#include <cassert> #include <array> #include <algorithm> #include <functional> #include <iostream> #include <iterator> #include <sstream> #include "poszukiwania.h" #include "message.h" //#define DEBUG #ifdef DEBUG static constexpr const bool debug = true; #else static constexpr const bool debug = false; #endif #define LOG(x) \ if(debug) { \ std::stringstream str; \ str << "Node " << MyNodeId() << "/" << NumberOfNodes() << ": "; \ str x; \ std::cerr << str.str(); \ } template<class T, class E, class Fn, class Init> T iterate(T base, Init init, E exponent, Fn &&fn) { T result = init; while(exponent > 0) { if(exponent % 2 == 1) result = fn(result, base); base = fn(base, base); exponent /= 2; } return result; } // ------------------------ hashing ------------------------- using hash_t = int32_t; using bigger_hash_t = int64_t; struct hash_setup_t { hash_t prime, base; }; static constexpr const hash_setup_t setup[] = { // { (1ll << 62) - 153, (1ll << 50) - 131 } // { (1ll << 62) - 471, (1ll << 42) - 11 } // { (1ll << 62) - 203, (1ll << 56) - 5 } // { (1 << 30) - 107, (1 << 28) - 213 }, { (1 << 30) - 153, (1 << 29) - 43 }, { (1 << 30) - 161, (1 << 29) - 3 } }; static constexpr const size_t prime_count = sizeof(setup) / sizeof(*setup); using hash_array_t = std::array<hash_t, prime_count>; __attribute__((pure)) hash_array_t make_powers(uint64_t exponent) { hash_array_t arr; for(size_t idx = 0; idx < prime_count; ++idx) { const auto op = [&idx](const hash_t x, const hash_t y) { return static_cast<hash_t>((static_cast<bigger_hash_t>(x) * y) % setup[idx].prime); }; const auto pw = iterate(setup[idx].base, 1, exponent, op); arr[idx] = pw; } return arr; } struct hash_block_t { hash_array_t hash; ssize_t length; hash_block_t() : length(0) { std::fill(std::begin(hash), std::end(hash), 0); } explicit hash_block_t(bigger_hash_t value) : length(1) { for(size_t idx = 0; idx < prime_count; ++idx) hash[idx] = value % setup[idx].prime; } __attribute__((pure)) hash_block_t operator+(const hash_block_t &rhs) const { hash_block_t result; result.length = length + rhs.length; for(size_t idx = 0; idx < prime_count; ++idx) { // g++ does a better job with inlining this stuff when it is defined locally const auto op = [&idx](const hash_t x, const hash_t y) { return static_cast<hash_t>((static_cast<bigger_hash_t>(x) * y) % setup[idx].prime); }; const auto pw = iterate(setup[idx].base, 1, length, op); result.hash[idx] = hash[idx] + op(pw, rhs.hash[idx]); if(result.hash[idx] >= setup[idx].prime) result.hash[idx] -= setup[idx].prime; } return result; } __attribute__((pure)) hash_block_t extend(const hash_block_t &rhs, const hash_array_t &powers) const { hash_block_t result; result.length = length + rhs.length; for(size_t idx = 0; idx < prime_count; ++idx) { const auto op = [&idx](const hash_t x, const hash_t y) { return static_cast<hash_t>((static_cast<bigger_hash_t>(x) * y) % setup[idx].prime); }; result.hash[idx] = hash[idx] + op(powers[idx], rhs.hash[idx]); if(result.hash[idx] >= setup[idx].prime) result.hash[idx] -= setup[idx].prime; } return result; } hash_block_t operator+=(const hash_block_t &that) { return operator=(*this + that); } __attribute__((pure)) hash_block_t trim(const hash_block_t &rhs) const { return trim(rhs, make_powers(length - rhs.length)); } __attribute__((pure)) hash_block_t trim(const hash_block_t &rhs, const hash_array_t &powers) const { hash_block_t result; result.length = length - rhs.length; for(size_t idx = 0; idx < prime_count; ++idx) { const auto op = [&idx](const hash_t x, const hash_t y) { return static_cast<hash_t>((static_cast<bigger_hash_t>(x) * y) % setup[idx].prime); }; result.hash[idx] = hash[idx] - op(powers[idx], rhs.hash[idx]); if(result.hash[idx] < 0) result.hash[idx] += setup[idx].prime; } return