view dep/pugixml/docs/samples/load_memory.cpp @ 187:9613d72b097e

*: multiple performance improvements like marking `static const` when it makes sense... date: change old stupid heap-based method to a structure which should make copying the thing actually make a copy. also many performance-based changes, like removing the std::tie dependency and forward-declaring nlohmann json *: replace every instance of QString::fromUtf8 to Strings::ToQString. the main difference is that our function will always convert exactly what is in the string, while some other times it would only convert up to the nearest NUL byte
author Paper <mrpapersonic@gmail.com>
date Wed, 06 Dec 2023 13:43:54 -0500
parents d10b6c6b432e
children
line wrap: on
line source

#include "pugixml.hpp"

#include <iostream>
#include <cstring>

int main()
{
// tag::decl[]
    const char source[] = "<mesh name='sphere'><bounds>0 0 1 1</bounds></mesh>";
    size_t size = sizeof(source);
// end::decl[]

    pugi::xml_document doc;

    {
    // tag::load_buffer[]
        // You can use load_buffer to load document from immutable memory block:
        pugi::xml_parse_result result = doc.load_buffer(source, size);
    // end::load_buffer[]

        std::cout << "Load result: " << result.description() << ", mesh name: " << doc.child("mesh").attribute("name").value() << std::endl;
    }

    {
    // tag::load_buffer_inplace_begin[]
        // You can use load_buffer_inplace to load document from mutable memory block; the block's lifetime must exceed that of document
        char* buffer = new char[size];
        memcpy(buffer, source, size);

        // The block can be allocated by any method; the block is modified during parsing
        pugi::xml_parse_result result = doc.load_buffer_inplace(buffer, size);
    // end::load_buffer_inplace_begin[]

        std::cout << "Load result: " << result.description() << ", mesh name: " << doc.child("mesh").attribute("name").value() << std::endl;

    // tag::load_buffer_inplace_end[]
        // You have to destroy the block yourself after the document is no longer used
        delete[] buffer;
    // end::load_buffer_inplace_end[]
    }

    {
    // tag::load_buffer_inplace_own[]
        // You can use load_buffer_inplace_own to load document from mutable memory block and to pass the ownership of this block
        // The block has to be allocated via pugixml allocation function - using i.e. operator new here is incorrect
        char* buffer = static_cast<char*>(pugi::get_memory_allocation_function()(size));
        memcpy(buffer, source, size);

        // The block will be deleted by the document
        pugi::xml_parse_result result = doc.load_buffer_inplace_own(buffer, size);
    // end::load_buffer_inplace_own[]

        std::cout << "Load result: " << result.description() << ", mesh name: " << doc.child("mesh").attribute("name").value() << std::endl;
    }

    {
    // tag::load_string[]
        // You can use load to load document from null-terminated strings, for example literals:
        pugi::xml_parse_result result = doc.load_string("<mesh name='sphere'><bounds>0 0 1 1</bounds></mesh>");
    // end::load_string[]

        std::cout << "Load result: " << result.description() << ", mesh name: " << doc.child("mesh").attribute("name").value() << std::endl;
    }
}

// vim:et