1 files changed, 106 insertions, 0 deletions
diff --git a/src/base/platform/unix/UnixFileStream.cpp b/src/base/platform/unix/UnixFileStream.cpp
new file mode 100644
index 00000000..c53bbbaa
--- /dev/null
+++ b/src/base/platform/unix/UnixFileStream.cpp
@@ -0,0 +1,106 @@
+#include "cru/base/platform/unix/UnixFileStream.h"
+#include "cru/base/Exception.h"
+#include "cru/base/Format.h"
+#include "cru/base/io/Stream.h"
+#include "cru/base/log/Logger.h"
+
+#include <fcntl.h>
+#include <sys/fcntl.h>
+#include <unistd.h>
+#include <cerrno>
+
+namespace cru::platform::unix {
+using namespace cru::io;
+
+namespace {
+bool OflagCanSeek([[maybe_unused]] int oflag) {
+  // Treat every file seekable.
+  return true;
+}
+
+bool OflagCanRead(int oflag) {
+  // There is a problem: O_RDONLY is 0. So we must test it specially.
+  // If it is not write-only. Then it can read.
+  return !(oflag & O_WRONLY);
+}
+
+bool OflagCanWrite(int oflag) { return oflag & O_WRONLY || oflag & O_RDWR; }
+
+int MapSeekOrigin(Stream::SeekOrigin origin) {
+  switch (origin) {
+    case Stream::SeekOrigin::Begin:
+      return SEEK_SET;
+    case Stream::SeekOrigin::Current:
+      return SEEK_CUR;
+    case Stream::SeekOrigin::End:
+      return SEEK_END;
+    default:
+      throw Exception(u"Invalid seek origin.");
+  }
+}
+}  // namespace
+
+UnixFileStream::UnixFileStream(const char *path, int oflag, mode_t mode) {
+  file_descriptor_ = ::open(path, oflag, mode);
+  if (file_descriptor_ == -1) {
+    throw ErrnoException(
+        Format(u"Failed to open file {} with oflag {}, mode {}.",
+               String::FromUtf8(path), oflag, mode));
+  }
+
+  SetSupportedOperations(
+      {OflagCanSeek(oflag), OflagCanRead(oflag), OflagCanWrite(oflag)});
+
+  auto_close_ = true;
+}
+
+UnixFileStream::UnixFileStream(int fd, bool can_seek, bool can_read,
+                               bool can_write, bool auto_close)
+    : Stream(can_seek, can_read, can_write) {
+  file_descriptor_ = fd;
+  auto_close_ = auto_close;
+}
+
+UnixFileStream::~UnixFileStream() {
+  if (auto_close_ && file_descriptor_ >= 0) {
+    if (::close(file_descriptor_) == -1) {
+      // We are in destructor, so we can not throw.
+      CRU_LOG_WARN(u"Failed to close file descriptor {}, errno {}.",
+                   file_descriptor_, errno);
+    }
+  }
+}
+
+Index UnixFileStream::DoSeek(Index offset, SeekOrigin origin) {
+  off_t result = ::lseek(file_descriptor_, offset, MapSeekOrigin(origin));
+  if (result == -1) {
+    throw ErrnoException(u"Failed to seek file.");
+  }
+  return result;
+}
+
+Index UnixFileStream::DoRead(std::byte *buffer, Index offset, Index size) {
+  auto result = ::read(file_descriptor_, buffer + offset, size);
+  if (result == -1) {
+    throw ErrnoException(u"Failed to read file.");
+  }
+  return result;
+}
+
+Index UnixFileStream::DoWrite(const std::byte *buffer, Index offset,
+                              Index size) {
+  auto result = ::write(file_descriptor_, buffer + offset, size);
+  if (result == -1) {
+    throw ErrnoException(u"Failed to write file.");
+  }
+  return result;
+}
+
+void UnixFileStream::DoClose() {
+  CRU_STREAM_BEGIN_CLOSE
+  if (auto_close_ && ::close(file_descriptor_) == -1) {
+    throw ErrnoException(u"Failed to close file.");
+  }
+  file_descriptor_ = -1;
+}
+}  // namespace cru::platform::unix