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//
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//
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// Copyright (c) 2021 Vinnie Falco (vinnie.falco@gmail.com)
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// Copyright (c) 2021 Vinnie Falco (vinnie.falco@gmail.com)
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// Copyright (c) 2025 Mohammad Nejati
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// Copyright (c) 2025 Mohammad Nejati
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//
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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//
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// Official repository: https://github.com/cppalliance/http
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// Official repository: https://github.com/cppalliance/http
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//
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//
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#ifndef BOOST_HTTP_ZLIB_DEFLATE_HPP
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#ifndef BOOST_HTTP_ZLIB_DEFLATE_HPP
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#define BOOST_HTTP_ZLIB_DEFLATE_HPP
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#define BOOST_HTTP_ZLIB_DEFLATE_HPP
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#include <boost/http/detail/config.hpp>
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#include <boost/http/detail/config.hpp>
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#include <boost/http/zlib/service.hpp>
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#include <boost/http/zlib/service.hpp>
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#include <boost/http/zlib/stream.hpp>
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#include <boost/http/zlib/stream.hpp>
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#include <boost/capy/ex/execution_context.hpp>
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#include <boost/capy/ex/execution_context.hpp>
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#include <cstddef>
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#include <cstddef>
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namespace boost {
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namespace boost {
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namespace http {
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namespace http {
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namespace zlib {
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namespace zlib {
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/** Provides the ZLib compression API.
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/** Provides the ZLib compression API.
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    This service interface exposes the ZLib deflate (compression)
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    This service interface exposes the ZLib deflate (compression)
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    functionality through a set of virtual functions. The deflate
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    functionality through a set of virtual functions. The deflate
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    algorithm compresses data by finding repeated byte sequences
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    algorithm compresses data by finding repeated byte sequences
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    and encoding them efficiently using a combination of LZ77 and
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    and encoding them efficiently using a combination of LZ77 and
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    Huffman coding.
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    Huffman coding.
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    The windowBits parameter in init2() controls the format:
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    The windowBits parameter in init2() controls the format:
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    - 8..15: zlib format with specified window size
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    - 8..15: zlib format with specified window size
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    - -8..-15: raw deflate format (no header/trailer)
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    - -8..-15: raw deflate format (no header/trailer)
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    - 16+windowBits: gzip format
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    - 16+windowBits: gzip format
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    @code
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    @code
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    // Example: Basic compression
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    // Example: Basic compression
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    boost::http::datastore ctx;
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    boost::http::datastore ctx;
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    auto& deflate_svc = boost::http::zlib::install_deflate_service(ctx);
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    auto& deflate_svc = boost::http::zlib::install_deflate_service(ctx);
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    boost::http::zlib::stream st = {};
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    boost::http::zlib::stream st = {};
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    std::vector<unsigned char> input_data = get_data();
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    std::vector<unsigned char> input_data = get_data();
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    std::vector<unsigned char> output(input_data.size() * 2);
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    std::vector<unsigned char> output(input_data.size() * 2);
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    st.zalloc = nullptr;
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    st.zalloc = nullptr;
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    st.zfree = nullptr;
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    st.zfree = nullptr;
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    st.opaque = nullptr;
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    st.opaque = nullptr;
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    deflate_svc.init(st, boost::http::zlib::default_compression);
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    deflate_svc.init(st, boost::http::zlib::default_compression);
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    st.avail_in = input_data.size();
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    st.avail_in = input_data.size();
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    st.next_in = input_data.data();
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    st.next_in = input_data.data();
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    st.avail_out = output.size();
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    st.avail_out = output.size();
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    st.next_out = output.data();
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    st.next_out = output.data();
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    deflate_svc.deflate(st, boost::http::zlib::finish);
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    deflate_svc.deflate(st, boost::http::zlib::finish);
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    output.resize(st.total_out);
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    output.resize(st.total_out);
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    deflate_svc.deflate_end(st);
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    deflate_svc.deflate_end(st);
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    @endcode
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    @endcode
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    @code
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    @code
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    // Example: Gzip compression with custom window size
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    // Example: Gzip compression with custom window size
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    boost::http::zlib::stream st = {};
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    boost::http::zlib::stream st = {};
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    st.zalloc = nullptr;
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    st.zalloc = nullptr;
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    st.zfree = nullptr;
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    st.zfree = nullptr;
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    // Use gzip format (16 + 15 for max window)
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    // Use gzip format (16 + 15 for max window)
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    deflate_svc.init2(st,
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    deflate_svc.init2(st,
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        6,                                      // level
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        6,                                      // level
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        boost::http::zlib::deflated,           // method
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        boost::http::zlib::deflated,           // method
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        16 + 15,                                // gzip format
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        16 + 15,                                // gzip format
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        8,                                      // memLevel
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        8,                                      // memLevel
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        boost::http::zlib::default_strategy);   // strategy
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        boost::http::zlib::default_strategy);   // strategy
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    // Compress data...
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    // Compress data...
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    deflate_svc.deflate_end(st);
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    deflate_svc.deflate_end(st);
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    @endcode
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    @endcode
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*/
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*/
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struct BOOST_SYMBOL_VISIBLE
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struct BOOST_SYMBOL_VISIBLE
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    deflate_service
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    deflate_service
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    : capy::execution_context::service
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    : capy::execution_context::service
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{
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{
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    /** Return the ZLib version string. */
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    /** Return the ZLib version string. */
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    virtual char const* version() const noexcept = 0;
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    virtual char const* version() const noexcept = 0;
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    /** Initialize deflate compression.
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    /** Initialize deflate compression.
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        @param st The stream to initialize.
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        @param st The stream to initialize.
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        @param level The compression level.
