Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 1 | // Copyright 2013 The Chromium Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "chrome/browser/profile_resetter/jtl_interpreter.h" |
| 6 | |
| 7 | #include "base/memory/scoped_vector.h" |
| 8 | #include "base/strings/string_number_conversions.h" |
| 9 | #include "base/strings/string_util.h" |
| 10 | #include "chrome/browser/profile_resetter/jtl_foundation.h" |
| 11 | #include "crypto/hmac.h" |
| 12 | |
| 13 | namespace { |
| 14 | |
| 15 | class ExecutionContext; |
| 16 | |
| 17 | // An operation in an interpreted program. |
| 18 | class Operation { |
| 19 | public: |
| 20 | virtual ~Operation() {} |
| 21 | // Executes the operation on the specified context and instructs the context |
| 22 | // to continue execution with the next instruction if appropriate. |
| 23 | // Returns true if we should continue with any potential backtracking that |
| 24 | // needs to be done. |
| 25 | virtual bool Execute(ExecutionContext* context) = 0; |
| 26 | }; |
| 27 | |
| 28 | // An execution context of operations. |
| 29 | class ExecutionContext { |
| 30 | public: |
| 31 | // |input| is the root of a dictionary that stores the information the |
| 32 | // sentence is evaluated on. |
| 33 | ExecutionContext(const jtl_foundation::Hasher* hasher, |
| 34 | const std::vector<Operation*>& sentence, |
| 35 | const DictionaryValue* input, |
| 36 | DictionaryValue* working_memory) |
| 37 | : hasher_(hasher), |
| 38 | sentence_(sentence), |
| 39 | next_instruction_index_(0u), |
| 40 | working_memory_(working_memory), |
| 41 | error_(false) { |
| 42 | stack_.push_back(input); |
| 43 | } |
| 44 | ~ExecutionContext() {} |
| 45 | |
| 46 | // Returns true in case of success. |
| 47 | bool ContinueExecution() { |
| 48 | if (error_ || stack_.empty()) { |
| 49 | error_ = true; |
| 50 | return false; |
| 51 | } |
| 52 | if (next_instruction_index_ >= sentence_.size()) |
| 53 | return true; |
| 54 | |
| 55 | Operation* op = sentence_[next_instruction_index_]; |
| 56 | next_instruction_index_++; |
| 57 | bool continue_traversal = op->Execute(this); |
| 58 | next_instruction_index_--; |
| 59 | return continue_traversal; |
| 60 | } |
| 61 | |
| 62 | std::string GetHash(const std::string& input) { |
| 63 | return hasher_->GetHash(input); |
| 64 | } |
| 65 | |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 66 | // Calculates the |hash| of a string, integer or double |value|, and returns |
| 67 | // true. Returns false otherwise. |
| 68 | bool GetValueHash(const Value& value, std::string* hash) { |
| 69 | DCHECK(hash); |
| 70 | std::string value_as_string; |
| 71 | int tmp_int = 0; |
| 72 | double tmp_double = 0.0; |
| 73 | if (value.GetAsInteger(&tmp_int)) |
| 74 | value_as_string = base::IntToString(tmp_int); |
| 75 | else if (value.GetAsDouble(&tmp_double)) |
| 76 | value_as_string = base::DoubleToString(tmp_double); |
| 77 | else if (!value.GetAsString(&value_as_string)) |
| 78 | return false; |
| 79 | *hash = GetHash(value_as_string); |
| 80 | return true; |
| 81 | } |
| 82 | |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 83 | const Value* current_node() const { return stack_.back(); } |
| 84 | std::vector<const Value*>* stack() { return &stack_; } |
| 85 | DictionaryValue* working_memory() { return working_memory_; } |
| 86 | bool error() const { return error_; } |
