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/********************************************************************************
* *
* I / O B u f f e r C l a s s *
* *
*********************************************************************************
* Copyright (C) 2005,2022 by Jeroen van der Zijp. All Rights Reserved. *
*********************************************************************************
* This library is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/> *
********************************************************************************/
#include "xincs.h"
#include "fxver.h"
#include "fxdefs.h"
#include "fxmath.h"
#include "fxascii.h"
#include "FXArray.h"
#include "FXHash.h"
#include "FXStream.h"
#include "FXString.h"
#include "FXIO.h"
#include "FXIOBuffer.h"
/*
Notes:
- A fixed size memory buffer that can be accessed through file API.
*/
using namespace FX;
/*******************************************************************************/
namespace FX {
// Construct
FXIOBuffer::FXIOBuffer():buffer(nullptr),space(0){
}
// Construct and open
FXIOBuffer::FXIOBuffer(FXuchar* ptr,FXuval sz):buffer(nullptr),space(0){
open(ptr,sz);
}
// Open buffer
FXbool FXIOBuffer::open(FXuchar* ptr,FXuval sz){
if(ptr!=nullptr && 0<sz){
buffer=ptr;
pointer=0;
space=sz;
return true;
}
return false;
}
// Return true if open
FXbool FXIOBuffer::isOpen() const {
return buffer!=nullptr;
}
// Return true if serial access only
FXbool FXIOBuffer::isSerial() const {
return false;
}
// Get position
FXlong FXIOBuffer::position() const {
return pointer;
}
// Move to position
FXlong FXIOBuffer::position(FXlong offset,FXuint from){
FXuval ptr=FXIO::Error;
if(from==FXIO::Current){ ptr=pointer+offset; }
else if(from==FXIO::End){ ptr=space+offset; }
else if(from==FXIO::Begin){ ptr=offset; }
if(0<=ptr && ptr<=space){ pointer=ptr; }
return ptr;
}
// Read block
FXival FXIOBuffer::readBlock(void* ptr,FXival count){
if(buffer!=nullptr && ptr!=nullptr){
FXival remaining=space-pointer;
if(remaining<count) count=remaining;
memcpy(ptr,&buffer[pointer],count);
pointer+=count;
return count;
}
return FXIO::Error;
}
// Write block
FXival FXIOBuffer::writeBlock(const void* ptr,FXival count){
if(buffer!=nullptr && ptr!=nullptr){
FXival remaining=space-pointer;
if(remaining<count) count=remaining;
memcpy(&buffer[pointer],ptr,count);
pointer+=count;
return count;
}
return FXIO::Error;
}
// Truncate file
FXlong FXIOBuffer::truncate(FXlong sz){
if(buffer!=nullptr && 0<=sz && sz<=(FXlong)space){
if(pointer>sz) pointer=sz;
space=sz;
return sz;
}
return FXIO::Error;
}
// Synchronize disk with cached data
FXbool FXIOBuffer::flush(){
return true;
}
// Test if we're at the end; -1 if error
FXint FXIOBuffer::eof(){
return pointer>=(FXlong)space;
}
// Return file size
FXlong FXIOBuffer::size(){
return space;
}
// Close file
FXbool FXIOBuffer::close(){
buffer=nullptr;
pointer=0L;
space=0L;
return true;
}
// Destroy
FXIOBuffer::~FXIOBuffer(){
close();
}
}
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