src/engine/e_msg.pas

   1 (* Copyright (C)  Doom 2D: Forever Developers
   2  *
   3  * This program is free software: you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation, either version 3 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  *)
  16 {$INCLUDE ../shared/a_modes.inc}
  17 unit e_msg;
  18
  19 interface
  20
  21 uses md5;
  22
  23 type
  24   TMsg = record
  25     Data: Pointer;
  26     Overflow: Boolean;
  27     MaxSize: Integer;
  28     CurSize: Integer;
  29     ReadCount: Integer;
  30     Bit: Integer;
  31     OwnMemory: Boolean;
  32
  33     function Init(V: Pointer; N: Integer; Full: Boolean = False): Boolean;
  34     procedure Alloc(N: Integer);
  35     procedure Clear();
  36     procedure Free();
  37     procedure CopyFrom(var From: TMsg; V: Pointer; N: Integer);
  38     function Allocated(): Boolean;
  39     function AssignBuffer(P: Pointer; N: Integer; Full: Boolean = False): Boolean;
  40
  41     procedure BeginReading();
  42     function ReadData(V: Pointer; N: Integer): Integer;
  43     function ReadChar(): Char;
  44     function ReadByte(): Byte;
  45     function ReadWord(): Word;
  46     function ReadLongWord(): LongWord;
  47     function ReadShortInt(): ShortInt;
  48     function ReadSmallInt(): SmallInt;
  49     function ReadLongInt(): LongInt;
  50     function ReadInt64(): Int64;
  51     function ReadString(): String;
  52     function ReadMD5(): TMD5Digest;
  53
  54     procedure WriteData(V: Pointer; N: Integer);
  55     procedure Write(V: Byte); overload;
  56     procedure Write(V: Word); overload;
  57     procedure Write(V: LongWord); overload;
  58     procedure Write(V: ShortInt); overload;
  59     procedure Write(V: SmallInt); overload;
  60     procedure Write(V: LongInt); overload;
  61     procedure Write(V: Int64); overload;
  62     procedure Write(V: String); overload;
  63     procedure Write(V: TMD5Digest); overload;
  64   end;
  65
  66 type
  67   pTMsg = ^TMsg;
  68
  69 implementation
  70
  71 uses SysUtils, e_log;
  72
  73 function TMsg.Init(V: Pointer; N: Integer; Full: Boolean = False): Boolean;
  74 begin
  75   Overflow := False;
  76   if Full then CurSize := N else CurSize := 0;
  77   ReadCount := 0;
  78   Bit := 0;
  79   MaxSize := N;
  80   Data := V;
  81   OwnMemory := False;
  82   Result := (N > 0) and (V <> nil);
  83 end;
  84
  85 procedure TMsg.Alloc(N: Integer);
  86 var
  87   P: Pointer;
  88 begin
  89   P := GetMem(N);
  90   if P = nil then
  91     raise Exception.Create('TMsg.Alloc: no mem');
  92   Init(P, N);
  93   OwnMemory := True;
  94 end;
  95
  96 procedure TMsg.Free();
  97 begin
  98   if not OwnMemory then
  99     raise Exception.Create('TMsg.Free: called on borrowed memory');
 100   OwnMemory := False;
 101   FreeMem(Data);
 102   Data := nil;
 103   MaxSize := 0;
 104 end;
 105
 106 procedure TMsg.Clear();
 107 begin
 108   CurSize := 0;
 109   ReadCount := 0;
 110   Overflow := False;
 111   Bit := 0;
 112 end;
 113
 114 function TMsg.Allocated(): Boolean;
 115 begin
 116   Result := OwnMemory;
 117 end;
 118
 119 procedure TMsg.CopyFrom(var From: TMsg; V: Pointer; N: Integer);
 120 begin
 121   if N < From.CurSize then
 122     raise Exception.Create('TMsg.Copy: can''t copy into a smaller TMsg');
 123   Move(From, Self, SizeOf(TMsg));
 124   Data := V;
 125   Move(From.Data^, Data^, From.CurSize);
 126 end;
 127
 128 function TMsg.AssignBuffer(P: Pointer; N: Integer; Full: Boolean = False): Boolean;
 129 begin
 130   if OwnMemory then Self.Free();
