1 files changed, 126 insertions, 0 deletions
diff --git a/include/cru/base/io/Stream.h b/include/cru/base/io/Stream.h
new file mode 100644
index 00000000..e0b61627
--- /dev/null
+++ b/include/cru/base/io/Stream.h
@@ -0,0 +1,126 @@
+#pragma once
+
+#include "../Base.h"
+
+#include "../Exception.h"
+#include "../String.h"
+
+#include <cstddef>
+
+namespace cru::io {
+class CRU_BASE_API StreamOperationNotSupportedException : public Exception {
+ public:
+  explicit StreamOperationNotSupportedException(String operation);
+
+  CRU_DEFAULT_DESTRUCTOR(StreamOperationNotSupportedException)
+
+ public:
+  String GetOperation() const { return operation_; }
+
+ public:
+  static void CheckSeek(bool seekable);
+  static void CheckRead(bool readable);
+  static void CheckWrite(bool writable);
+
+ private:
+  String operation_;
+};
+
+class CRU_BASE_API StreamAlreadyClosedException : public Exception {
+ public:
+  StreamAlreadyClosedException();
+
+  CRU_DEFAULT_DESTRUCTOR(StreamAlreadyClosedException)
+
+  static void Check(bool closed);
+};
+
+#define CRU_STREAM_IMPLEMENT_CLOSE_BY_DO_CLOSE \
+  void Close() override { DoClose(); }
+
+#define CRU_STREAM_BEGIN_CLOSE \
+  if (GetClosed()) return;     \
+  CloseGuard close_guard(this);
+
+/**
+ * All stream is thread-unsafe by default unless being documented.
+ */
+class CRU_BASE_API Stream : public Object {
+ protected:
+  struct SupportedOperations {
+    std::optional<bool> can_seek;
+    std::optional<bool> can_read;
+    std::optional<bool> can_write;
+  };
+
+  struct CloseGuard {
+    explicit CloseGuard(Stream* stream) : stream(stream) {}
+    ~CloseGuard() { stream->SetClosed(true); }
+    Stream* stream;
+  };
+
+ protected:
+  explicit Stream(SupportedOperations supported_operations = {});
+  Stream(std::optional<bool> can_seek, std::optional<bool> can_read,
+         std::optional<bool> can_write);
+
+ public:
+  enum class SeekOrigin { Current, Begin, End };
+
+  CRU_DELETE_COPY(Stream)
+  CRU_DELETE_MOVE(Stream)
+
+  ~Stream() override = default;
+
+ public:
+  bool CanSeek();
+  Index Seek(Index offset, SeekOrigin origin = SeekOrigin::Current);
+  Index Tell();
+  void Rewind();
+  Index GetSize();
+
+  bool CanRead();
+  Index Read(std::byte* buffer, Index offset, Index size);
+  Index Read(std::byte* buffer, Index size);
+  Index Read(char* buffer, Index offset, Index size);
+  Index Read(char* buffer, Index size);
+
+  bool CanWrite();
+  Index Write(const std::byte* buffer, Index offset, Index size);
+  Index Write(const std::byte* buffer, Index size);
+  Index Write(const char* buffer, Index offset, Index size);
+  Index Write(const char* buffer, Index size);
+
+  void Flush();
+  virtual void Close() = 0;
+
+  virtual Buffer ReadToEnd(Index grow_size = 256);
+
+  // Utf8 encoding.
+  String ReadToEndAsUtf8String();
+
+ protected:
+  virtual bool DoCanSeek();
+  virtual bool DoCanRead();
+  virtual bool DoCanWrite();
+  virtual Index DoSeek(Index offset, SeekOrigin origin);
+  virtual Index DoTell();
+  virtual void DoRewind();
+  virtual Index DoGetSize();
+  virtual Index DoRead(std::byte* buffer, Index offset, Index size);
+  virtual Index DoWrite(const std::byte* buffer, Index offset, Index size);
+  virtual void DoFlush();
+
+  void SetSupportedOperations(SupportedOperations supported_operations) {
+    supported_operations_ = std::move(supported_operations);
+  }
+
+  bool GetClosed() { return closed_; }
+  void SetClosed(bool closed) { closed_ = closed; }
+  void CheckClosed() { StreamAlreadyClosedException::Check(closed_); }
+
+ private:
+  std::optional<SupportedOperations> supported_operations_;
+  bool closed_;
+};
+}  // namespace cru::io