| 87 | |
| 88 | private: |
| 89 | // A hasher used to hash node names in a dictionary. |
| 90 | const jtl_foundation::Hasher* hasher_; |
| 91 | // The sentence to be executed. |
| 92 | const std::vector<Operation*> sentence_; |
| 93 | // Position in |sentence_|. |
| 94 | size_t next_instruction_index_; |
| 95 | // A stack of Values, indicating a navigation path from the root node of |
| 96 | // |input| (see constructor) to the current node on which the |
| 97 | // sentence_[next_instruction_index_] is evaluated. |
| 98 | std::vector<const Value*> stack_; |
| 99 | // Memory into which values can be stored by the program. |
| 100 | DictionaryValue* working_memory_; |
| 101 | // Whether a runtime error occurred. |
| 102 | bool error_; |
| 103 | DISALLOW_COPY_AND_ASSIGN(ExecutionContext); |
| 104 | }; |
| 105 | |
| 106 | class NavigateOperation : public Operation { |
| 107 | public: |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 108 | explicit NavigateOperation(const std::string& hashed_key) |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 109 | : hashed_key_(hashed_key) {} |
| 110 | virtual ~NavigateOperation() {} |
| 111 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 112 | const DictionaryValue* dict = NULL; |
| 113 | if (!context->current_node()->GetAsDictionary(&dict)) { |
| 114 | // Just ignore this node gracefully as this navigation is a dead end. |
| 115 | // If this NavigateOperation occurred after a NavigateAny operation, those |
| 116 | // may still be fulfillable, so we allow continuing the execution of the |
| 117 | // sentence on other nodes. |
| 118 | return true; |
| 119 | } |
| 120 | for (DictionaryValue::Iterator i(*dict); !i.IsAtEnd(); i.Advance()) { |
| 121 | if (context->GetHash(i.key()) != hashed_key_) |
| 122 | continue; |
| 123 | context->stack()->push_back(&i.value()); |
| 124 | bool continue_traversal = context->ContinueExecution(); |
| 125 | context->stack()->pop_back(); |
| 126 | if (!continue_traversal) |
| 127 | return false; |
| 128 | } |
| 129 | return true; |
| 130 | } |
| 131 | |
| 132 | private: |
| 133 | std::string hashed_key_; |
| 134 | DISALLOW_COPY_AND_ASSIGN(NavigateOperation); |
| 135 | }; |
| 136 | |
| 137 | class NavigateAnyOperation : public Operation { |
| 138 | public: |
| 139 | NavigateAnyOperation() {} |
| 140 | virtual ~NavigateAnyOperation() {} |
| 141 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 142 | const DictionaryValue* dict = NULL; |
| 143 | const ListValue* list = NULL; |
| 144 | if (context->current_node()->GetAsDictionary(&dict)) { |
| 145 | for (DictionaryValue::Iterator i(*dict); !i.IsAtEnd(); i.Advance()) { |
| 146 | context->stack()->push_back(&i.value()); |
| 147 | bool continue_traversal = context->ContinueExecution(); |
| 148 | context->stack()->pop_back(); |
| 149 | if (!continue_traversal) |
| 150 | return false; |
| 151 | } |
| 152 | } else if (context->current_node()->GetAsList(&list)) { |
| 153 | for (ListValue::const_iterator i = list->begin(); i != list->end(); ++i) { |
| 154 | context->stack()->push_back(*i); |
| 155 | bool continue_traversal = context->ContinueExecution(); |
| 156 | context->stack()->pop_back(); |
| 157 | if (!continue_traversal) |
| 158 | return false; |
| 159 | } |
| 160 | } else { |
| 161 | // Do nothing, just ignore this node. |
| 162 | } |
| 163 | return true; |
