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yap-6.3/os/fmem.c
2018-09-29 14:43:27 -05:00

347 lines
8.7 KiB
C
Executable File

/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: mem.c *
* Last rev: 5/2/88 *
* mods: *
* comments: Input/Output C implemented predicates *
* *
*************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif
/*
* This file includes the definition of a socket related IO.
*
*/
#define _GNU_SOURCE
#include "YapText.h"
#include "format.h"
#include "sysbits.h"
#if HAVE_FMEMOPEN
int format_synch(int sno, int sno0, format_info *fg) {
const char *s;
int n;
if (sno != sno0) {
fflush(GLOBAL_Stream[sno].file);
n = ftell(GLOBAL_Stream[sno].file);
s = GLOBAL_Stream[sno].nbuf;
if (GLOBAL_Stream[sno0].vfs) {
int ch;
int (*f)() = GLOBAL_Stream[sno0].vfs->put_char;
while ((ch = *s++)) {
f(sno0, ch);
}
} else {
fwrite(s, n, 1, GLOBAL_Stream[sno0].file);
}
rewind(GLOBAL_Stream[sno].file);
fg->lstart = 0;
fg->phys_start = 0;
fg->gapi = 0;
}
Yap_flush(sno0);
return sno;
}
bool fill_pads(int sno, int sno0, int total, format_info *fg USES_REGS)
// uses directly the buffer in the memory stream.
{
int nfillers, fill_space, lfill_space, nchars;
int (*f_putc)(int, int);
const char *buf;
int phys_end;
f_putc = GLOBAL_Stream[sno0].stream_putc;
if (fflush(GLOBAL_Stream[sno].file) == 0) {
buf = GLOBAL_Stream[sno].nbuf;
phys_end = ftell(GLOBAL_Stream[sno].file);
} else
return false;
if (fg->gapi == 0) {
fg->gap[0].phys = phys_end;
fg->gap[0].filler = ' ';
fg->gapi = 1;
}
nchars = total - GLOBAL_Stream[sno].linepos;
if (nchars < 0)
nchars = 0; /* ignore */
nfillers = fg->gapi;
fill_space = nchars / nfillers;
lfill_space = nchars % nfillers;
int i = fg->phys_start;
gap_t *padi = fg->gap;
while (i < phys_end) {
if (i == padi->phys) {
int j;
for (j = 0; j < fill_space; j++)
f_putc(sno0, padi->filler);
padi++;
/* last gap??*/
if (padi - fg->gap == fg->gapi) {
for (j = 0; j < fill_space; j++)
f_putc(sno0, (padi - 1)->filler);
}
}
f_putc(sno0, buf[i++]);
}
// final gap
if (i == padi->phys) {
int j;
for (j = 0; j < fill_space + lfill_space; j++)
f_putc(sno0, padi->filler);
};
rewind(GLOBAL_Stream[sno].file);
Yap_flush(sno0);
GLOBAL_Stream[sno].linecount = 1;
GLOBAL_Stream[sno].linepos += nchars;
GLOBAL_Stream[sno].charcount = 0;
GLOBAL_Stream[sno].buf.on = false;
fg->phys_start = 0;
fg->lstart = GLOBAL_Stream[sno].linepos;
fg->gapi = 0;
return true;
}
bool Yap_set_stream_to_buf(StreamDesc *st, const char *buf,
size_t nchars USES_REGS) {
FILE *f;
// like any file stream.
st->file = f = fmemopen((char *)buf, nchars, "r");
st->status = Input_Stream_f | Seekable_Stream_f | InMemory_Stream_f;
st->vfs = NULL;
st->buf.on = false;
st->encoding = LOCAL_encoding;
Yap_DefaultStreamOps(st);
st->linecount = 0;
st->linepos = st->charcount = 0;
return true;
}
char *Yap_StrPrefix( const char *buf, size_t n) {
char *b = (char*)malloc(n);
strncpy(b, buf, n - 1);
if (strlen(buf) > n - 1)
b[15] = '\0';
return b;
}
int Yap_open_buf_read_stream(const char *buf, size_t nchars,
encoding_t *encp, memBufSource src, Atom fname,
Term uname) {
CACHE_REGS
int sno;
StreamDesc *st;
FILE *f;
encoding_t encoding;
stream_flags_t flags;
sno = GetFreeStreamD();
if (sno < 0)
return (PlIOError(RESOURCE_ERROR_MAX_STREAMS, TermNil,
"new stream not available for open_mem_read_stream/1"));
st = GLOBAL_Stream + sno;
if (encp)
encoding = *encp;
else
encoding = LOCAL_encoding;
// like any file stream.
f = st->file = fmemopen((void *)buf, nchars, "r");
st->vfs = NULL;
flags = Input_Stream_f | InMemory_Stream_f | Seekable_Stream_f;
Yap_initStream(sno, f, fname, "r", uname, encoding, flags, NULL);
// like any file stream.
