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yap-6.3/os/readutil.c
Vítor Santos Costa f7d23f9deb Simplify Input/Output
get rid of string I/O, did not add much
getc is never actually used by Prolog
try to use system I/O, even if it may be slower, at least for now.
extend IO C-interface to allow reading clauses
2016-02-21 19:06:25 +00:00

305 lines
8.3 KiB
C

/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: readutil.c *
* Last rev: 2/8/06 *
* mods: *
* comments: readutil library support *
* *
*************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif
#include "Yap.h"
#include "Yatom.h"
#include "YapHeap.h"
#include "yapio.h"
#include "iopreds.h"
#include "YapText.h"
#include "encoding.h"
/// @addtogroup readutil
static Int
rl_to_codes(Term TEnd, int do_as_binary, int arity USES_REGS)
{
int sno = Yap_CheckStream (ARG1, Input_Stream_f, "read_line_to_codes/2");
StreamDesc *st = GLOBAL_Stream+sno;
Int status;
UInt max_inp, buf_sz, sz;
int *buf;
bool binary_stream;
if (sno < 0)
return FALSE;
status = GLOBAL_Stream[sno].status;
binary_stream = GLOBAL_Stream[sno].status & Binary_Stream_f;
if (status & Eof_Stream_f) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
return Yap_unify_constant(ARG2, MkAtomTerm (AtomEof));
}
max_inp = (ASP-HR)/2-1024;
buf = (int *)TR;
buf_sz = (int *)LOCAL_TrailTop-buf;
while (TRUE) {
if ( buf_sz > max_inp ) {
buf_sz = max_inp;
}
if (do_as_binary && !binary_stream) {
GLOBAL_Stream[sno].status |= Binary_Stream_f;
}
if (st->status & Binary_Stream_f) {
char *b = (char *)TR;
sz = fread( b,1 , buf_sz, GLOBAL_Stream[sno].file);
} else {
int ch;
int *pt = buf;
do {
*pt++ = ch = st->stream_wgetc_for_read(sno);
if (pt+1 == buf+buf_sz)
break;
} while (ch != '\n');
sz = pt-buf;
}
if (do_as_binary && !binary_stream)
GLOBAL_Stream[sno].status &= ~Binary_Stream_f;
if (sz == -1 || sz == 0) {
if (GLOBAL_Stream[sno].status & Eof_Stream_f) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
return Yap_unify_constant(ARG2, MkAtomTerm (AtomEof));
}
UNLOCK(GLOBAL_Stream[sno].streamlock);
return FALSE;
}
if (GLOBAL_Stream[sno].status & Eof_Stream_f || buf[sz-1] == 10) {
/* we're done */
Term end;
if (!(do_as_binary || GLOBAL_Stream[sno].status & Eof_Stream_f)) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
/* handle CR before NL */
if ((Int)sz-2 >= 0 && buf[sz-2] == 13)
buf[sz-2] = '\0';
else
buf[sz-1] = '\0';
} else {
UNLOCK(GLOBAL_Stream[sno].streamlock);
}
if (arity == 2)
end = TermNil;
else
end = Deref(XREGS[arity]);
if (GLOBAL_Stream[sno].encoding == ENC_ISO_UTF8)
return Yap_unify(ARG2, Yap_UTF8ToDiffListOfCodes((const char *)TR, end PASS_REGS)) ;
else if (GLOBAL_Stream[sno].encoding == ENC_WCHAR)
return Yap_unify(ARG2, Yap_WCharsToDiffListOfCodes((const wchar_t *)TR, end PASS_REGS)) ;
return Yap_unify(ARG2, Yap_CharsToDiffListOfCodes((const char *)TR, end, ENC_ISO_LATIN1 PASS_REGS)) ;
}
buf += (buf_sz-1);
max_inp -= (buf_sz-1);
if (max_inp <= 0) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
Yap_Error(RESOURCE_ERROR_STACK, ARG1, "read_line_to_codes/%d", arity);
return FALSE;
}
}
}
static Int
read_line_to_codes(USES_REGS1)
{
return rl_to_codes(TermNil, FALSE, 2 PASS_REGS);
}
static Int
read_line_to_codes2(USES_REGS1)
{
return rl_to_codes(TermNil, TRUE, 3 PASS_REGS);
}
static Int
read_line_to_string( USES_REGS1 )
{
int sno = Yap_CheckStream (ARG1, Input_Stream_f, "read_line_to_codes/2");
Int status;
UInt max_inp, buf_sz;
int *buf;
StreamDesc *st = GLOBAL_Stream+sno;
if (sno < 0)
return FALSE;
status = GLOBAL_Stream[sno].status;
if (status & Eof_Stream_f) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
return Yap_unify_constant(ARG2, MkAtomTerm (AtomEof));
}
max_inp = (ASP-HR)/2-1024;
buf = (int *)TR;
buf_sz = (int *)LOCAL_TrailTop-buf;
while (true) {
size_t sz;
