xbmc/filesystem/PipesManager.h

   1 /*
   2  * Many concepts and protocol are taken from
   3  * the Boxee project. http://www.boxee.tv
   4  *
   5  *  Copyright (C) 2011-2018 Team Kodi
   6  *  This file is part of Kodi - https://kodi.tv
   7  *
   8  *  SPDX-License-Identifier: GPL-2.0-or-later
   9  *  See LICENSES/README.md for more information.
  10  */
  11
  12 #pragma once
  13
  14 #include "threads/CriticalSection.h"
  15 #include "threads/Event.h"
  16 #include "utils/RingBuffer.h"
  17
  18 #include <map>
  19 #include <string>
  20 #include <vector>
  21
  22 #define PIPE_DEFAULT_MAX_SIZE (6 * 1024 * 1024)
  23
  24 namespace XFILE
  25 {
  26
  27 class IPipeListener
  28 {
  29 public:
  30   virtual ~IPipeListener() = default;
  31   virtual void OnPipeOverFlow() = 0;
  32   virtual void OnPipeUnderFlow() = 0;
  33 };
  34
  35 class Pipe
  36   {
  37   public:
  38     Pipe(const std::string &name, int nMaxSize = PIPE_DEFAULT_MAX_SIZE );
  39     virtual ~Pipe();
  40     const std::string &GetName();
  41
  42     void AddRef();
  43     void DecRef();   // a pipe does NOT delete itself with ref-count 0.
  44     int  RefCount();
  45
  46     bool IsEmpty();
  47
  48     /**
  49      * Read into the buffer from the Pipe the num of bytes asked for
  50      * blocking forever (which happens to be 5 minutes in this case).
  51      *
  52      * In the case where nWaitMillis is provided block for that number
  53      * of milliseconds instead.
  54      */
  55     int  Read(char *buf, int nMaxSize, int nWaitMillis = -1);
  56
  57     /**
  58      * Write into the Pipe from the buffer the num of bytes asked for
  59      * blocking forever.
  60      *
  61      * In the case where nWaitMillis is provided block for that number
  62      * of milliseconds instead.
  63      */
  64     bool Write(const char *buf, int nSize, int nWaitMillis = -1);
  65
  66     void Flush();
  67
  68     void CheckStatus();
  69     void Close();
  70
  71     void AddListener(IPipeListener *l);
  72     void RemoveListener(IPipeListener *l);
  73
  74     void SetEof();
  75     bool IsEof();
  76
  77     int GetAvailableRead();
  78     void SetOpenThreshold(int threshold);
  79
  80   protected:
  81
  82     bool        m_bOpen;
  83     bool        m_bReadyForRead;
  84
  85     bool        m_bEof;
  86     CRingBuffer m_buffer;
  87     std::string  m_strPipeName;
  88     int         m_nRefCount;
  89     int         m_nOpenThreshold;
  90
  91     CEvent     m_readEvent;
  92     CEvent     m_writeEvent;
  93
  94     std::vector<XFILE::IPipeListener *> m_listeners;
  95
  96     CCriticalSection m_lock;
  97   };
  98
  99
 100 class PipesManager
 101 {
 102 public:
 103   virtual ~PipesManager();
 104   static PipesManager &GetInstance();
 105
 106   std::string   GetUniquePipeName();
 107   XFILE::Pipe *CreatePipe(const std::string &name="", int nMaxPipeSize = PIPE_DEFAULT_MAX_SIZE);
 108   XFILE::Pipe *OpenPipe(const std::string &name);
 109   void         ClosePipe(XFILE::Pipe *pipe);
 110   bool         Exists(const std::string &name);
 111
 112 protected:
 113   int    m_nGenIdHelper = 1;
 114   std::map<std::string, XFILE::Pipe *> m_pipes;
 115
 116   CCriticalSection m_lock;
 117 };
 118
 119 }
 120