1 files changed, 56 insertions, 0 deletions
diff --git a/src/base/io/AutoReadStream.cpp b/src/base/io/AutoReadStream.cpp
new file mode 100644
index 00000000..c24f61d1
--- /dev/null
+++ b/src/base/io/AutoReadStream.cpp
@@ -0,0 +1,56 @@
+#include "cru/base/io/AutoReadStream.h"
+#include "cru/base/io/Stream.h"
+
+#include <thread>
+
+namespace cru::io {
+
+AutoReadStream::AutoReadStream(Stream* stream, bool auto_delete,
+                               const AutoReadStreamOptions& options)
+    : Stream(false, true, stream->CanSeek()) {
+  auto buffer_stream_options = options.GetBufferStreamOptions();
+  stream_ = stream;
+  size_per_read_ = buffer_stream_options.GetBlockSizeOrDefault();
+  buffer_stream_ = std::make_unique<BufferStream>(buffer_stream_options);
+  background_thread_ = std::thread(&AutoReadStream::BackgroundThreadRun, this);
+}
+
+AutoReadStream::~AutoReadStream() {
+  if (auto_delete_) {
+    delete stream_;
+  }
+}
+
+Index AutoReadStream::DoRead(std::byte* buffer, Index offset, Index size) {
+  std::unique_lock lock(buffer_stream_mutex_);
+  return buffer_stream_->Read(buffer, offset, size);
+}
+
+Index AutoReadStream::DoWrite(const std::byte* buffer, Index offset,
+                              Index size) {
+  return stream_->Write(buffer, offset, size);
+}
+
+void AutoReadStream::DoFlush() { stream_->Flush(); }
+
+void AutoReadStream::DoClose() {}
+
+void AutoReadStream::BackgroundThreadRun() {
+  std::vector<std::byte> buffer(size_per_read_);
+  while (true) {
+    try {
+      auto read = stream_->Read(buffer.data(), buffer.size());
+      if (read == 0) {
+        buffer_stream_->SetEof();
+        break;
+      } else {
+        buffer_stream_->Write(buffer.data(), read);
+      }
+    } catch (const StreamAlreadyClosedException& exception) {
+      buffer_stream_->SetEof();
+      break;
+    }
+  }
+}
+
+}  // namespace cru::io