测试std::map与boost::unordered_map性能

测试方法：加载文件，将数据分别插入到std::map和boost::unordered_map中，分别保存string作为key和int作为key的map数据，计算插入时间，根据列表分别在对应的map中查找一次所有的key值，计算查找耗时：

测试结果：插入耗时boost::unordered_map是std map的一半左右，查找耗时是std map的1/3左右

测试代码：

#include <boost/unordered/unordered_map.hpp>
#include <map>
#include <iostream>
#include <vector>
#include <stdio.h>
#include <string.h>
#include <sstream>
#include <fstream>
#include <sys/time.h>

using namespace std;

void ParseDataList(const string &typelist, vector<string> &vecList)
{
	vecList.clear();
	if (typelist.length() == 0)
		return;

	const char split = ',';
	const char* pBegin = typelist.c_str();
	if (pBegin == NULL)
		return;
	const char* pEnd = pBegin;

	while (*pEnd != '\0')
	{
		bool bFH = false;
		if (*pEnd == '"')//csv文件里，如果字段里含有,的，整个字段会加""
		{
			bFH = true;
			pEnd++;
			pBegin++;
		}
		char cTemp[2048] = { 0 };
		if (bFH)
		{
			while (*pEnd != '"' && *pEnd != '\0') pEnd++;
		}
		else
		{
			while (*pEnd != split && *pEnd != '\0') pEnd++;
		}
		if (*pEnd == '\0')
		{
			strncpy(cTemp, pBegin, pEnd - pBegin);
			vecList.push_back(cTemp);
			break;
		}
		strncpy(cTemp, pBegin, pEnd - pBegin);
		vecList.push_back(cTemp);
		pEnd++;
		if (bFH) pEnd++;
		pBegin = pEnd;
	}
}

map<string, unsigned long long> mapStockToInner;
boost::unordered_map<string, unsigned long long> unmapStockToInner;

map<unsigned long long, string> mapInnerToString;
boost::unordered_map<unsigned long long, string> unmapInnerToString;

vector<string> vecCodeList;
vector<unsigned long long> vecInnerList;

static string MakeCodeKey(unsigned short nMarket, const char* code)
{
	stringstream ss;
	ss << nMarket;
	ss << code;
	return ss.str();
}

long long Time2Int()
{
	struct timeval timeNow;
	gettimeofday(&timeNow, NULL);

	long long iTime = (((long)timeNow.tv_sec) * 1000 * 1000 + (long)timeNow.tv_usec);
	return iTime;
}

template<typename TKEY, typename TValue, typename TMap>
unsigned long long InnserToMap(TKEY &key, TValue &value, TMap &tmap)
{
	long long timeStart = Time2Int();
	tmap[key] = value;
	long long timeEnd = Time2Int();
	return timeEnd - timeStart;
}

bool Load(const char* file)
{
	ifstream ifs(file);
	if (!ifs.is_open())
	{
		cout << "open file failed." << file << endl;
		return false;
	}
	string line;
	unsigned long long mapkeytime = 0;
	unsigned long long mapinnertime = 0;

	unsigned long long unmapkeytime = 0;
	unsigned long long unmapinnertime = 0;

	while (getline(ifs, line))
	{
		vector<string> vecTemp;
		ParseDataList(line, vecTemp);
		short nMarket = atoi(vecTemp[1].c_str());
		string code = vecTemp[2];
		unsigned long long incode = atoll(vecTemp[3].c_str());
		string key = MakeCodeKey(nMarket, code.c_str());

		mapkeytime += InnserToMap(key, incode, mapStockToInner);
		unmapkeytime += InnserToMap(key, incode, unmapStockToInner);

		mapinnertime += InnserToMap(incode, key, mapInnerToString);
		unmapinnertime += InnserToMap(incode, key, unmapInnerToString);

		vecCodeList.push_back(key);
		vecInnerList.push_back(incode);
	}

	ifs.close();

	cout << "std map string insert time:" << mapkeytime
		<< ",std map int insert time:" << mapinnertime
		<< ",un map string insert time:" << unmapkeytime
		<< ",un map int insert time:" << unmapinnertime
		<< endl;
	return true;
}

template<typename vecT, typename mapT>
void TestMap(vecT& vt, mapT &mt, const char* name)
{
	long long timeStart = Time2Int();
	for (size_t i = 0; i < vt.size(); ++i)
	{
		typename mapT::iterator it = mt.find(vt[i]);
		if (it == mt.end())
		{
			cout << "not find key " << vt[i] << endl;
		}
		
	}
	long long timeEnd = Time2Int();
	cout << name<<"find time=" << timeEnd - timeStart<<endl;
}

void Test()
{
	//test std map key->code
	TestMap(vecInnerList, mapInnerToString, "std map innercode->key ");

	//test boost unorder map key->code
	TestMap(vecInnerList, unmapInnerToString, "boost unorderedmap innercode->key ");

	//test std map code->key
	TestMap(vecCodeList, mapStockToInner, "std map key->innercode ");

	//test std map code->key
	TestMap(vecCodeList, unmapStockToInner, "boost unorderedmap key->innercode ");
}

int main()
{
	if (Load("dict.txt") == false)
	{
		cout << "load file failed." << endl;
		return -1;
	}

	Test();
}

标签：std,map,long,pEnd,key,include,boost
来源： https://blog.csdn.net/XiaoWhy/article/details/112543216