dhtPersist.pas

   1 unit dhtPersist;
   2 {
   3   Initialize DHT local node ID from file.
   4   Restore DHT routing table from file.
   5   Save DHT routing table on exit and periodically.
   6 }
   7
   8 INTERFACE
   9
  10 IMPLEMENTATION
  11 uses NetAddr,ServerLoop,DHT,SysUtils,Store1;
  12
  13 const ndfn='nodes.dat';
  14 const idfn='idhash.txt';
  15
  16 procedure Save;
  17  var nd: FILE of tPeerPub;
  18  var node:tPeerPub;
  19  var nnp:pointer=nil;
  20  var nni:byte=0;
  21  begin
  22  assign(nd,'_'+ndfn);
  23  ReWrite(nd);
  24  try
  25  repeat
  26   dht.GetNextNode(nnp,nni,node);
  27   if node.addr.isNil then break;
  28   //writeln('dhtPersist: save ',string(node.addr));
  29   write(nd,node);
  30  until false;
  31  finally
  32   close(nd);
  33  end;
  34  rename(nd,ndfn);
  35 end;
  36
  37 procedure Load;
  38  var nd: FILE of tPeerPub;
  39  var node:tPeerPub;
  40  var pos:Word;
  41  begin
  42  assign(nd,ndfn);
  43  try
  44   ReSet(nd);
  45  except
  46   writeln('dhtPersist: can not open state file ',ndfn);
  47  exit end;
  48  {need to read the file backwards}
  49  pos:=FileSize(nd);
  50  if pos=0 then exit;
  51  for pos:=pos-1 downto 0 do begin
  52   Seek(nd,pos);
  53   Read(nd,node);
  54   //writeln('dhtPersist: load ',string(node.addr));
  55   dht.InsertNode(node);
  56  end;
  57  close(nd);
  58 end;
  59
  60 procedure LoadID;
  61  var nd: TextFile;
  62  var line:string;
  63  begin
  64  assign(nd,idfn);
  65  try
  66   ReSet(nd);
  67  except
  68   writeln('dhtPersist: can not open id file ',idfn);
  69  exit end;
  70  readln(nd,line);
  71  writeln('dhtPersist: set ID to ',line);
  72  dht.MyID:=line;
  73  close(nd);
  74 end;
  75
  76 procedure LoadIDFromArgs;
  77  var oi:word;
  78  const opt='-id';
  79  begin
  80  oi:=OptIndex(opt);
  81  if oi>0 then begin
  82   assert(OptParamCount(oi)=1,opt+'(pid:sha1)');
  83   writeln('dhtPersist: set ID to '+paramstr(oi+1));
  84   MyID:=tPID(paramstr(oi+1));
  85  end;
  86 end;
  87 procedure LoadIDRandom;
  88  var oi:word;
  89  const opt='-id-rnd';
  90  var b:byte;
  91  begin
  92  oi:=OptIndex(opt);
  93  if oi>0 then begin
  94   assert(OptParamCount(oi)=0,opt+'()');
  95   for b:=0 to 19 do MyID[b]:=Random(256);
  96   writeln('dhtPersist: set ID to ',string(MyID));
  97  end;
  98 end;
  99
 100 type t=object
 101  pot:procedure;
 102  procedure Init;
 103  procedure doPeriodic;
 104  procedure doSoon;
 105 end;
 106
 107 procedure doLast;
 108  begin
 109  Save;
 110 end;
 111
 112 procedure t.doSoon;
 113  begin
 114  Load;
 115 end;
 116
 117 procedure t.doPeriodic;
 118  begin
 119  Save;
 120  Shedule(61273,@doPeriodic);
 121 end;
 122
 123 procedure t.Init;
 124  begin
 125  LoadID;
 126  LoadIDFromArgs;
 127  LoadIDRandom;
 128  Shedule(2000,@doSoon);
 129  Shedule(25000,@doPeriodic);
 130  {
 131  pot:=ServerLoop.OnTerminate;
 132  ServerLoop.OnTerminate:=@doLast;
 133  }
 134 end;
 135
 136 var o:t;
 137 BEGIN
 138  o.init;
 139 END.