boost/iostreams/filter/zlib.hpp
// (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) // (C) Copyright 2003-2007 Jonathan Turkanis // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) // See http://www.boost.org/libs/iostreams for documentation. // Note: custom allocators are not supported on VC6, since that compiler // had trouble finding the function zlib_base::do_init. #ifndef BOOST_IOSTREAMS_ZLIB_HPP_INCLUDED #define BOOST_IOSTREAMS_ZLIB_HPP_INCLUDED #if defined(_MSC_VER) # pragma once #endif #include <cassert> #include <iosfwd> // streamsize. #include <memory> // allocator, bad_alloc. #include <new> #include <boost/config.hpp> // MSVC, STATIC_CONSTANT, DEDUCED_TYPENAME, DINKUM. #include <boost/cstdint.hpp> // uint*_t #include <boost/detail/workaround.hpp> #include <boost/iostreams/constants.hpp> // buffer size. #include <boost/iostreams/detail/config/auto_link.hpp> #include <boost/iostreams/detail/config/dyn_link.hpp> #include <boost/iostreams/detail/config/wide_streams.hpp> #include <boost/iostreams/detail/config/zlib.hpp> #include <boost/iostreams/detail/ios.hpp> // failure, streamsize. #include <boost/iostreams/filter/symmetric.hpp> #include <boost/iostreams/pipeline.hpp> #include <boost/type_traits/is_same.hpp> // Must come last. #ifdef BOOST_MSVC # pragma warning(push) # pragma warning(disable:4251 4275 4231 4660) // Dependencies not exported. #endif #include <boost/config/abi_prefix.hpp> namespace boost { namespace iostreams { namespace zlib { // Typedefs typedef uint32_t uint; typedef uint8_t byte; typedef uint32_t ulong; // Prefix 'x' prevents symbols from being redefined when Z_PREFIX is defined typedef void* (*xalloc_func)(void*, zlib::uint, zlib::uint); typedef void (*xfree_func)(void*, void*); // Compression levels BOOST_IOSTREAMS_DECL extern const int no_compression; BOOST_IOSTREAMS_DECL extern const int best_speed; BOOST_IOSTREAMS_DECL extern const int best_compression; BOOST_IOSTREAMS_DECL extern const int default_compression; // Compression methods BOOST_IOSTREAMS_DECL extern const int deflated; // Compression strategies BOOST_IOSTREAMS_DECL extern const int default_strategy; BOOST_IOSTREAMS_DECL extern const int filtered; BOOST_IOSTREAMS_DECL extern const int huffman_only; // Status codes BOOST_IOSTREAMS_DECL extern const int okay; BOOST_IOSTREAMS_DECL extern const int stream_end; BOOST_IOSTREAMS_DECL extern const int stream_error; BOOST_IOSTREAMS_DECL extern const int version_error; BOOST_IOSTREAMS_DECL extern const int data_error; BOOST_IOSTREAMS_DECL extern const int mem_error; BOOST_IOSTREAMS_DECL extern const int buf_error; // Flush codes BOOST_IOSTREAMS_DECL extern const int finish; BOOST_IOSTREAMS_DECL extern const int no_flush; BOOST_IOSTREAMS_DECL extern const int sync_flush; // Code for current OS //BOOST_IOSTREAMS_DECL extern const int os_code; // Null pointer constant. const int null = 0; // Default values const int default_window_bits = 15; const int default_mem_level = 8; const bool default_crc = false; const bool default_noheader = false; } // End namespace zlib. // // Class name: zlib_params. // Description: Encapsulates the parameters passed to deflateInit2 // and inflateInit2 to customize compression and decompression. // struct zlib_params { // Non-explicit constructor. zlib_params( int level = zlib::default_compression, int method = zlib::deflated, int window_bits = zlib::default_window_bits, int mem_level = zlib::default_mem_level, int strategy = zlib::default_strategy, bool noheader = zlib::default_noheader, bool calculate_crc = zlib::default_crc ) : level(level), method(method), window_bits(window_bits), mem_level(mem_level), strategy(strategy), noheader(noheader), calculate_crc(calculate_crc) { } int level; int method; int window_bits; int mem_level; int strategy; bool noheader; bool calculate_crc; }; // // Class name: zlib_error. // Description: Subclass of std::ios::failure thrown to indicate // zlib errors other than out-of-memory conditions. // class BOOST_IOSTREAMS_DECL zlib_error : public BOOST_IOSTREAMS_FAILURE { public: explicit zlib_error(int error); int error() const { return error_; } static void check BOOST_PREVENT_MACRO_SUBSTITUTION(int error); private: int error_; }; namespace detail { template<typename Alloc> struct