| 1 | #include "substdio.h" |
| 2 | #include "byte.h" |
| 3 | #include "error.h" |
| 4 | |
| 5 | static int oneread(op,fd,buf,len) |
| 6 | register int (*op)(); |
| 7 | register int fd; |
| 8 | register char *buf; |
| 9 | register int len; |
| 10 | { |
| 11 | register int r; |
| 12 | |
| 13 | for (;;) { |
| 14 | r = op(fd,buf,len); |
| 15 | if (r == -1) if (errno == error_intr) continue; |
| 16 | return r; |
| 17 | } |
| 18 | } |
| 19 | |
| 20 | static int getthis(s,buf,len) |
| 21 | register substdio *s; |
| 22 | register char *buf; |
| 23 | register int len; |
| 24 | { |
| 25 | register int r; |
| 26 | register int q; |
| 27 | |
| 28 | r = s->p; |
| 29 | q = r - len; |
| 30 | if (q > 0) { r = len; s->p = q; } else s->p = 0; |
| 31 | byte_copy(buf,r,s->x + s->n); |
| 32 | s->n += r; |
| 33 | return r; |
| 34 | } |
| 35 | |
| 36 | int substdio_feed(s) |
| 37 | register substdio *s; |
| 38 | { |
| 39 | register int r; |
| 40 | register int q; |
| 41 | |
| 42 | if (s->p) return s->p; |
| 43 | q = s->n; |
| 44 | r = oneread(s->op,s->fd,s->x,q); |
| 45 | if (r <= 0) return r; |
| 46 | s->p = r; |
| 47 | q -= r; |
| 48 | s->n = q; |
| 49 | if (q > 0) /* damn, gotta shift */ byte_copyr(s->x + q,r,s->x); |
| 50 | return r; |
| 51 | } |
| 52 | |
| 53 | int substdio_bget(s,buf,len) |
| 54 | register substdio *s; |
| 55 | register char *buf; |
| 56 | register int len; |
| 57 | { |
| 58 | register int r; |
| 59 | |
| 60 | if (s->p > 0) return getthis(s,buf,len); |
| 61 | r = s->n; if (r <= len) return oneread(s->op,s->fd,buf,r); |
| 62 | r = substdio_feed(s); if (r <= 0) return r; |
| 63 | return getthis(s,buf,len); |
| 64 | } |
| 65 | |
| 66 | int substdio_get(s,buf,len) |
| 67 | register substdio *s; |
| 68 | register char *buf; |
| 69 | register int len; |
| 70 | { |
| 71 | register int r; |
| 72 | |
| 73 | if (s->p > 0) return getthis(s,buf,len); |
| 74 | if (s->n <= len) return oneread(s->op,s->fd,buf,len); |
| 75 | r = substdio_feed(s); if (r <= 0) return r; |
| 76 | return getthis(s,buf,len); |
| 77 | } |
| 78 | |
| 79 | char *substdio_peek(s) |
| 80 | register substdio *s; |
| 81 | { |
| 82 | return s->x + s->n; |
| 83 | } |
| 84 | |
| 85 | void substdio_seek(s,len) |
| 86 | register substdio *s; |
| 87 | register int len; |
| 88 | { |
| 89 | s->n += len; |
| 90 | s->p -= len; |
| 91 | } |