result; } bool operator==(const hash_block_t &that) const { assert(length == that.length); return hash == that.hash; } }; template<class Fn> hash_block_t hash_sequence(ssize_t begin, ssize_t end, Fn &&fn) { hash_block_t result{}; assert(begin <= end); if(begin != end) for(ssize_t idx = end - 1; idx >= begin; --idx) { result = hash_block_t{fn(idx)} + result; } return result; } struct request_t { hash_block_t hash; ssize_t hash_begin, hash_end; ssize_t begin, end; }; // ------------------------ messaging ----------------------- enum class message_type_t { HASH_SIGNAL_PART, HASH_SEQUENCE_PART, HASH_SIGNAL_FULL, SUBSEQUENCE, RESULT, NOP }; using node_t = int; namespace communication { template<unsigned size> struct communication_traits { }; #define GEN_TRAITS(type, name) \ template<> \ struct communication_traits<sizeof(type)> { \ template<class T> \ static void put(node_t target, T value) { \ static_assert(sizeof(T) == sizeof(type), "Size mismatch between T and " #type);\ Put ## name(target, static_cast<type>(value)); \ } \ \ template<class T> \ static T get(node_t target) { \ static_assert(sizeof(T) == sizeof(type), "Size mismatch between T and " #type);\ return static_cast<T>(Get ## name(target)); \ } \ }; GEN_TRAITS(char, Char) GEN_TRAITS(int, Int) GEN_TRAITS(long long, LL) template<class T> void put(node_t target, T value) { communication_traits<sizeof(value)>::put(target, value); } template<class T> void get(node_t target, T *number) { *number = communication_traits<sizeof(*number)>::template get<T>(target); } template<class T, size_t n> void put(node_t target, const std::array<T, n> &arr) { for(size_t idx = 0; idx < n; ++idx) put(target, arr[idx]); } template<class T, size_t n> void get(node_t target, std::array<T, n> *arr) { for(size_t idx = 0; idx < n; ++idx) get<T>(target, &(*arr)[idx]); } void put(node_t node, const hash_block_t &block) { put(node, block.length); put(node, block.hash); } void get(node_t node, hash_block_t *block) { get(node, &block->length); get(node, &block->hash); } void put(node_t node, const request_t &rq) { put(node, rq.hash); put(node, rq.hash_begin); put(node, rq.hash_end); put(node, rq.begin); put(node, rq.end); } void get(node_t node, request_t *rq) { get(node, &rq->hash); get(node, &rq->hash_begin); get(node, &rq->hash_end); get(node, &rq->begin); get(node, &rq->end); } void _send(node_t) { } void _recv(node_t) { } template<class Arg, class... Args> void _send(node_t node, Arg&& value, Args&&... args) { put(node, std::forward<Arg>(value)); _send(node, std::forward<Args>(args)...); } template<class Arg, class... Args> void _recv(node_t node, Arg *value, Args*... args) { get(node, value); _recv(node, args...); } template<class... Args> void send(node_t node, message_type_t type, Args&&... args) { _send(node, type, std::forward<Args>(args)...); Send(node); } template<class... Args> void recv(node_t node, message_type_t type, Args*... args) { Receive(node); message_type_t got; _recv(node, &got); assert(got == type); _recv(node, args...); } } using communication::send; using communication::recv; // --------------------- solution ------------------------------ constexpr const node_t MASTER = 0; template<class LengthFun> size_t block_length(size_t num_workers, LengthFun &&length) { const auto len = static_cast<size_t>(std::forward<LengthFun>(length)()); const auto len_per_worker = (len + num_workers - 1) / num_workers; return len_per_worker; } class worker_t { public: worker_t(size_t worker_id, size_t num_workers) : worker_id{worker_id} , num_workers{num_workers} { } void do_hash_signal() { worker_hash_subsequence(message_type_t::HASH_SIGNAL_PART, SignalLength, SignalAt); } void do_hash_sequence() { worker_hash_subsequence(message_type_t::HASH_SEQUENCE_PART, SeqLength, SeqAt); } void