zlib_allocator_traits { #ifndef BOOST_NO_STD_ALLOCATOR typedef typename Alloc::template rebind<char>::other type; #else typedef std::allocator<char> type; #endif }; template< typename Alloc, typename Base = // VC6 workaround (C2516) BOOST_DEDUCED_TYPENAME zlib_allocator_traits<Alloc>::type > struct zlib_allocator : private Base { private: typedef typename Base::size_type size_type; public: BOOST_STATIC_CONSTANT(bool, custom = (!is_same<std::allocator<char>, Base>::value)); typedef typename zlib_allocator_traits<Alloc>::type allocator_type; static void* allocate(void* self, zlib::uint items, zlib::uint size); static void deallocate(void* self, void* address); }; class BOOST_IOSTREAMS_DECL zlib_base { public: typedef char char_type; protected: zlib_base(); ~zlib_base(); void* stream() { return stream_; } template<typename Alloc> void init( const zlib_params& p, bool compress, zlib_allocator<Alloc>& zalloc ) { bool custom = zlib_allocator<Alloc>::custom; do_init( p, compress, custom ? zlib_allocator<Alloc>::allocate : 0, custom ? zlib_allocator<Alloc>::deallocate : 0, &zalloc ); } void before( const char*& src_begin, const char* src_end, char*& dest_begin, char* dest_end ); void after( const char*& src_begin, char*& dest_begin, bool compress ); int xdeflate(int flush); // Prefix 'x' prevents symbols from being int xinflate(int flush); // redefined when Z_PREFIX is defined void reset(bool compress, bool realloc); public: zlib::ulong crc() const { return crc_; } int total_in() const { return total_in_; } int total_out() const { return total_out_; } private: void do_init( const zlib_params& p, bool compress, zlib::xalloc_func, zlib::xfree_func, void* derived ); void* stream_; // Actual type: z_stream*. bool calculate_crc_; zlib::ulong crc_; zlib::ulong crc_imp_; int total_in_; int total_out_; }; // // Template name: zlib_compressor_impl // Description: Model of C-Style Filte implementing compression by // delegating to the zlib function deflate. // template<typename Alloc = std::allocator<char> > class zlib_compressor_impl : public zlib_base, public zlib_allocator<Alloc> { public: zlib_compressor_impl(const zlib_params& = zlib::default_compression); ~zlib_compressor_impl(); bool filter( const char*& src_begin, const char* src_end, char*& dest_begin, char* dest_end, bool flush ); void close(); }; // // Template name: zlib_compressor // Description: Model of C-Style Filte implementing decompression by // delegating to the zlib function inflate. // template<typename Alloc = std::allocator<char> > class zlib_decompressor_impl : public zlib_base, public zlib_allocator<Alloc> { public: zlib_decompressor_impl(const zlib_params&); zlib_decompressor_impl(int window_bits = zlib::default_window_bits); ~zlib_decompressor_impl(); bool filter( const char*& begin_in, const char* end_in, char*& begin_out, char* end_out, bool flush ); void close(); bool eof() const { return eof_; } private: bool eof_; }; } // End namespace detail. // // Template name: zlib_compressor // Description: Model of InputFilter and OutputFilter implementing // compression using zlib. // template<typename Alloc = std::allocator<char> > struct basic_zlib_compressor : symmetric_filter<detail::zlib_compressor_impl<Alloc>, Alloc> { private: typedef detail::zlib_compressor_impl<Alloc> impl_type; typedef symmetric_filter<impl_type, Alloc> base_type; public: typedef typename base_type::char_type char_type; typedef typename base_type::category category; basic_zlib_compressor( const zlib_params& = zlib::default_compression, int buffer_size = default_device_buffer_size ); zlib::ulong crc() { return this->filter().crc(); } int total_in() { return this->filter().total_in(); } }; BOOST_IOSTREAMS_PIPABLE(basic_zlib_compressor, 1) typedef basic_zlib_compressor<> zlib_compressor; // // Template name: zlib_decompressor // Description: Model of InputFilter and OutputFilter implementing // decompression using zlib. // template<typename Alloc = std::allocator<char> > struct basic_zlib_decompressor : symmetric_filter<detail::zlib_decompressor_impl<Alloc>, Alloc> { private: typedef detail::zlib_decompressor_impl<Alloc> impl_type; typedef symmetric_filter<impl_type, Alloc> base_type; public: typedef typename base_type::char_type char_type; typedef typename