Add ctor & print method to BufferedFile.

posix.cc

@@ -70,6 +70,16 @@ fmt::BufferedFile::~BufferedFile() FMT_NOEXCEPT(true) {
     fmt::report_system_error(errno, "cannot close file");
 }
 
+fmt::BufferedFile::BufferedFile(fmt::StringRef filename, fmt::StringRef mode) {
+  for (;;) {
+    file_ = FMT_SYSTEM(fopen(filename.c_str(), mode.c_str()));
+    if (file_)
+      return;
+    if (errno != EINTR)
+      throw SystemError(errno, "cannot open file");
+  }
+}
+
 void fmt::BufferedFile::close() {
   if (!file_)
     return;

posix.h

@@ -162,6 +162,9 @@ public:
   }
 #endif
 
+  // Opens a file.
+  BufferedFile(fmt::StringRef filename, fmt::StringRef mode);
+
   // Closes the file.
   void close();
 
@@ -169,6 +172,11 @@ public:
   FILE *get() const { return file_; }
 
   int fileno() const;
+
+  void print(fmt::StringRef format_str, const ArgList &args) {
+    fmt::print(file_, format_str, args);
+  }
+  FMT_VARIADIC(void, print, fmt::StringRef)
 };
 
 // A file. Closed file is represented by a File object with descriptor -1.

test/posix-test.cc

@@ -50,6 +50,7 @@ int fdopen_count;
 int read_count;
 int write_count;
 int pipe_count;
+int fopen_count;
 int fclose_count;
 int fileno_count;
 std::size_t read_nbyte;
@@ -123,6 +124,11 @@ int test::pipe(int *pfds, unsigned psize, int textmode) {
 }
 #endif
 
+FILE *test::fopen(const char *filename, const char *mode) {
+  EMULATE_EINTR(fopen, 0);
+  return ::fopen(filename, mode);
+}
+
 int test::fclose(FILE *stream) {
   EMULATE_EINTR(fclose, EOF);
   return ::fclose(stream);
@@ -148,10 +154,16 @@ int test::fileno(FILE *stream) {
 # define EXPECT_EQ_POSIX(expected, actual)
 #endif
 
+void write_file(fmt::StringRef filename, fmt::StringRef content) {
+  fmt::BufferedFile f(filename, "w");
+  fmt::print(f.get(), "{}", content);
+}
+
 TEST(FileTest, OpenRetry) {
+  write_file("test", "there must be something here");
   File *f = 0;
-  EXPECT_RETRY(f = new File("CMakeLists.txt", File::RDONLY),
-               open, "cannot open file CMakeLists.txt");
+  EXPECT_RETRY(f = new File("test", File::RDONLY),
+               open, "cannot open file test");
 #ifndef _WIN32
   char c = 0;
   f->read(&c, 1);
@@ -289,6 +301,18 @@ TEST(FileTest, FdopenNoRetry) {
   fdopen_count = 0;
 }
 
+TEST(BufferedFileTest, OpenRetry) {
+  write_file("test", "there must be something here");
+  BufferedFile *f = 0;
+  EXPECT_RETRY(f = new BufferedFile("test", "r"),
+               fopen, "cannot open file test");
+#ifndef _WIN32
+  char c = 0;
+  fread(&c, 1, 1, f->get());
+#endif
+  delete f;
+}
+
 TEST(BufferedFileTest, CloseNoRetryInDtor) {
   File read_end, write_end;
   File::pipe(read_end, write_end);

test/posix-test.h

@@ -61,6 +61,7 @@ int pipe(int fildes[2]);
 int pipe(int *pfds, unsigned psize, int textmode);
 #endif
 
+FILE *fopen(const char *filename, const char *mode);
 int fclose(FILE *stream);
 int fileno(FILE *stream);