TnbReader.h

[詳解]

#pragma once
#include "TnbSerializer.h"
#include "TnbVector.h"
 
 
 
//TNB Library
namespace TNB
{
 
 
 
struct IReader : IDeserializer
{
    enum ESeekMode
    {
        TOP     = FILE_BEGIN,       
        CURRENT = FILE_CURRENT,     
        END     = FILE_END          
    };
 
    virtual LPCTSTR GetOpenName(void) const = 0;
 
    virtual void Close(void) = 0;
 
    virtual bool CanRead(void) const = 0;
 
    virtual LONGLONG GetSize(void) const = 0;
 
    virtual LONGLONG Seek(LONGLONG llOffset, ESeekMode eSeek = TOP) const = 0;
 
    virtual size_t Read(size_t size, LPVOID _P) const = 0;
 
    LONGLONG GetLeftoverSize(void) const
    {
        LONGLONG lc = Seek(0, CURRENT);
        LONGLONG le = GetSize();
        if ( lc >= 0 && le >= 0 )
        {
            return le - lc;
        }
        return -1;
    }
 
    void ReadExactly(size_t size, LPVOID _P) const
    {
        if ( ! CanRead() )
        { 
            throw CReadFailureException(ERROR_INVALID_HANDLE); 
        }
        if ( Read(size, _P) != size )
        {
            throw CShortOfDataException();
        }
    }
 
    CByteVector ReadExactly(size_t size = 0) const
    {
        CByteVector vb = ReadInto(size);
        if ( size > 0 && size != vb.GetSize() )
        {
            throw CShortOfDataException();
        }
        return vb;
    }
 
    CByteVector ReadInto(size_t size = 0) const
    {
        if ( ! CanRead() )
        {
            throw CReadFailureException(ERROR_INVALID_HANDLE); 
        }
        CByteVector vb;
        if ( size == 0 )
        {
            size = ToIndex(GetLeftoverSize());
        }
        if ( size > 0 )
        {
            size_t i = Read(size, vb.GetBuffer(size));
            vb.ReleaseBuffer();
            vb.SetSize(i);
        }
        return vb;
    }
 
    size_t ReadInto(ICollectionT<BYTE>& _out, size_t size = 0, size_t oneBlockSize = 4096) const
    {
        if ( ! CanRead() )
        {
            throw CReadFailureException(ERROR_INVALID_HANDLE); 
        }
        CByteVector vb;
        if ( size == 0 )
        {
            size = ToIndex(GetLeftoverSize());
        }
        size_t r = 0;
        while ( size > 0 )
        {
            size_t l = size;
            if ( l > oneBlockSize ){ l = oneBlockSize; }
            vb = ReadInto(l);
            l = vb.GetSize();
            if ( l == 0 ){ break; }
            _out.Append(vb);
            size -= l;
            r += l;
        }
        return r;
    }
 
    virtual void GetRaw(size_t size, LPVOID _P) const
    {
        ReadExactly(size, _P);
    }
};
 
 
 
}; //TNB