cgi the program on C ++, compressed HTTP

Roman_Rus · 07-12-2005, 11:34 PM

Hi all!

Who be created function for a compression of a content in cgi to the program written on C?

Share a simple example!

Has written the for gzip and deflate but does not work: (

Code:

#include <stdio.h>
#include <assert.h>

/**/ 
#include <zlib.h>

static void *g_zalloc_wrapper(voidpf opaque, uInt items, uInt size) {
	void *ptr = malloc(items * size);
	return ptr;
}

static void g_zfree_wrapper(voidpf opaque, voidpf address) {
	free(address);
}


/// gzip = 1 > gzip, gzip = 0 > deflate
static int zlib_encode(Bytef *mg, int gzip)
{
static int gz_magic[2] = {0x1f, 0x8b}; 
#define OS_CODE			0x03  /*FIXME */

	z_stream stream;
    //char *new_body;

	stream.next_in = mg;
	stream.avail_in = strlen(mg);
	
	stream.total_in = 0;
	
	//new_body = 
		stream.next_out = malloc(strlen(mg) + 75); /* overly generous */

    assert(stream.next_out);

	

	stream.avail_out = strlen(mg) + 64;
	stream.total_out = 0;
	
	stream.zalloc = g_zalloc_wrapper;
	stream.zfree = g_zfree_wrapper;
	stream.opaque = NULL;
	
	stream.data_type = Z_ASCII;

/* 
*/
	if (deflateInit2(
		    &stream, 
		    3 /* compression level, 1-9, default 6 (Z_DEFAULT_COMPRESSION) */, 
		    Z_DEFLATED, 
		    ((gzip!=0)?16:0)+15 /* gzip headers? (16) + window size (15b) */, 
		    3 /* memory level, 1-9, default 8 */, 
		    Z_DEFAULT_STRATEGY
		    ) != Z_OK) {
		/* failed to initialize, bail out */
	 	deflateEnd(&stream);
		return -1;
	}
		 
	while (stream.avail_in != 0) {
		switch(deflate(&stream, Z_FINISH)) {
		case Z_STREAM_END: /* success */
			break;
			
		case Z_OK: /* need more buffer space !?  bail out... */
			deflateEnd(&stream);
			return -1;
			
		default: /* other error cases */
			deflateEnd(&stream); 
			return -1;
		}
	}
	
if(gzip!=0) 
{
 	printf("Content-Encoding: gzip\n\r");	 
}
else
{
	printf("Content-Encoding: deflate\n\r"); 
}

printf("Content-type: text/html\n\r\n\r"); 

int ifd = dup(fileno(stdout)); 
FILE *Out = fdopen(ifd, "w+b");


if(gzip!=0) {
	char *s2[10];
	        s2[0] = gz_magic[0];
	        s2[1] = gz_magic[1];
	        s2[2] = Z_DEFLATED;
	        s2[3] = s2[4] = s2[5] = s2[6] = s2[7] = s2[8] = 0;  
	        s2[9] = OS_CODE;

			fwrite(&s2 , 10 , 1 ,Out);
}

fwrite(&stream.next_out , stream.total_out , 1 ,Out);

 

if(gzip!=0) {
	char *trailer[9];

			uLong crc = crc32(0L, Z_NULL, 0);

			crc = crc32(crc, (const Bytef *) mg, strlen(mg));

			/* write crc & stream.total_in in LSB order */
			trailer[0] = (char) crc & 0xFF;
			trailer[1] = (char) (crc >> 8) & 0xFF;
			trailer[2] = (char) (crc >> 16) & 0xFF;
			trailer[3] = (char) (crc >> 24) & 0xFF;
			trailer[4] = (char) stream.total_in & 0xFF;
			trailer[5] = (char) (stream.total_in >> 8) & 0xFF;
			trailer[6] = (char) (stream.total_in >> 16) & 0xFF;
			trailer[7] = (char) (stream.total_in >> 24) & 0xFF;
			trailer[8] = '\0';

			fwrite(&trailer , 9 , 1 ,Out);
}
deflateEnd(&stream);
}


 



int main()
{

	
zlib_encode ("<html>test gggkljgjklhkj hkjhlkjhkljhl jkhkj hlkjhlkjhlkh lkjhlkjhlkh lkhlkjjh lhj lkk hjk gdfggdfgdg"
			 "ghfjghjgj ghhhhhjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj gfjfjghfgjg                     gghjgjghjg"
			 "gfjgfhjfjg ghjggggggggggggjjgjghjgjg gjgjfhjfghfjgjgf gjfjghgf fgjhgj fgj gjghj jgjhgf fgj fgjg"
			 "yujjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjgjhgjghjgjhghgjghjgjghjghh"
			 "fghfhfhhldsgffdhgjkdhgdklghkjhdlkfjhgldhgklshdljkfghkjsdhgldshglkjdhglkdshglkdhglkdhgldhg</html>", 0);
 

}

Roman_Rus · 07-15-2005, 09:46 PM

There are no opinions?

lowpro2k3 · 07-17-2005, 06:09 PM

Your question is a little confusing... maybe you can reword it? I tried reading your code but I'm not that good yet...

Roman_Rus · 07-21-2005, 06:10 PM

I need to make in the cgi program function such as, ob_start ("ob_gzhandler"); in PHP which compresses a content.

That I have found the only thing is above example, but it does not work. How correctly to make it?

sind · 07-21-2005, 11:31 PM

In what way doesn't it work?

Compile error?
Crash?
Web server error?
Unexpected result?

What is the setup you are using to test it? For instance, which web server and which web browser?

~sind

Roman_Rus · 07-22-2005, 03:41 PM

Web browser shows empty a web page.