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 - 0x8000;
  28         } else {
  29                 CHAR out;
  30                 char *outPtr = (char *)&out;
  31                 outPtr[0] = bufPtr[1]; outPtr[1] = bufPtr[0];
  32                 return out - 0x8000;
  33         }
  34 }
  35
  36 void Reader::readLChar(CHAR *buf, size_t len) {
  37         for (int i = 0; i < len; ++i) {
  38                 buf[i] = readLChar();
  39         }
  40         /*
  41         char *bufPtr = (char *)buf;
  42         int len2 = len * 2;
  43         d_rider.read(bufPtr, len2);
  44         if (isBigEndian()) {
  45                 char tmp;
  46                 for (int i = 0; i < len2; i += 2) {
  47                         tmp = bufPtr[i];
  48                         bufPtr[i] = bufPtr[i + 1];
  49                         bufPtr[i + 1] = tmp;
  50                 }
  51         }
  52         */
  53 }
  54
  55 BYTE Reader::readByte() {
  56         BYTE out;
  57         d_rider.read((char*)&out, 1);
  58         return out;
  59 }
  60
  61 SHORTINT Reader::readSInt() {
  62         SHORTINT buf;
  63         char *bufPtr = (char*)&buf;
  64         d_rider.read(bufPtr, 2);
  65         if (isLittleEndian()) {
  66                 return buf;
  67         } else {
  68                 SHORTINT out;
  69                 char *outPtr = (char *)&out;
  70                 outPtr[0] = bufPtr[1]; outPtr[1] = bufPtr[0];
  71                 return out;
  72         }
  73 }
  74
  75 INTEGER Reader::readInt() {
  76         INTEGER buf;
  77         char *bufPtr = (char*)&buf;
  78         d_rider.read(bufPtr, 4);
  79         if (isLittleEndian()) {
  80                 return buf;
  81         } else {
  82                 INTEGER out;
  83                 char *outPtr = (char *)&out;
  84                 outPtr[0] = bufPtr[3]; outPtr[1] = bufPtr[2]; outPtr[2] = bufPtr[1]; outPtr[3] = bufPtr[0];
  85                 return out;
  86         }
  87 }
  88
  89 void Reader::readSString(SHORTCHAR *out) {
  90         while (*out = readSChar()) {
  91                 ++out;
  92         }
  93 }
  94
  95 void Reader::turnIntoAlien(int cause) {
  96         assert(cause > 0);
  97         d_cancelled = true;
  98         d_cause = cause;
  99         d_readAlien = true;
 100 }
 101
 102 bool Reader::isCancelled() {
 103         return d_cancelled;
 104 }
 105
 106 INTEGER Reader::readVersion(INTEGER min, INTEGER max) {
 107         INTEGER version = readByte();
 108         if (version < min || version > max) {
 109                 turnIntoAlien(ALIENVERSION);
 110         }
 111         return version;
 112 }
 113
 114 Store* Reader::readStore() {
 115         SHORTCHAR kind = readSChar();
 116         if (kind == Store::NIL) {
 117                 //std::cout << "NIL STORE" << std::endl;
 118                 return readNilStore();
 119         } else if (kind == Store::LINK) {
 120                 //std::cout << "LINK STORE" << std::endl;
 121                 return readLinkStore();
 122         } else if (kind == Store::NEWLINK) {
 123                 //std::cout << "NEWLINK STORE" << std::endl;
 124                 return readNewLinkStore();
 125         } else if (kind == Store::STORE) {
 126                 //std::cout << "STORE STORE" << std::endl;
 127                 return readStoreOrElemStore(false);
 128         } else if (kind == Store::ELEM) {
 129                 //std::cout << "ELEM STORE" << std::endl;
 130                 return readStoreOrElemStore(true);
 131         } else {
 132                 //std::cout << std::hex << (unsigned int)kind << std::endl;
 133                 throw 20;
 134         }
 135 }
 136 //      PROCEDURE (VAR rd: Reader) ReadStore* (OUT x: Store), NEW;
 137 //              VAR a: Alien; t: Kernel.Type;
 138 //                      len, pos, pos1, id, comment, next, down, downPos, nextTypeId, nextElemId, nextStoreId: INTEGER;
 139 //                      kind: SHORTCHAR; path: TypePath; type: TypeName;
 140 //                      save: ReaderState;
 141
 142 Store *Reader::readNilStore() {
 143         INTEGER comment = readInt();
 144         std::streamoff next = readInt();
 145         d_state->end = d_rider.tellg();
 146         if (next > 0 || (next == 0 && comment % 2 == 1)) {