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        @param level The compression level.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int init(stream& st, int level) const = 0;
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    virtual int init(stream& st, int level) const = 0;
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    /** Initialize deflate compression with extended parameters.
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    /** Initialize deflate compression with extended parameters.
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        @param st The stream to initialize.
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        @param st The stream to initialize.
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        @param level The compression level.
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        @param level The compression level.
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        @param method The compression method.
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        @param method The compression method.
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        @param windowBits The base-2 logarithm of the window size.
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        @param windowBits The base-2 logarithm of the window size.
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        @param memLevel Memory usage level (1-9).
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        @param memLevel Memory usage level (1-9).
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        @param strategy The compression strategy.
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        @param strategy The compression strategy.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int init2(stream& st, int level, int method,
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    virtual int init2(stream& st, int level, int method,
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        int windowBits, int memLevel, int strategy) const = 0;
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        int windowBits, int memLevel, int strategy) const = 0;
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    /** Set the compression dictionary.
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    /** Set the compression dictionary.
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        @param st The stream.
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        @param st The stream.
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        @param dict Pointer to the dictionary data.
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        @param dict Pointer to the dictionary data.
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        @param len Length of the dictionary.
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        @param len Length of the dictionary.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int set_dict(stream& st, unsigned char const* dict, unsigned len) const = 0;
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    virtual int set_dict(stream& st, unsigned char const* dict, unsigned len) const = 0;
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    /** Return the current compression dictionary.
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    /** Return the current compression dictionary.
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        @param st The stream.
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        @param st The stream.
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        @param dest Destination buffer for the dictionary.
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        @param dest Destination buffer for the dictionary.
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        @param len Pointer to variable receiving dictionary length.
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        @param len Pointer to variable receiving dictionary length.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int get_dict(stream& st, unsigned char* dest, unsigned* len) const = 0;
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    virtual int get_dict(stream& st, unsigned char* dest, unsigned* len) const = 0;
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    /** Duplicate a deflate stream.
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    /** Duplicate a deflate stream.
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        @param dest The destination stream.
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        @param dest The destination stream.
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        @param src The source stream to duplicate.
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        @param src The source stream to duplicate.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int dup(stream& dest, stream& src) const = 0;
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    virtual int dup(stream& dest, stream& src) const = 0;
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    /** Compress data in the stream.
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    /** Compress data in the stream.
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        @param st The stream containing data to compress.
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        @param st The stream containing data to compress.
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        @param flush The flush mode.
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        @param flush The flush mode.
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        @return Status code indicating compression state.
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        @return Status code indicating compression state.
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    */
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    */
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    virtual int deflate(stream& st, int flush) const = 0;
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    virtual int deflate(stream& st, int flush) const = 0;
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    /** Release all resources held by the deflate stream.
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    /** Release all resources held by the deflate stream.
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        @param st The stream to finalize.
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        @param st The stream to finalize.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int deflate_end(stream& st) const = 0;
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    virtual int deflate_end(stream& st) const = 0;
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    /** Reset the deflate stream state.
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    /** Reset the deflate stream state.
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        @param st The stream to reset.
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        @param st The stream to reset.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int reset(stream& st) const = 0;
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    virtual int reset(stream& st) const = 0;
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    /** Dynamically update compression parameters.
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    /** Dynamically update compression parameters.
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        @param st The stream.
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        @param st The stream.
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        @param level The new compression level.
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        @param level The new compression level.
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        @param strategy The new compression strategy.
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        @param strategy The new compression strategy.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int params(stream& st, int level, int strategy) const = 0;
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    virtual int params(stream& st, int level, int strategy) const = 0;
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    /** Return an upper bound on compressed size.
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    /** Return an upper bound on compressed size.
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        @param st The stream.
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        @param st The stream.
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        @param sourceLen The length of source data.
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        @param sourceLen The length of source data.
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        @return Maximum possible compressed size.
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        @return Maximum possible compressed size.
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    */
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    */
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    virtual std::size_t bound(stream& st, unsigned long sourceLen) const = 0;
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    virtual std::size_t bound(stream& st, unsigned long sourceLen) const = 0;
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    /** Return the number of pending output bytes.
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    /** Return the number of pending output bytes.
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        @param st The stream.
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        @param st The stream.
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        @param pending Pointer to variable receiving pending byte count.
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        @param pending Pointer to variable receiving pending byte count.
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        @param bits Pointer to variable receiving pending bit count.
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        @param bits Pointer to variable receiving pending bit count.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int pending(stream& st, unsigned* pending, int* bits) const = 0;
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    virtual int pending(stream& st, unsigned* pending, int* bits) const = 0;
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    /** Insert bits into the compressed stream.
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    /** Insert bits into the compressed stream.
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        @param st The stream.
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        @param st The stream.
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        @param bits Number of bits to insert.
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        @param bits Number of bits to insert.
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        @param value The bit pattern to insert.
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        @param value The bit pattern to insert.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int prime(stream& st, int bits, int value) const = 0;
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    virtual int prime(stream& st, int bits, int value) const = 0;
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    /** Set the gzip header information.
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    /** Set the gzip header information.
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        @param st The stream.
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        @param st The stream.
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        @param header Pointer to gzip header structure.
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        @param header Pointer to gzip header structure.
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        @return Zero on success, or an error code.
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        @return Zero on success, or an error code.
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    */
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    */
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    virtual int set_header(stream& st, void* header) const = 0;
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    virtual int set_header(stream& st, void* header) const = 0;
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protected:
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protected:
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    void shutdown() override {}
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    void shutdown() override {}
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};
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};
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} // zlib
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} // zlib
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} // http
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} // http
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} // boost
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} // boost
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#endif
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#endif