1 /*
2 http://code.google.com/p/inferno-os/source/browse/libbio/brdline.c
3
4 Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
5 Revisions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com). All rights reserved.
6
7 Permission is hereby granted, free of charge, to any person obtaining a copy
8 of this software and associated documentation files (the "Software"), to deal
9 in the Software without restriction, including without limitation the rights
10 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 copies of the Software, and to permit persons to whom the Software is
12 furnished to do so, subject to the following conditions:
13
14 The above copyright notice and this permission notice shall be included in
15 all copies or substantial portions of the Software.
16
17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 THE SOFTWARE.
24 */
25
26 #include <u.h>
27 #include <libc.h>
28 #include <bio.h>
29
30 void*
31 Brdline(Biobuf *bp, int delim)
32 {
33 char *ip, *ep;
34 int i, j;
35
36 i = -bp->icount;
37 if(i == 0) {
38 /*
39 * eof or other error
40 */
41 if(bp->state != Bractive) {
42 if(bp->state == Bracteof)
43 bp->state = Bractive;
44 bp->rdline = 0;
45 bp->gbuf = bp->ebuf;
46 return 0;
47 }
48 }
49
50 /*
51 * first try in remainder of buffer (gbuf doesn't change)
52 */
53 ip = (char*)bp->ebuf - i;
54 ep = memchr(ip, delim, i);
55 if(ep) {
56 j = (ep - ip) + 1;
57 bp->rdline = j;
58 bp->icount += j;
59 return ip;
60 }
61
62 /*
63 * copy data to beginning of buffer
64 */
65 if(i < bp->bsize)
66 memmove(bp->bbuf, ip, i);
67 bp->gbuf = bp->bbuf;
68
69 /*
70 * append to buffer looking for the delim
71 */
72 ip = (char*)bp->bbuf + i;
73 while(i < bp->bsize) {
74 j = read(bp->fid, ip, bp->bsize-i);
75 if(j <= 0) {
76 /*
77 * end of file with no delim
78 */
79 memmove(bp->ebuf-i, bp->bbuf, i);
80 bp->rdline = i;
81 bp->icount = -i;
82 bp->gbuf = bp->ebuf-i;
83 return 0;
84 }
85 bp->offset += j;
86 i += j;
87 ep = memchr(ip, delim, j);
88 if(ep) {
89 /*
90 * found in new piece
91 * copy back up and reset everything
92 */
93 ip = (char*)bp->ebuf - i;
94 if(i < bp->bsize){
95 memmove(ip, bp->bbuf, i);
96 bp->gbuf = (unsigned char*)ip;
97 }
98 j = (ep - (char*)bp->bbuf) + 1;
99 bp->rdline = j;
100 bp->icount = j - i;
101 return ip;
102 }
103 ip += j;
104 }
105
106 /*
107 * full buffer without finding
108 */
109 bp->rdline = bp->bsize;
110 bp->icount = -bp->bsize;
111 bp->gbuf = bp->bbuf;
112 return 0;
113 }
114
115 int
116 Blinelen(Biobuf *bp)
117 {
118
119 return bp->rdline;
120 }