 147                 d_state->next = d_state->end + next;
 148         } else {
 149                 d_state->next = 0;
 150         }
 151         return 0;
 152 }
 153 //              IF kind = nil THEN
 154 //                      rd.ReadInt(comment); rd.ReadInt(next);
 155 //                      rd.st.end := rd.Pos();
 156 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 157 //                      x := NIL
 158
 159 Store *Reader::readLinkStore() {
 160         throw "Reader::readLinkStore() not implemented";
 161 }
 162 //              ELSIF kind = link THEN
 163 //                      rd.ReadInt(id); rd.ReadInt(comment); rd.ReadInt(next);
 164 //                      rd.st.end := rd.Pos();
 165 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 166 //                      x := ThisStore(rd.eDict, id)
 167
 168 Store *Reader::readNewLinkStore() {
 169         throw "Reader::readNewLinkStore() not implemented";
 170 }
 171 //              ELSIF kind = newlink THEN
 172 //                      rd.ReadInt(id); rd.ReadInt(comment); rd.ReadInt(next);
 173 //                      rd.st.end := rd.Pos();
 174 //                      IF (next > 0) OR ((next = 0) & ODD(comment)) THEN rd.st.next := rd.st.end + next ELSE rd.st.next := 0 END;
 175 //                      x := ThisStore(rd.sDict, id)
 176
 177 Store *Reader::readStoreOrElemStore(bool isElem) {
 178         INTEGER id = isElem ? d_elemList.size() : d_storeList.size();
 179         TypePath path = readPath();
 180         //std::cout << path.toString() << std::endl;
 181         const std::string &type = path[0];
 182         INTEGER comment = readInt();
 183         std::streampos pos1 = d_rider.tellg();
 184         std::streamoff next = readInt();
 185         std::streamoff down = readInt();
 186         std::streamoff len = readInt();
 187         std::streampos pos = d_rider.tellg();
 188         if (next > 0) {
 189                 d_state->next = pos1 + next + (std::streamoff)4;
 190         } else {
 191                 d_state->next = 0;
 192         }
 193         int downPos = 0;
 194         if (down > 0) {
 195                 downPos = pos1 + down + (std::streamoff)8;
 196         }
 197         d_state->end = pos + len;
 198         d_cause = 0;
 199         assert(len >= 0);
 200         if (next != 0) {
 201                 assert(d_state->next > pos1);
 202                 if (down != 0) {
 203                         assert(downPos < d_state->next);
 204                 }
 205         }
 206         if (down > 0) {
 207                 assert(downPos > pos1);
 208                 assert(downPos < d_state->end);
 209         }
 210
 211         const TypeProxyBase *t = TypeRegister::getInstance().get(type); // FIXME type lookup here
 212         Store *x = 0;
 213         if (t != 0) {
 214                 x = t->newInstance(id);
 215         } else {
 216                 d_cause = TYPENOTFOUND;
 217         }
 218
 219         if (x != 0) { // IF READING SUCCEEDS, INSERT MORE CHECKS HERE
 220                 if (true) { // samePath(x, path)
 221                         ReaderState *save = d_state;
 222                         d_state = new ReaderState();
 223                         x->internalize(*this);
 224                         delete d_state;
 225                         d_state = save;
 226
 227                         if (d_cause != 0) {
 228                                 x = 0;
 229                         }
 230                         assert(d_rider.tellg() == d_state->end);
 231                         assert(!d_rider.eof());
 232                 } else {
 233 //                                      rd.cause := inconsistentType; AlienTypeReport(rd.cause, type);
 234                         x = 0;
 235                 }
 236         }
 237
 238         if (x != 0) {
 239                 if (d_store == 0) {
 240                         d_store = x;
 241                 } else {
 242                         // join(d_store, x)
 243                 }
 244                 if (isElem) {
 245                         d_elemList.push_back(x);
 246                 } else {
 247                         d_storeList.push_back(x);
 248                 }
 249         } else {
 250                 d_rider.seekg(pos); // x->internalize() could have left us anywhere
