rename NativeFile -> NFile

common/nfile_unix.cc

@@ -0,0 +1,69 @@
+#include "common/nfile.hh"
+
+extern "C" {
+#include <fcntl.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+}
+
+
+namespace nf7 {
+
+void NFile::Init() {
+  int flags = 0;
+  if ((flags_ & kRead) && (flags_ & kWrite)) {
+    flags |= O_RDWR | O_CREAT;
+  } else if (flags_ & kRead) {
+    flags |= O_RDONLY;
+  } else if (flags_ & kWrite) {
+    flags |= O_WRONLY | O_CREAT;
+  }
+
+  int fd = open(path_.string().c_str(), flags, 0600);
+  if (fd < 0) {
+    throw NFile::Exception {"open failure"};
+  }
+  handle_ = static_cast<uint64_t>(fd);
+}
+NFile::~NFile() noexcept {
+  const auto fd = static_cast<int>(handle_);
+  if (close(fd) == -1) {
+    // ;(
+  }
+}
+
+size_t NFile::Read(size_t offset, uint8_t* buf, size_t size) {
+  const auto fd  = static_cast<int>(handle_);
+  const auto off = static_cast<off_t>(offset);
+  if (lseek(fd, off, SEEK_SET) == off-1) {
+    throw NFile::Exception {"lseek failure"};
+  }
+  const auto ret = read(fd, buf, size);
+  if (ret == -1) {
+    throw NFile::Exception {"read failure"};
+  }
+  return static_cast<size_t>(ret);
+}
+size_t NFile::Write(size_t offset, const uint8_t* buf, size_t size) {
+  const auto fd  = static_cast<int>(handle_);
+  const auto off = static_cast<off_t>(offset);
+  if (lseek(fd, off, SEEK_SET) == off-1) {
+    throw nf7::NFile::Exception {"lseek failure"};
+  }
+  const auto ret = write(fd, buf, size);
+  if (ret == -1) {
+    throw nf7::NFile::Exception {"write failure"};
+  }
+  return static_cast<size_t>(ret);
+}
+size_t NFile::Truncate(size_t size) {
+  const auto fd  = static_cast<int>(handle_);
+  if (ftruncate(fd, static_cast<off_t>(size)) == 0) {
+    throw nf7::NFile::Exception {"ftruncate failure"};
+  }
+  return size;
+}
+
+}  // namespace nf7