48 lines
1.5 KiB
C++
48 lines
1.5 KiB
C++
#include "parallel_finder.h"
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#include <mutex>
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#include <thread>
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using std::mutex, std::thread, std::lock_guard;
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ParallelFinder::ParallelFinder(const vector<string> &word_list,
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size_t thread_count)
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: word_list_(word_list), thread_count_(thread_count) {}
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vector<const string *>
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ParallelFinder::find_prefix(string_view search_term) const {
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vector<const string *> result;
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mutex result_mutex;
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vector<thread> threads;
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for (size_t thread_index = 0; thread_index < thread_count_; ++thread_index) {
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const size_t first_word_index =
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thread_index * (word_list_.size() / thread_count_);
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const size_t last_word_index =
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(thread_index == thread_count_ - 1)
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? word_list_.size()
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: (thread_index + 1) * (word_list_.size() / thread_count_);
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threads.emplace_back(
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[](const vector<string> &word_list, const string_view &search_term,
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vector<const string *> &result, size_t start_index, size_t end_index,
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mutex &result_mutex) {
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for (size_t index = start_index; index < end_index; ++index) {
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const auto ¤t_word = word_list[index];
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if (current_word.starts_with(search_term)) {
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const lock_guard<mutex> lock(result_mutex);
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result.push_back(¤t_word);
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}
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}
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},
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cref(word_list_), cref(search_term), ref(result), first_word_index,
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last_word_index, ref(result_mutex));
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}
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for (auto &thread : threads) {
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thread.join();
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}
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return result;
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}
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