| 164 | } |
| 165 | |
| 166 | private: |
| 167 | DISALLOW_COPY_AND_ASSIGN(NavigateAnyOperation); |
| 168 | }; |
| 169 | |
| 170 | class NavigateBackOperation : public Operation { |
| 171 | public: |
| 172 | NavigateBackOperation() {} |
| 173 | virtual ~NavigateBackOperation() {} |
| 174 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 175 | const Value* current_node = context->current_node(); |
| 176 | context->stack()->pop_back(); |
| 177 | bool continue_traversal = context->ContinueExecution(); |
| 178 | context->stack()->push_back(current_node); |
| 179 | return continue_traversal; |
| 180 | } |
| 181 | |
| 182 | private: |
| 183 | DISALLOW_COPY_AND_ASSIGN(NavigateBackOperation); |
| 184 | }; |
| 185 | |
| 186 | class StoreValue : public Operation { |
| 187 | public: |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 188 | StoreValue(const std::string& hashed_name, scoped_ptr<Value> value) |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 189 | : hashed_name_(hashed_name), |
| 190 | value_(value.Pass()) { |
| 191 | DCHECK(IsStringUTF8(hashed_name)); |
| 192 | DCHECK(value_); |
| 193 | } |
| 194 | virtual ~StoreValue() {} |
| 195 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 196 | context->working_memory()->Set(hashed_name_, value_->DeepCopy()); |
| 197 | return context->ContinueExecution(); |
| 198 | } |
| 199 | |
| 200 | private: |
| 201 | std::string hashed_name_; |
| 202 | scoped_ptr<Value> value_; |
| 203 | DISALLOW_COPY_AND_ASSIGN(StoreValue); |
| 204 | }; |
| 205 | |
| 206 | class CompareStoredValue : public Operation { |
| 207 | public: |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 208 | CompareStoredValue(const std::string& hashed_name, |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 209 | scoped_ptr<Value> value, |
| 210 | scoped_ptr<Value> default_value) |
| 211 | : hashed_name_(hashed_name), |
| 212 | value_(value.Pass()), |
| 213 | default_value_(default_value.Pass()) { |
| 214 | DCHECK(IsStringUTF8(hashed_name)); |
| 215 | DCHECK(value_); |
| 216 | DCHECK(default_value_); |
| 217 | } |
| 218 | virtual ~CompareStoredValue() {} |
| 219 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 220 | const Value* actual_value = NULL; |
| 221 | if (!context->working_memory()->Get(hashed_name_, &actual_value)) |
| 222 | actual_value = default_value_.get(); |
| 223 | if (!value_->Equals(actual_value)) |
| 224 | return true; |
| 225 | return context->ContinueExecution(); |
| 226 | } |
| 227 | |
| 228 | private: |
| 229 | std::string hashed_name_; |
| 230 | scoped_ptr<Value> value_; |
| 231 | scoped_ptr<Value> default_value_; |
| 232 | DISALLOW_COPY_AND_ASSIGN(CompareStoredValue); |
| 233 | }; |
| 234 | |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 235 | template<bool ExpectedTypeIsBooleanNotHashable> |
| 236 | class StoreNodeValue : public Operation { |
| 237 | public: |
| 238 | explicit StoreNodeValue(const std::string& hashed_name) |
| 239 | : hashed_name_(hashed_name) { |
| 240 | DCHECK(IsStringUTF8(hashed_name)); |
| 241 | } |
| 242 | virtual ~StoreNodeValue() {} |
| 243 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 244 | scoped_ptr<base::Value> value; |
| 245 | if (ExpectedTypeIsBooleanNotHashable) { |
| 246 | if (!context->current_node()->IsType(base::Value::TYPE_BOOLEAN)) |
| 247 | return true; |
| 248 | value.reset(context->current_node()->DeepCopy()); |
