1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
/* Copyright (C) 2003 Russ Cox, Massachusetts Institute of Technology */
/* See COPYRIGHT */
#include <u.h>
#include <libc.h>
#include <fcall.h>
#include <9pclient.h>
#include "fsimpl.h"
long
fspread(CFid *fid, void *buf, long n, vlong offset)
{
Fcall tx, rx;
void *freep;
uint msize;
msize = fid->fs->msize - IOHDRSZ;
if(n > msize)
n = msize;
tx.type = Tread;
tx.fid = fid->fid;
if(offset == -1){
qlock(&fid->lk);
tx.offset = fid->offset;
qunlock(&fid->lk);
}else
tx.offset = offset;
tx.count = n;
if(_fsrpc(fid->fs, &tx, &rx, &freep) < 0)
return -1;
if(rx.type == Rerror){
werrstr("%s", rx.ename);
free(freep);
return -1;
}
if(rx.count){
memmove(buf, rx.data, rx.count);
if(offset == -1){
qlock(&fid->lk);
fid->offset += rx.count;
qunlock(&fid->lk);
}
}
free(freep);
return rx.count;
}
long
fsread(CFid *fid, void *buf, long n)
{
return fspread(fid, buf, n, -1);
}
long
fsreadn(CFid *fid, void *buf, long n)
{
long tot, nn;
for(tot=0; tot<n; tot+=nn){
nn = fsread(fid, (char*)buf+tot, n-tot);
if(nn <= 0){
if(tot == 0)
return nn;
break;
}
}
return tot;
}
|