MICmnLog.h

//===-- MICmnLog.h ----------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#pragma once

// Third party headers:
#include <map>

// In-house headers:
#include "MIUtilString.h"
#include "MICmnBase.h"
#include "MIUtilSingletonBase.h"

//++ ============================================================================
// Details: MI common code implementation class. Handle application trace
//          activity logging. Medium objects derived from the Medium abstract
///          class are registered with this logger. The function Write is called
//          by a client callee to log information. That information is given to
//          registered relevant mediums. The medium file is registered during
//          *this logs initialization so it will always have a file log for the
//          application.
//          Singleton class.
//--
class CMICmnLog : public MI::ISingleton<CMICmnLog>
{
    friend MI::ISingleton<CMICmnLog>;

    // Enumeration:
  public:
    //++
    // Description: Data given to the Logger can be of several types. The Logger can be
    //              set at levels of verbosity. Can determine how data is sent to one or
    //              mediums.
    //--
    enum ELogVerbosity
    {                                         // Descriptions of what 'may' occur, depends ultimately on the medium itself. See the medium.
        eLogVerbosity_FnTrace = 0x00000004,   // Debug function stack call tracing
        eLogVerbosity_DbgOp = 0x00000008,     // Send a string to the debugger for display (not implemented)
        eLogVerbosity_ClientMsg = 0x00000010, // A client using MI can insert messages into the log (not implemented)
        eLogVerbosity_Log = 0x00000020        // Send to only the Log file.
    };

    // Class:
  public:
    //++
    // Description: Register a medium derived from this interface which will be
    //              called writing log trace data i.e. a file or a console.
    //              Medium objects registered are not owned by *this logger.
    //--
    class IMedium
    {
      public:
        virtual bool Initialize() = 0;
        virtual const CMIUtilString &GetName() const = 0;
        virtual bool Write(const CMIUtilString &vData, const ELogVerbosity veType) = 0;
        virtual const CMIUtilString &GetError() const = 0;
        virtual bool Shutdown() = 0;

        // Not part of the interface, ignore
        // AD:  This virtual destructor seems to hit a bug in the stdlib
        //      where vector delete is incorrectly called.  Workaround is
        //      to comment this out while I investigate.
        /* dtor */ virtual ~IMedium() {}
    };

    // Statics:
  public:
    static bool WriteLog(const CMIUtilString &vData);

    // Methods:
  public:
    bool RegisterMedium(const IMedium &vrMedium);
    bool UnregisterMedium(const IMedium &vrMedium);
    bool Write(const CMIUtilString &vData, const ELogVerbosity veType);
    bool SetEnabled(const bool vbYes);
    bool GetEnabled() const;

    // MI common object handling - duplicate of CMICmnBase functions, necessary for LINUX build
    // Done to stop locking on object construction init circular dependency.
    const CMIUtilString &GetErrorDescription() const;
    void SetErrorDescription(const CMIUtilString &vrTxt) const;
    void ClrErrorDescription() const;

    // Overridden:
  public:
    // From MI::ISingleton
    bool Initialize() override;
    bool Shutdown() override;

    // Methods:
  private:
    /* ctor */ CMICmnLog();
    /* ctor */ CMICmnLog(const CMICmnLog &);
    void operator=(const CMICmnLog &);

    // Overridden:
  private:
    // From CMICmnBase
    /* dtor */ ~CMICmnLog() override;

    // Typedef:
  private:
    typedef std::map<IMedium *, CMIUtilString> MapMediumToName_t;
    typedef std::pair<IMedium *, CMIUtilString> MapPairMediumToName_t;

    // Methods:
  private:
    bool HaveMediumAlready(const IMedium &vrMedium) const;
    bool UnregisterMediumAll();

    // Attributes:
  private:
    bool m_bRecursiveDive; // True = yes recursive, false = no
    MapMediumToName_t m_mapMediumToName;
    bool m_bEnabled;         // True = Logger enabled for writing to mediums, false = medium not written to
    bool m_bInitializingATM; // True = Yes in process of initing *this logger, false = not initing
    //
    // MI common object handling - duplicate of CMICmnBase functions, necessary for LINUX build
    bool m_bInitialized; // True = yes successfully initialized, false = no yet or failed
    mutable CMIUtilString m_strMILastErrorDescription;
    MIint m_clientUsageRefCnt; // Count of client using *this object so not shutdown() object to early
};