 251                 assert(d_cause != 0);
 252                 Alien *alien = new Alien(id, path); //, d_cause); //,file
 253                 if (d_store == 0) {
 254                         d_store = alien;
 255                 } else {
 256                         // join(d_store, alien)
 257                 }
 258                 if (isElem) {
 259                         d_elemList.push_back(alien);
 260                 } else {
 261                         d_storeList.push_back(alien);
 262                 }
 263                 ReaderState *save = d_state;
 264                 d_state = new ReaderState();
 265                 internalizeAlien(alien, downPos, save->end);
 266                 delete d_state;
 267                 d_state = save;
 268                 assert(d_rider.tellg() == d_state->end);
 269
 270                 // we've just read the alien, so reset the state
 271                 d_cause = 0;
 272                 d_cancelled = false;
 273                 d_readAlien = true;
 274                 return alien;
 275         }
 276
 277         return x;
 278 }
 279
 280
 281 void Reader::internalizeAlien(Alien *alien, std::streampos down, std::streampos end) {
 282         std::streampos next = down != 0 ? down : end;
 283         while (d_rider.tellg() < end) {
 284                 if (d_rider.tellg() < next) { // for some reason, this means its a piece (unstructured)
 285                         size_t len = next - d_rider.tellg();
 286                         char *buf = new char[len];
 287                         d_rider.read(buf, len);
 288                         AlienComponent *comp = new AlienPiece(buf, len);
 289                         alien->getComponents().push_back(comp);
 290                 } else { // that means we've got a store
 291                         d_rider.seekg(next);
 292                         AlienComponent *comp = new AlienPart(readStore());
 293                         alien->getComponents().push_back(comp);
 294                         next = d_state->next > 0 ? d_state->next : end;
 295                 }
 296         }
 297 }
 298
 299 std::string &Reader::fixTypeName(std::string &name) {
 300         size_t pos = name.size() - 4;
 301         if (pos > 0 && name.substr(pos, 4).compare("Desc") == 0) {
 302                 return name.replace(pos, 4, "^");
 303         }
 304         return name;
 305 }
 306
 307 TypePath Reader::readPath() {
 308         TypePath path;
 309         SHORTCHAR kind = readSChar();
 310         SHORTCHAR *buf = new SHORTCHAR[64]; // TypeName has a maximum of length 64 (including terminator).
 311         int i;
 312         for (i = 0; kind == Store::NEWEXT; ++i) {
 313                 readSString(buf);
 314                 std::string name(buf);
 315                 path.push_back(fixTypeName(name));
 316                 addPathComponent(i == 0, path[i]);
 317 //                      IF path[i] # elemTName THEN INC(i) END;
 318                 kind = readSChar();
 319         }
 320
 321         if (kind == Store::NEWBASE) {
 322                 readSString(buf);
 323                 std::string name(buf);
 324                 path.push_back(fixTypeName(name));
 325                 addPathComponent(i == 0, path[i]);
 326                 ++i;
 327         } else if (kind == Store::OLDTYPE) {
 328                 int id = readInt();
 329                 if (i > 0) {
 330                         d_typeList[d_typeList.size() - 1]->baseId = id;
 331                 }
 332                 while (id != -1) {
 333                         path.push_back(d_typeList[id]->name);
 334                         id = d_typeList[id]->baseId;
 335 //                              IF path[i] # elemTName THEN INC(i) END
 336                         ++i;
 337                 }
 338         } else {
 339                 throw 100;
 340         }
 341         return path;
 342 }
 343
 344 void Reader::addPathComponent(bool first, const std::string &typeName) {
 345         int next = d_typeList.size();
 346         int curr = next - 1;
 347         if (!first) {
 348                 d_typeList[curr]->baseId = next;
 349         }
 350         d_typeList.push_back(new TypeEntry(typeName));
 351 }
 352
 353 } // namespace odc