do_compute() { request_t request; recv(MASTER, message_type_t::HASH_SIGNAL_FULL, &hash_signal); LOG(<< "Got hash of the signal" << std::endl); recv(MASTER, message_type_t::SUBSEQUENCE, &request); LOG(<< "Got subsequence" << std::endl); size_t result = 0; send(MASTER, message_type_t::NOP, result); if(request.begin != 0) { const auto signal_length = static_cast<ssize_t>(SignalLength()); LOG(<< " will calculate [" << request.begin << ", " << request.end << ")," " first: [" << request.end - 1 << ", " << request.end - 1 + signal_length << ") knowing [" << request.hash_begin << ", " << request.hash_end << ")" << std::endl); hash_block_t hash; if(request.hash_begin == request.hash_end) hash = hash_sequence(request.end - 1, request.end + signal_length - 1, SeqAt); else hash = hash_sequence(request.end - 1, request.hash_begin, SeqAt) + request.hash + hash_sequence(request.hash_end, request.end + signal_length - 1, SeqAt); assert(hash.length == signal_length); assert(hash_signal.length == signal_length); const auto trim_powers = make_powers(signal_length - 1); for(ssize_t pos = request.end - 1; pos >= request.begin;) { if(hash == hash_signal) { result++; } if(--pos < request.begin) break; hash = hash_block_t{SeqAt(pos)} + hash.trim(hash_block_t{SeqAt(pos + signal_length)}, trim_powers); } LOG(<< "matching among [" << request.begin << ", " << request.end << "): " << result << std::endl); } send(MASTER, message_type_t::RESULT, result); } private: template<class Length, class At> void worker_hash_subsequence(const message_type_t type, Length &&length, At &&at) { const auto len = static_cast<ssize_t>(length()); const auto len_per_worker = block_length(num_workers, std::forward<Length>(length)); const auto begin = std::min<ssize_t>(1 + len_per_worker * worker_id, 1 + len); const auto end = std::min<ssize_t>(1 + len_per_worker * (worker_id + 1), 1 + len); LOG(<< "Computing [" << begin << "," << end << "), per worker: " << len_per_worker << std::endl); const auto hash = hash_sequence(begin, end, std::forward<At>(at)); send(MASTER, type, hash); } size_t worker_id; size_t num_workers; hash_block_t hash_signal; }; class master_t { public: master_t(node_t first_worker, node_t last_worker) : num_workers(last_worker - first_worker + 1) , first_worker{first_worker} , last_worker{last_worker} { } void do_hash_signal() { hash_block_t hash; for(node_t worker = first_worker; worker <= last_worker; ++worker) { hash_block_t current; recv(worker, message_type_t::HASH_SIGNAL_PART, ¤t); hash += current; } hash_signal = hash; assert(hash_signal.length == static_cast<ssize_t>(SignalLength())); for(node_t worker = first_worker; worker <= last_worker; ++worker) { send(worker, message_type_t::HASH_SIGNAL_FULL, hash); } } void do_hash_sequence() { hash_sequence.resize(num_workers); for(node_t worker = first_worker; worker <= last_worker; ++worker) { recv(worker, message_type_t::HASH_SEQUENCE_PART, &hash_sequence[worker - first_worker]); } } size_t do_compute() { const auto seq_length = static_cast<ssize_t>(SeqLength()); const auto signal_length = static_cast<ssize_t>(SignalLength()); const auto possible = seq_length - signal_length + 1; const auto possible_per_worker = (possible + num_workers) / num_workers; LOG(<< "possible: " << possible << ", per worker: " << possible_per_worker << std::endl); hash_block_t hash; auto hash_begin = 1 + seq_length, hash_end = 1 + seq_length; auto hash_block_begin = hash_sequence.size(), hash_block_end = hash_sequence.size(); auto last = possible + 1; node_t worker_cnt = 0; while(last > 1) { const auto idx = std::max<decltype(last)>(1, last - possible_per_worker); while(hash_block_begin > 0 && last - 1 + hash_sequence[hash_block_begin - 1].length <= hash_begin) { hash_block_begin--; hash = hash_sequence[hash_block_begin] + hash; hash_begin -= hash_sequence[hash_block_begin].length; } while(hash_block_end > hash_block_begin && last - 1 + signal_length < hash_end) { hash_block_end--; hash = hash.trim(hash_sequence[hash_block_end]); hash_end -= hash_sequence[hash_block_end].length; } LOG(<< "last: [" << last << ", " << last + signal_length << "), hashed: [" << hash_begin << ", " << hash_end << ") " << "at " << hash_block_begin << ", " << hash_block_end << std::endl); assert(hash.length == hash_end - hash_begin); assert(worker_cnt < num_workers); send(static_cast<node_t>(first_worker + worker_cnt), message_type_t::SUBSEQUENCE, request_t{hash, hash_begin, hash_end, idx, last}); last = idx; LOG(<< "Sent to " << first_worker + worker_cnt << std::endl); worker_cnt++; } for(node_t worker = first_worker + worker_cnt; worker <= last_worker; ++worker) send(worker, message_type_t::SUBSEQUENCE, request_t{hash, hash_begin, hash_end, 0, 0}); } size_t do_collect() { size_t sum = 0; for(node_t worker = first_worker; worker <= last_worker; ++worker) { size_t cur; recv(worker, message_type_t::NOP, &cur); recv(worker, message_type_t::RESULT, &cur); sum += cur; } return sum; } private: ssize_t num_workers; node_t first_worker, last_worker; hash_block_t hash_signal; std::vector<hash_block_t> hash_sequence; }; template<class T> void perform(T &&t) { t.do_hash_signal(); LOG(<< "Done do_hash_signal" << std::endl); t.do_hash_sequence(); LOG(<< "Done do_hash_sequence" << std::endl); t.do_compute(); LOG(<< "Done do_compute" << std::endl); } int main() { const auto my_id = MyNodeId(); const auto number_of_nodes = NumberOfNodes(); if(my_id == MASTER) { master_t master(1, number_of_nodes - 1); perform(master); std::cout << master.do_collect() << std::endl; } else perform(worker_t(my_id - 1, number_of_nodes - 1)); LOG(<< "Exiting" << std::endl); }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 | #include <cassert> #include <array> #include <algorithm> #include <functional> #include <iostream> #include <iterator> #include <sstream> #include "poszukiwania.h" #include "message.h" //#define DEBUG #ifdef DEBUG static constexpr const bool debug = true; #else static constexpr const bool debug = false; #endif #define LOG(x) \ if(debug) { \ std::stringstream str; \ str << "Node " << MyNodeId() << "/" << NumberOfNodes() << ": "; \ str x; \ std::cerr << str.str(); \ } template<class T, class E, class Fn, class Init> T iterate(T base, Init init, E exponent, Fn &&fn) { T result = init; while(exponent > 0) { if(exponent % 2 == 1) result = fn(result, base); base = fn(base, base); exponent /= 2; } return result; } // ------------------------ hashing ------------------------- using hash_t = int32_t; using bigger_hash_t = int64_t; struct hash_setup_t { hash_t prime, base; }; static constexpr const hash_setup_t setup[] = { // { (1ll << 62) - 153, (1ll << 50) - 131 } // { (1ll << 62) - 471, (1ll << 42) - 11 } // { (1ll << 62) - 203, (1ll << 56) - 5 } // { (1 << 30) - 107, (1 << 28) - 213 }, { (1 << 30) - 153, (1 << 29) - 43 }, { (1 << 30) - 161, (1 << 29) - 3 } }; static constexpr const size_t prime_count = sizeof(setup) / sizeof(*setup); using hash_array_t = std::array<hash_t, prime_count>; __attribute__((pure)) hash_array_t make_powers(uint64_t exponent) { hash_array_t arr; for(size_t idx = 0; idx < prime_count; ++idx) { const auto op = [&idx](const hash_t x, const hash_t y) { return static_cast<hash_t>((static_cast<bigger_hash_t>(x) * y) % setup[idx].prime); }; const auto pw = iterate(setup[idx].base, 1, exponent, op); arr[idx] = pw; } return arr; } struct hash_block_t { hash_array_t hash; ssize_t length; hash_block_t() : length(0) { std::fill(std::begin(hash), std::end(hash), 0); } explicit hash_block_t(bigger_hash_t value) : length(1) { for(size_t