1 files changed, 133 insertions, 0 deletions
diff --git a/xbmc/filesystem/CacheStrategy.h b/xbmc/filesystem/CacheStrategy.h
new file mode 100644
index 0000000..76c66bb
--- /dev/null
+++ b/xbmc/filesystem/CacheStrategy.h
@@ -0,0 +1,133 @@
+/*
+ *  Copyright (C) 2005-2018 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#pragma once
+
+#include "threads/Event.h"
+
+#include <stdint.h>
+#include <string>
+
+namespace XFILE {
+
+#define CACHE_RC_OK  0
+#define CACHE_RC_ERROR -1
+#define CACHE_RC_WOULD_BLOCK -2
+#define CACHE_RC_TIMEOUT -3
+
+class IFile; // forward declaration
+
+class CCacheStrategy{
+public:
+  virtual ~CCacheStrategy();
+
+  virtual int Open() = 0;
+  virtual void Close() = 0;
+
+  virtual size_t GetMaxWriteSize(const size_t& iRequestSize) = 0;
+  virtual int WriteToCache(const char *pBuffer, size_t iSize) = 0;
+  virtual int ReadFromCache(char *pBuffer, size_t iMaxSize) = 0;
+  virtual int64_t WaitForData(uint32_t iMinAvail, std::chrono::milliseconds timeout) = 0;
+
+  virtual int64_t Seek(int64_t iFilePosition) = 0;
+
+  /*!
+   \brief Reset cache position
+   \param iSourcePosition position to reset to
+   \return Whether a full reset was performed, or not (e.g. only cache swap)
+   \sa CCacheStrategy
+   */
+  virtual bool Reset(int64_t iSourcePosition) = 0;
+
+  virtual void EndOfInput(); // mark the end of the input stream so that Read will know when to return EOF
+  virtual bool IsEndOfInput();
+  virtual void ClearEndOfInput();
+
+  virtual int64_t CachedDataEndPosIfSeekTo(int64_t iFilePosition) = 0;
+  virtual int64_t CachedDataStartPos() = 0;
+  virtual int64_t CachedDataEndPos() = 0;
+  virtual bool IsCachedPosition(int64_t iFilePosition) = 0;
+
+  virtual CCacheStrategy *CreateNew() = 0;
+
+  CEvent m_space;
+protected:
+  bool  m_bEndOfInput = false;
+};
+
+/**
+*/
+class CSimpleFileCache : public CCacheStrategy {
+public:
+  CSimpleFileCache();
+  ~CSimpleFileCache() override;
+
+  int Open() override;
+  void Close() override;
+
+  size_t GetMaxWriteSize(const size_t& iRequestSize) override;
+  int WriteToCache(const char *pBuffer, size_t iSize) override;
+  int ReadFromCache(char *pBuffer, size_t iMaxSize) override;
+  int64_t WaitForData(uint32_t iMinAvail, std::chrono::milliseconds timeout) override;
+
+  int64_t Seek(int64_t iFilePosition) override;
+  bool Reset(int64_t iSourcePosition) override;
+  void EndOfInput() override;
+
+  int64_t CachedDataEndPosIfSeekTo(int64_t iFilePosition) override;
+  int64_t CachedDataStartPos() override;
+  int64_t CachedDataEndPos() override;
+  bool IsCachedPosition(int64_t iFilePosition) override;
+
+  CCacheStrategy *CreateNew() override;
+
+  int64_t  GetAvailableRead();
+
+protected:
+  std::string m_filename;
+  IFile*   m_cacheFileRead;
+  IFile*   m_cacheFileWrite;
+  CEvent*  m_hDataAvailEvent;
+  volatile int64_t m_nStartPosition = 0;
+  volatile int64_t m_nWritePosition = 0;
+  volatile int64_t m_nReadPosition = 0;
+};
+
+class CDoubleCache : public CCacheStrategy{
+public:
+  explicit CDoubleCache(CCacheStrategy *impl);
+  ~CDoubleCache() override;
+
+  int Open() override;
+  void Close() override;
+
+  size_t GetMaxWriteSize(const size_t& iRequestSize) override;
+  int WriteToCache(const char *pBuffer, size_t iSize) override;
+  int ReadFromCache(char *pBuffer, size_t iMaxSize) override;
+  int64_t WaitForData(uint32_t iMinAvail, std::chrono::milliseconds timeout) override;
+
+  int64_t Seek(int64_t iFilePosition) override;
+  bool Reset(int64_t iSourcePosition) override;
+  void EndOfInput() override;
+  bool IsEndOfInput() override;
+  void ClearEndOfInput() override;
+
+  int64_t CachedDataEndPosIfSeekTo(int64_t iFilePosition) override;
+  int64_t CachedDataStartPos() override;
+  int64_t CachedDataEndPos() override;
+  bool IsCachedPosition(int64_t iFilePosition) override;
+
+  CCacheStrategy *CreateNew() override;
+
+protected:
+  CCacheStrategy *m_pCache;
+  CCacheStrategy *m_pCacheOld;
+};
+
+}
+