sys/src/libbio/brdline.c

   1 #include        <u.h>
   2 #include        <libc.h>
   3 #include        <bio.h>
   4
   5 void*
   6 Brdline(Biobufhdr *bp, int delim)
   7 {
   8         char *ip, *ep;
   9         int i, j;
  10
  11         i = -bp->icount;
  12         if(i == 0) {
  13                 /*
  14                  * eof or other error
  15                  */
  16                 if(bp->state != Bractive) {
  17                         if(bp->state == Bracteof)
  18                                 bp->state = Bractive;
  19                         bp->rdline = 0;
  20                         bp->gbuf = bp->ebuf;
  21                         return 0;
  22                 }
  23         }
  24
  25         /*
  26          * first try in remainder of buffer (gbuf doesn't change)
  27          */
  28         ip = (char*)bp->ebuf - i;
  29         ep = memchr(ip, delim, i);
  30         if(ep) {
  31                 j = (ep - ip) + 1;
  32                 bp->rdline = j;
  33                 bp->icount += j;
  34                 return ip;
  35         }
  36
  37         /*
  38          * copy data to beginning of buffer
  39          */
  40         if(i < bp->bsize)
  41                 memmove(bp->bbuf, ip, i);
  42         bp->gbuf = bp->bbuf;
  43
  44         /*
  45          * append to buffer looking for the delim
  46          */
  47         ip = (char*)bp->bbuf + i;
  48         while(i < bp->bsize) {
  49                 j = bp->iof(bp, ip, bp->bsize-i);
  50                 if(j < 0)
  51                         Berror(bp, "read error: %r");
  52                 if(j <= 0) {
  53                         /*
  54                          * end of file with no delim
  55                          */
  56                         memmove(bp->ebuf-i, bp->bbuf, i);
  57                         bp->rdline = i;
  58                         bp->icount = -i;
  59                         bp->gbuf = bp->ebuf-i;
  60                         return 0;
  61                 }
  62                 bp->offset += j;
  63                 i += j;
  64                 ep = memchr(ip, delim, j);
  65                 if(ep) {
  66                         /*
  67                          * found in new piece
  68                          * copy back up and reset everything
  69                          */
  70                         ip = (char*)bp->ebuf - i;
  71                         if(i < bp->bsize){
  72                                 memmove(ip, bp->bbuf, i);
  73                                 bp->gbuf = (uchar*)ip;
  74                         }
  75                         j = (ep - (char*)bp->bbuf) + 1;
  76                         bp->rdline = j;
  77                         bp->icount = j - i;
  78                         return ip;
  79                 }
  80                 ip += j;
  81         }
  82
  83         /*
  84          * full buffer without finding
  85          */
  86         bp->rdline = bp->bsize;
  87         bp->icount = -bp->bsize;
  88         bp->gbuf = bp->bbuf;
  89         return 0;
  90 }
  91
  92 int
  93 Blinelen(Biobufhdr *bp)
  94 {
  95
  96         return bp->rdline;
  97 }