Compleated Code

writer.hpp

@@ -0,0 +1,76 @@
+/* -*- Mode: C++; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+#pragma once
+#ifndef WRITER_HPP
+#define WRITER_HPP
+
+#include <cstdint>
+#include <filesystem>
+#include <fstream>
+#include <future>
+#include <iostream>
+#include <string>
+
+#include <ff/ff.hpp>
+
+#include "task.hpp"
+
+using namespace ff;
+
+template <typename T> class Writer : public ff::ff_node_t<Task<T>, void> {
+  public:
+    void *svc(Task<T> *);
+    void operator()(std::vector<std::shared_future<Task<T> *>> *);
+};
+
+// svc function for fastflow library
+template <typename T> void *Writer<T>::svc(Task<T> *in) {
+    write_one_image(in);
+    return this->GO_ON;
+}
+
+// operator for std thread
+template <typename T>
+void Writer<T>::operator()(
+    std::vector<std::shared_future<Task<T> *>> *ResultsVector) {
+    if (!ResultsVector) {
+        std::cerr << "Error: invalid pointer to vector of futures "
+                     "[Writer::operator()]"
+                  << std::endl;
+        return;
+    }
+    for (auto Result : *ResultsVector) {
+        Task<T> *t = Result.get();
+        write_one_image(t);
+        delete (t);
+    }
+}
+
+// writes out just one image, prepend the output image with "out_"
+template <typename T> void write_one_image(Task<T> *t) {
+    std::string Pre = "out_";
+    std::filesystem::path Path = t->PathName;
+    std::string NameNew = Pre + Path.filename().string();
+    Path.replace_filename(NameNew);
+
+    std::fstream File{Path, File.out | File.binary};
+    if (!File.is_open()) {
+        std::cerr << "Error: Failed to open " << t->PathName.string() << std::endl;
+        return;
+    } else {
+        File.write(reinterpret_cast<char *>(&t->Rows), sizeof(t->Rows));
+        File.write(reinterpret_cast<char *>(&t->Cols), sizeof(t->Cols));
+
+        // use temporary buffer to not call the write function too frequently
+        T *buffer = new T[t->Cols];
+        for (int x = 0; x < t->Rows; ++x) {
+            for (int y = 0; y < t->Cols; ++y) {
+                buffer[y] = (*t->VectorData)[x][y];
+            }
+            File.write(reinterpret_cast<char *>(buffer), t->Cols * sizeof(T));
+        }
+        delete[] buffer;
+        File.close();
+    }
+}
+
+#endif /* WRITER_HPP */