idx = 0; idx < prime_count; ++idx) hash[idx] = value % setup[idx].prime; } __attribute__((pure)) hash_block_t operator+(const hash_block_t &rhs) const { hash_block_t result; result.length = length + rhs.length; for(size_t idx = 0; idx < prime_count; ++idx) { // g++ does a better job with inlining this stuff when it is defined locally const auto op = [&idx](const hash_t x, const hash_t y) { return static_cast<hash_t>((static_cast<bigger_hash_t>(x) * y) % setup[idx].prime); }; const auto pw = iterate(setup[idx].base, 1, length, op); result.hash[idx] = hash[idx] + op(pw, rhs.hash[idx]); if(result.hash[idx] >= setup[idx].prime) result.hash[idx] -= setup[idx].prime; } return result; } __attribute__((pure)) hash_block_t extend(const hash_block_t &rhs, const hash_array_t &powers) const { hash_block_t result; result.length = length + rhs.length; for(size_t idx = 0; idx < prime_count; ++idx) { const auto op = [&idx](const hash_t x, const hash_t y) { return static_cast<hash_t>((static_cast<bigger_hash_t>(x) * y) % setup[idx].prime); }; result.hash[idx] = hash[idx] + op(powers[idx], rhs.hash[idx]); if(result.hash[idx] >= setup[idx].prime) result.hash[idx] -= setup[idx].prime; } return result; } hash_block_t operator+=(const hash_block_t &that) { return operator=(*this + that); } __attribute__((pure)) hash_block_t trim(const hash_block_t &rhs) const { return trim(rhs, make_powers(length - rhs.length)); } __attribute__((pure)) hash_block_t trim(const hash_block_t &rhs, const hash_array_t &powers) const { hash_block_t result; result.length = length - rhs.length; for(size_t idx = 0; idx < prime_count; ++idx) { const auto op = [&idx](const hash_t x, const hash_t y) { return static_cast<hash_t>((static_cast<bigger_hash_t>(x) * y) % setup[idx].prime); }; result.hash[idx] = hash[idx] - op(powers[idx], rhs.hash[idx]); if(result.hash[idx] < 0) result.hash[idx] += setup[idx].prime; } return result; } bool operator==(const hash_block_t &that) const { assert(length == that.length); return hash == that.hash; } }; template<class Fn> hash_block_t hash_sequence(ssize_t begin, ssize_t end, Fn &&fn) { hash_block_t result{}; assert(begin <= end); if(begin != end) for(ssize_t idx = end - 1; idx >= begin; --idx) { result = hash_block_t{fn(idx)} + result; } return result; } struct request_t { hash_block_t hash; ssize_t hash_begin, hash_end; ssize_t begin, end; }; // ------------------------ messaging ----------------------- enum class message_type_t { HASH_SIGNAL_PART, HASH_SEQUENCE_PART, HASH_SIGNAL_FULL, SUBSEQUENCE, RESULT, NOP }; using node_t = int; namespace communication { template<unsigned size> struct communication_traits { }; #define GEN_TRAITS(type, name) \ template<> \ struct communication_traits<sizeof(type)> { \ template<class T> \ static void put(node_t target, T value) { \ static_assert(sizeof(T) == sizeof(type), "Size mismatch between T and " #type);\ Put ## name(target, static_cast<type>(value)); \ } \ \ template<class T> \ static T get(node_t target) { \ static_assert(sizeof(T) == sizeof(type), "Size mismatch between T and " #type);\ return static_cast<T>(Get ## name(target)); \ } \ }; GEN_TRAITS(char, Char) GEN_TRAITS(int, Int) GEN_TRAITS(long long, LL) template<class T> void put(node_t target, T value) { communication_traits<sizeof(value)>::put(target, value); } template<class T> void get(node_t target, T *number) { *number = communication_traits<sizeof(*number)>::template get<T>(target); } template<class T, size_t n> void put(node_t target, const std::array<T, n> &arr) { for(size_t idx = 0; idx < n; ++idx) put(target, arr[idx]); } template<class T, size_t n> void get(node_t target, std::array<T, n> *arr) { for(size_t idx = 0; idx < n; ++idx) get<T>(target, &(*arr)[idx]); } void put(node_t node, const