/* HTGuess.c
** STREAM TO GUESS CONTENT-TYPE
**
** (c) COPYRIGHT MIT 1995.
** Please first read the full copyright statement in the file COPYRIGH.
**
** This version of the stream object just writes its input
** to its output, but prepends Content-Type: field and an
** empty line after it.
**
** HISTORY:
** 8 Jul 94 FM Insulate free() from _free structure element.
**
*/
/* Library include files */
#include "tcp.h"
#include "HTUtils.h"
#include "HTString.h"
#include "HTFormat.h"
#include "HTAlert.h"
#include "HTList.h"
#include "HTFWrite.h"
#include "HTGuess.h"
#define SAMPLE_SIZE 200 /* Number of chars to look at */
/* Stream Object
** ------------
*/
struct _HTStream {
CONST HTStreamClass * isa;
HTRequest * req;
HTParentAnchor * anchor;
HTFormat output_format;
HTStream * output_stream;
HTStream * target;
BOOL transparent;
int cnt;
int text_cnt;
int lf_cnt;
int cr_cnt;
int pg_cnt;
int ctrl_cnt;
int high_cnt;
char * write_ptr;
char buffer[ SAMPLE_SIZE + 1 ];
};
#define PUT_CHAR(c) (*me->target->isa->put_character)(me->target,c)
#define PUT_STRING(s) (*me->target->isa->put_string)(me->target,s)
#define PUT_BLOCK(b,l) (*me->target->isa->put_block)(me->target,b,l)
#define CONTENT_TYPE(t) HTAnchor_setFormat(me->anchor, HTAtom_for(t))
#define CONTENT_ENCODING(t) HTAnchor_setEncoding(me->anchor, HTAtom_for(t))
/* ------------------------------------------------------------------------- */
PRIVATE BOOL is_html (char * buf)
{
char * p = strchr(buf,'<');
if (p && (!strncasecomp(p, "<HTML>", 6) ||
!strncasecomp(p, "<HEAD", 5) ||
!strncasecomp(p, "<TITLE>", 7) ||
!strncasecomp(p, "<BODY>", 6) ||
!strncasecomp(p, "<PLAINTEXT>", 11) ||
(p[0]=='<' && TOUPPER(p[1]) == 'H' && p[3]=='>')))
return YES;
else
return NO;
}
PRIVATE int HTGuess_flush (HTStream * me)
{
if (!me->transparent) {
if (STREAM_TRACE)
TTYPrint(TDEST,"GUESSING.... text=%d newline=%d ctrl=%d high=%d\n",
me->text_cnt, me->lf_cnt, me->ctrl_cnt, me->high_cnt);
if (me->cnt) {
if (STREAM_TRACE) TTYPrint(TDEST,
"Percentages. text=%d%% newlines=%d%% ctrl=%d%% high=%d%%\n",
(int)(100*me->text_cnt/me->cnt + 0.5),
(int)(100*me->lf_cnt /me->cnt + 0.5),
(int)(100*me->ctrl_cnt/me->cnt + 0.5),
(int)(100*me->high_cnt/me->cnt + 0.5));
}
if (!me->ctrl_cnt ||
me->text_cnt + me->lf_cnt >= 16 * (me->ctrl_cnt + me->high_cnt)) {
char *ptr;
/* some kind of text */
*me->write_ptr = 0; /* terminate buffer */
if (me->high_cnt > 0)
CONTENT_ENCODING("8bit");
else
CONTENT_ENCODING("7bit");
if (is_html(me->buffer))
CONTENT_TYPE("text/html");
else if (!strncmp(me->buffer, "%!", 2))
CONTENT_TYPE("application/postscript");
else if (strstr(me->buffer, "#define") &&
strstr(me->buffer, "_width") &&
strstr(me->buffer, "_bits"))
CONTENT_TYPE("image/x-xbitmap");
else if ((ptr = strstr(me->buffer, "converted with BinHex"))!=NULL)
CONTENT_ENCODING("macbinhex");
else if (!strncmp(me->buffer, "begin ", 6))
CONTENT_ENCODING("base64");
else
CONTENT_TYPE("text/plain");
}
else {
if (!strncmp(me->buffer, "GIF", 3))
CONTENT_TYPE("image/gif");
else if (!strncmp(me->buffer, "\377\330\377\340", 4))
CONTENT_TYPE("image/jpeg");