| 249 | } else { |
| 250 | std::string hash; |
| 251 | if (!context->GetValueHash(*context->current_node(), &hash)) |
| 252 | return true; |
| 253 | value.reset(new base::StringValue(hash)); |
| 254 | } |
| 255 | context->working_memory()->Set(hashed_name_, value.release()); |
| 256 | return context->ContinueExecution(); |
| 257 | } |
| 258 | |
| 259 | private: |
| 260 | std::string hashed_name_; |
| 261 | DISALLOW_COPY_AND_ASSIGN(StoreNodeValue); |
| 262 | }; |
| 263 | |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 264 | class CompareNodeBool : public Operation { |
| 265 | public: |
| 266 | explicit CompareNodeBool(bool value) : value_(value) {} |
| 267 | virtual ~CompareNodeBool() {} |
| 268 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 269 | bool actual_value = false; |
| 270 | if (!context->current_node()->GetAsBoolean(&actual_value)) |
| 271 | return true; |
| 272 | if (actual_value != value_) |
| 273 | return true; |
| 274 | return context->ContinueExecution(); |
| 275 | } |
| 276 | |
| 277 | private: |
| 278 | bool value_; |
| 279 | DISALLOW_COPY_AND_ASSIGN(CompareNodeBool); |
| 280 | }; |
| 281 | |
| 282 | class CompareNodeHash : public Operation { |
| 283 | public: |
| 284 | explicit CompareNodeHash(const std::string& hashed_value) |
| 285 | : hashed_value_(hashed_value) {} |
| 286 | virtual ~CompareNodeHash() {} |
| 287 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 288 | std::string actual_hash; |
| 289 | if (!context->GetValueHash(*context->current_node(), &actual_hash) || |
| 290 | actual_hash != hashed_value_) |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 291 | return true; |
| 292 | return context->ContinueExecution(); |
| 293 | } |
| 294 | |
| 295 | private: |
| 296 | std::string hashed_value_; |
| 297 | DISALLOW_COPY_AND_ASSIGN(CompareNodeHash); |
| 298 | }; |
| 299 | |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 300 | class CompareNodeHashNot : public Operation { |
| 301 | public: |
| 302 | explicit CompareNodeHashNot(const std::string& hashed_value) |
| 303 | : hashed_value_(hashed_value) {} |
| 304 | virtual ~CompareNodeHashNot() {} |
| 305 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 306 | std::string actual_hash; |
| 307 | if (context->GetValueHash(*context->current_node(), &actual_hash) && |
| 308 | actual_hash == hashed_value_) |
| 309 | return true; |
| 310 | return context->ContinueExecution(); |
| 311 | } |
| 312 | |
| 313 | private: |
| 314 | std::string hashed_value_; |
| 315 | DISALLOW_COPY_AND_ASSIGN(CompareNodeHashNot); |
| 316 | }; |
| 317 | |
| 318 | template<bool ExpectedTypeIsBooleanNotHashable> |
| 319 | class CompareNodeToStored : public Operation { |
| 320 | public: |
| 321 | explicit CompareNodeToStored(const std::string& hashed_name) |
| 322 | : hashed_name_(hashed_name) {} |
| 323 | virtual ~CompareNodeToStored() {} |
| 324 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 325 | const Value* stored_value = NULL; |
| 326 | if (!context->working_memory()->Get(hashed_name_, &stored_value)) |
| 327 | return true; |
| 328 | if (ExpectedTypeIsBooleanNotHashable) { |
| 329 | if (!context->current_node()->IsType(base::Value::TYPE_BOOLEAN) || |
| 330 | !context->current_node()->Equals(stored_value)) |
| 331 | return true; |
| 332 | } else { |
| 333 | std::string actual_hash; |
