1 #include <u.h>
2 #include <libc.h>
3 #include <fcall.h>
4 #include <thread.h>
5 #include <9p.h>
6 
7 static char Ebad[] = "something bad happened";
8 static char Enomem[] = "no memory";
9 
10 typedef struct Ramfile	Ramfile;
11 struct Ramfile {
12 	char *data;
13 	int ndata;
14 };
15 
16 void
17 fsread(Req *r)
18 {
19 	Ramfile *rf;
20 	vlong offset;
21 	long count;
22 
23 	rf = r->fid->file->aux;
24 	offset = r->ifcall.offset;
25 	count = r->ifcall.count;
26 
27 /*print("read %ld %lld\n", *count, offset); */
28 	if(offset >= rf->ndata){
29 		r->ofcall.count = 0;
30 		respond(r, nil);
31 		return;
32 	}
33 
34 	if(offset+count >= rf->ndata)
35 		count = rf->ndata - offset;
36 
37 	memmove(r->ofcall.data, rf->data+offset, count);
38 	r->ofcall.count = count;
39 	respond(r, nil);
40 }
41 
42 void
43 fswrite(Req *r)
44 {
45 	void *v;
46 	Ramfile *rf;
47 	vlong offset;
48 	long count;
49 
50 	rf = r->fid->file->aux;
51 	offset = r->ifcall.offset;
52 	count = r->ifcall.count;
53 
54 	if(offset+count >= rf->ndata){
55 		v = realloc(rf->data, offset+count);
56 		if(v == nil){
57 			respond(r, Enomem);
58 			return;
59 		}
60 		rf->data = v;
61 		rf->ndata = offset+count;
62 		r->fid->file->dir.length = rf->ndata;
63 	}
64 	memmove(rf->data+offset, r->ifcall.data, count);
65 	r->ofcall.count = count;
66 	respond(r, nil);
67 }
68 
69 void
70 fscreate(Req *r)
71 {
72 	Ramfile *rf;
73 	File *f;
74 
75 	if(f = createfile(r->fid->file, r->ifcall.name, r->fid->uid, r->ifcall.perm, nil)){
76 		rf = emalloc9p(sizeof *rf);
77 		f->aux = rf;
78 		r->fid->file = f;
79 		r->ofcall.qid = f->dir.qid;
80 		respond(r, nil);
81 		return;
82 	}
83 	respond(r, Ebad);
84 }
85 
86 void
87 fsopen(Req *r)
88 {
89 	Ramfile *rf;
90 
91 	rf = r->fid->file->aux;
92 
93 	if(rf && (r->ifcall.mode&OTRUNC)){
94 		rf->ndata = 0;
95 		r->fid->file->dir.length = 0;
96 	}
97 
98 	respond(r, nil);
99 }
100 
101 void
102 fsdestroyfile(File *f)
103 {
104 	Ramfile *rf;
105 
106 /*fprint(2, "clunk\n"); */
107 	rf = f->aux;
108 	if(rf){
109 		free(rf->data);
110 		free(rf);
111 	}
112 }
113 
114 Srv fs = {
115 	.open=	fsopen,
116 	.read=	fsread,
117 	.write=	fswrite,
118 	.create=	fscreate,
119 };
120 
121 void
122 usage(void)
123 {
124 	fprint(2, "usage: ramfs [-D] [-s srvname] [-m mtpt]\n");
125 	threadexitsall("usage");
126 }
127 
128 int
129 threadmaybackground(void)
130 {
131 	return 1;
132 }
133 
134 void
135 threadmain(int argc, char **argv)
136 {
137 	char *srvname = nil;
138 	char *mtpt = nil;
139 	Qid q;
140 
141 	fs.tree = alloctree(nil, nil, DMDIR|0777, fsdestroyfile);
142 	q = fs.tree->root->dir.qid;
143 
144 	ARGBEGIN{
145 	case 'D':
146 		chatty9p++;
147 		break;
148 	case 's':
149 		srvname = EARGF(usage());
150 		break;
151 	case 'm':
152 		mtpt = EARGF(usage());
153 		break;
154 	default:
155 		usage();
156 	}ARGEND;
157 
158 	if(argc)
159 		usage();
160 
161 	if(chatty9p)
162 		fprint(2, "ramsrv.nopipe %d srvname %s mtpt %s\n", fs.nopipe, srvname, mtpt);
163 	if(srvname == nil && mtpt == nil)
164 		sysfatal("you should at least specify a -s or -m option");
165 
166 	threadpostmountsrv(&fs, srvname, mtpt, MREPL|MCREATE);
167 	threadexits(0);
168 }