if ( buf_sz > max_inp ) {
buf_sz = max_inp;
}
if (st->status & Binary_Stream_f) {
char *b = (char *)TR;
sz = fread( b,1 , buf_sz, GLOBAL_Stream[sno].file);
} else {
int ch;
int *pt = buf;
do {
*pt++ = ch = st->stream_wgetc_for_read(sno);
if (pt+1 == buf+buf_sz)
break;
} while (ch != '\n');
sz = pt-buf;
}
if (sz == -1 || sz == 0) {
if (GLOBAL_Stream[sno].status & Eof_Stream_f) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
return Yap_unify_constant(ARG2, MkAtomTerm (AtomEof));
}
UNLOCK(GLOBAL_Stream[sno].streamlock);
return false;
}
if (GLOBAL_Stream[sno].status & Eof_Stream_f || buf[sz-1] == 10) {
/* we're done */
if (!(GLOBAL_Stream[sno].status & Eof_Stream_f)) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
/* handle CR before NL */
if ((Int)sz-2 >= 0 && buf[sz-2] == 13)
buf[sz-2] = '\0';
else {
buf[sz-1] = '\0';
}
} else {
UNLOCK(GLOBAL_Stream[sno].streamlock);
}
}
if (GLOBAL_Stream[sno].encoding == ENC_ISO_UTF8) {
return Yap_unify(ARG2, Yap_UTF8ToString((const char *)TR PASS_REGS)) ;
} else if (GLOBAL_Stream[sno].encoding == ENC_WCHAR) {
return Yap_unify(ARG2, Yap_WCharsToString((const wchar_t *)TR PASS_REGS)) ;
}else {
return Yap_unify(ARG2, Yap_CharsToString((const char *)TR, ENC_ISO_LATIN1 PASS_REGS) );
}
buf += (buf_sz-1);
max_inp -= (buf_sz-1);
if (max_inp <= 0) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
Yap_Error(RESOURCE_ERROR_STACK, ARG1, NULL);
return FALSE;
}
}
}
static Int
read_stream_to_codes(USES_REGS1)
{
int sno = Yap_CheckStream (ARG1, Input_Stream_f, "reaMkAtomTerm (AtomEofd_line_to_codes/2");
CELL *HBASE = HR;
CELL *h0 = &ARG4;
if (sno < 0)
return FALSE;
while (!(GLOBAL_Stream[sno].status & Eof_Stream_f)) {
/* skip errors */
Int ch = GLOBAL_Stream[sno].stream_getc(sno);
Term t;
if (ch == EOFCHAR)
break;
t = MkIntegerTerm(ch);
h0[0] = AbsPair(HR);
*HR = t;
HR+=2;
h0 = HR-1;
yhandle_t news, news1, st = Yap_StartSlots();
if (HR >= ASP-1024) {
RESET_VARIABLE(h0);
news = Yap_InitSlot(AbsPair(HBASE));
news1 = Yap_InitSlot( (CELL)(h0));
if (!Yap_gcl((ASP-HBASE)*sizeof(CELL), 3, ENV, Yap_gcP())) {
Yap_Error(RESOURCE_ERROR_STACK, ARG1, "read_stream_to_codes/3");
return false;
}
/* build a legal term again */
h0 = (CELL*)(Yap_GetFromSlot(news1));
HBASE = RepPair(Yap_GetFromSlot(news));
}
Yap_CloseSlots(st);
}
UNLOCK(GLOBAL_Stream[sno].streamlock);
if (HR == HBASE)
return Yap_unify(ARG2,ARG3);
RESET_VARIABLE(HR-1);
Yap_unify(HR[-1],ARG3);
return Yap_unify(AbsPair(HBASE),ARG2);
}
static Int
read_stream_to_terms(USES_REGS1)
{
int sno = Yap_CheckStream (ARG1, Input_Stream_f, "read_line_to_codes/2");
Term t, hd;
yhandle_t tails, news;
if (sno < 0)
return FALSE;
t = AbsPair(HR);
RESET_VARIABLE(HR);
Yap_InitSlot( (CELL)(HR) );
tails = Yap_InitSlot( (CELL)(HR) );
news = Yap_InitSlot( (CELL)(HR) );
HR++;
while (!(GLOBAL_Stream[sno].status & Eof_Stream_f)) {
RESET_VARIABLE(HR);
RESET_VARIABLE(HR+1);
hd = (CELL)HR;
Yap_PutInSlot(news, (CELL)(HR+1));
HR += 2;
while ((hd=Yap_read_term(sno, TermNil, 2)) == 0L)
;
// just ignore failure
CELL *pt = VarOfTerm(Yap_GetFromSlot(tails));
if (Deref(hd) == TermEOfCode) {
*pt = Deref(ARG3);
break;
} else {
CELL *newpt = (CELL*)Yap_GetFromSlot(news);
*pt =AbsPair(newpt-1);
Yap_PutInSlot(tails, (CELL)newpt);
}
}
UNLOCK(GLOBAL_Stream[sno].streamlock);
return Yap_unify(t,ARG2);
}
void
Yap_InitReadUtil(void)
{
CACHE_REGS
Term cm = CurrentModule;
CurrentModule = READUTIL_MODULE;
Yap_InitCPred("read_line_to_string", 2, read_line_to_string, SyncPredFlag);
Yap_InitCPred("read_line_to_codes", 2, read_line_to_codes, SyncPredFlag);
Yap_InitCPred("read_line_to_codes", 3, read_line_to_codes2, SyncPredFlag);
Yap_InitCPred("read_stream_to_codes", 3, read_stream_to_codes, SyncPredFlag);
Yap_InitCPred("read_stream_to_terms", 3, read_stream_to_terms, SyncPredFlag);
CurrentModule = cm;
}