direct_buffered_file -> ostream

include/fmt/os.h

@@ -343,8 +343,8 @@ class file {
 // Returns the memory page size.
 long getpagesize();
 
-// A buffered file with a direct buffer access and no synchronization.
-class direct_buffered_file : private detail::buffer<char> {
+// A fast output stream without synchronization.
+class ostream : private detail::buffer<char> {
  private:
   file file_;
   char buffer_[BUFSIZ];
@@ -357,25 +357,33 @@ class direct_buffered_file : private detail::buffer<char> {
 
   void grow(size_t) final;
 
- public:
-  direct_buffered_file(cstring_view path, int oflag)
+  ostream(cstring_view path, int oflag)
       : buffer<char>(buffer_, 0, BUFSIZ), file_(path, oflag) {}
 
-  ~direct_buffered_file() { flush(); }
+ public:
+  ostream(ostream&& other)
+      : buffer<char>(buffer_, 0, BUFSIZ), file_(std::move(other.file_)) {
+    append(other.begin(), other.end());
+    other.clear();
+  }
+  ~ostream() { flush(); }
+
+  friend ostream output_file(cstring_view path, int oflag);
 
   void close() {
     flush();
     file_.close();
   }
 
   template <typename S, typename... Args>
-  friend void print(direct_buffered_file& f, const S& format_str,
-                    const Args&... args);
+  void print(const S& format_str, const Args&... args) {
+    format_to(detail::buffer_appender<char>(*this), format_str, args...);
+  }
 };
 
-template <typename S, typename... Args>
-void print(direct_buffered_file& f, const S& format_str, const Args&... args) {
-  format_to(detail::buffer_appender<char>(f), format_str, args...);
+inline ostream output_file(cstring_view path,
+                           int oflag = file::WRONLY | file::CREATE) {
+  return {path, oflag};
 }
 #endif  // FMT_USE_FCNTL
 

src/os.cc

@@ -314,7 +314,7 @@ long getpagesize() {
 #  endif
 }
 
-void direct_buffered_file::grow(size_t) {
+void ostream::grow(size_t) {
   if (this->size() == BUFSIZ) flush();
 }
 #endif  // FMT_USE_FCNTL

test/os-test.cc

@@ -287,21 +287,19 @@ TEST(BufferedFileTest, Fileno) {
   EXPECT_READ(copy, FILE_CONTENT);
 }
 
-TEST(DirectBufferedFileTest, Print) {
-  fmt::direct_buffered_file out("test-file",
-                                fmt::file::WRONLY | fmt::file::CREATE);
-  fmt::print(out, "The answer is {}.\n", 42);
+TEST(OStreamTest, Print) {
+  fmt::ostream out = fmt::output_file("test-file");
+  out.print("The answer is {}.\n", 42);
   out.close();
   file in("test-file", file::RDONLY);
   EXPECT_READ(in, "The answer is 42.\n");
 }
 
-TEST(DirectBufferedFileTest, BufferBoundary) {
+TEST(OStreamTest, BufferBoundary) {
   auto str = std::string(4096, 'x');
-  fmt::direct_buffered_file out("test-file",
-                                fmt::file::WRONLY | fmt::file::CREATE);
-  fmt::print(out, "{}", str);
-  fmt::print(out, "{}", str);
+  fmt::ostream out = fmt::output_file("test-file");
+  out.print("{}", str);
+  out.print("{}", str);
   out.close();
   file in("test-file", file::RDONLY);
   EXPECT_READ(in, str + str);