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// ============================================================================ |
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// gzstream, C++ iostream classes wrapping the zlib compression library. |
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// Copyright (C) 2001 Deepak Bandyopadhyay, Lutz Kettner |
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// |
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// This library is free software; you can redistribute it and/or |
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// modify it under the terms of the GNU Lesser General Public |
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// License as published by the Free Software Foundation; either |
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// version 2.1 of the License, or (at your option) any later version. |
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// |
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// This library 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 GNU |
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// Lesser General Public License for more details. |
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// |
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// You should have received a copy of the GNU Lesser General Public |
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// License along with this library; if not, write to the Free Software |
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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// ============================================================================ |
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// |
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// File : gzstream.h |
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// Revision : $Revision$ |
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// Revision_date : $Date$ |
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// Author(s) : Deepak Bandyopadhyay, Lutz Kettner |
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// |
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// Standard streambuf implementation following Nicolai Josuttis, "The |
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// Standard C++ Library". |
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// ============================================================================ |
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|
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#ifndef IO_GZSTREAM_HPP |
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#define IO_GZSTREAM_HPP |
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|
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// standard C++ with new header file names and std:: namespace |
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#include <iostream> |
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#include <fstream> |
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#include <zlib.h> |
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|
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namespace OpenMD { |
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|
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|
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// ---------------------------------------------------------------------------- |
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// Internal classes to implement gzstream. See below for user classes. |
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// ---------------------------------------------------------------------------- |
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|
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class gzstreambuf : public std::streambuf { |
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private: |
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static const int bufferSize = 47+256; // size of data buff |
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// totals 512 bytes under g++ for igzstream at the end. |
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|
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gzFile file; // file handle for compressed file |
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char buffer[bufferSize]; // data buffer |
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char opened; // open/close state of stream |
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int mode; // I/O mode |
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|
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int flush_buffer(); |
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public: |
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gzstreambuf() : opened(0) { |
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setp( buffer, buffer + (bufferSize-1)); |
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setg( buffer + 4, // beginning of putback area |
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buffer + 4, // read position |
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buffer + 4); // end position |
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// ASSERT: both input & output capabilities will not be used together |
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} |
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int is_open() { return opened; } |
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gzstreambuf* open( const char* name, int open_mode); |
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gzstreambuf* close(); |
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~gzstreambuf() { close(); } |
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|
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virtual int overflow( int c = EOF); |
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virtual int underflow(); |
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virtual int sync(); |
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}; |
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|
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class gzstreambase : virtual public std::ios { |
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protected: |
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gzstreambuf buf; |
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public: |
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gzstreambase() { init(&buf); } |
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gzstreambase( const char* name, int open_mode); |
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~gzstreambase(); |
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void open( const char* name, int open_mode); |
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void close(); |
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gzstreambuf* rdbuf() { return &buf; } |
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}; |
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|
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// ---------------------------------------------------------------------------- |
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// User classes. Use igzstream and ogzstream analogously to ifstream and |
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// ofstream respectively. They read and write files based on the gz* |
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// function interface of the zlib. Files are compatible with gzip compression. |
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// ---------------------------------------------------------------------------- |
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|
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class igzstream : public gzstreambase, public std::istream { |
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public: |
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igzstream() : std::istream( &buf) {} |
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igzstream( const char* name, int open_mode = std::ios::in) |
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: gzstreambase( name, open_mode), std::istream( &buf) {} |
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gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); } |
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void open( const char* name, int open_mode = std::ios::in) { |
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gzstreambase::open( name, open_mode); |
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} |
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}; |
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|
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class ogzstream : public gzstreambase, public std::ostream { |
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public: |
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ogzstream() : std::ostream( &buf) {} |
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ogzstream( const char* name, int mode = std::ios::out) |
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: gzstreambase( name, mode), std::ostream( &buf) {} |
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gzstreambuf* rdbuf() { return gzstreambase::rdbuf(); } |
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void open( const char* name, int open_mode = std::ios::out) { |
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gzstreambase::open( name, open_mode); |
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} |
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}; |
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|
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} |
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#endif |
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