base_type::category category; basic_zlib_decompressor( int window_bits = zlib::default_window_bits, int buffer_size = default_device_buffer_size ); basic_zlib_decompressor( const zlib_params& p, int buffer_size = default_device_buffer_size ); zlib::ulong crc() { return this->filter().crc(); } int total_out() { return this->filter().total_out(); } bool eof() { return this->filter().eof(); } }; BOOST_IOSTREAMS_PIPABLE(basic_zlib_decompressor, 1) typedef basic_zlib_decompressor<> zlib_decompressor; //----------------------------------------------------------------------------// //------------------Implementation of zlib_allocator--------------------------// namespace detail { template<typename Alloc, typename Base> void* zlib_allocator<Alloc, Base>::allocate (void* self, zlib::uint items, zlib::uint size) { size_type len = items * size; char* ptr = static_cast<allocator_type*>(self)->allocate (len + sizeof(size_type) #if BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, == 1) , (char*)0 #endif ); *reinterpret_cast<size_type*>(ptr) = len; return ptr + sizeof(size_type); } template<typename Alloc, typename Base> void zlib_allocator<Alloc, Base>::deallocate(void* self, void* address) { char* ptr = reinterpret_cast<char*>(address) - sizeof(size_type); size_type len = *reinterpret_cast<size_type*>(ptr) + sizeof(size_type); static_cast<allocator_type*>(self)->deallocate(ptr, len); } //------------------Implementation of zlib_compressor_impl--------------------// template<typename Alloc> zlib_compressor_impl<Alloc>::zlib_compressor_impl(const zlib_params& p) { init(p, true, static_cast<zlib_allocator<Alloc>&>(*this)); } template<typename Alloc> zlib_compressor_impl<Alloc>::~zlib_compressor_impl() { reset(true, false); } template<typename Alloc> bool zlib_compressor_impl<Alloc>::filter ( const char*& src_begin, const char* src_end, char*& dest_begin, char* dest_end, bool flush ) { before(src_begin, src_end, dest_begin, dest_end); int result = xdeflate(flush ? zlib::finish : zlib::no_flush); after(src_begin, dest_begin, true); zlib_error::check BOOST_PREVENT_MACRO_SUBSTITUTION(result); return result != zlib::stream_end; } template<typename Alloc> void zlib_compressor_impl<Alloc>::close() { reset(true, true); } //------------------Implementation of zlib_decompressor_impl------------------// template<typename Alloc> zlib_decompressor_impl<Alloc>::zlib_decompressor_impl(const zlib_params& p) : eof_(false) { init(p, false, static_cast<zlib_allocator<Alloc>&>(*this)); } template<typename Alloc> zlib_decompressor_impl<Alloc>::~zlib_decompressor_impl() { reset(false, false); } template<typename Alloc> zlib_decompressor_impl<Alloc>::zlib_decompressor_impl(int window_bits) { zlib_params p; p.window_bits = window_bits; init(p, false, static_cast<zlib_allocator<Alloc>&>(*this)); } template<typename Alloc> bool zlib_decompressor_impl<Alloc>::filter ( const char*& src_begin, const char* src_end, char*& dest_begin, char* dest_end, bool /* flush */ ) { before(src_begin, src_end, dest_begin, dest_end); int result = xinflate(zlib::sync_flush); after(src_begin, dest_begin, false); zlib_error::check BOOST_PREVENT_MACRO_SUBSTITUTION(result); return !(eof_ = result == zlib::stream_end); } template<typename Alloc> void zlib_decompressor_impl<Alloc>::close() { eof_ = false; reset(false, true); } } // End namespace detail. //------------------Implementation of zlib_decompressor-----------------------// template<typename Alloc> basic_zlib_compressor<Alloc>::basic_zlib_compressor (const zlib_params& p, int buffer_size) : base_type(buffer_size, p) { } //------------------Implementation of zlib_decompressor-----------------------// template<typename Alloc> basic_zlib_decompressor<Alloc>::basic_zlib_decompressor (int window_bits, int buffer_size) : base_type(buffer_size, window_bits) { } template<typename Alloc> basic_zlib_decompressor<Alloc>::basic_zlib_decompressor (const zlib_params& p, int buffer_size) : base_type(buffer_size, p) { } //----------------------------------------------------------------------------// } } // End namespaces iostreams, boost. #include <boost/config/abi_suffix.hpp> // Pops abi_suffix.hpp pragmas. #ifdef BOOST_MSVC # pragma warning(pop) #endif #endif // #ifndef BOOST_IOSTREAMS_ZLIB_HPP_INCLUDED