serializer uses configuration service

Closes #142

Author: ashtum

include/boost/http_proto/parser.hpp

@@ -93,22 +93,33 @@ class parser
         */
         std::uint64_t body_limit = 64 * 1024;
 
-        /** True if parser can decode deflate transfer and content encodings.
+        /** True if parser can decode deflate Content-Encoding.
 
-            The zlib service must already be
+            The @ref zlib::inflate_service must already be
             installed thusly, or else an exception
             is thrown.
         */
         bool apply_deflate_decoder = false;
 
-        /** True if parser can decode gzip transfer and content encodings.
+        /** True if parser can decode gzip Content-Encoding.
 
-            The zlib service must already be
+            The @ref zlib::inflate_service must already be
             installed thusly, or else an exception
             is thrown.
         */
         bool apply_gzip_decoder = false;
 
+        /** Specifies the zlib windows bits 9..15.
+
+            The windows bits must be greater than or equal to
+            the windows bits value used for compression.
+
+            If a compressed message has a larger window size,
+            parsing ends with @ref zlib::error::data_err instead
+            of allocating a bigger window.
+        */
+        int zlib_window_bits = 15;
+
         /** Minimum space for payload buffering.
 
             This value controls the following

include/boost/http_proto/serializer.hpp

@@ -33,6 +33,7 @@ namespace boost {
 namespace http_proto {
 
 #ifndef BOOST_HTTP_PROTO_DOCS
+class serializer_service;
 class message_view_base;
 #endif
 
@@ -66,6 +67,73 @@ class serializer
     using const_buffers_type =
         buffers::const_buffer_span;
 
+    /** Serializer configuration settings.
+    */
+    struct config
+    {
+        /** True if serializer can encode deflate Content-Encoding.
+
+            The @ref zlib::deflate_service must already be
+            installed thusly, or else an exception
+            is thrown.
+        */
+        bool apply_deflate_encoder = false;
+
+        /** True if serializer can encode gzip Content-Encoding.
+
+            The @ref zlib::deflate_service must already be
+            installed thusly, or else an exception
+            is thrown.
+        */
+        bool apply_gzip_encoder = false;
+
+        /** Specifies the zlib compression level 0..9.
+
+            A compression level of 1 provides the fastest speed,
+            while level 9 offers the best compression. Level 0
+            applies no compression at all.
+        */
+        int zlib_comp_level = 6;
+
+        /** Specifies the zlib windows bits 9..15.
+
+            The windows bits controls the size of the history
+            buffer used when compressing data. Larger values
+            produce better compression at the expense of
+            greater memory usage.
+        */
+        int zlib_window_bits = 15;
+
+        /** Specifies the zlib memory level 1..9.
+
+            The memory level controls the amount of memory
+            used for the internal compression state. Larger
+            values use more memory, but are faster and
+            produce smaller output.
+        */
+        int zlib_mem_level = 8;
+
+        /** Minimum space for payload buffering.
+
+            This cannot be zero.
+        */
+        std::size_t payload_buffer = 8192;
+
+        /** Space to reserve for type-erasure.
+
+            This space is used for the following
+            purposes:
+
+            @li Storing an instance of the user-provided
+                @ref source objects.
+
+            @li Storing an instance of the user-provided
+                ConstBufferSequence.
+
+        */
+        std::size_t max_type_erase = 1024;
+    };
+
     struct stream;
 
     /** Destructor
@@ -82,19 +150,12 @@ class serializer
     /** Constructor
 
         @param ctx The serializer will access services
-                   registered with this context.
+            registered with this context.
     */
     BOOST_HTTP_PROTO_DECL
     serializer(
         context& ctx);
 
-    /** Constructor
-    */
-    BOOST_HTTP_PROTO_DECL
-    serializer(
-        context& ctx,
-        std::size_t buffer_size);
-
     //--------------------------------------------
 
     /** Prepare the serializer for a new stream
@@ -216,6 +277,7 @@ class serializer
     consume(std::size_t n);
 
 private:
+    friend class serializer_service;
     class filter;
     class const_buf_gen_base;
     template<class>
@@ -282,6 +344,8 @@ class serializer
     };
 
     context& ctx_;
+    serializer_service& svc_;
+
     detail::workspace ws_;
 
     const_buf_gen_base* buf_gen_;
@@ -304,6 +368,16 @@ class serializer
 
 //------------------------------------------------
 
+/** Install the serializer service.
+*/
+BOOST_HTTP_PROTO_DECL
+void
+install_serializer_service(
+    context& ctx,
+    serializer::config const& cfg);
+
+//------------------------------------------------
+
 /** The type used for caller-provided body data during
     serialization.
 

