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PIPE.C
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C/C++ Source or Header
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1993-10-07
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6KB
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205 lines
/*
* pipe.c -- Pipe support for GSVIEW.EXE, a graphical interface for
* MS-Windows Ghostscript
* Copyright (C) 1993 Russell Lang
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Author: Russell Lang
* Internet: rjl@monu1.cc.monash.edu.au
*/
#define STRICT
#include <windows.h>
#include <windowsx.h>
#include <commdlg.h>
#include <shellapi.h>
#include <mmsystem.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <dir.h>
#include <io.h>
#define NeedFunctionPrototypes 1
#include "ps.h"
#include "gsview.h"
/* routines to be visible outside this module */
extern void pipeinit();
extern FILE *pipeopen(void); /* open pipe for first time */
extern void pipeclose(void); /* finished with pipe, close & delete temp files */
extern void pipereset(void); /* pipe is empty, do cleanup */
extern void piperequest(void); /* request from gswin for pipe data */
extern void pipeflush(void); /* start sending data through pipe */
extern BOOL is_pipe_done(void); /* true if pipe has just been reset */
/* internal to this module */
/* imitation pipes using SHAREABLE GLOBAL MEMORY */
#define PIPE_DATASIZE 16384 /* maximum block size */
/* Data is passed to gswin in a global shareable memory block.
* The global handle is passed in the LOWORD of lParam
* and the HIWORD contains the byte count.
* The maximum number of bytes passed is PIPE_DATASIZE.
* EOF is signified by count = 0 (hglobal must still be valid)
*/
char pipe_name[MAXSTR]; /* pipe filename */
FILE *pipe_file; /* pipe file */
fpos_t pipe_wpos;
fpos_t pipe_rpos;
BOOL pipe_empty;
int piperead(char *buf, int size);
char *pipebuf;
/* this is called before gswin is started */
/* so we can tell when we get the first piperequest */
void
pipeinit(void)
{
pipe_empty = FALSE; /* so we wait for first request */
}
FILE *
pipeopen(void)
{
if (pipe_file != (FILE *)NULL) {
fclose(pipe_file);
pipe_file = (FILE *)NULL;
unlink(pipe_name);
pipe_name[0] = '\0';
}
if ((pipe_file = gp_open_scratch_file(szScratch, pipe_name, "w+b")) == (FILE *)NULL) {
gserror(IDS_PIPEERR, NULL, NULL, SOUND_ERROR);
unlink(pipe_name);
pipe_name[0] = '\0';
return (FILE *)NULL;
}
pipebuf = malloc(PIPE_DATASIZE);
pipereset();
return pipe_file;
}
void
pipeclose(void)
{
HGLOBAL hglobal;
if (pipebuf != (char *)NULL) {
free(pipebuf);
pipebuf = (char *)NULL;
}
if (pipe_file != (FILE *)NULL) {
fclose(pipe_file);
pipe_file = (FILE *)NULL;
unlink(pipe_name);
pipe_name[0] = '\0';
}
if (hwndtext != (HWND)NULL) {
/* send an EOF (zero length block) */
hglobal = GlobalAlloc(GMEM_MOVEABLE | GMEM_SHARE, 1);
if (hglobal == (HGLOBAL)NULL) {
gserror(IDS_PIPEERR, NULL, NULL, SOUND_ERROR);
return;
}
PostMessage(hwndtext, WM_GSVIEW, PIPE_DATA, MAKELPARAM(hglobal,0));
}
pipe_empty = TRUE;
}
/* rpos and wpos are now empty so reset the file */
void
pipereset(void)
{
if ( (pipe_file == (FILE *)NULL) || (pipe_name[0] == '\0') )
return;
if ((pipe_file = freopen(pipe_name, "w+b", pipe_file)) == (FILE *)NULL) {
gserror(IDS_PIPEERR, NULL, NULL, SOUND_ERROR);
unlink(pipe_name);
pipe_name[0] = '\0';
return;
}
fgetpos(pipe_file, &pipe_rpos);
fgetpos(pipe_file, &pipe_wpos);
pipe_empty = TRUE;
info_wait(FALSE);
}
/* give another block of data to gswin */
/* called from WndImgProc */
void
piperequest(void)
{
HGLOBAL hglobal;
LPBYTE lpb;
UINT count;
if (pipe_file == (FILE *)NULL) {
pipe_empty = TRUE;
return;
}
count = piperead(pipebuf, PIPE_DATASIZE);
if (count==0)
return;
hglobal = GlobalAlloc(GMEM_MOVEABLE | GMEM_SHARE, PIPE_DATASIZE);
if (hglobal == (HGLOBAL)NULL) {
gserror(IDS_PIPEERR, NULL, NULL, SOUND_ERROR);
return;
}
lpb = GlobalLock(hglobal);
_fmemcpy(lpb, pipebuf, count);
GlobalUnlock(hglobal);
/* we may be processing SendMessage so use PostMessage to avoid lockups */
PostMessage(hwndtext, WM_GSVIEW, PIPE_DATA, MAKELPARAM(hglobal,count));
}
/* write pipe_file to pipe */
void
pipeflush(void)
{
if (pipe_empty) {
pipe_empty = FALSE;
piperequest(); /* repeat the request */
}
info_wait(TRUE);
}
/* true if pipereset was last called */
/* false if pipeflush was last called */
int
is_pipe_done(void)
{
return pipe_empty;
}
/* read a block from pipe */
/* return count of characters read */
/* reset pipe if empty */
int
piperead(char *buf, int size)
{
int rcount;
fflush(pipe_file);
fgetpos(pipe_file,&pipe_wpos);
fsetpos(pipe_file,&pipe_rpos);
rcount = fread(buf, 1, size, pipe_file);
fgetpos(pipe_file,&pipe_rpos);
fsetpos(pipe_file,&pipe_wpos);
if (rcount == 0)
pipereset();
return rcount;
}