Yap_DefaultStreamOps(st);
UNLOCK(st->streamlock);
return sno;
}
static Int
open_mem_read_stream(USES_REGS1) /* $open_mem_read_stream(+List,-Stream) */
{
Term t, ti;
int sno;
const char *buf;
ti = Deref(ARG1);
int l = push_text_stack();
buf = Yap_TextTermToText(ti);
if (!buf) {
pop_text_stack(l);
return false;
}
buf = pop_output_text_stack(l, buf);
sno = Yap_open_buf_read_stream(buf, strlen(buf) + 1, &LOCAL_encoding,
MEM_BUF_MALLOC, Yap_LookupAtom(Yap_StrPrefix((char *)buf,16)), TermNone);
t = Yap_MkStream(sno);
return Yap_unify(ARG2, t);
}
// open a buffer for writing, currently just ignores buf and nchars.
int Yap_open_buf_write_stream(encoding_t enc, memBufSource src) {
CACHE_REGS
int sno;
StreamDesc *st;
sno = GetFreeStreamD();
if (sno < 0)
return -1;
st = GLOBAL_Stream + sno;
st->status = Output_Stream_f | InMemory_Stream_f;
st->linepos = 0;
st->charcount = 0;
st->linecount = 1;
st->encoding = enc;
st->vfs = NULL;
st->buf.on = true;
st->nbuf = NULL;
st->status |= Seekable_Stream_f;
#if HAVE_OPEN_MEMSTREAM
st->file = open_memstream(&st->nbuf, &st->nsize);
// setbuf(st->file, NULL);
#else
st->file = fmemopen((void *)st->nbuf, st->nsize, "w+");
#endif
Yap_DefaultStreamOps(st);
UNLOCK(st->streamlock);
return sno;
}
int Yap_OpenBufWriteStream(USES_REGS1) {
return Yap_open_buf_write_stream(
GLOBAL_Stream[LOCAL_c_output_stream].encoding, 0);
}
static Int
open_mem_write_stream(USES_REGS1) /* $open_mem_write_stream(-Stream) */
{
Term t;
int sno;
sno = Yap_OpenBufWriteStream(PASS_REGS1);
if (sno == -1)
return (PlIOError(SYSTEM_ERROR_INTERNAL, TermNil,
"new stream not available for open_mem_read_stream/1"));
t = Yap_MkStream(sno);
GLOBAL_Stream[sno].status |= InMemory_Stream_f;
return (Yap_unify(ARG1, t));
}
/**
* Yap_PeekMemwriteStream() shows the current buffer for a memory stream.
*
* @param sno, the in-memory stream
*
* @return temporary buffer, discarded by close and may be moved away
* by other writes..
*/
char *Yap_MemExportStreamPtr(int sno) {
FILE *f = GLOBAL_Stream[sno].file;
if (fflush(f) < 0) {
return NULL;
}
if (fseek(f, 0, SEEK_END) < 0) {
return NULL;
}
size_t len = ftell(f);
char *buf = malloc(len+1);
#if HAVE_OPEN_MEMSTREAM
char *s = GLOBAL_Stream[sno].nbuf;
memcpy(buf, s, len);
// s[fseek(GLOBAL_Stream[sno].file, 0, SEEK_END)] = '\0';
#else
fread(buf, len, 1, GLOBAL_Stream[sno].file);
#endif
buf[len] = '\0';
return buf;
}
static Int peek_mem_write_stream(
USES_REGS1) { /* '$peek_mem_write_stream'(+GLOBAL_Stream,?S0,?S) */
Int sno =
Yap_CheckStream(ARG1, (Output_Stream_f | InMemory_Stream_f), "close/2");
Term tf = ARG2;
CELL *HI;
char *ptr;
int ch;
if (sno < 0)
return (FALSE);
char *p = ptr = Yap_MemExportStreamPtr(sno);
restart:
HI = HR;
while ((ch = *p++)) {
HR[0] = MkIntTerm(ch);
HR[1] = AbsPair(HR+2);
HR += 2;
if (HR + 1024 >= ASP) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
HR = HI;
if (!Yap_gcl((ASP - HI) * sizeof(CELL), 3, ENV, Yap_gcP())) {
UNLOCK(GLOBAL_Stream[sno].streamlock);
Yap_Error(RESOURCE_ERROR_STACK, TermNil, LOCAL_ErrorMessage);
return (FALSE);
}
LOCK(GLOBAL_Stream[sno].streamlock);
goto restart;
}
}
HR[-1] = tf;
UNLOCK(GLOBAL_Stream[sno].streamlock);
free(ptr);
return (Yap_unify(ARG3, AbsPair(HI)));
}
void Yap_MemOps(StreamDesc *st) {
st->stream_putc = FilePutc;
st->stream_getc = PlGetc;
}
bool Yap_CloseMemoryStream(int sno) {
if ((GLOBAL_Stream[sno].status & Output_Stream_f) &&
GLOBAL_Stream[sno].file) {
fflush(GLOBAL_Stream[sno].file);
fclose(GLOBAL_Stream[sno].file);
if (GLOBAL_Stream[sno].status & FreeOnClose_Stream_f)
free(GLOBAL_Stream[sno].nbuf);
} else {
if (GLOBAL_Stream[sno].file)
fclose(GLOBAL_Stream[sno].file);
if (GLOBAL_Stream[sno].status & FreeOnClose_Stream_f)
free(GLOBAL_Stream[sno].nbuf);
}
return true;
}
void Yap_InitMems(void) {
CACHE_REGS
Yap_InitCPred("open_mem_read_stream", 2, open_mem_read_stream, SyncPredFlag);
Yap_InitCPred("open_mem_write_stream", 1, open_mem_write_stream,
SyncPredFlag);
Yap_InitCPred("peek_mem_write_stream", 3, peek_mem_write_stream,
SyncPredFlag);
}
#endif