| 334 | std::string stored_hash; |
| 335 | if (!context->GetValueHash(*context->current_node(), &actual_hash) || |
| 336 | !stored_value->GetAsString(&stored_hash) || |
| 337 | actual_hash != stored_hash) |
| 338 | return true; |
| 339 | } |
| 340 | return context->ContinueExecution(); |
| 341 | } |
| 342 | |
| 343 | private: |
| 344 | std::string hashed_name_; |
| 345 | DISALLOW_COPY_AND_ASSIGN(CompareNodeToStored); |
| 346 | }; |
| 347 | |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 348 | class StopExecutingSentenceOperation : public Operation { |
| 349 | public: |
| 350 | StopExecutingSentenceOperation() {} |
| 351 | virtual ~StopExecutingSentenceOperation() {} |
| 352 | virtual bool Execute(ExecutionContext* context) OVERRIDE { |
| 353 | return false; |
| 354 | } |
| 355 | |
| 356 | private: |
| 357 | DISALLOW_COPY_AND_ASSIGN(StopExecutingSentenceOperation); |
| 358 | }; |
| 359 | |
| 360 | class Parser { |
| 361 | public: |
| 362 | explicit Parser(const std::string& program) |
| 363 | : program_(program), |
| 364 | next_instruction_index_(0u) {} |
| 365 | ~Parser() {} |
| 366 | bool ParseNextSentence(ScopedVector<Operation>* output) { |
| 367 | ScopedVector<Operation> operators; |
| 368 | bool sentence_ended = false; |
| 369 | while (next_instruction_index_ < program_.size() && !sentence_ended) { |
| 370 | uint8 op_code = 0; |
| 371 | if (!ReadOpCode(&op_code)) |
| 372 | return false; |
| 373 | switch (static_cast<jtl_foundation::OpCodes>(op_code)) { |
| 374 | case jtl_foundation::NAVIGATE: { |
| 375 | std::string hashed_key; |
| 376 | if (!ReadHash(&hashed_key)) |
| 377 | return false; |
| 378 | operators.push_back(new NavigateOperation(hashed_key)); |
| 379 | break; |
| 380 | } |
| 381 | case jtl_foundation::NAVIGATE_ANY: |
| 382 | operators.push_back(new NavigateAnyOperation); |
| 383 | break; |
| 384 | case jtl_foundation::NAVIGATE_BACK: |
| 385 | operators.push_back(new NavigateBackOperation); |
| 386 | break; |
| 387 | case jtl_foundation::STORE_BOOL: { |
| 388 | std::string hashed_name; |
| 389 | if (!ReadHash(&hashed_name) || !IsStringUTF8(hashed_name)) |
| 390 | return false; |
| 391 | bool value = false; |
| 392 | if (!ReadBool(&value)) |
| 393 | return false; |
| 394 | operators.push_back(new StoreValue( |
| 395 | hashed_name, |
| 396 | scoped_ptr<Value>(new base::FundamentalValue(value)))); |
| 397 | break; |
| 398 | } |
| 399 | case jtl_foundation::COMPARE_STORED_BOOL: { |
| 400 | std::string hashed_name; |
| 401 | if (!ReadHash(&hashed_name) || !IsStringUTF8(hashed_name)) |
| 402 | return false; |
| 403 | bool value = false; |
| 404 | if (!ReadBool(&value)) |
| 405 | return false; |
| 406 | bool default_value = false; |
| 407 | if (!ReadBool(&default_value)) |
| 408 | return false; |
| 409 | operators.push_back(new CompareStoredValue( |
| 410 | hashed_name, |
| 411 | scoped_ptr<Value>(new base::FundamentalValue(value)), |
| 412 | scoped_ptr<Value>(new base::FundamentalValue(default_value)))); |
| 413 | break; |
| 414 | } |
| 415 | case jtl_foundation::STORE_HASH: { |
| 416 | std::string hashed_name; |
| 417 | if (!ReadHash(&hashed_name) || !IsStringUTF8(hashed_name)) |
| 418 | return false; |
| 419 | std::string hashed_value; |
| 420 | if (!ReadHash(&hashed_value)) |
| 421 | return false; |
| 422 | operators.push_back(new StoreValue( |
| 423 | hashed_name, |
