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 Store *Reader::readNilStore() {
 137         INTEGER comment = readInt();
 138         std::streamoff next = readInt();
 139         d_state->end = d_rider.tellg();
 140         if (next > 0 || (next == 0 && comment % 2 == 1)) {
 141                 d_state->next = d_state->end + next;
 142         } else {
 143                 d_state->next = 0;
 144         }
 145         return 0;
 146 }
 147 //              IF kind = nil THEN
 148 //                      rd.ReadInt(comment); rd.ReadInt(next);
 149 //                      rd.st.end := rd.Pos();
 150 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 151 //                      x := NIL
 152 Store *Reader::readLinkStore() {
 153         return 0;
 154 }
 155 //              ELSIF kind = link THEN
 156 //                      rd.ReadInt(id); rd.ReadInt(comment); rd.ReadInt(next);
 157 //                      rd.st.end := rd.Pos();
 158 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 159 //                      x := ThisStore(rd.eDict, id)
 160 Store *Reader::readNewLinkStore() {
 161         return 0;
 162 }
 163 //              ELSIF kind = newlink THEN
 164 //                      rd.ReadInt(id); rd.ReadInt(comment); rd.ReadInt(next);
 165 //                      rd.st.end := rd.Pos();
 166 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 167 //                      x := ThisStore(rd.sDict, id)
 168
 169 Store *Reader::readStoreOrElemStore(bool isElem) {
 170         INTEGER id = isElem ? d_elemList.size() : d_storeList.size();
 171         TypePath path = readPath();
 172         //std::cout << path.toString() << std::endl;
 173         const std::string &type = path[0];
 174         INTEGER comment = readInt();
 175         std::streampos pos1 = d_rider.tellg();
 176         std::streamoff next = readInt();
 177         std::streamoff down = readInt();
 178         std::streamoff len = readInt();
 179         std::streampos pos = d_rider.tellg();
 180         if (next > 0) {
 181                 d_state->next = pos1 + next + (std::streamoff)4;
 182         } else {
 183                 d_state->next = 0;
 184         }
 185         int downPos = 0;
 186         if (down > 0) {
 187                 downPos = pos1 + down + (std::streamoff)8;
 188         }
 189         d_state->end = pos + len;
 190         d_cause = 0;
 191         assert(len >= 0);
 192         if (next != 0) {
 193                 assert(d_state->next > pos1);
 194                 if (down != 0) {
 195                         assert(downPos < d_state->next);
 196                 }
 197         }
 198         if (down > 0) {
 199                 assert(downPos > pos1);
 200                 assert(downPos < d_state->end);
 201         }
 202
 203         const TypeProxyBase *t = TypeRegister::getInstance().get(type); // FIXME type lookup here
 204         Store *x = 0;
 205         if (t != 0) {
 206                 x = t->newInstance(id);
 207         } else {
 208                 d_cause = TYPENOTFOUND;
 209         }
 210
 211         if (x != 0) { // IF READING SUCCEEDS, INSERT MORE CHECKS HERE
 212                 if (true) { // samePath(x, path)
 213                         ReaderState *save = d_state;
 214                         d_state = new ReaderState();
 215                         x->internalize(*this);
 216                         delete d_state;
 217                         d_state = save;
 218
 219                         if (d_cause != 0) {
 220                                 x = 0;
 221                         }
 222                         assert(d_rider.tellg() == d_state->end);
 223                         assert(!d_rider.eof());
 224                 } else {
 225 //                                      rd.cause := inconsistentType; AlienTypeReport(rd.cause, type);
 226                         x = 0;
 227                 }
 228         }
 229
 230         if (x != 0) {
 231                 if (d_store == 0) {
 232                         d_store = x;
 233                 } else {
 234                         // join(d_store, x)
 235                         //std::cout << "Man, should have written join(.,.)" << std::endl;
 236                 }
 237                 if (isElem) {
 238                         d_elemList.push_back(x);
 239                 } else {
