mirror of https://github.com/Icinga/icinga2.git
149 lines
3.6 KiB
C++
149 lines
3.6 KiB
C++
/******************************************************************************
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* Icinga 2 *
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* Copyright (C) 2012-2017 Icinga Development Team (https://www.icinga.com/) *
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* *
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* This program is free software; you can redistribute it and/or *
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* modify it under the terms of the GNU General Public License *
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* as published by the Free Software Foundation; either version 2 *
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* of the License, or (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, write to the Free Software Foundation *
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. *
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******************************************************************************/
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#include "base/fifo.hpp"
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using namespace icinga;
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/**
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* Constructor for the FIFO class.
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*/
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FIFO::FIFO(void)
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: m_Buffer(NULL), m_DataSize(0), m_AllocSize(0), m_Offset(0)
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{ }
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/**
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* Destructor for the FIFO class.
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*/
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FIFO::~FIFO(void)
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{
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free(m_Buffer);
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}
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/**
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* Resizes the FIFO's buffer so that it is at least newSize bytes long.
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*
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* @param newSize The minimum new size of the FIFO buffer.
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*/
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void FIFO::ResizeBuffer(size_t newSize, bool decrease)
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{
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if (m_AllocSize >= newSize && !decrease)
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return;
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newSize = (newSize / FIFO::BlockSize + 1) * FIFO::BlockSize;
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if (newSize == m_AllocSize)
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return;
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char *newBuffer = static_cast<char *>(realloc(m_Buffer, newSize));
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if (newBuffer == NULL)
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BOOST_THROW_EXCEPTION(std::bad_alloc());
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m_Buffer = newBuffer;
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m_AllocSize = newSize;
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}
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/**
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* Optimizes memory usage of the FIFO buffer by reallocating
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* and moving the buffer.
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*/
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void FIFO::Optimize(void)
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{
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if (m_Offset > m_DataSize / 10 && m_Offset - m_DataSize > 1024) {
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std::memmove(m_Buffer, m_Buffer + m_Offset, m_DataSize);
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m_Offset = 0;
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if (m_DataSize > 0)
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ResizeBuffer(m_DataSize, true);
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return;
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}
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}
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size_t FIFO::Peek(void *buffer, size_t count, bool allow_partial)
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{
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ASSERT(allow_partial);
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if (count > m_DataSize)
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count = m_DataSize;
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if (buffer != NULL)
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std::memcpy(buffer, m_Buffer + m_Offset, count);
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return count;
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}
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/**
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* Implements IOQueue::Read.
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*/
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size_t FIFO::Read(void *buffer, size_t count, bool allow_partial)
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{
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ASSERT(allow_partial);
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if (count > m_DataSize)
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count = m_DataSize;
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if (buffer != NULL)
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std::memcpy(buffer, m_Buffer + m_Offset, count);
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m_DataSize -= count;
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m_Offset += count;
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Optimize();
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return count;
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}
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/**
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* Implements IOQueue::Write.
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*/
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void FIFO::Write(const void *buffer, size_t count)
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{
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ResizeBuffer(m_Offset + m_DataSize + count, false);
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std::memcpy(m_Buffer + m_Offset + m_DataSize, buffer, count);
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m_DataSize += count;
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SignalDataAvailable();
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}
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void FIFO::Close(void)
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{ }
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bool FIFO::IsEof(void) const
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{
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return false;
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}
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size_t FIFO::GetAvailableBytes(void) const
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{
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return m_DataSize;
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}
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bool FIFO::SupportsWaiting(void) const
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{
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return true;
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}
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bool FIFO::IsDataAvailable(void) const
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{
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return m_DataSize > 0;
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}
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