Moved threading into library.

include/search.hpp

@@ -61,19 +61,36 @@ namespace remwharead
                                                 const bool is_re) const;
 
         /*!
-     *  @brief  %Search in full text of database entries.
-     *
-     *  Searches in tags, title, description and full text.
-     *
-     *  @param  expression %Search expression.
-     *  @param  is_re      Is it a regular expression?
-     *
-     *  @return List of matching Database::entry.
-     *
-     *  @since  0.7.0
-     */
-    const list<Database::entry> search_all(string expression,
-                                           const bool is_re) const;
+         *  @brief  %Search in full text of database entries.
+         *
+         *  Searches in tags, title, description and full text.
+         *
+         *  @param  expression %Search expression.
+         *  @param  is_re      Is it a regular expression?
+         *
+         *  @return List of matching Database::entry.
+         *
+         *  @since  0.7.0
+         */
+        const list<Database::entry> search_all(string expression,
+                                               const bool is_re) const;
+
+        /*!
+         *  @brief  Spawn threads of search_all(), if it seems sensible.
+         *
+         *  Figure out if threads could be useful and spawn a sensible amount of
+         *  them.
+         *
+         *  @param  expression %Search expression.
+         *  @param  is_re      Is it a regular expression?
+         *
+         *  @return List of matching Database::entry.
+         *
+         *  @since  0.7.2
+         */
+        // TODO: Think of something more elegant.
+        const list<Database::entry> search_all_threaded(string expression,
+                                                        const bool is_re) const;
 
     private:
         const list<Database::entry> _entries;

src/cli/CMakeLists.txt

@@ -13,7 +13,7 @@ target_include_directories(${PROJECT_NAME}-cli
   PRIVATE "${PROJECT_BINARY_DIR}" "${CMAKE_CURRENT_SOURCE_DIR}")
 
 target_link_libraries(${PROJECT_NAME}-cli
-  PRIVATE ${PROJECT_NAME} pthread)
+  PRIVATE ${PROJECT_NAME})
 
 # If no Poco*Config.cmake recipes are found, look for headers in standard dirs.
 if(PocoUtil_FOUND)

src/cli/main.cpp

@@ -19,9 +19,6 @@
 #include <chrono>
 #include <fstream>
 #include <locale>
-#include <thread>
-#include <algorithm>
-#include <iterator>
 #include <list>
 #include <cerrno>
 #include "sqlite.hpp"
@@ -40,8 +37,6 @@ using std::endl;
 using std::string;
 using std::chrono::system_clock;
 using std::ofstream;
-using std::thread;
-using std::move;
 using std::list;
 
 int App::main(const std::vector<std::string> &args)
@@ -125,59 +120,8 @@ int App::main(const std::vector<std::string> &args)
         }
         else if (!_search_all.empty())
         {
-            const size_t len = entries.size();
-            constexpr size_t min_len = 100;
-            constexpr size_t min_per_thread = 50;
-            const size_t n_threads = thread::hardware_concurrency() / 3 + 1;
-            size_t cut_at = len;
-            if (len > min_len)
-            {   // If there are over `min_len` entries, use `n_threads` threads.
-                cut_at = len / n_threads;
-
-                // But don't use less than `min_per_thread` entries per thread.
-                if (cut_at < min_per_thread)
-                {
-                    cut_at = min_per_thread;
-                }
-            }
-
-            list<list<Database::entry>> segments;
-
-            // Use threads if list is big.
-            while (entries.size() > cut_at)
-            {
-                list<Database::entry> segment;
-
-                auto it = entries.begin();
-                std::advance(it, cut_at);
-
-                // Move the first `cut_at` entries into `segments`.
-                segment.splice(segment.begin(), entries, entries.begin(), it);
-                segments.push_back(move(segment));
-            }
-            // Move rest of `entries` into `segments`.
-            segments.push_back(move(entries));
-
-            list<thread> threads;
-            for (auto &segment : segments)
-            {
-                thread t(
-                    [&]
-                    {
-                        Search search(segment);
-                        // Replace `segment` with `result`.
-                        segment = search.search_all(_search_all, _regex);
-                    });
-                threads.push_back(move(t));
-            }
-
-            for (thread &t : threads)
-            {
-                t.join();
-                // Move each of `segments` into `entries`.
-                entries.splice(entries.end(), segments.front());
-                segments.pop_front();
-            }
+            Search search(entries);
+            entries = search.search_all_threaded(_search_all, _regex);
         }
 
         switch (_format)

src/lib/CMakeLists.txt

@@ -22,7 +22,7 @@ target_include_directories(${PROJECT_NAME}
   "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
 
 target_link_libraries(${PROJECT_NAME}
-  PRIVATE PkgConfig::libxdg-basedir
+  PRIVATE PkgConfig::libxdg-basedir pthread
   PUBLIC stdc++fs)
 
 # If no Poco*Config.cmake recipes are found, look for headers in standard dirs.

src/lib/search.cpp

@@ -18,6 +18,9 @@
 #include <algorithm>
 #include <locale>
 #include <list>
+#include <thread>
+#include <utility>
+#include <iterator>
 #include <Poco/UTF8String.h>
 #include "search.hpp"
 
@@ -29,6 +32,8 @@ namespace remwharead
     using std::smatch;
     using std::find;
     using std::find_if;
+    using std::thread;
+    using std::move;
 
     Search::Search(const list<Database::entry> &entries)
         :_entries(entries)
@@ -195,4 +200,66 @@ namespace remwharead
 
         return result;
     }
+
+    const list<Database::entry> Search::search_all_threaded(
+        string expression, const bool is_re) const
+    {
+        list<Database::entry> entries = _entries;
+
+        const size_t len = entries.size();
+        constexpr size_t min_len = 100;
+        constexpr size_t min_per_thread = 50;
+        const size_t n_threads = thread::hardware_concurrency() / 3 + 1;
+        size_t cut_at = len;
+        if (len > min_len)
+        {   // If there are over `min_len` entries, use `n_threads` threads.
+            cut_at = len / n_threads;
+
+            // But don't use less than `min_per_thread` entries per thread.
+            if (cut_at < min_per_thread)
+            {
+                cut_at = min_per_thread;
+            }
+        }
+
+        list<list<Database::entry>> segments;
+
+        // Use threads if list is big.
+        while (entries.size() > cut_at)
+        {
+            list<Database::entry> segment;
+
+            auto it = entries.begin();
+            std::advance(it, cut_at);
+
+            // Move the first `cut_at` entries into `segments`.
+            segment.splice(segment.begin(), entries, entries.begin(), it);
+            segments.push_back(move(segment));
+        }
+        // Move rest of `entries` into `segments`.
+        segments.push_back(move(entries));
+
+        list<thread> threads;
+        for (auto &segment : segments)
+        {
+            thread t(
+                [&]
+                {
+                    Search search(segment);
+                    // Replace `segment` with `result`.
+                    segment = search.search_all(expression, is_re);
+                });
+            threads.push_back(move(t));
+        }
+
+        for (thread &t : threads)
+        {
+            t.join();
+            // Move each of `segments` into `entries`.
+            entries.splice(entries.end(), segments.front());
+            segments.pop_front();
+        }
+
+        return entries;
+    }
 }