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/* STREAM TO GUESS CONTENT-TYPE HTGuess.c
** ============================
**
** 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.
**
*/
#define SAMPLE_SIZE 200 /* Number of chars to look at */
#include "HTGuess.h"
#include "HTFormat.h"
#include "HTAlert.h"
#include "HTList.h"
/* Stream Object
** ------------
*/
struct _HTStream {
CONST HTStreamClass * isa;
HTRequest * req;
HTStream * output_stream;
BOOL discard;
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 ];
};
PRIVATE BOOL is_html ARGS1(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;
}
#define PUT_CHAR(c) \
(*me->output_stream->isa->put_character)(me->output_stream,c)
#define PUT_STRING(s) \
(*me->output_stream->isa->put_string)(me->output_stream,s)
#define PUT_BLOCK(b,l) \
(*me->output_stream->isa->put_block)(me->output_stream,b,l)
#define CONTENT_TYPE(t) \
me->req->content_type = HTAtom_for(t)
#define CONTENT_ENCODING(t) \
me->req->content_encoding = HTAtom_for(t)
PRIVATE BOOL header_and_flush ARGS1(HTStream *, me)
{
CTRACE(stderr,"GUESSING.... text=%d newlines=%d ctrl=%d high=%d\n",
me->text_cnt, me->lf_cnt, me->ctrl_cnt, me->high_cnt);
if (me->cnt) {
CTRACE(stderr,
"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)) {
/* 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
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, ".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->req->content_type) CONTENT_TYPE("www/unknown");
if (!me->req->content_encoding) CONTENT_ENCODING("binary");
CTRACE(stderr,"Guessed..... %s\n", HTAtom_name(me->req->content_type));
CTRACE(stderr,"Encoding.... %s\n", HTAtom_name(me->req->content_encoding));
me->output_stream = HTStreamStack(me->req->content_type, me->req, NO);
if (!me->output_stream) {
me->discard = YES; /* Turning into a black hole */
return NO;
}
else {
PUT_BLOCK(me->buffer, me->cnt);
return YES;
}
}
PRIVATE void HTGuess_put_character ARGS2(HTStream *, me, char, c)
{
if (me->discard) return;
if (me->output_stream) PUT_CHAR(c);
else {
me->cnt++;
#if 0
if (c < 0) me->high_cnt++;
else
#endif
if (c == LF) me->lf_cnt++;
else if (c == CR) me->cr_cnt++;
else if (c == 12) me->pg_cnt++;
else if (c =='\t')me->text_cnt++;
else if ((unsigned char)c < 32) me->ctrl_cnt++;
else if ((unsigned char)c < 128) me->text_cnt++;
else me->high_cnt++;
*me->write_ptr++ = c;
if (me->cnt >= SAMPLE_SIZE) header_and_flush(me);
}
}
PRIVATE void HTGuess_put_string ARGS2(HTStream *, me, CONST char*, s)
{
if (me->discard) return;
if (me->output_stream) PUT_STRING(s);
else {
while (*s) {
HTGuess_put_character(me,*s);
s++;
}
}
}
PRIVATE void HTGuess_put_block ARGS3(HTStream *, me, CONST char*, b, int, l)
{
if (me->discard) return;
while (!me->output_stream && l > 0) {
HTGuess_put_character(me, *b);
b++;
l--;
}
if (l > 0) PUT_BLOCK(b,l);
}
PRIVATE void HTGuess_free ARGS1(HTStream *, me)
{
if (!me->discard && !me->output_stream)
header_and_flush(me);
if (me->output_stream)
(*me->output_stream->isa->_free)(me->output_stream);
free(me);
}
PRIVATE void HTGuess_abort ARGS2(HTStream *, me, HTError, e)
{
if (me->output_stream)
(*me->output_stream->isa->abort)(me,e);
free(me);
}
/* Guessing stream
** ---------------
*/
PRIVATE CONST HTStreamClass HTGuessClass =
{
"Guess",
HTGuess_free,
HTGuess_abort,
HTGuess_put_character,
HTGuess_put_string,
HTGuess_put_block
};
PUBLIC HTStream * HTGuess_new ARGS1(HTRequest *, req)
{
HTStream * me = (HTStream*)calloc(1,sizeof(HTStream));
if (!me) outofmem(__FILE__, "HTGuess_new");
me->isa = &HTGuessClass;
me->req =req;
me->write_ptr = me->buffer;
return me;
}
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