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comparison 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
comparison
equal deleted inserted replaced
-1:000000000000 0:2cb46628feec
1 #include "buffer.h"
2 #include "byte.h"
3 #include "error.h"
4
5 static int oneread(int (*op)(),int fd,char *buf,unsigned int len)
6 {
7 int r;
8
9 for (;;) {
10 r = op(fd,buf,len);
11 if (r == -1) if (errno == error_intr) continue;
12 return r;
13 }
14 }
15
16 static int getthis(buffer *s,char *buf,unsigned int len)
17 {
18 if (len > s->p) len = s->p;
19 s->p -= len;
20 byte_copy(buf,len,s->x + s->n);
21 s->n += len;
22 return len;
23 }
24
25 int buffer_feed(buffer *s)
26 {
27 int r;
28
29 if (s->p) return s->p;
30 r = oneread(s->op,s->fd,s->x,s->n);
31 if (r <= 0) return r;
32 s->p = r;
33 s->n -= r;
34 if (s->n > 0) byte_copyr(s->x + s->n,r,s->x);
35 return r;
36 }
37
38 int buffer_bget(buffer *s,char *buf,unsigned int len)
39 {
40 int r;
41
42 if (s->p > 0) return getthis(s,buf,len);
43 if (s->n <= len) return oneread(s->op,s->fd,buf,s->n);
44 r = buffer_feed(s); if (r <= 0) return r;
45 return getthis(s,buf,len);
46 }
47
48 int buffer_get(buffer *s,char *buf,unsigned int len)
49 {
50 int r;
51
52 if (s->p > 0) return getthis(s,buf,len);
53 if (s->n <= len) return oneread(s->op,s->fd,buf,len);
54 r = buffer_feed(s); if (r <= 0) return r;
55 return getthis(s,buf,len);
56 }
57
58 char *buffer_peek(buffer *s)
59 {
60 return s->x + s->n;
61 }
62
63 void buffer_seek(buffer *s,unsigned int len)
64 {
65 s->n += len;
66 s->p -= len;
67 }