sys/src/lib9p/ramfs.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <auth.h>
   4 #include <fcall.h>
   5 #include <thread.h>
   6 #include <9p.h>
   7
   8 static char Ebad[] = "something bad happened";
   9 static char Enomem[] = "no memory";
  10
  11 typedef struct Ramfile  Ramfile;
  12 struct Ramfile {
  13         char *data;
  14         int ndata;
  15 };
  16
  17 void
  18 fsread(Req *r)
  19 {
  20         Ramfile *rf;
  21         vlong offset;
  22         long count;
  23
  24         rf = r->fid->file->aux;
  25         offset = r->ifcall.offset;
  26         count = r->ifcall.count;
  27
  28 //print("read %ld %lld\n", *count, offset);
  29         if(offset >= rf->ndata){
  30                 r->ofcall.count = 0;
  31                 respond(r, nil);
  32                 return;
  33         }
  34
  35         if(offset+count >= rf->ndata)
  36                 count = rf->ndata - offset;
  37
  38         memmove(r->ofcall.data, rf->data+offset, count);
  39         r->ofcall.count = count;
  40         respond(r, nil);
  41 }
  42
  43 void
  44 fswrite(Req *r)
  45 {
  46         void *v;
  47         Ramfile *rf;
  48         vlong offset;
  49         long count;
  50
  51         rf = r->fid->file->aux;
  52         offset = r->ifcall.offset;
  53         count = r->ifcall.count;
  54
  55         if(offset+count >= rf->ndata){
  56                 v = realloc(rf->data, offset+count);
  57                 if(v == nil){
  58                         respond(r, Enomem);
  59                         return;
  60                 }
  61                 rf->data = v;
  62                 rf->ndata = offset+count;
  63                 r->fid->file->length = rf->ndata;
  64         }
  65         memmove(rf->data+offset, r->ifcall.data, count);
  66         r->ofcall.count = count;
  67         respond(r, nil);
  68 }
  69
  70 void
  71 fscreate(Req *r)
  72 {
  73         Ramfile *rf;
  74         File *f;
  75
  76         if(f = createfile(r->fid->file, r->ifcall.name, r->fid->uid, r->ifcall.perm, nil)){
  77                 rf = emalloc9p(sizeof *rf);
  78                 f->aux = rf;
  79                 r->fid->file = f;
  80                 r->ofcall.qid = f->qid;
  81                 respond(r, nil);
  82                 return;
  83         }
  84         respond(r, Ebad);
  85 }
  86
  87 void
  88 fsopen(Req *r)
  89 {
  90         Ramfile *rf;
  91
  92         rf = r->fid->file->aux;
  93
  94         if(rf && (r->ifcall.mode&OTRUNC)){
  95                 rf->ndata = 0;
  96                 r->fid->file->length = 0;
  97         }
  98
  99         respond(r, nil);
 100 }
 101
 102 void
 103 fsdestroyfile(File *f)
 104 {
 105         Ramfile *rf;
 106
 107 //fprint(2, "clunk\n");
 108         rf = f->aux;
 109         if(rf){
 110                 free(rf->data);
 111                 free(rf);
 112         }
 113 }
 114
 115 Srv fs = {
 116         .open=  fsopen,
 117         .read=  fsread,
 118         .write= fswrite,
 119         .create=        fscreate,
 120 };
 121
 122 void
 123 usage(void)
 124 {
 125         fprint(2, "usage: ramfs [-D] [-s srvname] [-m mtpt]\n");
 126         exits("usage");
 127 }
 128
 129 void
 130 main(int argc, char **argv)
 131 {
 132         char *addr = nil;
 133         char *srvname = nil;
 134         char *mtpt = nil;
 135         Qid q;
 136
 137         fs.tree = alloctree(nil, nil, DMDIR|0777, fsdestroyfile);
 138         q = fs.tree->root->qid;
 139
 140         ARGBEGIN{
 141         case 'D':
 142                 chatty9p++;
 143                 break;
 144         case 'a':
 145                 addr = EARGF(usage());
 146                 break;
 147         case 's':
 148                 srvname = EARGF(usage());
 149                 break;
 150         case 'm':
 151                 mtpt = EARGF(usage());
 152                 break;
 153         default:
 154                 usage();
 155         }ARGEND;
 156
 157         if(argc)
 158                 usage();
 159
 160         if(chatty9p)
 161                 fprint(2, "ramsrv.nopipe %d srvname %s mtpt %s\n", fs.nopipe, srvname, mtpt);
 162         if(addr == nil && srvname == nil && mtpt == nil)
 163                 sysfatal("must specify -a, -s, or -m option");
 164         if(addr)
 165                 listensrv(&fs, addr);
 166
 167         if(srvname || mtpt)
 168                 postmountsrv(&fs, srvname, mtpt, MREPL|MCREATE);
 169         exits(0);
 170 }