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254 lines
6.5 KiB
C++
254 lines
6.5 KiB
C++
//
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// BinaryReader.h
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//
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// Library: Foundation
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// Package: Streams
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// Module: BinaryReaderWriter
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//
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// Definition of the BinaryReader class.
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//
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// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
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// and Contributors.
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//
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// SPDX-License-Identifier: BSL-1.0
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//
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#ifndef Foundation_BinaryReader_INCLUDED
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#define Foundation_BinaryReader_INCLUDED
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#include <istream>
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#include <vector>
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#include "Poco/Buffer.h"
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#include "Poco/Foundation.h"
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#include "Poco/MemoryStream.h"
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namespace Poco
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{
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class TextEncoding;
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class TextConverter;
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class Foundation_API BinaryReader
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/// This class reads basic types (and std::vectors thereof)
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/// in binary form into an input stream.
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/// It provides an extractor-based interface similar to istream.
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/// The reader also supports automatic conversion from big-endian
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/// (network byte order) to little-endian and vice-versa.
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/// Use a BinaryWriter to create a stream suitable for a BinaryReader.
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{
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public:
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enum StreamByteOrder
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{
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NATIVE_BYTE_ORDER = 1, /// the host's native byte-order
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BIG_ENDIAN_BYTE_ORDER = 2, /// big-endian (network) byte-order
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NETWORK_BYTE_ORDER = 2, /// big-endian (network) byte-order
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LITTLE_ENDIAN_BYTE_ORDER = 3, /// little-endian byte-order
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UNSPECIFIED_BYTE_ORDER = 4 /// unknown, byte-order will be determined by reading the byte-order mark
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};
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BinaryReader(std::istream & istr, StreamByteOrder byteOrder = NATIVE_BYTE_ORDER);
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/// Creates the BinaryReader.
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BinaryReader(std::istream & istr, TextEncoding & encoding, StreamByteOrder byteOrder = NATIVE_BYTE_ORDER);
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/// Creates the BinaryReader using the given TextEncoding.
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///
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/// Strings will be converted from the specified encoding
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/// to the currently set global encoding (see Poco::TextEncoding::global()).
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~BinaryReader();
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/// Destroys the BinaryReader.
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BinaryReader & operator>>(bool & value);
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BinaryReader & operator>>(char & value);
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BinaryReader & operator>>(unsigned char & value);
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BinaryReader & operator>>(signed char & value);
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BinaryReader & operator>>(short & value);
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BinaryReader & operator>>(unsigned short & value);
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BinaryReader & operator>>(int & value);
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BinaryReader & operator>>(unsigned int & value);
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BinaryReader & operator>>(long & value);
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BinaryReader & operator>>(unsigned long & value);
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BinaryReader & operator>>(float & value);
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BinaryReader & operator>>(double & value);
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#if !defined(POCO_LONG_IS_64_BIT)
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BinaryReader & operator>>(Int64 & value);
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BinaryReader & operator>>(UInt64 & value);
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#endif
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BinaryReader & operator>>(std::string & value);
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template <typename T>
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BinaryReader & operator>>(std::vector<T> & value)
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{
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Poco::UInt32 size(0);
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T elem;
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*this >> size;
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if (!good())
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return *this;
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value.reserve(size);
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while (this->good() && size-- > 0)
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{
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*this >> elem;
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value.push_back(elem);
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}
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return *this;
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}
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void read7BitEncoded(UInt32 & value);
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/// Reads a 32-bit unsigned integer in compressed format.
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/// See BinaryWriter::write7BitEncoded() for a description
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/// of the compression algorithm.
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void read7BitEncoded(UInt64 & value);
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/// Reads a 64-bit unsigned integer in compressed format.
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/// See BinaryWriter::write7BitEncoded() for a description
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/// of the compression algorithm.
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void readRaw(std::streamsize length, std::string & value);
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/// Reads length bytes of raw data into value.
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void readRaw(char * buffer, std::streamsize length);
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/// Reads length bytes of raw data into buffer.
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void readCString(std::string& value);
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/// Reads zero-terminated C-string into value.
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void readBOM();
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/// Reads a byte-order mark from the stream and configures
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/// the reader for the encountered byte order.
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/// A byte-order mark is a 16-bit integer with a value of 0xFEFF,
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/// written in host byte order.
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bool good();
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/// Returns _istr.good();
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bool fail();
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/// Returns _istr.fail();
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bool bad();
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/// Returns _istr.bad();
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bool eof();
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/// Returns _istr.eof();
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std::istream & stream() const;
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/// Returns the underlying stream.
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StreamByteOrder byteOrder() const;
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/// Returns the byte-order used by the reader, which is
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/// either BIG_ENDIAN_BYTE_ORDER or LITTLE_ENDIAN_BYTE_ORDER.
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void setExceptions(std::ios_base::iostate st = (std::istream::failbit | std::istream::badbit));
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/// Sets the stream to throw exception on specified state (default failbit and badbit);
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std::streamsize available() const;
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/// Returns the number of available bytes in the stream.
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private:
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std::istream & _istr;
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bool _flipBytes;
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TextConverter * _pTextConverter;
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};
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template <typename T>
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class BasicMemoryBinaryReader : public BinaryReader
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/// A convenient wrapper for using Buffer and MemoryStream with BinaryReader.
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{
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public:
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BasicMemoryBinaryReader(const Buffer<T> & data, StreamByteOrder byteOrder = NATIVE_BYTE_ORDER)
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: BinaryReader(_istr, byteOrder), _data(data), _istr(data.begin(), data.capacity())
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{
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}
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BasicMemoryBinaryReader(const Buffer<T> & data, TextEncoding & encoding, StreamByteOrder byteOrder = NATIVE_BYTE_ORDER)
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: BinaryReader(_istr, encoding, byteOrder), _data(data), _istr(data.begin(), data.capacity())
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{
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}
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~BasicMemoryBinaryReader() { }
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const Buffer<T> & data() const { return _data; }
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const MemoryInputStream & stream() const { return _istr; }
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MemoryInputStream & stream() { return _istr; }
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private:
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const Buffer<T> & _data;
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MemoryInputStream _istr;
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};
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typedef BasicMemoryBinaryReader<char> MemoryBinaryReader;
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//
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// inlines
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//
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inline bool BinaryReader::good()
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{
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return _istr.good();
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}
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inline bool BinaryReader::fail()
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{
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return _istr.fail();
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}
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inline bool BinaryReader::bad()
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{
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return _istr.bad();
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}
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inline bool BinaryReader::eof()
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{
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return _istr.eof();
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}
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inline std::istream & BinaryReader::stream() const
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{
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return _istr;
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}
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inline BinaryReader::StreamByteOrder BinaryReader::byteOrder() const
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{
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#if defined(POCO_ARCH_BIG_ENDIAN)
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return _flipBytes ? LITTLE_ENDIAN_BYTE_ORDER : BIG_ENDIAN_BYTE_ORDER;
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#else
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return _flipBytes ? BIG_ENDIAN_BYTE_ORDER : LITTLE_ENDIAN_BYTE_ORDER;
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#endif
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}
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inline void BinaryReader::setExceptions(std::ios_base::iostate st)
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{
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_istr.exceptions(st);
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}
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inline std::streamsize BinaryReader::available() const
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{
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return _istr.rdbuf()->in_avail();
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}
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} // namespace Poco
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#endif // Foundation_BinaryReader_INCLUDED
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