reader.cc

   1 #include <reader.h>
   2 #include <alien.h>
   3
   4 #include <string>
   5 #include <assert.h>
   6
   7 namespace odc {
   8
   9 Reader::Reader(std::istream &rider): d_rider(rider), d_cancelled(false), d_readAlien(false), d_typeList(),
  10         d_state(new ReaderState()) {}
  11
  12 SHORTCHAR Reader::readSChar() {
  13         SHORTCHAR out;
  14         d_rider.read(&out, 1);
  15         return out;
  16 }
  17
  18 void Reader::readSChar(SHORTCHAR *buf, size_t len) {
  19         d_rider.read(buf, len);
  20 }
  21
  22 CHAR Reader::readLChar() {
  23         CHAR buf;
  24         char *bufPtr = (char *)&buf;
  25         d_rider.read(bufPtr, 2);
  26         if (isLittleEndian()) {
  27                 return buf;
  28         } else {
  29                 CHAR out;
  30                 char *outPtr = (char *)&out;
  31                 outPtr[0] = bufPtr[1]; outPtr[1] = bufPtr[0];
  32                 return out;
  33         }
  34 }
  35
  36 void Reader::readLChar(CHAR *buf, size_t len) {
  37         char *bufPtr = (char *)buf;
  38         int len2 = len * 2;
  39         d_rider.read(bufPtr, len2);
  40         if (isBigEndian()) {
  41                 char tmp;
  42                 for (int i = 0; i < len2; i += 2) {
  43                         tmp = bufPtr[i];
  44                         bufPtr[i] = bufPtr[i + 1];
  45                         bufPtr[i + 1] = tmp;
  46                 }
  47         }
  48 }
  49
  50 BYTE Reader::readByte() {
  51         BYTE out;
  52         d_rider.read((char*)&out, 1);
  53         return out;
  54 }
  55
  56 SHORTINT Reader::readSInt() {
  57         SHORTINT buf;
  58         char *bufPtr = (char*)&buf;
  59         d_rider.read(bufPtr, 2);
  60         if (isLittleEndian()) {
  61                 return buf;
  62         } else {
  63                 SHORTINT out;
  64                 char *outPtr = (char *)&out;
  65                 outPtr[0] = bufPtr[1]; outPtr[1] = bufPtr[0];
  66                 return out;
  67         }
  68 }
  69
  70 INTEGER Reader::readInt() {
  71         INTEGER buf;
  72         char *bufPtr = (char*)&buf;
  73         d_rider.read(bufPtr, 4);
  74         if (isLittleEndian()) {
  75                 return buf;
  76         } else {
  77                 INTEGER out;
  78                 char *outPtr = (char *)&out;
  79                 outPtr[0] = bufPtr[3]; outPtr[1] = bufPtr[2]; outPtr[2] = bufPtr[1]; outPtr[3] = bufPtr[0];
  80                 return out;
  81         }
  82 }
  83
  84 void Reader::readSString(SHORTCHAR *out) {
  85         while (*out = readSChar()) {
  86                 ++out;
  87         }
  88 }
  89
  90 void Reader::turnIntoAlien(int cause) {
  91         assert(cause > 0);
  92         d_cancelled = true;
  93         d_cause = cause;
  94         d_readAlien = true;
  95 }
  96
  97 bool Reader::isCancelled() {
  98         return d_cancelled;
  99 }
 100
 101 INTEGER Reader::readVersion(INTEGER min, INTEGER max) {
 102         INTEGER version = readByte();
 103         if (version < min || version > max) {
 104                 turnIntoAlien(ALIENVERSION);
 105         }
 106         return version;
 107 }
 108
 109 Store* Reader::readStore() {
 110         SHORTCHAR kind = readSChar();
 111         if (kind == Store::NIL) {
 112                 //std::cout << "NIL STORE" << std::endl;
 113                 return readNilStore();
 114         } else if (kind == Store::LINK) {
 115                 //std::cout << "LINK STORE" << std::endl;
 116                 return readLinkStore();
 117         } else if (kind == Store::NEWLINK) {
 118                 //std::cout << "NEWLINK STORE" << std::endl;
 119                 return readNewLinkStore();
 120         } else if (kind == Store::STORE) {
 121                 //std::cout << "STORE STORE" << std::endl;
 122                 return readStoreOrElemStore(false);
 123         } else if (kind == Store::ELEM) {
 124                 //std::cout << "ELEM STORE" << std::endl;
 125                 return readStoreOrElemStore(true);
 126         } else {
 127                 //std::cout << std::hex << (unsigned int)kind << std::endl;
 128                 throw 20;
 129         }
 130 }
 131 //      PROCEDURE (VAR rd: Reader) ReadStore* (OUT x: Store), NEW;
 132 //              VAR a: Alien; t: Kernel.Type;
 133 //                      len, pos, pos1, id, comment, next, down, downPos, nextTypeId, nextElemId, nextStoreId: INTEGER;
