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XPath: Document order comparator refactoring, document order is now a total order even for nodes from different documents

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git-svn-id: http://pugixml.googlecode.com/svn/trunk@695 99668b35-9821-0410-8761-19e4c4f06640
This commit is contained in:
arseny.kapoulkine 2010-08-29 15:51:03 +00:00
parent 70115fa9ab
commit b1939bd6f8
1 changed files with 19 additions and 11 deletions
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28
src/pugixml.cpp
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@ -4819,25 +4819,26 @@ namespace
return result; return result;
} }
// precondition: node_height of ln is <= node_height of rn, ln != rn
bool node_is_before(xml_node ln, unsigned int lh, xml_node rn, unsigned int rh) bool node_is_before(xml_node ln, unsigned int lh, xml_node rn, unsigned int rh)
{ {
assert(lh <= rh); // normalize heights
for (unsigned int h = rh; h < lh; h++) ln = ln.parent();
for (unsigned int h = lh; h < rh; h++) rn = rn.parent();
while (lh < rh) // one node is the ancestor of the other
{ if (ln == rn) return lh < rh;
--rh;
rn = rn.parent();
}
if (ln == rn) return true;
// find common ancestor
while (ln.parent() != rn.parent()) while (ln.parent() != rn.parent())
{ {
ln = ln.parent(); ln = ln.parent();
rn = rn.parent(); rn = rn.parent();
} }
// there is no common ancestor (the shared parent is null), nodes are from different documents
if (!ln.parent()) return ln < rn;
// determine sibling order
for (; ln; ln = ln.next_sibling()) for (; ln; ln = ln.next_sibling())
if (ln == rn) if (ln == rn)
return true; return true;
@ -4858,15 +4859,19 @@ namespace
{ {
xml_node ln = lhs.node(), rn = rhs.node(); xml_node ln = lhs.node(), rn = rhs.node();
// optimized document order based check
const void* lo = lhs.attribute() ? lhs.attribute().document_order() : ln.document_order(); const void* lo = lhs.attribute() ? lhs.attribute().document_order() : ln.document_order();
const void* ro = rhs.attribute() ? rhs.attribute().document_order() : rn.document_order(); const void* ro = rhs.attribute() ? rhs.attribute().document_order() : rn.document_order();
if (lo && ro) return lo < ro; if (lo && ro) return lo < ro;
// compare attributes
if (lhs.attribute() && rhs.attribute()) if (lhs.attribute() && rhs.attribute())
{ {
// shared parent
if (lhs.parent() == rhs.parent()) if (lhs.parent() == rhs.parent())
{ {
// determine sibling order
for (xml_attribute a = lhs.attribute(); a; a = a.next_attribute()) for (xml_attribute a = lhs.attribute(); a; a = a.next_attribute())
if (a == rhs.attribute()) if (a == rhs.attribute())
return true; return true;
@ -4874,17 +4879,20 @@ namespace
return false; return false;
} }
// compare attribute parents
ln = lhs.parent(); ln = lhs.parent();
rn = rhs.parent(); rn = rhs.parent();
} }
else if (lhs.attribute()) else if (lhs.attribute())
{ {
// attributes go after the parent element
if (lhs.parent() == rhs.node()) return false; if (lhs.parent() == rhs.node()) return false;
ln = lhs.parent(); ln = lhs.parent();
} }
else if (rhs.attribute()) else if (rhs.attribute())
{ {
// attributes go after the parent element
if (rhs.parent() == lhs.node()) return true; if (rhs.parent() == lhs.node()) return true;
rn = rhs.parent(); rn = rhs.parent();
@ -4895,7 +4903,7 @@ namespace
unsigned int lh = node_height(ln); unsigned int lh = node_height(ln);
unsigned int rh = node_height(rn); unsigned int rh = node_height(rn);
return (lh <= rh) ? node_is_before(ln, lh, rn, rh) : !node_is_before(rn, rh, ln, lh); return node_is_before(ln, lh, rn, rh);
} }
}; };