자바가 C(or C++?) 보다 8배 느리다?

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <iconv.h>
#include <errno.h>
 
static char *buff;
 
char *substring(char *src,char *find)
{
 
	int length;
	char *result = NULL;
 
	length = strlen(src) - strlen(find);
	result = (char *)malloc(length +1);
 
	strncpy(result,src,length);
	result[length]='\0';
 
	return result;
}
 
char *append(char *new_char)
{
	int new_char_len;
	static int allocate_length;
	static int next;
 
	new_char_len = strlen(new_char);
 
	if(buff == NULL)
	{
		allocate_length = 0;
		next = 0;
		allocate_length += new_char_len +1;
		buff = (char *)malloc(allocate_length);
		if(buff == NULL)
			exit(EXIT_FAILURE);
	}
	else
	{
		buff = (char *)realloc(buff,allocate_length + new_char_len);
 
		if(buff == NULL)
			exit(EXIT_FAILURE);
		else
		{
 
			allocate_length += new_char_len;
		}
	}
 
	strncpy(buff+next,new_char,new_char_len);
	next += new_char_len;
	buff[next] = '\0';
 
	return buff;
 
}
 
char *convert_utf8(char *encode,char *src,size_t src_size)
{
	int retval;
	size_t in_size = src_size;
	size_t dst_size;
	size_t out_size;
	size_t last_size;
 
	char *dst = NULL;
	char *in,*out;
	iconv_t convert = (iconv_t) -1;
 
	if(strcmp(encode,"UTF-8") == 0)
	{
		dst = (char *)malloc(src_size+1);
		if(dst == NULL)
		{
			perror("malloc() ");
			goto error_proc_convert;
		}
		memcpy(dst,src,src_size);
		dst[src_size]='\0';
		return dst;
	}
 
	dst_size = 2*src_size;
	out_size = dst_size;
	dst = (char *)malloc(dst_size);
 
	if(dst == NULL)
	{
		perror("malloc() ");
		goto error_proc_convert;
	}
 
	in = src;
	out = dst;
 
	convert = iconv_open("UTF-8",encode);
 
	if(convert < 0)
	{
		perror("iconv_open() ");
		goto error_proc_convert;
	}
 
	retval = iconv(convert, &in, &in_size, &out, &out_size);
 
	if(retval < 0)
	{
		perror("iconv() ");
		goto error_proc_convert;
	}
 
	if(in_size != 0)
	{
		fprintf(stdout,"something wrong iconv() \n");
		goto error_proc_convert;
	}
 
	if(out_size != dst_size)
	{
		last_size = dst_size - out_size;
		dst = (char *)realloc(dst, dst_size - out_size);
 
		if(dst == NULL)
		{
			perror("realloc() ");
			goto error_proc_convert;
		}
		dst[last_size]='\0';
	}
 
	iconv_close(convert);
	return dst;
 
error_proc_convert:
	if(dst != NULL)
		free(dst);
	if(convert >= 0)
		iconv_close(convert);
	return NULL;
}
 
char *replace(char *src, char *replace, char *new_char)
{
 
	int replace_len = strlen(replace);
 
	char *temp = NULL;
	char *find;
	char *prev = src;
	char *retval = NULL;
 
	if(replace == NULL || new_char == NULL)
		return NULL;
 
	for(buff = NULL; (find = strstr(prev,replace)) != NULL ;)
	{
		retval = append((temp=substring(prev,find)));
		retval = append(new_char);
		prev = find +replace_len;
	}
 
	retval = append(prev);
 
	if(temp != NULL)
		free(temp);
 
	return retval;
}
 
void test01(void)
{
	char *retval = NULL;
	char src[] = { 0xc7, 0xd1 , 0xb1 , 0xdb , 0xc5 , 0xd7 , 0xbd , 0xba , 0xc6 , 0xae}; // 한글테스트 의 euc-kr raw data
	char find[] = { 0xed , 0x95 , 0x9c , 0xea , 0xb8 , 0x80};// 한글 의 utf-8 raw data
	char rep[] = { 0xfe , 0xff , 0xc6 , 0x01 , 0xc5 , 0xb4};// 영어 의 utf-16 raw data
 
