sys/src/lib9p/ramfs.c

   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->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->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->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         exits("usage");
 126 }
 127
 128 void
 129 main(int argc, char **argv)
 130 {
 131         char *addr = nil;
 132         char *srvname = nil;
 133         char *mtpt = nil;
 134         Qid q;
 135
 136         fs.tree = alloctree(nil, nil, DMDIR|0777, fsdestroyfile);
 137         q = fs.tree->root->qid;
 138
 139         ARGBEGIN{
 140         case 'D':
 141                 chatty9p++;
 142                 break;
 143         case 'a':
 144                 addr = EARGF(usage());
 145                 break;
 146         case 's':
 147                 srvname = EARGF(usage());
 148                 break;
 149         case 'm':
 150                 mtpt = EARGF(usage());
 151                 break;
 152         default:
 153                 usage();
 154         }ARGEND;
 155
 156         if(argc)
 157                 usage();
 158
 159         if(chatty9p)
 160                 fprint(2, "srvname %s mtpt %s\n", srvname, mtpt);
 161         if(addr == nil && srvname == nil && mtpt == nil)
 162                 sysfatal("must specify -a, -s, or -m option");
 163         if(addr)
 164                 listensrv(&fs, addr);
 165
 166         if(srvname || mtpt)
 167                 postmountsrv(&fs, srvname, mtpt, MREPL|MCREATE);
 168         exits(0);
 169 }