| 424 | scoped_ptr<Value>(new base::StringValue(hashed_value)))); |
| 425 | break; |
| 426 | } |
| 427 | case jtl_foundation::COMPARE_STORED_HASH: { |
| 428 | std::string hashed_name; |
| 429 | if (!ReadHash(&hashed_name) || !IsStringUTF8(hashed_name)) |
| 430 | return false; |
| 431 | std::string hashed_value; |
| 432 | if (!ReadHash(&hashed_value)) |
| 433 | return false; |
| 434 | std::string hashed_default_value; |
| 435 | if (!ReadHash(&hashed_default_value)) |
| 436 | return false; |
| 437 | operators.push_back(new CompareStoredValue( |
| 438 | hashed_name, |
| 439 | scoped_ptr<Value>(new base::StringValue(hashed_value)), |
| 440 | scoped_ptr<Value>(new base::StringValue(hashed_default_value)))); |
| 441 | break; |
| 442 | } |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 443 | case jtl_foundation::STORE_NODE_BOOL: { |
| 444 | std::string hashed_name; |
| 445 | if (!ReadHash(&hashed_name) || !IsStringUTF8(hashed_name)) |
| 446 | return false; |
| 447 | operators.push_back(new StoreNodeValue<true>(hashed_name)); |
| 448 | break; |
| 449 | } |
| 450 | case jtl_foundation::STORE_NODE_HASH: { |
| 451 | std::string hashed_name; |
| 452 | if (!ReadHash(&hashed_name) || !IsStringUTF8(hashed_name)) |
| 453 | return false; |
| 454 | operators.push_back(new StoreNodeValue<false>(hashed_name)); |
| 455 | break; |
| 456 | } |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 457 | case jtl_foundation::COMPARE_NODE_BOOL: { |
| 458 | bool value = false; |
| 459 | if (!ReadBool(&value)) |
| 460 | return false; |
| 461 | operators.push_back(new CompareNodeBool(value)); |
| 462 | break; |
| 463 | } |
| 464 | case jtl_foundation::COMPARE_NODE_HASH: { |
| 465 | std::string hashed_value; |
| 466 | if (!ReadHash(&hashed_value)) |
| 467 | return false; |
| 468 | operators.push_back(new CompareNodeHash(hashed_value)); |
| 469 | break; |
| 470 | } |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 471 | case jtl_foundation::COMPARE_NODE_HASH_NOT: { |
| 472 | std::string hashed_value; |
| 473 | if (!ReadHash(&hashed_value)) |
| 474 | return false; |
| 475 | operators.push_back(new CompareNodeHashNot(hashed_value)); |
| 476 | break; |
| 477 | } |
| 478 | case jtl_foundation::COMPARE_NODE_TO_STORED_BOOL: { |
| 479 | std::string hashed_name; |
| 480 | if (!ReadHash(&hashed_name) || !IsStringUTF8(hashed_name)) |
| 481 | return false; |
| 482 | operators.push_back(new CompareNodeToStored<true>(hashed_name)); |
| 483 | break; |
| 484 | } |
| 485 | case jtl_foundation::COMPARE_NODE_TO_STORED_HASH: { |
| 486 | std::string hashed_name; |
| 487 | if (!ReadHash(&hashed_name) || !IsStringUTF8(hashed_name)) |
| 488 | return false; |
| 489 | operators.push_back(new CompareNodeToStored<false>(hashed_name)); |
| 490 | break; |
| 491 | } |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 492 | case jtl_foundation::STOP_EXECUTING_SENTENCE: |
| 493 | operators.push_back(new StopExecutingSentenceOperation); |
| 494 | break; |
| 495 | case jtl_foundation::END_OF_SENTENCE: |
| 496 | sentence_ended = true; |
| 497 | break; |
| 498 | default: |
| 499 | return false; |
| 500 | } |
| 501 | } |
| 502 | output->swap(operators); |
| 503 | return true; |
| 504 | } |
| 505 | |
| 506 | bool HasNextSentence() const { |
| 507 | return next_instruction_index_ < program_.size(); |
| 508 | } |
| 509 | |
| 510 | private: |
