From 628197f8c8d54c6ed3260ee4a2fe6b92b281aa0e Mon Sep 17 00:00:00 2001
From: "arseny.kapoulkine"
<arseny.kapoulkine@99668b35-9821-0410-8761-19e4c4f06640>
Date: Mon, 13 Sep 2010 20:34:53 +0000
Subject: [PATCH] XPath: Minor speed/memory improvements
git-svn-id: http://pugixml.googlecode.com/svn/trunk@726 99668b35-9821-0410-8761-19e4c4f06640
---
src/pugixml.cpp | 85 ++++++++++++++++++++++++++++---------------------
1 file changed, 49 insertions(+), 36 deletions(-)
diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index 3e322177..1303939f 100644
--- a/src/pugixml.cpp
+++ b/src/pugixml.cpp
@@ -4787,19 +4787,24 @@ namespace pugi
void* reallocate(void* ptr, size_t old_size, size_t new_size)
{
+ // align size so that we're able to store pointers in subsequent blocks
+ old_size = (old_size + sizeof(void*) - 1) & ~(sizeof(void*) - 1);
+ new_size = (new_size + sizeof(void*) - 1) & ~(sizeof(void*) - 1);
+
// we can only reallocate the last object
- assert(static_cast<char*>(ptr) + old_size == _root->data + _root_size);
+ assert(ptr == 0 || static_cast<char*>(ptr) + old_size == _root->data + _root_size);
// adjust root size so that we have not allocated the object at all
- _root_size -= old_size;
- bool only_object = (_root_size == 0);
+ bool only_object = (_root_size == old_size);
+
+ if (ptr) _root_size -= old_size;
// allocate a new version (this will obviously reuse the memory if possible)
void* result = allocate(new_size);
if (!result) return 0; // $$ out of memory
// we have a new block
- if (result != ptr)
+ if (result != ptr && ptr)
{
// copy old data
assert(new_size > old_size);
@@ -4975,12 +4980,13 @@ namespace
size_t length = target_length + source_length;
// allocate new buffer
- char_t* result = static_cast<char_t*>(alloc->allocate((length + 1) * sizeof(char_t)));
+ char_t* result = static_cast<char_t*>(alloc->reallocate(_uses_heap ? const_cast<char_t*>(_buffer) : 0, (target_length + 1) * sizeof(char_t), (length + 1) * sizeof(char_t)));
if (!result) return; // $$ out of memory
- // $$ reallocate
- // append both strings in the new buffer
- memcpy(result, _buffer, target_length * sizeof(char_t));
+ // append first string to the new buffer in case there was no reallocation
+ if (!_uses_heap) memcpy(result, _buffer, target_length * sizeof(char_t));
+
+ // append second string to the new buffer
memcpy(result + target_length, o._buffer, source_length * sizeof(char_t));
result[length] = 0;
@@ -5874,21 +5880,8 @@ namespace
size_t new_capacity = capacity + capacity / 2 + 1;
// reallocate the old array or allocate a new one
- xpath_node* data = 0;
-
- if (_begin)
- {
- data = static_cast<xpath_node*>(alloc->reallocate(_begin, capacity * sizeof(xpath_node), new_capacity * sizeof(xpath_node)));
- if (!data) return; // $$ out of memory
- }
- else
- {
- data = static_cast<xpath_node*>(alloc->allocate(new_capacity * sizeof(xpath_node)));
- if (!data) return; // $$ out of memory
-
- memcpy(data, _begin, capacity * sizeof(xpath_node));
- }
-
+ xpath_node* data = static_cast<xpath_node*>(alloc->reallocate(_begin, capacity * sizeof(xpath_node), new_capacity * sizeof(xpath_node)));
+ if (!data) return; // $$ out of memory
// finalize
_begin = data;
@@ -5899,6 +5892,28 @@ namespace
*_end++ = node;
}
+ void append(const xpath_node* begin, const xpath_node* end, xpath_allocator* alloc)
+ {
+ size_t size = static_cast<size_t>(_end - _begin);
+ size_t capacity = static_cast<size_t>(_eos - _begin);
+ size_t count = static_cast<size_t>(end - begin);
+
+ if (size + count > capacity)
+ {
+ // reallocate the old array or allocate a new one
+ xpath_node* data = static_cast<xpath_node*>(alloc->reallocate(_begin, capacity * sizeof(xpath_node), (size + count) * sizeof(xpath_node)));
+ if (!data) return; // $$ out of memory
+
+ // finalize
+ _begin = data;
+ _end = data + size;
+ _eos = data + size + count;
+ }
+
+ memcpy(_end, begin, count * sizeof(xpath_node));
+ _end += count;
+ }
+
void sort()
{
_type = xpath_sort(_begin, _end, _type, false);
@@ -7419,7 +7434,11 @@ namespace pugi
xpath_node_set_raw ns = _left->eval_node_set(c, stack);
for (const xpath_node* it = ns.begin(); it != ns.end(); ++it)
+ {
+ xpath_allocator_capture cri(stack.result);
+
r += convert_string_to_number(string_value(*it, stack.result).c_str());
+ }
return r;
}
@@ -7488,7 +7507,7 @@ namespace pugi
xpath_allocator_capture ct(stack.temp);
// count the string number
- unsigned int count = 1;
+ size_t count = 1;
for (xpath_ast_node* nc = _right; nc; nc = nc->_next) count++;
// gather all strings
@@ -7513,7 +7532,7 @@ namespace pugi
// get total length
size_t length = 0;
- for (unsigned int i = 0; i < count; ++i) length += buffer[i].length();
+ for (size_t i = 0; i < count; ++i) length += buffer[i].length();
// create final string
char_t* result = static_cast<char_t*>(stack.result->allocate((length + 1) * sizeof(char_t)));
@@ -7522,7 +7541,7 @@ namespace pugi
{
char_t* ri = result;
- for (unsigned int i = 0; i < count; ++i)
+ for (size_t i = 0; i < count; ++i)
for (const char_t* bi = buffer[i].c_str(); *bi; ++bi)
*ri++ = *bi;
@@ -7677,11 +7696,9 @@ namespace pugi
assert(1 <= pos && pos <= end && end <= s_length + 1);
const char_t* rbegin = s.c_str() + (pos - 1);
+ const char_t* rend = s.c_str() + (end - 1);
- if (end == s_length + 1)
- return s.uses_heap() ? xpath_string(rbegin, stack.result) : xpath_string_const(rbegin);
- else
- return xpath_string(s.c_str() + (pos - 1), s.c_str() + (end - 1), stack.result);
+ return (end == s_length + 1 && !s.uses_heap()) ? xpath_string_const(rbegin) : xpath_string(rbegin, rend, stack.result);
}
case ast_func_normalize_space_0:
@@ -7771,9 +7788,7 @@ namespace pugi
// we can optimize merging two sorted sets, but this is a very rare operation, so don't bother
rs.set_type(xpath_node_set::type_unsorted);
- for (const xpath_node* li = ls.begin(); li != ls.end(); ++li)
- rs.push_back(*li, stack.result);
-
+ rs.append(ls.begin(), ls.end(), stack.result);
rs.remove_duplicates();
return rs;
@@ -7866,9 +7881,7 @@ namespace pugi
xpath_node_set_raw ns;
ns.set_type(s.type());
-
- for (xpath_node_set::const_iterator i = s.begin(); i != s.end(); ++i)
- ns.push_back(*i, stack.result);
+ ns.append(s.begin(), s.end(), stack.result);
return ns;
}
--
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