stat_date: par regex

stat_date.cpp

@@ -1,8 +1,16 @@
+#include <execution>
 #include <map>
+#include <numeric>
 #include <regex>
 #include <vector>
 #include "defs.hpp"
 
+template <class T> using vec = std::vector<T>;
+using dmap                   = std::map<std::string, size_t>;
+using smap                   = std::map<size_t, size_t>;
+using pss                    = std::pair<std::string, size_t>;
+using pvec                   = vec<pss>;
+
 const std::regex date_match[] = {
     // YYYY MM DD
     std::regex(R"((?:19|20)\d{2}(?:0[1-9]|1[0-2])(?:0[1-9]|[1-2][0-9]|3[0-1]))"),
@@ -34,22 +42,44 @@ const std::regex date_match[] = {
 void stat_date(const DataSource &source) {
     timeit(fmt::format("stat_date({})", magic_enum::enum_name(source)));
 
-    std::map<std::string, size_t> date_map;
-    std::map<size_t, size_t>      type_map;
+    // 35s
+    vec<std::string> passwords_vec;
+    vec<pvec>        partial;
+    dmap             date_map;
+    smap             type_map;
 
-    for (auto const &password : passwords(source)) {
+    auto eval = [](auto const &str) {
+        vec<pss> ret;
         for (int i = 0; i < sizeof(date_match) / sizeof(date_match[0]); i++) {
             const auto &match = date_match[i];
-            auto        bgn   = std::sregex_iterator(password.begin(), password.end(), match);
+            auto        bgn   = std::sregex_iterator(str.begin(), str.end(), match);
             auto        end   = std::sregex_iterator();
 
             if (bgn != end) {
                 auto date = bgn->str();
-                date_map[date]++;
-                type_map[i]++;
+                ret.emplace_back(std::make_pair(date, i));
                 break;
             }
         }
+        return ret;
+    };
+
+    std::ranges::copy(passwords(source), std::back_inserter(passwords_vec));
+    partial.resize(passwords_vec.size());
+
+    {
+        timeit("regex find date");
+        std::transform(std::execution::par, passwords_vec.begin(), passwords_vec.end(), partial.begin(), eval);
+    }
+
+    {
+        timeit("count result");
+        for (auto const &p : partial) {
+            for (auto const &r : p) {
+                date_map[r.first]++;
+                type_map[r.second]++;
+            }
+        }
     }
 
     std::vector<std::pair<std::string, size_t>> date_vec(date_map.begin(), date_map.end());