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#include "pugixml.hpp"
#include <string>
#include <stdio.h>
//[code_save_custom_writer
struct xml_string_writer: pugi::xml_writer
{
std::string result;
virtual void write(const void* data, size_t size)
{
result += std::string(static_cast<const char*>(data), size);
}
};
//]
struct xml_memory_writer: pugi::xml_writer
{
char* buffer;
size_t capacity;
size_t result;
xml_memory_writer(): buffer(0), capacity(0), result(0)
{
}
xml_memory_writer(char* buffer, size_t capacity): buffer(buffer), capacity(capacity), result(0)
{
}
size_t written_size() const
{
return result < capacity ? result : capacity;
}
virtual void write(const void* data, size_t size)
{
if (result < capacity)
{
size_t chunk = (capacity - result < size) ? capacity - result : size;
memcpy(buffer + result, data, chunk);
}
result += size;
}
};
std::string node_to_string(pugi::xml_node node)
{
xml_string_writer writer;
node.print(writer);
return writer.result;
}
char* node_to_buffer(pugi::xml_node node, char* buffer, size_t size)
{
if (size == 0) return buffer;
// leave one character for null terminator
xml_memory_writer writer(buffer, size - 1);
node.print(writer);
// null terminate
buffer[writer.written_size()] = 0;
return buffer;
}
char* node_to_buffer_heap(pugi::xml_node node)
{
// first pass: get required memory size
xml_memory_writer counter;
node.print(counter);
// allocate necessary size (+1 for null termination)
char* buffer = new char[counter.result + 1];
// second pass: actual printing
xml_memory_writer writer(buffer, counter.result);
node.print(writer);
// null terminate
buffer[writer.written_size()] = 0;
return buffer;
}
int main()
{
// get a test document
pugi::xml_document doc;
doc.load("<foo bar='baz'>hey</foo>");
// get contents as std::string (single pass)
printf("contents: [%s]\n", node_to_string(doc).c_str());
// get contents into fixed-size buffer (single pass)
char large_buf[128];
printf("contents: [%s]\n", node_to_buffer(doc, large_buf, sizeof(large_buf)));
// get contents into fixed-size buffer (single pass, shows truncating behavior)
char small_buf[22];
printf("contents: [%s]\n", node_to_buffer(doc, small_buf, sizeof(small_buf)));
// get contents into heap-allocated buffer (two passes)
char* heap_buf = node_to_buffer_heap(doc);
printf("contents: [%s]\n", heap_buf);
delete[] heap_buf;
}
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