 240                         d_storeList.push_back(x);
 241                 }
 242         } else {
 243                 d_rider.seekg(pos); // x->internalize() could have left us anywhere
 244                 assert(d_cause != 0);
 245                 Alien *alien = new Alien(id, path); //, d_cause); //,file
 246                 if (d_store == 0) {
 247                         d_store = alien;
 248                 } else {
 249                         // join(d_store, alien)
 250                         //std::cout << "Man, should have written join(.,.)" << std::endl;
 251                 }
 252                 if (isElem) {
 253                         d_elemList.push_back(alien);
 254                 } else {
 255                         d_storeList.push_back(alien);
 256                 }
 257                 ReaderState *save = d_state;
 258                 d_state = new ReaderState();
 259                 internalizeAlien(alien, downPos, save->end);
 260                 delete d_state;
 261                 d_state = save;
 262                 assert(d_rider.tellg() == d_state->end);
 263
 264                 // we've just read the alien, so reset the state
 265                 d_cause = 0;
 266                 d_cancelled = false;
 267                 d_readAlien = true;
 268                 return alien;
 269         }
 270
 271         return x;
 272 }
 273
 274
 275 void Reader::internalizeAlien(Alien *alien, std::streampos down, std::streampos end) {
 276         std::streampos next = down != 0 ? down : end;
 277         while (d_rider.tellg() < end) {
 278                 if (d_rider.tellg() < next) { // for some reason, this means its a piece (unstructured)
 279                         //std::cout << "Alien Piece" << std::endl;
 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                         //std::cout << "Alien Store" << std::endl;
 287                         d_rider.seekg(next);
 288                         AlienComponent *comp = new AlienPart(readStore());
 289                         alien->getComponents().push_back(comp);
 290                         next = d_state->next > 0 ? d_state->next : end;
 291                 }
 292         }
 293 }
 294
 295 std::string &Reader::fixTypeName(std::string &name) {
 296         size_t pos = name.size() - 4;
 297         if (pos > 0 && name.substr(pos, 4).compare("Desc") == 0) {
 298                 return name.replace(pos, 4, "^");
 299         }
 300         return name;
 301 }
 302
 303 TypePath Reader::readPath() {
 304         TypePath path;
 305         SHORTCHAR kind = readSChar();
 306         SHORTCHAR *buf = new SHORTCHAR[64]; // TypeName has a maximum of length 64 (including terminator).
 307         int i;
 308         for (i = 0; kind == Store::NEWEXT; ++i) {
 309                 readSString(buf);
 310                 std::string name(buf);
 311                 path.push_back(fixTypeName(name));
 312                 addPathComponent(i == 0, path[i]);
 313 //                      IF path[i] # elemTName THEN INC(i) END;
 314                 kind = readSChar();
 315         }
 316
 317         if (kind == Store::NEWBASE) {
 318                 readSString(buf);
 319                 std::string name(buf);
 320                 path.push_back(fixTypeName(name));
 321                 addPathComponent(i == 0, path[i]);
 322                 ++i;
 323         } else if (kind == Store::OLDTYPE) {
 324                 int id = readInt();
 325                 if (i > 0) {
 326                         d_typeList[d_typeList.size() - 1]->baseId = id;
 327                 }
 328                 while (id != -1) {
 329                         path.push_back(d_typeList[id]->name);
 330                         id = d_typeList[id]->baseId;
 331 //                              IF path[i] # elemTName THEN INC(i) END
 332                         ++i;
 333                 }
 334         } else {
 335                 throw 100;
 336         }
 337         return path;
 338 }
 339
 340 void Reader::addPathComponent(bool first, const std::string &typeName) {
 341         int next = d_typeList.size();
 342         int curr = next - 1;
 343         if (!first) {
 344                 d_typeList[curr]->baseId = next;
 345         }
 346         d_typeList.push_back(new TypeEntry(typeName));
 347 }
 348
 349 } // namespace odc