1 /* Copyright (C) 2003 Russ Cox, Massachusetts Institute of Technology */
2 /* See COPYRIGHT */
3 
4 #include <u.h>
5 #include <libc.h>
6 #include <fcall.h>
7 #include <9pclient.h>
8 #include "fsimpl.h"
9 
10 long
11 fspread(CFid *fid, void *buf, long n, vlong offset)
12 {
13 	Fcall tx, rx;
14 	void *freep;
15 	uint msize;
16 
17 	msize = fid->fs->msize - IOHDRSZ;
18 	if(n > msize)
19 		n = msize;
20 	tx.type = Tread;
21 	tx.fid = fid->fid;
22 	if(offset == -1){
23 		qlock(&fid->lk);
24 		tx.offset = fid->offset;
25 		qunlock(&fid->lk);
26 	}else
27 		tx.offset = offset;
28 	tx.count = n;
29 
30 	if(_fsrpc(fid->fs, &tx, &rx, &freep) < 0)
31 		return -1;
32 	if(rx.type == Rerror){
33 		werrstr("%s", rx.ename);
34 		free(freep);
35 		return -1;
36 	}
37 	if(rx.count){
38 		memmove(buf, rx.data, rx.count);
39 		if(offset == -1){
40 			qlock(&fid->lk);
41 			fid->offset += rx.count;
42 			qunlock(&fid->lk);
43 		}
44 	}
45 	free(freep);
46 	
47 	return rx.count;
48 }
49 
50 long
51 fsread(CFid *fid, void *buf, long n)
52 {
53 	return fspread(fid, buf, n, -1);
54 }
55 
56 long
57 fsreadn(CFid *fid, void *buf, long n)
58 {
59 	long tot, nn;
60 
61 	for(tot=0; tot<n; tot+=nn){
62 		nn = fsread(fid, (char*)buf+tot, n-tot);
63 		if(nn <= 0){
64 			if(tot == 0)
65 				return nn;
66 			break;
67 		}
68 	}
69 	return tot;
70 }
71 			
72