WORKING: add Buffer and AutoReadStream.

7 files changed, 188 insertions, 0 deletions

diff --git a/include/cru/common/Buffer.h b/include/cru/common/Buffer.h
new file mode 100644
index 00000000..5390ebb4
--- /dev/null
+++ b/include/cru/common/Buffer.h
@@ -0,0 +1,50 @@
+#pragma once
+
+#include "Base.h"
+
+namespace cru {
+class Buffer {
+ public:
+  explicit Buffer(Index size);
+
+  Buffer(const Buffer& other);
+  Buffer(Buffer&& other) noexcept;
+
+  Buffer& operator=(const Buffer& other);
+  Buffer& operator=(Buffer&& other) noexcept;
+
+  ~Buffer();
+
+ private:
+  Index GetSize() const;
+  Index GetUsedSize() const;
+  bool IsFull() const { return GetSize() == GetUsedSize(); }
+  bool IsNotFull() const { return !IsFull(); }
+
+  std::byte& GetAt(Index index);
+  std::byte GetAt(Index index) const;
+
+  Index PushEnd(std::byte* other, Index other_size);
+  Index PopEnd(Index size);
+
+  std::byte* Data();
+  const std::byte* Data() const;
+
+  operator std::byte*() { return Data(); }
+  operator const std::byte*() const { return Data(); }
+
+ private:
+  std::byte* ptr_;
+  Index size_;
+  Index used_size_;
+};
+
+void swap(Buffer& left, Buffer& right);
+
+class BufferList {
+  public:
+  explicit BufferList(Index buffer_size);
+  private:
+
+};
+}  // namespace cru
diff --git a/include/cru/common/io/AutoReadStream.h b/include/cru/common/io/AutoReadStream.h
new file mode 100644
index 00000000..7857e8b9
--- /dev/null
+++ b/include/cru/common/io/AutoReadStream.h
@@ -0,0 +1,88 @@
+#pragma once
+
+#include "Stream.h"
+#include "../Buffer.h"
+
+#include <condition_variable>
+#include <list>
+#include <mutex>
+#include <thread>
+#include <vector>
+
+namespace cru::io {
+struct AutoReadStreamOptions {
+  /**
+   * @brief The size of a single buffer allocated each time new space is needed.
+   * Use default value if <= 0.
+   *
+   * When current buffer is full and there is no space for following data, a new
+   * buffer will be allocated and appended to the buffer list. Note if sum size
+   * of all buffers reaches the total_buffer_size, no more buffer will be
+   * allocated but wait.
+   */
+  int buffer_block_size = 0;
+
+  /**
+   * @brief Total size limit of saved data in buffer. Use default value if < 0.
+   * No limit if == 0.
+   *
+   * When the buffer is filled, it will block and wait for user to read to get
+   * free space of buffer to continue read.
+   */
+  int total_buffer_size = 0;
+};
+
+/**
+ * @brief A stream that wraps another stream and auto read it into a buffer in a
+ * background thread.
+ */
+class CRU_BASE_API AutoReadStream : public Stream {
+ private:
+   class BufferBlock {
+     
+   };
+
+ public:
+  /**
+   * @brief Wrap a stream and auto read it in background.
+   * @param stream The stream to auto read.
+   * @param auto_delete Whether to delete the stream object in destructor.
+   * @param options Options to modify the behavior.
+   */
+  AutoReadStream(
+      Stream* stream, bool auto_delete,
+      const AutoReadStreamOptions& options = AutoReadStreamOptions());
+
+  ~AutoReadStream() override;
+
+ public:
+  bool CanSeek() override;
+  Index Seek(Index offset, SeekOrigin origin = SeekOrigin::Current) override;
+
+  bool CanRead() = 0;
+  virtual Index Read(std::byte* buffer, Index offset, Index size) = 0;
+
+  bool CanWrite() override;
+  Index Write(const std::byte* buffer, Index offset, Index size) override;
+
+  void Flush() override;
+
+  void Close() = 0;
+
+ private:
+  void BackgroundThreadRun();
+
+ private:
+  Stream* stream_;
+  bool auto_delete_;
+
+  int buffer_block_size_;
+  int total_buffer_size_;
+
+  std::mutex buffer_mutex_;
+  std::condition_variable buffer_condition_variable_;
+  std::list<Buffer> buffer_list_;
+
+  std::thread background_thread_;
+};
+}  // namespace cru::io
diff --git a/include/cru/common/platform/unix/PosixSpawnSubProcess.h b/include/cru/common/platform/unix/PosixSpawnSubProcess.h
index a55c2c1c..0a0f0ad4 100644
--- a/include/cru/common/platform/unix/PosixSpawnSubProcess.h
+++ b/include/cru/common/platform/unix/PosixSpawnSubProcess.h
@@ -17,6 +17,11 @@ class PosixSpawnSubProcess : public PlatformSubProcessBase {
   explicit PosixSpawnSubProcess(const PlatformSubProcessStartInfo& start_info);
   ~PosixSpawnSubProcess();
 
