/* External procedures for weave */
/*   Written by: H. Trickey, 11/17/83   */

/* Modified for 8-bit input --- don  8/31/89 */

/* Note: these procedures aren't necessary; the default input_ln and
* flush_buffer routines in tangle/weave work fine on UNIX.
* However a very big time improvement is achieved by using these.
*
* These procedures are the same as for tangle, except for a slight offset
* in which characters are output from outbuf in linewrite.
*/

#define BUF_SIZE 100            /* should agree with tangle.web */

#include "h00vars.h"            /* defines Pascal I/O structure */

extern short buffer[];          /* 0..BUF_SIZE.  Input goes here */
extern short outbuf[];          /* 0..OUT_BUF_SIZE. Output from here */
extern short xord[];
extern char xchr[];     /* character translation arrays */
extern short limit;             /* index into buffer.  Note that limit
                                  is 0..long_buf_size in weave.web; this
                                  differs from the definition in tangle.web */

/*
* lineread reads from the Pascal text file with iorec pointer filep
* into buffer[0], buffer[1],..., buffer[limit-1] (and
* setting "limit").
* Characters are read until a newline is found (which isn't put in the
* buffer) or until the next character would go into buffer[BUF_SIZE].
* And trailing blanks are to be ignored, so limit is really set to
* one past the last non-blank.
* The characters need to be translated, so really xord[c] is put into
* the buffer when c is read.
* If end-of-file is encountered, the funit field of *filep is set
* appropriately.
*/
lineread(filep)
struct iorec *filep;
{
       register c;
       register short *cs; /* pointer into buffer where next char goes */
       register short *cnb; /* last non-blank character input */
       register FILE *iop; /* stdio-style FILE pointer */
       register int l; /* how many chars allowed before buffer overflow */

       iop = filep->fbuf;
       cnb = cs = &(buffer[0]);
       l = BUF_SIZE;
         /* overflow when next char would go into buffer[BUF_SIZE] */
       while (--l>=0 && (c = getc(iop)) != EOF && c!='\n')
           if((*cs++ = xord[c])!=' ') cnb = cs;
       if (c == EOF)
           filep->funit |= EOFF; /* we hit end-of-file */
       limit = cnb-&(buffer[0]);
}

/*
* linewrite writes to the Pascal text file with iorec pointer filep
* from outbuf[1], outbuf[1],..., outbuf[cnt].
* (Note the offset of indices vis a vis the tangext version of this.)
* Translation is done, so that xchr[c] is output instead of c.
*/
linewrite(filep,cnt)
struct iorec *filep;
int cnt;
{
       register FILE *iop; /* stdio-style FILE pointer */
       register short *cs; /* pointer to next character to output */
       register int l; /* how many characters left to output */

       iop = filep->fbuf;
       cs = &(outbuf[1]);
       l = cnt;
       while (--l>=0) putc(xchr[*cs++],iop);
}

/*
**      testeof(filep)
**
**  Test whether or not the Pascal text file with iorec pointer filep
**  has reached end-of-file (when the only I/O on it is done with
**  lineread, above).
**  We may have to read the next character and unget it to see if perhaps
**  the end-of-file is next.
*/

bool
testeof(filep)
register struct iorec *filep;
{
       register char c;
       register FILE *iop; /* stdio-style FILE pointer */
       if (filep->funit & EOFF)
               return(TRUE);
       else { /* check to see if next is EOF */
               iop = filep->fbuf;
               c = getc(iop);
               if (c == EOF)
                       return(TRUE);
               else {
                       ungetc(c,iop);
                       return(FALSE);
                       }
       }
}