot node...
*/
while ((tempr > left) &&
index_compare(ind, ind->nodes[tempr], pivot) > 0)
tempr --;
/*
* Swap nodes if needed...
*/
if (templ < tempr)
{
temp = ind->nodes[templ];
ind->nodes[templ] = ind->nodes[tempr];
ind->nodes[tempr] = temp;
}
}
/*
* When we get here, the right (tempr) node is the new position for the
* pivot node...
*/
if (index_compare(ind, pivot, ind->nodes[tempr]) > 0)
{
ind->nodes[left] = ind->nodes[tempr];
ind->nodes[tempr] = pivot;
}
/*
* Recursively sort the left partition as needed...
*/
if (left < (tempr - 1))
index_sort(ind, left, tempr - 1);
}
while (right > (left = tempr + 1));
}