| 511 | // Reads an uint8 and returns whether this operation was successful. |
| 512 | bool ReadUint8(uint8* out) { |
| 513 | if (next_instruction_index_ + 1u > program_.size()) |
| 514 | return false; |
| 515 | *out = static_cast<uint8>(program_[next_instruction_index_]); |
| 516 | ++next_instruction_index_; |
| 517 | return true; |
| 518 | } |
| 519 | |
| 520 | // Reads an operator code and returns whether this operation was successful. |
| 521 | bool ReadOpCode(uint8* out) { return ReadUint8(out); } |
| 522 | |
| 523 | bool ReadHash(std::string* out) { |
| 524 | if (next_instruction_index_ + jtl_foundation::kHashSizeInBytes > |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 525 | program_.size()) |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 526 | return false; |
Torne (Richard Coles) | 1e9bf3e | 2013-10-31 11:16:26 +0000 | [diff] [blame] | 527 | *out = program_.substr(next_instruction_index_, |
| 528 | jtl_foundation::kHashSizeInBytes); |
| 529 | next_instruction_index_ += jtl_foundation::kHashSizeInBytes; |
| 530 | DCHECK(jtl_foundation::Hasher::IsHash(*out)); |
Torne (Richard Coles) | 68043e1 | 2013-09-26 13:24:57 +0100 | [diff] [blame] | 531 | return true; |
| 532 | } |
| 533 | |
| 534 | bool ReadBool(bool* out) { |
| 535 | uint8 value = 0; |
| 536 | if (!ReadUint8(&value)) |
| 537 | return false; |
| 538 | if (value == 0) |
| 539 | *out = false; |
| 540 | else if (value == 1) |
| 541 | *out = true; |
| 542 | else |
| 543 | return false; |
| 544 | return true; |
| 545 | } |
| 546 | |
| 547 | std::string program_; |
| 548 | size_t next_instruction_index_; |
| 549 | DISALLOW_COPY_AND_ASSIGN(Parser); |
| 550 | }; |
| 551 | |
| 552 | } // namespace |
| 553 | |
| 554 | JtlInterpreter::JtlInterpreter( |
| 555 | const std::string& hasher_seed, |
| 556 | const std::string& program, |
| 557 | const DictionaryValue* input) |
| 558 | : hasher_seed_(hasher_seed), |
| 559 | program_(program), |
| 560 | input_(input), |
| 561 | working_memory_(new DictionaryValue), |
| 562 | result_(OK) { |
| 563 | DCHECK(input->IsType(Value::TYPE_DICTIONARY)); |
| 564 | } |
| 565 | |
| 566 | JtlInterpreter::~JtlInterpreter() {} |
| 567 | |
| 568 | void JtlInterpreter::Execute() { |
| 569 | jtl_foundation::Hasher hasher(hasher_seed_); |
| 570 | Parser parser(program_); |
| 571 | while (parser.HasNextSentence()) { |
| 572 | ScopedVector<Operation> sentence; |
| 573 | if (!parser.ParseNextSentence(&sentence)) { |
| 574 | result_ = PARSE_ERROR; |
| 575 | return; |
| 576 | } |
| 577 | ExecutionContext context( |
| 578 | &hasher, sentence.get(), input_, working_memory_.get()); |
| 579 | context.ContinueExecution(); |
| 580 | if (context.error()) { |
| 581 | result_ = RUNTIME_ERROR; |
| 582 | return; |
| 583 | } |
| 584 | } |
| 585 | } |
| 586 | |
| 587 | bool JtlInterpreter::GetOutputBoolean(const std::string& unhashed_key, |
| 588 | bool* output) const { |
| 589 | std::string hashed_key = |
| 590 | jtl_foundation::Hasher(hasher_seed_).GetHash(unhashed_key); |
| 591 | return working_memory_->GetBoolean(hashed_key, output); |
| 592 | } |
| 593 | |
| 594 | bool JtlInterpreter::GetOutputString(const std::string& unhashed_key, |
| 595 | std::string* output) const { |
| 596 | std::string hashed_key = |
| 597 | jtl_foundation::Hasher(hasher_seed_).GetHash(unhashed_key); |
| 598 | return working_memory_->GetString(hashed_key, output); |
| 599 | } |