 
	char *src_utf = NULL;
	char *find_utf = NULL;
	char *rep_utf = NULL;
 
	src_utf = convert_utf8("EUC-KR",src,sizeof(src));
	if( src_utf == NULL )
		goto error_proc_test01;
 
	find_utf = convert_utf8("UTF-8",find,sizeof(find));
	if( find_utf == NULL )
		goto error_proc_test01;
 
	rep_utf = convert_utf8("UTF-16",rep,sizeof(rep));
	if( rep_utf == NULL )
		goto error_proc_test01;
 
	retval = replace(src_utf,find_utf,rep_utf);
 
	if(retval != NULL)
	{
		FILE *fp;
 
		fp = fopen("unicode.html","w");
 
		if(fp == NULL)
		{
			perror("fopen() ");
			goto error_proc_test01;
		}
 
		fprintf(fp,"test01() <br>");
		fprintf(fp,"src:%s(%d)<br>",src_utf,strlen(src_utf));
		fprintf(fp,"find:%s(%d)<br>",find_utf,strlen(find_utf));
		fprintf(fp,"replace:%s(%d)<br>",rep_utf,strlen(rep_utf));
		fprintf(fp,"return %s(%d)<br><br>",retval,strlen(retval));
		fclose(fp);
	}
 
error_proc_test01:
	if(src_utf != NULL)
		free(src_utf);
	if(find_utf != NULL)
		free(find_utf);
	if(rep_utf != NULL)
		free(rep_utf);
	if(retval != NULL)
		free(retval);
 
}
 
void test02(void)
{
	char *retval = NULL;
	char src[] = { 0xc7, 0xd1 , 0xb1 , 0xdb , 0xc5 , 0xd7 , 0xbd , 0xba , 0xc6 , 0xae}; // 한글테스트 의 euc-kr raw data
	char find[] = { 0xed , 0x95 , 0x9c , 0xea , 0xb8 , 0x80};// 한글 의 utf-8 raw data
	char rep[] = { 0xfe , 0xff , 0xc6 , 0x01 , 0xc5 , 0xb4,0xfe,0xff,0x00,0x64};// 영어d 의 utf-16 raw data
 
 
	char *src_utf = NULL;
	char *find_utf = NULL;
	char *rep_utf = NULL;
 
	src_utf = convert_utf8("EUC-KR",src,sizeof(src));
	if( src_utf == NULL )
		goto error_proc_test02;
 
	find_utf = convert_utf8("UTF-8",find,sizeof(find));
	if( find_utf == NULL )
		goto error_proc_test02;
 
	rep_utf = convert_utf8("UTF-16",rep,sizeof(rep));
	if( rep_utf == NULL )
		goto error_proc_test02;
 
	retval = replace(src_utf,find_utf,rep_utf);
 
	if(retval != NULL)
	{
		FILE *fp;
 
		fp = fopen("unicode.html","a");
 
		if(fp == NULL)
		{
			perror("fopen() ");
			goto error_proc_test02;
		}
 
		fprintf(fp,"test02() <br>");
		fprintf(fp,"src:%s(%d)<br>",src_utf,strlen(src_utf));
		fprintf(fp,"find:%s(%d)<br>",find_utf,strlen(find_utf));
		fprintf(fp,"replace:%s(%d)<br>",rep_utf,strlen(rep_utf));
		fprintf(fp,"return %s(%d)<br>",retval,strlen(retval));
		fclose(fp);
	}
 
error_proc_test02:
	if(src_utf != NULL)
		free(src_utf);
	if(find_utf != NULL)
		free(find_utf);
	if(rep_utf != NULL)
		free(rep_utf);
	if(retval != NULL)
		free(retval);
}
 
int main(void)
{
	test01();
	test02();
	return 0;
}