Merge pull request #1003 from isanae/file-list-improvements

Refresh optimizations

1 files changed, 193 insertions, 0 deletions

diff --git a/src/envfs.h b/src/envfs.h
new file mode 100644
index 00000000..8790b071
--- /dev/null
+++ b/src/envfs.h
@@ -0,0 +1,193 @@
+#ifndef ENV_ENVFS_H
+#define ENV_ENVFS_H
+
+#include <thread>
+
+namespace env
+{
+
+struct File
+{
+  std::wstring name;
+  std::wstring lcname;
+  FILETIME lastModified;
+
+  File(std::wstring_view name, FILETIME ft);
+};
+
+struct Directory
+{
+  std::wstring name;
+  std::wstring lcname;
+
+  std::vector<Directory> dirs;
+  std::vector<File> files;
+
+  Directory();
+  Directory(std::wstring_view name);
+};
+
+
+template <class T>
+class ThreadPool
+{
+public:
+  ThreadPool(std::size_t max=1)
+  {
+    setMax(max);
+  }
+
+  ~ThreadPool()
+  {
+    stopAndJoin();
+  }
+
+  void setMax(std::size_t n)
+  {
+    m_threads.resize(n);
+  }
+
+  void stopAndJoin()
+  {
+    for (auto& ti : m_threads) {
+      ti.stop = true;
+      ti.wakeup();
+    }
+
+    for (auto& ti : m_threads) {
+      if (ti.thread.joinable()) {
+        ti.thread.join();
+      }
+    }
+  }
+
+  void waitForAll()
+  {
+    for (;;) {
+      bool done = true;
+
+      for (auto& ti : m_threads) {
+        if (ti.busy) {
+          done = false;
+          break;
+        }
+      }
+
+      if (done) {
+        break;
+      }
+
+      std::this_thread::sleep_for(std::chrono::milliseconds(1));
+    }
+  }
+
+  T& request()
+  {
+    if (m_threads.empty()) {
+      std::terminate();
+    }
+
+    for (;;) {
+      for (auto& ti : m_threads) {
+        bool expected = false;
+
+        if (ti.busy.compare_exchange_strong(expected, true)) {
+          ti.wakeup();
+          return ti.o;
+        }
+      }
+
+      std::this_thread::sleep_for(std::chrono::milliseconds(1));
+    }
+  }
+
+  template <class F>
+  void forEach(F&& f)
+  {
+    for (auto& ti : m_threads) {
+      f(ti.o);
+    }
+  }
+
+private:
+  struct ThreadInfo
+  {
+    std::thread thread;
+    std::atomic<bool> busy;
+    T o;
+
+    std::condition_variable cv;
+    std::mutex mutex;
+    bool ready;
+
+    std::atomic<bool> stop;
+
+    ThreadInfo()
+      : busy(true), ready(false), stop(false)
+    {
+      thread = std::thread([&]{ run(); });
+    }
+
+    void wakeup()
+    {
+      {
+        std::scoped_lock lock(mutex);
+        ready = true;
+      }
+
+      cv.notify_one();
+    }
+
+    void run()
+    {
+      busy = false;
+
+      while (!stop) {
+        std::unique_lock lock(mutex);
+        cv.wait(lock, [&]{ return ready; });
+
+        if (stop) {
+          break;
+        }
+
+        o.run();
+
+        ready = false;
+        busy = false;
+      }
+    }
+  };
+
+  std::list<ThreadInfo> m_threads;
+};
+
+
+using DirStartF = void (void*, std::wstring_view);
+using DirEndF = void (void*, std::wstring_view);
+using FileF = void (void*, std::wstring_view, FILETIME);
+
+void setHandleCloserThreadCount(std::size_t n);
+
+
+class DirectoryWalker
+{
+public:
+  void forEachEntry(
+    const std::wstring& path, void* cx,
+    DirStartF* dirStartF, DirEndF* dirEndF, FileF* fileF);
+
+private:
+  std::vector<std::unique_ptr<unsigned char[]>> m_buffers;
+};
+
+
+void forEachEntry(
+  const std::wstring& path, void* cx,
+  DirStartF* dirStartF, DirEndF* dirEndF, FileF* fileF);
+
+Directory getFilesAndDirs(const std::wstring& path);
+Directory getFilesAndDirsWithFind(const std::wstring& path);
+
+} // namespace
+
+#endif // ENV_ENVFS_H