hash_block_t &block) { put(node, block.length); put(node, block.hash); } void get(node_t node, hash_block_t *block) { get(node, &block->length); get(node, &block->hash); } void put(node_t node, const request_t &rq) { put(node, rq.hash); put(node, rq.hash_begin); put(node, rq.hash_end); put(node, rq.begin); put(node, rq.end); } void get(node_t node, request_t *rq) { get(node, &rq->hash); get(node, &rq->hash_begin); get(node, &rq->hash_end); get(node, &rq->begin); get(node, &rq->end); } void _send(node_t) { } void _recv(node_t) { } template<class Arg, class... Args> void _send(node_t node, Arg&& value, Args&&... args) { put(node, std::forward<Arg>(value)); _send(node, std::forward<Args>(args)...); } template<class Arg, class... Args> void _recv(node_t node, Arg *value, Args*... args) { get(node, value); _recv(node, args...); } template<class... Args> void send(node_t node, message_type_t type, Args&&... args) { _send(node, type, std::forward<Args>(args)...); Send(node); } template<class... Args> void recv(node_t node, message_type_t type, Args*... args) { Receive(node); message_type_t got; _recv(node, &got); assert(got == type); _recv(node, args...); } } using communication::send; using communication::recv; // --------------------- solution ------------------------------ constexpr const node_t MASTER = 0; template<class LengthFun> size_t block_length(size_t num_workers, LengthFun &&length) { const auto len = static_cast<size_t>(std::forward<LengthFun>(length)()); const auto len_per_worker = (len + num_workers - 1) / num_workers; return len_per_worker; } class worker_t { public: worker_t(size_t worker_id, size_t num_workers) : worker_id{worker_id} , num_workers{num_workers} { } void do_hash_signal() { worker_hash_subsequence(message_type_t::HASH_SIGNAL_PART, SignalLength, SignalAt); } void do_hash_sequence() { worker_hash_subsequence(message_type_t::HASH_SEQUENCE_PART, SeqLength, SeqAt); } void do_compute() { request_t request; recv(MASTER, message_type_t::HASH_SIGNAL_FULL, &hash_signal); LOG(<< "Got hash of the signal" << std::endl); recv(MASTER, message_type_t::SUBSEQUENCE, &request); LOG(<< "Got subsequence" << std::endl); size_t result = 0; send(MASTER, message_type_t::NOP, result); if(request.begin != 0) { const auto signal_length = static_cast<ssize_t>(SignalLength()); LOG(<< " will calculate [" << request.begin << ", " << request.end << ")," " first: [" << request.end - 1 << ", " << request.end - 1 + signal_length << ") knowing [" << request.hash_begin << ", " << request.hash_end << ")" << std::endl); hash_block_t hash; if(request.hash_begin == request.hash_end) hash = hash_sequence(request.end - 1, request.end + signal_length - 1, SeqAt); else hash = hash_sequence(request.end - 1, request.hash_begin, SeqAt) + request.hash + hash_sequence(request.hash_end, request.end + signal_length - 1, SeqAt); assert(hash.length == signal_length); assert(hash_signal.length == signal_length); const auto trim_powers = make_powers(signal_length - 1); for(ssize_t pos = request.end - 1; pos >= request.begin;) { if(hash == hash_signal) { result++; } if(--pos < request.begin) break; hash = hash_block_t{SeqAt(pos)} + hash.trim(hash_block_t{SeqAt(pos + signal_length)}, trim_powers); } LOG(<< "matching among [" << request.begin << ", " << request.end << "): " << result << std::endl); } send(MASTER, message_type_t::RESULT, result); } private: template<class Length, class At> void worker_hash_subsequence(const message_type_t type, Length &&length, At &&at) { const auto len = static_cast<ssize_t>(length()); const auto len_per_worker = block_length(num_workers, std::forward<Length>(length)); const auto begin = std::min<ssize_t>(1 + len_per_worker * worker_id, 1 + len); const auto end = std::min<ssize_t>(1 + len_per_worker * (worker_id + 1), 1 + len); LOG(<< "Computing [" << begin << "," << end << "), per worker: " << len_per_worker << std::endl); const auto hash = hash_sequence(begin, end, std::forward<At>(at)); send(MASTER, type, hash); } size_t worker_id; size_t num_workers; hash_block_t hash_signal; }; class master_t { public: master_t(node_t first_worker, node_t last_worker) : num_workers(last_worker - first_worker + 1) , first_worker{first_worker} , last_worker{last_worker} { } void do_hash_signal() { hash_block_t hash; for(node_t worker = first_worker; worker <= last_worker; ++worker) { hash_block_t current; recv(worker, message_type_t::HASH_SIGNAL_PART, ¤t); hash += current; } hash_signal = hash; assert(hash_signal.length == static_cast<ssize_t>(SignalLength())); for(node_t worker = first_worker; worker <= last_worker; ++worker) { send(worker, message_type_t::HASH_SIGNAL_FULL, hash); } } void do_hash_sequence() { hash_sequence.resize(num_workers); for(node_t worker = first_worker; worker <= last_worker; ++worker) { recv(worker, message_type_t::HASH_SEQUENCE_PART, &hash_sequence[worker - first_worker]); } } size_t do_compute() { const auto seq_length = static_cast<ssize_t>(SeqLength()); const auto signal_length = static_cast<ssize_t>(SignalLength()); const auto possible = seq_length - signal_length + 1; const auto possible_per_worker = (possible + num_workers) / num_workers; LOG(<< "possible: " << possible << ", per worker: " << possible_per_worker << std::endl); hash_block_t hash; auto hash_begin = 1 + seq_length, hash_end = 1 + seq_length; auto hash_block_begin = hash_sequence.size(), hash_block_end = hash_sequence.size(); auto last = possible + 1; node_t worker_cnt = 0; while(last > 1) { const auto idx = std::max<decltype(last)>(1, last - possible_per_worker); while(hash_block_begin > 0 && last - 1 + hash_sequence[hash_block_begin - 1].length <= hash_begin) { hash_block_begin--; hash = hash_sequence[hash_block_begin] + hash; hash_begin -= hash_sequence[hash_block_begin].length; } while(hash_block_end > hash_block_begin && last - 1 + signal_length < hash_end) { hash_block_end--; hash = hash.trim(hash_sequence[hash_block_end]); hash_end -= hash_sequence[hash_block_end].length; } LOG(<< "last: [" << last << ", " << last + signal_length << "), hashed: [" << hash_begin << ", " << hash_end << ") " << "at " << hash_block_begin << ", " << hash_block_end << std::endl); assert(hash.length == hash_end - hash_begin); assert(worker_cnt < num_workers); send(static_cast<node_t>(first_worker + worker_cnt), message_type_t::SUBSEQUENCE, request_t{hash, hash_begin, hash_end, idx, last}); last = idx; LOG(<< "Sent to " << first_worker + worker_cnt << std::endl); worker_cnt++; } for(node_t worker = first_worker + worker_cnt; worker <= last_worker; ++worker) send(worker, message_type_t::SUBSEQUENCE, request_t{hash, hash_begin, hash_end, 0, 0}); } size_t do_collect() { size_t sum = 0; for(node_t worker = first_worker; worker <= last_worker; ++worker) { size_t cur; recv(worker, message_type_t::NOP, &cur); recv(worker, message_type_t::RESULT, &cur); sum += cur; } return sum; } private: ssize_t num_workers; node_t first_worker, last_worker; hash_block_t hash_signal; std::vector<hash_block_t> hash_sequence; }; template<class T> void perform(T &&t) { t.do_hash_signal(); LOG(<< "Done do_hash_signal" << std::endl); t.do_hash_sequence(); LOG(<< "Done do_hash_sequence" << std::endl); t.do_compute(); LOG(<< "Done do_compute" << std::endl); } int main() { const auto my_id = MyNodeId(); const auto number_of_nodes = NumberOfNodes(); if(my_id == MASTER) { master_t master(1, number_of_nodes - 1); perform(master); std::cout << master.do_collect() << std::endl; } else perform(worker_t(my_id - 1, number_of_nodes - 1)); LOG(<< "Exiting" << std::endl); } |