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,ECC;
  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,' from '+idfn);
  72  dht.MyID:=line;
  73  close(nd);
  74 end;
  75
  76 procedure LoadIDFromECC;
  77  var id:dht.tPID;
  78  begin
  79  Move(ECC.PublicKey,id,20);
  80  writeln('dhtPersist: set ID to ',string(id),' from ECC');
  81  dht.MyID:=id;
  82 end;
  83
  84 procedure LoadIDFromArgs;
  85  var oi:word;
  86  const opt='-id';
  87  begin
  88  oi:=OptIndex(opt);
  89  if oi>0 then begin
  90   assert(OptParamCount(oi)=1,opt+'(pid:sha1)');
  91   writeln('dhtPersist: set ID to '+paramstr(oi+1),' from '+opt);
  92   MyID:=tPID(paramstr(oi+1));
  93  end;
  94 end;
  95 procedure LoadIDRandom;
  96  var oi:word;
  97  const opt='-id-rnd';
  98  var b:byte;
  99  begin
 100  oi:=OptIndex(opt);
 101  if oi>0 then begin
 102   assert(OptParamCount(oi)=0,opt+'()');
 103   for b:=0 to 19 do MyID[b]:=Random(256);
 104   writeln('dhtPersist: set ID to ',string(MyID),' random');
 105  end;
 106 end;
 107
 108 type t=object
 109  pot:procedure;
 110  procedure Init;
 111  procedure doPeriodic;
 112  procedure doSoon;
 113 end;
 114
 115 procedure doLast;
 116  begin
 117  Save;
 118 end;
 119
 120 procedure t.doSoon;
 121  begin
 122  Load;
 123 end;
 124
 125 procedure t.doPeriodic;
 126  begin
 127  Save;
 128  Shedule(61273,@doPeriodic);
 129 end;
 130
 131 procedure t.Init;
 132  begin
 133  (*LoadID*);
 134  LoadIDFromECC;
 135  LoadIDFromArgs;
 136  LoadIDRandom;
 137  Shedule(2000,@doSoon);
 138  Shedule(25000,@doPeriodic);
 139  {
 140  pot:=ServerLoop.OnTerminate;
 141  ServerLoop.OnTerminate:=@doLast;
 142  }
 143 end;
 144
 145 var o:t;
 146 BEGIN
 147  o.init;
 148 END.