asio.c

Functions

Flushfield        X
bflush            X
bflush1           X
bflushc           X
bopen             X
bwrite            X

Variables

biobufsize        X
biofd             X
bwrerror          X

Macros

error             X

   1: /*
   2:  * Copyright (c) 1982 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: static char sccsid[] = "@(#)asio.c	5.1 (Berkeley) 4/30/85";
   9: #endif not lint
  10: 
  11: #include <stdio.h>
  12: #include "as.h"
  13: /*
  14:  *	Block I/O routines for logical I/O concurrently in
  15:  *	more than one place in the same file.
  16:  */
  17: int biofd;          /* file descriptor for block I/O file */
  18: int biobufsize;     /* optimal block size for I/O */
  19: off_t   boffset;        /* physical position in logical file */
  20: BFILE   *biobufs;       /* the block I/O buffers */
  21: 
  22: #define error(severity, message) \
  23:     {yyerror(message); if (severity) delexit();}
  24: 
  25: Flushfield(n)
  26:     register int n;
  27: {
  28:     while (n>0) {
  29:         outb(bitfield);
  30:         bitfield >>= 8;
  31:         n -= 8;
  32:     }
  33:     bitoff=0;
  34:     bitfield=0;
  35: }
  36: 
  37: /*
  38:  *	Block I/O Routines
  39:  */
  40: bopen(bp, off)
  41:     struct biobuf *bp;
  42:     off_t   off;
  43: {
  44: 
  45:     bp->b_ptr = bp->b_buf = Calloc(1, biobufsize);
  46:     bp->b_nleft = biobufsize - (off % biobufsize);
  47:     bp->b_off = off;
  48:     bp->b_link = biobufs;
  49:     biobufs = bp;
  50: }
  51: 
  52: int bwrerror;
  53: 
  54: bwrite(p, cnt, bp)
  55:     register char *p;
  56:     register int cnt;
  57:     register struct biobuf *bp;
  58: {
  59:     register int put;
  60:     register char *to;
  61: 
  62: top:
  63:     if (cnt == 0)
  64:         return;
  65:     if (bp->b_nleft) {
  66:         put = bp->b_nleft;
  67:         if (put > cnt)
  68:             put = cnt;
  69:         bp->b_nleft -= put;
  70:         to = bp->b_ptr;
  71: #ifdef lint
  72:         *to = *to;
  73: #endif lint
  74:         asm("movc3 r8,(r11),(r7)");
  75:         bp->b_ptr += put;
  76:         p += put;
  77:         cnt -= put;
  78:         goto top;
  79:     }
  80:     if (cnt >= biobufsize) {
  81:         if (bp->b_ptr != bp->b_buf)
  82:             bflush1(bp);
  83:         put = cnt - cnt % biobufsize;
  84:         if (boffset != bp->b_off)
  85:             (void)lseek(biofd, (long)bp->b_off, 0);
  86:         if (write(biofd, p, put) != put) {
  87:             bwrerror = 1;
  88:             error(1, "Output write error");
  89:         }
  90:         bp->b_off += put;
  91:         boffset = bp->b_off;
  92:         p += put;
  93:         cnt -= put;
  94:         goto top;
  95:     }
  96:     bflush1(bp);
  97:     goto top;
  98: }
  99: 
 100: bflush()
 101: {
 102:     register struct biobuf *bp;
 103: 
 104:     if (bwrerror)
 105:         return;
 106:     for (bp = biobufs; bp; bp = bp->b_link)
 107:         bflush1(bp);
 108: }
 109: 
 110: bflush1(bp)
 111:     register struct biobuf *bp;
 112: {
 113:     register int cnt = bp->b_ptr - bp->b_buf;
 114: 
 115:     if (cnt == 0)
 116:         return;
 117:     if (boffset != bp->b_off)
 118:         (void)lseek(biofd, (long)bp->b_off, 0);
 119:     if (write(biofd, bp->b_buf, cnt) != cnt) {
 120:         bwrerror = 1;
 121:         error(1, "Output write error");
 122:     }
 123:     bp->b_off += cnt;
 124:     boffset = bp->b_off;
 125:     bp->b_ptr = bp->b_buf;
 126:     bp->b_nleft = biobufsize;
 127: }
 128: 
 129: bflushc(bp, c)
 130:     register struct biobuf *bp;
 131:     char    c;
 132: {
 133:     bflush1(bp);
 134:     bputc(c, bp);
 135: }