/*									 HTee.c**	TEE CLASS STREAM DEFINITION****	(c) COPYRIGHT MIT 1995.**	Please first read the full copyright statement in the file COPYRIGH.**	@(#) $Id: HTTee.c,v 2.20 1999/02/22 22:10:12 frystyk Exp $****	The Tee class just writes to two streams.  Easy.**	See also the Black Hole stream which is even easier.**** HISTORY:**	 8 Jul 94  FM	Insulate free() from _free structure element.***//* Library include files */#include "wwwsys.h"#include "WWWUtil.h"#include "HTTee.h"/*		Stream Object**		------------*/struct _HTStream {    const HTStreamClass *	isa;    HTStream *			s1;    HTStream *			s2;    HTComparer *		resolver;};/***	Algorithm produced by H&kon*/PRIVATE int default_resolver (const void *a, const void *b){    if (*(int *) a < 0)        return *(int *) a;    if (*(int *) b < 0)        return *(int *) b;    if (*(int *) a == 0)        return *(int *) b;    return *(int *) a;}PRIVATE int HTTee_put_character (HTStream * me, char c){    int ret1 = (*me->s1->isa->put_character)(me->s1, c);    int ret2 = (*me->s2->isa->put_character)(me->s2, c);    return me->resolver(&ret1, &ret2);}PRIVATE int HTTee_put_string (HTStream * me, const char* s){    int ret1 = (*me->s1->isa->put_string)(me->s1, s);    int ret2 = (*me->s2->isa->put_string)(me->s2, s);    return me->resolver(&ret1, &ret2);}PRIVATE int HTTee_write (HTStream * me, const char* s, int l){    int ret1 = (*me->s1->isa->put_block)(me->s1, s, l);    int ret2 = (*me->s2->isa->put_block)(me->s2, s, l);    return me->resolver(&ret1, &ret2);}PRIVATE int HTTee_flush (HTStream * me){    int ret1 = (*me->s1->isa->flush)(me->s1);    int ret2 = (*me->s2->isa->flush)(me->s2);    return me->resolver(&ret1, &ret2);}/***	BUGS: We do not handle WOULD_BLOCK here. This is tricky as we don't**	know which one actually blocked.*/PRIVATE int HTTee_free (HTStream * me){    if (me) {	int ret1 = me->s1 ? (*me->s1->isa->_free)(me->s1) : HT_OK;	int ret2 = me->s2 ? (*me->s2->isa->_free)(me->s2) : HT_OK;	int ret = me->resolver(&ret1, &ret2);	me->s1 = me->s2 = NULL;	HT_FREE(me);	return ret;    }    return HT_OK;}PRIVATE int HTTee_abort (HTStream * me, HTList * e){    if (me) {	if (me->s1) (*me->s1->isa->abort)(me->s1, e);	if (me->s2) (*me->s2->isa->abort)(me->s2, e);	me->s1 = me->s2 = NULL;	HT_FREE(me);    }    return HT_ERROR;}/*	Tee stream**	----------*/PRIVATE const HTStreamClass HTTeeClass ={			"Tee",	HTTee_flush,	HTTee_free,	HTTee_abort,	HTTee_put_character, 	HTTee_put_string,	HTTee_write}; /*	Tee Stream creation**	-------------------**	You can create a T stream using this method. Each stream returns a**	return value and in order to resolve conflicts in the return code**	you can specify a resolver callback function. Each time any of the **	data methods are called the resolver function is then called with**	the return codes from the two streams. The return code of the T stream**	itself will be the result of the resolver function. If you pass NULL**	as the resolver routine then a default resolver is used.*/PUBLIC HTStream * HTTee(HTStream * s1, HTStream * s2, HTComparer * resolver){    HTStream * me;    if ((me = (HTStream  *) HT_CALLOC(1, sizeof(*me))) == NULL)        HT_OUTOFMEM("HTTee");    me->isa = &HTTeeClass;    me->s1 = s1 ? s1 : HTBlackHole();    me->s2 = s2 ? s2 : HTBlackHole();    me->resolver = resolver ? resolver : default_resolver;    HTTRACE(STREAM_TRACE, "Tee......... Created stream %p with resolver %p\n" _ 		me _ me->resolver);    return me;}