map和hashmap性能测试

测试代码

#include "stdafx.h"
#include 
#include 
#include 
#include 
#include 
#include 

#include 
#include 
#pragma comment(lib,"psapi.lib")

#define DATA_SIZE 100000
#define SEARCH_DATA 1000000

void showMemoryInfo(void)
{
	HANDLE handle = GetCurrentProcess();
	PROCESS_MEMORY_COUNTERS pmc;
	GetProcessMemoryInfo(handle, &pmc, sizeof(pmc));
	std::cout << "内存使用:" << pmc.WorkingSetSize / 1000 << "K/" << pmc.PeakWorkingSetSize / 1000 << "K + " << 
		pmc.PagefileUsage / 1000 << "K/" << pmc.PeakPagefileUsage / 1000 << "K" << std::endl;
}

void main(){
	std::ofstream ofs("d:\\test_map.txt");
	std::cout.set_rdbuf(ofs.rdbuf());

	std::vector datas(DATA_SIZE);
	std::vector searchs(SEARCH_DATA);

	for (int i = 0; i < DATA_SIZE; i++)
	{
		int random = rand();
		datas[i] = random;
		//std::cout << random << "  ";
	}

	std::cout << std::endl << std::endl;
	for (int i = 0; i < SEARCH_DATA; i++)
	{
		int random = rand();
		searchs[i] = random;
		//std::cout << random << "  ";
	}


	showMemoryInfo();
	std::cout << std::endl << std::endl;

	//seach --set
	TimeSpan span;
	span.start();

	std::multiset sets;
	for each (auto one in datas)
	{
		sets.insert(one);
	}
	std::cout << "set build use time : " << span.elapsed() << std::endl;

	span.restart();
	for each (auto one in searchs)
	{
		sets.find(one);
	}

	std::cout << "set use time : " << span.elapsed() << std::endl;
	showMemoryInfo();
	std::cout << std::endl << std::endl;

	//search - hashset
	span.restart();
	std::hash_multiset hsets;
	for each (auto one in datas)
	{
		hsets.insert(one);
	}
	std::cout << "hashset use time : " << span.elapsed() << std::endl;

	span.restart();
	for each (auto one in searchs)
	{
		hsets.find(one);
	}

	std::cout << "hashset use time : " << span.elapsed() << std::endl;
	showMemoryInfo();
	std::cout << std::endl << std::endl;

	//normal search
	span.restart();
	for each (auto one in searchs)
	{
		std::find(datas.begin(), datas.end(), one);
	}

	std::cout << "normal use time : " << span.elapsed() << std::endl;
	showMemoryInfo();

	// redirect cout to /dev/null
	ofs.close();
}

测试结果

内存使用:6905K/6905K + 5050K/5050K

set build use time : 51
set use time : 382
内存使用:10149K/10149K + 8269K/8269K

hashset use time : 24
hashset use time : 52
内存使用:13643K/13643K + 11771K/11771K

normal use time : 9810
内存使用:13643K/13643K + 11771K/11771K

 

 

可以看出

1. 数据随机性比较大的情况下，hashmap的性能是最好的， 建表时间也优于map。

2. 内存使用hashmap和map差不多。