读写注册表中的一个键值和读写一个小文件中(<1K)的一个值，那个快？
循环10000，测试结果如下: millisecond
| Read Registry |
Write Registry |
Read File |
Write File |
| 453 |
421 |
811 |
14140 |
读注册表比读文件大约快2倍
写注册表比写文件快了30多倍
可能windows对注册表的操作做了很多优化，譬如写，可能直接写到内存中，而不是真正放到磁盘中，这样会快很多。
测试代码如下：
// regVSfile.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <windows.h>
const int TEST_TIMES = 10000;
void TestReadRegistry()
{
for (int i = 0; i < TEST_TIMES; i++)
{
HKEY m_hKey = 0;
long retcode = RegCreateKeyExA(HKEY_LOCAL_MACHINE, "software\xxxxx\abc",
0, "", REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &m_hKey, NULL);
const int MAX_KEY_VALUE_LENGTH = 256;
char szTmp[MAX_KEY_VALUE_LENGTH+1];
DWORD dwLen = sizeof(szTmp) -1;
DWORD dwType = REG_SZ;
retcode = RegQueryValueExA(m_hKey, "InitialCollect", NULL, &dwType, (LPBYTE)szTmp, &dwLen);
if (0 != retcode)
{
MessageBox(0, "abc", "error", MB_OK);
}
RegCloseKey(m_hKey);
}
}
void TestWriteRegistry()
{
for (int i = 0; i < TEST_TIMES; i++)
{
HKEY m_hKey = 0;
long retcode = RegCreateKeyExA(HKEY_LOCAL_MACHINE, "software\xxxxx\abc",
0, "", REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &m_hKey, NULL);
retcode = RegSetValueExA(m_hKey, "InitialCollect", NULL, REG_SZ, (LPBYTE)"abc", 3);
if (0 != retcode)
{
MessageBox(0, "abc", "error", MB_OK);
}
RegCloseKey(m_hKey);
}
}
void TestReadFile()
{
for (int i = 0; i < TEST_TIMES; i++)
{
HANDLE hFile= CreateFile("D:\vctest\regVSfile\test.txt", GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
const int MAX_KEY_VALUE_LENGTH = 256;
char szTmp[MAX_KEY_VALUE_LENGTH+1];
DWORD dwLen = sizeof(szTmp) -1;
DWORD dwRead = 0;
BOOL bRet = ReadFile(hFile, szTmp, dwLen, &dwRead, 0);
if (!bRet)
{
MessageBox(0, "abc", "error", MB_OK);
}
CloseHandle(hFile);
}
}
void TestWriteFile()
{
const char* szString = "Michael vckbase haha";
int nLen = strlen(szString);
for (int i = 0; i < TEST_TIMES; i++)
{
HANDLE hFile= CreateFile("D:\vctest\regVSfile\test.txt", GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
DWORD dwWritten = 0;
BOOL bRet = WriteFile(hFile, szString, nLen, &dwWritten, 0);
if (!bRet)
{
MessageBox(0, "abc", "error", MB_OK);
}
CloseHandle(hFile);
}
}
int main(int argc, char* argv[])
{
DWORD dwBegin = GetTickCount();
//TestReadRegistry();
TestWriteRegistry();
//TestReadFile();
//TestWriteFile();
DWORD dwInterval = GetTickCount() - dwBegin;
printf("Hello World: %d miliseconds! ", dwInterval);
return 0;
}