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annotate buffer_get.c @ 0:2cb46628feec

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from cdb-0.75 per http://cr.yp.to/cdb.html, retrieved 2025-01-03, contents appear to have been create on 2000-02-19
author Henry S. Thompson <ht@inf.ed.ac.uk>
date Wed, 29 Jan 2025 10:50:34 +0000
parents
children 3bfef1f22a97
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
0
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
diff changeset
1 #include "buffer.h"
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2 #include "byte.h"
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3 #include "error.h"
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4
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Henry S. Thompson <ht@inf.ed.ac.uk>
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5 static int oneread(int (*op)(),int fd,char *buf,unsigned int len)
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Henry S. Thompson <ht@inf.ed.ac.uk>
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6 {
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Henry S. Thompson <ht@inf.ed.ac.uk>
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7 int r;
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8
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Henry S. Thompson <ht@inf.ed.ac.uk>
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9 for (;;) {
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Henry S. Thompson <ht@inf.ed.ac.uk>
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10 r = op(fd,buf,len);
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11 if (r == -1) if (errno == error_intr) continue;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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12 return r;
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13 }
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14 }
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15
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Henry S. Thompson <ht@inf.ed.ac.uk>
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16 static int getthis(buffer *s,char *buf,unsigned int len)
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Henry S. Thompson <ht@inf.ed.ac.uk>
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17 {
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Henry S. Thompson <ht@inf.ed.ac.uk>
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18 if (len > s->p) len = s->p;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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19 s->p -= len;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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20 byte_copy(buf,len,s->x + s->n);
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21 s->n += len;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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22 return len;
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23 }
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24
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Henry S. Thompson <ht@inf.ed.ac.uk>
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25 int buffer_feed(buffer *s)
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26 {
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27 int r;
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28
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Henry S. Thompson <ht@inf.ed.ac.uk>
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29 if (s->p) return s->p;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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30 r = oneread(s->op,s->fd,s->x,s->n);
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31 if (r <= 0) return r;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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32 s->p = r;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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33 s->n -= r;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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34 if (s->n > 0) byte_copyr(s->x + s->n,r,s->x);
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35 return r;
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36 }
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37
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Henry S. Thompson <ht@inf.ed.ac.uk>
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38 int buffer_bget(buffer *s,char *buf,unsigned int len)
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39 {
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Henry S. Thompson <ht@inf.ed.ac.uk>
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40 int r;
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41
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
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42 if (s->p > 0) return getthis(s,buf,len);
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
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43 if (s->n <= len) return oneread(s->op,s->fd,buf,s->n);
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
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44 r = buffer_feed(s); if (r <= 0) return r;
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
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45 return getthis(s,buf,len);
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Henry S. Thompson <ht@inf.ed.ac.uk>
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46 }
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47
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
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48 int buffer_get(buffer *s,char *buf,unsigned int len)
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Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
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49 {
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Henry S. Thompson <ht@inf.ed.ac.uk>
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50 int r;
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51
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Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
diff changeset
52 if (s->p > 0) return getthis(s,buf,len);
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
diff changeset
53 if (s->n <= len) return oneread(s->op,s->fd,buf,len);
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
diff changeset
54 r = buffer_feed(s); if (r <= 0) return r;
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
diff changeset
55 return getthis(s,buf,len);
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
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56 }
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57
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Henry S. Thompson <ht@inf.ed.ac.uk>
parents:
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58 char *buffer_peek(buffer *s)
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59 {
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60 return s->x + s->n;
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61 }
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62
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parents:
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63 void buffer_seek(buffer *s,unsigned int len)
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Henry S. Thompson <ht@inf.ed.ac.uk>
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64 {
2cb46628feec from cdb-0.75 per http://cr.yp.to/cdb.html,
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65 s->n += len;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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66 s->p -= len;
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Henry S. Thompson <ht@inf.ed.ac.uk>
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67 }