completed BitReader class; small improvements

experiment/meta_header
Martchus 8 years ago
parent b6355ac01b
commit 6bf736af0e

@ -127,8 +127,7 @@ string BinaryReader::readString(size_t length)
{
unique_ptr<char []> buff = make_unique<char []>(length);
m_stream->read(buff.get(), length);
string res(buff.get(), length);
return res;
return string(buff.get(), length);
}
/*!

@ -1,15 +1,82 @@
#ifndef IOUTILITIES_BITREADER_H
#define IOUTILITIES_BITREADER_H
#include "../conversion/types.h"
#include "../application/global.h"
#include <ios>
namespace IoUtilities {
class BitReader
class LIB_EXPORT BitReader
{
public:
BitReader();
BitReader(const char *buffer, std::size_t bufferSize);
BitReader(const char *buffer, const char *end);
template<typename intType> intType readBits(byte bitCount);
void skipBits(std::size_t bitCount);
std::size_t bitsAvailable();
private:
const byte *m_buffer;
const byte *m_end;
byte m_bitsAvail;
};
/*!
* \brief Constructs a new BitReader.
* \remarks Does not destroy the specified \a buffer.
*/
inline BitReader::BitReader(const char *buffer, std::size_t bufferSize) :
m_buffer(reinterpret_cast<const byte *>(buffer)),
m_end(reinterpret_cast<const byte *>(buffer + bufferSize)),
m_bitsAvail(8)
{}
/*!
* \brief Constructs a new BitReader.
* \remarks Does not destroy the specified \a buffer.
*/
inline BitReader::BitReader(const char *buffer, const char *end) :
m_buffer(reinterpret_cast<const byte *>(buffer)),
m_end(reinterpret_cast<const byte *>(end)),
m_bitsAvail(8)
{}
/*!
* \brief Reads the specified number of bits from the buffer.
* \param bitCount Specifies the number of bits read.
* \tparam intType Specifies the return value type.
* \remarks Does not check whether intType is big enough to hold result.
* \throws Throws ios_base::failure if the end of the buffer is exceeded.
* The reader becomes invalid in that case.
*/
template<typename intType>
intType BitReader::readBits(byte bitCount)
{
intType val = 0;
for(byte readAtOnce; bitCount; bitCount -= readAtOnce) {
readAtOnce = std::min(bitCount, m_bitsAvail);
val = (val << readAtOnce) | (((*m_buffer) >> (m_bitsAvail -= readAtOnce)) & (0xFF >> (0x08 - readAtOnce)));
if(!m_bitsAvail) {
m_bitsAvail = 8;
if(++m_buffer >= m_end) {
throw std::ios_base::failure("end of buffer exceeded");
}
}
}
return val;
}
/*!
* \brief Returns the number of bits which are still available to read.
*/
inline std::size_t BitReader::bitsAvailable()
{
return ((m_end - m_buffer) * 8) + m_bitsAvail;
}
} // namespace IoUtilities
#endif // IOUTILITIES_BITREADER_H

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