include/boost/http_proto/service/zlib_service.hpp

@@ -34,7 +34,7 @@ struct stream
     unsigned int   avail_out; // remaining free space at next_out
     unsigned long  total_out; // total number of bytes output so far
 
-    char*         msg;       // last error message, NULL if no error
+    char*          msg;       // last error message, NULL if no error
     void*          state;     // not visible by applications
 
     alloc_func     zalloc;    // used to allocate internal state

src/detail/zlib_filter.cpp

@@ -0,0 +1,127 @@
+//
+// Copyright (c) 2023 Vinnie Falco (vinnie.falco@gmail.com)
+// Copyright (c) 2024 Mohammad Nejati
+//
+// 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)
+//
+// Official repository: https://github.com/cppalliance/buffers
+//
+
+#include "src/detail/zlib_filter.hpp"
+
+#include <boost/buffers/front.hpp>
+#include <boost/buffers/sans_prefix.hpp>
+#include <boost/buffers/size.hpp>
+
+namespace boost {
+namespace http_proto {
+namespace detail {
+
+namespace {
+
+void*
+zalloc(
+    void* opaque,
+    unsigned items,
+    unsigned size) noexcept
+{
+    return reinterpret_cast<workspace*>(opaque)
+        ->try_reserve_front(items * size);
+}
+
+void
+zfree(
+    void* /* opaque */,
+    void* /* addr */) noexcept
+{
+    // no-op
+}
+
+unsigned int
+saturate_cast(std::size_t n) noexcept
+{
+    if(n >= std::numeric_limits<unsigned int>::max())
+        return std::numeric_limits<unsigned int>::max();
+    return static_cast<unsigned int>(n);
+}
+
+} // namespace
+
+zlib_filter::
+zlib_filter(workspace& ws)
+{
+    strm_.zalloc = &zalloc;
+    strm_.zfree  = &zfree;
+    strm_.opaque = &ws;
+}
+
+auto
+zlib_filter::
+process(
+    buffers::mutable_buffer_subspan out,
+    buffers::const_buffer_pair in,
+    bool more,
+    bool force_flush) -> results
+{
+    results rv;
+    auto flush = zlib::no_flush;
+    for(;;)
+    {
+        auto ob = buffers::front(out);
+        auto ib = buffers::front(in);
+
+        if(!more && flush != zlib::finish && in[1].size() == 0)
+        {
+            if(buffers::size(out) < min_out_buffer())
+            {
+                rv.out_short = true;
+                return rv;
+            }
+            flush = zlib::finish;
+        }
+
+        strm_.next_in   = static_cast<unsigned char*>(const_cast<void *>(ib.data()));
+        strm_.avail_in  = saturate_cast(ib.size());
+        strm_.next_out  = static_cast<unsigned char*>(ob.data());
+        strm_.avail_out = saturate_cast(ob.size());
+
+        auto ec = BOOST_HTTP_PROTO_ERR(
+            do_process(flush));
+
+        const std::size_t in_bytes  = saturate_cast(ib.size()) - strm_.avail_in;
+        const std::size_t out_bytes = saturate_cast(ob.size()) - strm_.avail_out;
+
+        rv.in_bytes  += in_bytes;
+        rv.out_bytes += out_bytes;
+
+        if(ec.failed())
+            return rv;
+
+        if(ec == zlib::error::stream_end)
+        {
+            rv.finished = true;
+            return rv;
+        }
+
+        out = buffers::sans_prefix(out, out_bytes);
+        in  = buffers::sans_prefix(in, in_bytes);
+
+        if(buffers::size(out) == 0)
+            return rv;
+
+        if(buffers::size(in) == 0 && strm_.avail_out != 0)
+        {
+            if(force_flush && rv.out_bytes == 0)
+            {
+                flush = zlib::block;
+                continue;
+            }
+            return rv;
+        }
+    }
+}
+
+} // detail
+} // http_proto
+} // boost