+ protected:
+  void PlatformCreateProcess() override;
+  PlatformSubProcessExitResult PlatformWaitForProcess() override;
+  void PlatformKillProcess() override;
+
  private:
   pid_t pid_;
   int exit_code_;
diff --git a/src/common/Buffer.cpp b/src/common/Buffer.cpp
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/src/common/Buffer.cpp
diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index aaff70fe..bf3156ac 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -1,5 +1,6 @@
 add_library(CruBase
 	Base.cpp
+	Buffer.cpp
 	Exception.cpp
 	Format.cpp
 	PropertyTree.cpp
@@ -7,6 +8,7 @@ add_library(CruBase
 	StringToNumberConverter.cpp
 	StringUtil.cpp
 	SubProcess.cpp
+	io/AutoReadStream.cpp
 	io/CFileStream.cpp
 	io/Stream.cpp
 	io/ProxyStream.cpp
diff --git a/src/common/io/AutoReadStream.cpp b/src/common/io/AutoReadStream.cpp
new file mode 100644
index 00000000..7cdc1268
--- /dev/null
+++ b/src/common/io/AutoReadStream.cpp
@@ -0,0 +1,36 @@
+#include "cru/common/io/AutoReadStream.h"
+#include <vector>
+#include "cru/common/io/Stream.h"
+
+namespace cru::io {
+
+AutoReadStream::AutoReadStream(Stream* stream, bool auto_delete,
+                               const AutoReadStreamOptions& options) {
+  background_thread_ = std::thread(&AutoReadStream::BackgroundThreadRun, this);
+}
+
+bool AutoReadStream::CanSeek() { return false; }
+
+Index AutoReadStream::Seek(Index offset, SeekOrigin origin) {
+  throw StreamOperationNotSupportedException(
+      u"AutoReadStream does not support seek.");
+}
+
+bool AutoReadStream::CanWrite() { return stream_->CanWrite(); }
+
+Index AutoReadStream::Write(const std::byte* buffer, Index offset, Index size) {
+  return stream_->Write(buffer, offset, size);
+}
+
+void AutoReadStream::Flush() { stream_->Flush(); }
+
+void AutoReadStream::BackgroundThreadRun() {
+  std::unique_lock<std::mutex> lock(buffer_mutex_);
+  std::vector<std::byte>* buffer = nullptr;
+  if (!buffer_list_.empty()) {
+  }
+  stream_->Read();
+}
+}
+
+}  // namespace cru::io
diff --git a/src/common/platform/unix/PosixSpawnSubProcess.cpp b/src/common/platform/unix/PosixSpawnSubProcess.cpp
index a356de77..7d5ba6e4 100644
--- a/src/common/platform/unix/PosixSpawnSubProcess.cpp
+++ b/src/common/platform/unix/PosixSpawnSubProcess.cpp
@@ -23,4 +23,11 @@ PosixSpawnSubProcess::PosixSpawnSubProcess(
 
 PosixSpawnSubProcess::~PosixSpawnSubProcess() {}
 
+void PosixSpawnSubProcess::PlatformCreateProcess() {
+  
+}
+
+PlatformSubProcessExitResult PosixSpawnSubProcess::PlatformWaitForProcess() {}
+
+void PosixSpawnSubProcess::PlatformKillProcess() {}
 }  // namespace cru::platform::unix