External/pugixml
8
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Cache ~last position of merged PCDATA

Browse Source 
This allows us to fix the quadratic complexity of parse_merge_pcdata.
After parsing the first PCDATA we need to advance by its length; we
still compute the length of each fragment twice with this approach, but
it's constant time.
This commit is contained in:
Arseny Kapoulkine 2023-09-05 21:06:55 -07:00
parent e9d17a045e
commit dfb2b7f7b4
1 changed files with 7 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
src/pugixml.cpp
View File

@ -3291,6 +3291,7 @@ PUGI_IMPL_NS_BEGIN
char_t ch = 0; char_t ch = 0;
xml_node_struct* cursor = root; xml_node_struct* cursor = root;
char_t* mark = s; char_t* mark = s;
char_t* merged = s;
while (*s != 0) while (*s != 0)
{ {
@ -3495,13 +3496,17 @@ PUGI_IMPL_NS_BEGIN
} }
else if (PUGI_IMPL_OPTSET(parse_merge_pcdata) && cursor->first_child && PUGI_IMPL_NODETYPE(cursor->first_child->prev_sibling_c) == node_pcdata) else if (PUGI_IMPL_OPTSET(parse_merge_pcdata) && cursor->first_child && PUGI_IMPL_NODETYPE(cursor->first_child->prev_sibling_c) == node_pcdata)
{ {
strconcat(cursor->first_child->prev_sibling_c->value, parsed_pcdata); // Append PCDATA to the previous one. assert(merged >= cursor->first_child->prev_sibling_c->value);
merged += strlength(merged);
strconcat(merged, parsed_pcdata); // Append PCDATA to the previous one.
} }
else else
{ {
PUGI_IMPL_PUSHNODE(node_pcdata); // Append a new node on the tree. PUGI_IMPL_PUSHNODE(node_pcdata); // Append a new node on the tree.
cursor->value = parsed_pcdata; // Save the offset. cursor->value = parsed_pcdata; // Save the offset.
merged = parsed_pcdata; // Used for parse_merge_pcdata above, cheaper to save unconditionally
PUGI_IMPL_POPNODE(); // Pop since this is a standalone. PUGI_IMPL_POPNODE(); // Pop since this is a standalone.
} }
@ -3584,7 +3589,7 @@ PUGI_IMPL_NS_BEGIN
return make_parse_result(status_unrecognized_tag, length - 1); return make_parse_result(status_unrecognized_tag, length - 1);
// check if there are any element nodes parsed // check if there are any element nodes parsed
xml_node_struct* first_root_child_parsed = last_root_child ? last_root_child->next_sibling + 0 : root->first_child+ 0; xml_node_struct* first_root_child_parsed = last_root_child ? last_root_child->next_sibling + 0 : root->first_child + 0;
if (!PUGI_IMPL_OPTSET(parse_fragment) && !has_element_node_siblings(first_root_child_parsed)) if (!PUGI_IMPL_OPTSET(parse_fragment) && !has_element_node_siblings(first_root_child_parsed))
return make_parse_result(status_no_document_element, length - 1); return make_parse_result(status_no_document_element, length - 1);