else if (!strcmp(me->buffer, "MM")) /* MM followed by a zero */
CONTENT_TYPE("image/tiff");
else if (!strncmp(me->buffer, "\211PNG\r\n\032\n", 8))
CONTENT_TYPE("image/x-png");
else if (!strncmp(me->buffer, ".snd", 4))
CONTENT_TYPE("audio/basic");
else if (!strncmp(me->buffer, "\037\235", 2))
CONTENT_ENCODING("x-compress");
else if (!strncmp(me->buffer, "\037\213", 2))
CONTENT_ENCODING("x-gzip");
else
CONTENT_TYPE("application/octet-stream");
}
if (!me->anchor->content_type)
CONTENT_TYPE("application/octet-stream");
if (!me->anchor->content_encoding)
CONTENT_ENCODING("binary");
if (STREAM_TRACE) TTYPrint(TDEST,"Guessed..... %s\n",
HTAtom_name(me->anchor->content_type));
if (STREAM_TRACE) TTYPrint(TDEST,"Encoding.... %s\n",
HTAtom_name(me->anchor->content_encoding));
if ((me->target = HTStreamStack(me->anchor->content_type,
me->output_format, me->output_stream,
me->req, NO)) == NULL) {
if (STREAM_TRACE)
TTYPrint(TDEST, "HTGuess..... Can't convert media type\n");
me->target = HTBlackHole();
}
}
return PUT_BLOCK(me->buffer, me->cnt);
}
PRIVATE int HTGuess_put_block (HTStream * me, CONST char * b, int l)
{
while (!me->transparent && l-- > 0) {
int status;
if (me->target) {
if ((status = HTGuess_flush(me)) != HT_OK)
return status;
} else {
me->cnt++;
if (*b == LF)
me->lf_cnt++;
else if (*b == CR)
me->cr_cnt++;
else if (*b == 12)
me->pg_cnt++;
else if (*b =='\t')
me->text_cnt++;
else if ((unsigned char)*b < 32)
me->ctrl_cnt++;
else if ((unsigned char)*b < 128)
me->text_cnt++;
else
me->high_cnt++;
*me->write_ptr++ = *b++;
if (me->cnt >= SAMPLE_SIZE) {
if ((status = HTGuess_flush(me)) != HT_OK)
return status;
else
me->transparent = YES;
}
}
}
if (l > 0)
return PUT_BLOCK(b, l);
return HT_OK;
}
PRIVATE int HTGuess_put_character (HTStream * me, char c)
{
return HTGuess_put_block(me, &c, 1);
}
PRIVATE int HTGuess_put_string (HTStream * me, CONST char * s)
{
return HTGuess_put_block(me, s, (int) strlen(s));
}
PRIVATE int HTGuess_free (HTStream * me)
{
int status;
if (!me->transparent && (status = HTGuess_flush(me)) != HT_OK)
return status;
else
me->transparent = YES;
if ((status = (*me->target->isa->_free)(me->target)) != HT_OK)
return status;
free(me);
return HT_OK;
}
PRIVATE int HTGuess_abort (HTStream * me, HTList * e)
{
if (me->target) (*me->target->isa->abort)(me,e);
free(me);
return HT_ERROR;
}
/* Guessing stream
** ---------------
*/
PRIVATE CONST HTStreamClass HTGuessClass =
{
"GuessWhat",
HTGuess_flush,
HTGuess_free,
HTGuess_abort,
HTGuess_put_character,
HTGuess_put_string,
HTGuess_put_block
};
PUBLIC HTStream * HTGuess_new (HTRequest * req,
void * param,
HTFormat input_format,
HTFormat output_format,
HTStream * output_stream)
{
HTStream * me = (HTStream *) calloc(1,sizeof(HTStream));
if (!me) outofmem(__FILE__, "HTGuess_new");
me->isa = &HTGuessClass;
me->req = req;
me->anchor = HTRequest_anchor(req);
me->output_format = output_format;
me->output_stream = output_stream;
me->write_ptr = me->buffer;
return me;
}
Webmaster
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to HTGuess.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Public] / libwww / Library / src