 134 //                      kind: SHORTCHAR; path: TypePath; type: TypeName;
 135 //                      save: ReaderState;
 136
 137 Store *Reader::readNilStore() {
 138         INTEGER comment = readInt();
 139         std::streamoff next = readInt();
 140         d_state->end = d_rider.tellg();
 141         if (next > 0 || (next == 0 && comment % 2 == 1)) {
 142                 d_state->next = d_state->end + next;
 143         } else {
 144                 d_state->next = 0;
 145         }
 146         return 0;
 147 }
 148 //              IF kind = nil THEN
 149 //                      rd.ReadInt(comment); rd.ReadInt(next);
 150 //                      rd.st.end := rd.Pos();
 151 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 152 //                      x := NIL
 153
 154 Store *Reader::readLinkStore() {
 155         throw "Reader::readLinkStore() not implemented";
 156 }
 157 //              ELSIF kind = link THEN
 158 //                      rd.ReadInt(id); rd.ReadInt(comment); rd.ReadInt(next);
 159 //                      rd.st.end := rd.Pos();
 160 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 161 //                      x := ThisStore(rd.eDict, id)
 162
 163 Store *Reader::readNewLinkStore() {
 164         throw "Reader::readNewLinkStore() not implemented";
 165 }
 166 //              ELSIF kind = newlink THEN
 167 //                      rd.ReadInt(id); rd.ReadInt(comment); rd.ReadInt(next);
 168 //                      rd.st.end := rd.Pos();
 169 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 170 //                      x := ThisStore(rd.sDict, id)
 171
 172 Store *Reader::readStoreOrElemStore(bool isElem) {
 173         INTEGER id = isElem ? d_elemList.size() : d_storeList.size();
 174         TypePath path = readPath();
 175         //std::cout << path.toString() << std::endl;
 176         const std::string &type = path[0];
 177         INTEGER comment = readInt();
 178         std::streampos pos1 = d_rider.tellg();
 179         std::streamoff next = readInt();
 180         std::streamoff down = readInt();
 181         std::streamoff len = readInt();
 182         std::streampos pos = d_rider.tellg();
 183         if (next > 0) {
 184                 d_state->next = pos1 + next + (std::streamoff)4;
 185         } else {
 186                 d_state->next = 0;
 187         }
 188         int downPos = 0;
 189         if (down > 0) {
 190                 downPos = pos1 + down + (std::streamoff)8;
 191         }
 192         d_state->end = pos + len;
 193         d_cause = 0;
 194         assert(len >= 0);
 195         if (next != 0) {
 196                 assert(d_state->next > pos1);
 197                 if (down != 0) {
 198                         assert(downPos < d_state->next);
 199                 }
 200         }
 201         if (down > 0) {
 202                 assert(downPos > pos1);
 203                 assert(downPos < d_state->end);
 204         }
 205
 206         const TypeProxyBase *t = TypeRegister::getInstance().get(type); // FIXME type lookup here
 207         Store *x = 0;
 208         if (t != 0) {
 209                 x = t->newInstance(id);
 210         } else {
 211                 d_cause = TYPENOTFOUND;
 212         }
 213
 214         if (x != 0) { // IF READING SUCCEEDS, INSERT MORE CHECKS HERE
 215                 if (true) { // samePath(x, path)
 216                         ReaderState *save = d_state;
 217                         d_state = new ReaderState();
 218                         x->internalize(*this);
 219                         delete d_state;
 220                         d_state = save;
 221
 222                         if (d_cause != 0) {
 223                                 x = 0;
 224                         }
 225                         assert(d_rider.tellg() == d_state->end);
 226                         assert(!d_rider.eof());
 227                 } else {
 228 //                                      rd.cause := inconsistentType; AlienTypeReport(rd.cause, type);
 229                         x = 0;
 230                 }
 231         }
 232
 233         if (x != 0) {
 234                 if (d_store == 0) {
 235                         d_store = x;
 236                 } else {
 237                         // join(d_store, x)
 238                 }
 239                 if (isElem) {
 240                         d_elemList.push_back(x);
 241                 } else {
