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/* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */
#include "base/fifo.hpp"
using namespace icinga;
/**
* Destructor for the FIFO class.
*/
FIFO::~FIFO()
{
free(m_Buffer);
}
/**
* Resizes the FIFO's buffer so that it is at least newSize bytes long.
*
* @param newSize The minimum new size of the FIFO buffer.
*/
void FIFO::ResizeBuffer(size_t newSize, bool decrease)
{
if (m_AllocSize >= newSize && !decrease)
return;
newSize = (newSize / FIFO::BlockSize + 1) * FIFO::BlockSize;
if (newSize == m_AllocSize)
return;
auto *newBuffer = static_cast<char *>(realloc(m_Buffer, newSize));
if (!newBuffer)
BOOST_THROW_EXCEPTION(std::bad_alloc());
m_Buffer = newBuffer;
m_AllocSize = newSize;
}
/**
* Optimizes memory usage of the FIFO buffer by reallocating
* and moving the buffer.
*/
void FIFO::Optimize()
{
if (m_Offset > m_DataSize / 10 && m_Offset - m_DataSize > 1024) {
std::memmove(m_Buffer, m_Buffer + m_Offset, m_DataSize);
m_Offset = 0;
if (m_DataSize > 0)
ResizeBuffer(m_DataSize, true);
return;
}
}
size_t FIFO::Peek(void *buffer, size_t count, bool allow_partial)
{
ASSERT(allow_partial);
if (count > m_DataSize)
count = m_DataSize;
if (buffer)
std::memcpy(buffer, m_Buffer + m_Offset, count);
return count;
}
/**
* Implements IOQueue::Read.
*/
size_t FIFO::Read(void *buffer, size_t count, bool allow_partial)
{
ASSERT(allow_partial);
if (count > m_DataSize)
count = m_DataSize;
if (buffer)
std::memcpy(buffer, m_Buffer + m_Offset, count);
m_DataSize -= count;
m_Offset += count;
Optimize();
return count;
}
/**
* Implements IOQueue::Write.
*/
void FIFO::Write(const void *buffer, size_t count)
{
ResizeBuffer(m_Offset + m_DataSize + count, false);
std::memcpy(m_Buffer + m_Offset + m_DataSize, buffer, count);
m_DataSize += count;
SignalDataAvailable();
}
void FIFO::Close()
{ }
bool FIFO::IsEof() const
{
return false;
}
size_t FIFO::GetAvailableBytes() const
{
return m_DataSize;
}
bool FIFO::SupportsWaiting() const
{
return true;
}
bool FIFO::IsDataAvailable() const
{
return m_DataSize > 0;
}
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