 131   Clear();
 132   Data := P;
 133   MaxSize := N;
 134   if Full then CurSize := N;
 135   Result := (N > 0) and (P <> nil);
 136 end;
 137
 138 procedure TMsg.WriteData(V: Pointer; N: Integer);
 139 begin
 140   if CurSize + N > MaxSize then
 141   begin
 142     Overflow := True;
 143     raise Exception.Create('TMsg.WriteData: buffer overrun!');
 144     Exit;
 145   end;
 146   Move(V^, (Data + CurSize)^, N);
 147   CurSize := CurSize + N;
 148 end;
 149
 150 procedure TMsg.Write(V: Byte); overload;
 151 begin
 152   WriteData(@V, 1);
 153 end;
 154
 155 procedure TMsg.Write(V: Word); overload;
 156 begin
 157   WriteData(@V, 2);
 158 end;
 159
 160 procedure TMsg.Write(V: LongWord); overload;
 161 begin
 162   WriteData(@V, 4);
 163 end;
 164
 165 procedure TMsg.Write(V: ShortInt); overload;
 166 begin
 167   WriteData(@V, 1);
 168 end;
 169
 170 procedure TMsg.Write(V: SmallInt); overload;
 171 begin
 172   WriteData(@V, 2);
 173 end;
 174
 175 procedure TMsg.Write(V: LongInt); overload;
 176 begin
 177   WriteData(@V, 4);
 178 end;
 179
 180 procedure TMsg.Write(V: Int64); overload;
 181 begin
 182   WriteData(@V, 8);
 183 end;
 184
 185 procedure TMsg.Write(V: AnsiString); overload;
 186 var
 187   I: Integer;
 188 begin
 189   // TODO: Write(Word(Length(V)));
 190   Write(Byte(Length(V)));
 191   for I := 1 to High(V) do
 192     Write(Byte(V[I]));
 193 end;
 194
 195 procedure TMsg.Write(V: TMD5Digest); overload;
 196 var
 197   I: Integer;
 198 begin
 199   for I := 0 to 15 do
 200     Write(V[I]);
 201 end;
 202
 203 procedure TMsg.BeginReading();
 204 begin
 205   ReadCount := 0;
 206   Bit := 0;
 207 end;
 208
 209 function TMsg.ReadData(V: Pointer; N: Integer): Integer;
 210 begin
 211   Result := 0;
 212   if ReadCount + N > CurSize then
 213   begin
 214     // TODO: maybe partial reads?
 215     ReadCount := CurSize + 1;
 216     raise Exception.Create('TMsg.ReadData: buffer overrun!');
 217     Exit;
 218   end;
 219   Move((Data + ReadCount)^, V^, N);
 220   ReadCount := ReadCount + N;
 221   Result := N;
 222 end;
 223
 224 function TMsg.ReadChar(): Char;
 225 begin
 226   Result := #0;
 227   ReadData(@Result, 1);
 228 end;
 229
 230 function TMsg.ReadByte(): Byte;
 231 begin
 232   Result := 0;
 233   ReadData(@Result, 1);
 234 end;
 235
 236 function TMsg.ReadWord(): Word;
 237 begin
 238   Result := 0;
 239   ReadData(@Result, 2);
 240 end;
 241
 242 function TMsg.ReadLongWord(): LongWord;
 243 begin
 244   Result := 0;
 245   ReadData(@Result, 4);
 246 end;
 247
 248 function TMsg.ReadShortInt(): ShortInt;
 249 begin
 250   Result := 0;
 251   ReadData(@Result, 1);
 252 end;
 253
 254 function TMsg.ReadSmallInt(): SmallInt;
 255 begin
 256   Result := 0;
 257   ReadData(@Result, 2);
 258 end;
 259
 260 function TMsg.ReadLongInt(): LongInt;
 261 begin
 262   Result := 0;
 263   ReadData(@Result, 4);
 264 end;
 265
 266 function TMsg.ReadInt64(): Int64;
 267 begin
 268   Result := 0;
 269   ReadData(@Result, 8);
 270 end;
 271
 272 function TMsg.ReadString(): string;
 273 var
 274   I: Integer;
 275   L: Byte;
 276 begin
 277   Result := '';
 278   // TODO: L := ReadWord();
 279   L := ReadByte();
 280   if (L > 0) and (L <> Byte(-1)) then
 281   begin
 282     SetLength(Result, L);
 283     for I := 1 to L do
 284       Result[I] := ReadChar();
 285   end;
 286 end;
 287
 288 function TMsg.ReadMD5(): TMD5Digest;
 289 var
 290   I: Integer;
 291 begin
 292   for I := 0 to 15 do
 293     Result[I] := ReadByte();
 294 end;
 295
 296 end.