 242                         d_storeList.push_back(x);
 243                 }
 244         } else {
 245                 d_rider.seekg(pos); // x->internalize() could have left us anywhere
 246                 assert(d_cause != 0);
 247                 Alien *alien = new Alien(id, path); //, d_cause); //,file
 248                 if (d_store == 0) {
 249                         d_store = alien;
 250                 } else {
 251                         // join(d_store, alien)
 252                 }
 253                 if (isElem) {
 254                         d_elemList.push_back(alien);
 255                 } else {
 256                         d_storeList.push_back(alien);
 257                 }
 258                 ReaderState *save = d_state;
 259                 d_state = new ReaderState();
 260                 internalizeAlien(alien, downPos, save->end);
 261                 delete d_state;
 262                 d_state = save;
 263                 assert(d_rider.tellg() == d_state->end);
 264
 265                 // we've just read the alien, so reset the state
 266                 d_cause = 0;
 267                 d_cancelled = false;
 268                 d_readAlien = true;
 269                 return alien;
 270         }
 271
 272         return x;
 273 }
 274
 275
 276 void Reader::internalizeAlien(Alien *alien, std::streampos down, std::streampos end) {
 277         std::streampos next = down != 0 ? down : end;
 278         while (d_rider.tellg() < end) {
 279                 if (d_rider.tellg() < next) { // for some reason, this means its a piece (unstructured)
 280                         size_t len = next - d_rider.tellg();
 281                         char *buf = new char[len];
 282                         d_rider.read(buf, len);
 283                         AlienComponent *comp = new AlienPiece(buf, len);
 284                         alien->getComponents().push_back(comp);
 285                 } else { // that means we've got a store
 286                         d_rider.seekg(next);
 287                         AlienComponent *comp = new AlienPart(readStore());
 288                         alien->getComponents().push_back(comp);
 289                         next = d_state->next > 0 ? d_state->next : end;
 290                 }
 291         }
 292 }
 293
 294 std::string &Reader::fixTypeName(std::string &name) {
 295         size_t pos = name.size() - 4;
 296         if (pos > 0 && name.substr(pos, 4).compare("Desc") == 0) {
 297                 return name.replace(pos, 4, "^");
 298         }
 299         return name;
 300 }
 301
 302 TypePath Reader::readPath() {
 303         TypePath path;
 304         SHORTCHAR kind = readSChar();
 305         SHORTCHAR *buf = new SHORTCHAR[64]; // TypeName has a maximum of length 64 (including terminator).
 306         int i;
 307         for (i = 0; kind == Store::NEWEXT; ++i) {
 308                 readSString(buf);
 309                 std::string name(buf);
 310                 path.push_back(fixTypeName(name));
 311                 addPathComponent(i == 0, path[i]);
 312 //                      IF path[i] # elemTName THEN INC(i) END;
 313                 kind = readSChar();
 314         }
 315
 316         if (kind == Store::NEWBASE) {
 317                 readSString(buf);
 318                 std::string name(buf);
 319                 path.push_back(fixTypeName(name));
 320                 addPathComponent(i == 0, path[i]);
 321                 ++i;
 322         } else if (kind == Store::OLDTYPE) {
 323                 int id = readInt();
 324                 if (i > 0) {
 325                         d_typeList[d_typeList.size() - 1]->baseId = id;
 326                 }
 327                 while (id != -1) {
 328                         path.push_back(d_typeList[id]->name);
 329                         id = d_typeList[id]->baseId;
 330 //                              IF path[i] # elemTName THEN INC(i) END
 331                         ++i;
 332                 }
 333         } else {
 334                 throw 100;
 335         }
 336         return path;
 337 }
 338
 339 void Reader::addPathComponent(bool first, const std::string &typeName) {
 340         int next = d_typeList.size();
 341         int curr = next - 1;
 342         if (!first) {
 343                 d_typeList[curr]->baseId = next;
 344         }
 345         d_typeList.push_back(new TypeEntry(typeName));
 346 }
 347
 348 } // namespace odc