Refactor zlib tests and fix typo:

close #1744

* Fixed typo in enum name
* Added missing zlib error enumerator
* Marked caveat in zlib impl to avoid future confusion
* Created Compressor/Decompressor abstractions in Beast.zlib tests
* Applied abstractions on Beast.zlib tests
* Workaround Travis-CI' 10min silence timeout
* Add test for Beast.zlib's need_dict error
* Avoid breaking user-code dependant on deprecated enumerator interface

Signed-off-by: AeroStun <24841307+AeroStun@users.noreply.github.com>

CHANGELOG.md

@@ -6,6 +6,7 @@ Version 275:
 * Support Concepts for completion token params
 * https_get example sends the Host header
 * Fix async_close error code when async_read times out
+* Refactor zlib tests and fix enum typo
 
 --------------------------------------------------------------------------------
 

include/boost/beast/zlib/detail/deflate_stream.ipp

@@ -399,7 +399,7 @@ doWrite(z_params& zs, boost::optional<Flush> flush, error_code& ec)
         }
     }
     else if(zs.avail_in == 0 && (
-            old_flush && flush <= *old_flush
+            old_flush && flush <= *old_flush // Caution: depends on enum order
         ) && flush != Flush::finish)
     {
         /* Make sure there is something to do and avoid duplicate consecutive

include/boost/beast/zlib/error.hpp

@@ -66,6 +66,17 @@ enum class error
     */
     end_of_stream,
 
+    /** Preset dictionary required
+
+        This error indicates that a preset dictionary was not provided and is now
+        needed at this point.
+
+        This does not always indicate a failure condition.
+
+        @note This is the same as `Z_NEED_DICT` returned by ZLib.
+    */
+    need_dict,
+
     /** Invalid stream or parameters.
 
         This error is returned when invalid parameters are passed,
@@ -95,7 +106,10 @@ enum class error
     too_many_symbols,
 
     /// Invalid code lengths
-    invalid_code_lenths,
+    invalid_code_lengths,
+#ifndef BOOST_BEAST_NO_DEPRECATED
+    invalid_code_lenths = invalid_code_lengths,
+#endif
 
     /// Invalid bit length repeat
     invalid_bit_length_repeat,

include/boost/beast/zlib/impl/error.ipp

@@ -62,12 +62,13 @@ public:
         {
         case error::need_buffers: return "need buffers";
         case error::end_of_stream: return "unexpected end of deflate stream";
+        case error::need_dict: return "need dict";
         case error::stream_error: return "stream error";
 
         case error::invalid_block_type: return "invalid block type";
         case error::invalid_stored_length: return "invalid stored block length";
         case error::too_many_symbols: return "too many symbols";
-        case error::invalid_code_lenths: return "invalid code lengths";
+        case error::invalid_code_lengths: return "invalid code lengths";
         case error::invalid_bit_length_repeat: return "invalid bit length repeat";
         case error::missing_eob: return "missing end of block code";
         case error::invalid_literal_length: return "invalid literal/length code";

test/beast/zlib/deflate_stream.cpp

@@ -25,6 +25,138 @@ namespace zlib {
 
 class deflate_stream_test : public beast::unit_test::suite
 {
+    struct ICompressor {
+        virtual void init() = 0;
+        virtual void init(
+            int level,
+            int windowBits,
+            int memLevel,
+            int strategy) = 0;
+
+        virtual std::size_t avail_in() const noexcept = 0;
+        virtual void avail_in(std::size_t) noexcept = 0;
+        virtual void const* next_in() const noexcept = 0;
+        virtual void next_in(const void*) noexcept = 0;
+        virtual std::size_t avail_out() const noexcept = 0;
+        virtual void avail_out(std::size_t) noexcept = 0;
+        virtual void* next_out() const noexcept = 0;
+        virtual void next_out(void*) noexcept = 0;
+        virtual std::size_t total_out() const noexcept = 0;
+
+        virtual std::size_t bound(std::size_t) = 0;
+        virtual error_code write(Flush) = 0;
+        virtual ~ICompressor() = default;
+    };
+    class ZlibCompressor : public ICompressor {
+        z_stream zs{};
+
+    public:
+        ZlibCompressor() = default;
+        void init() override {
+            deflateEnd(&zs);
+            zs = {};
+            const auto res = deflateInit2(&zs, -1, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY);
+            if(res != Z_OK)
+               throw std::invalid_argument{"zlib compressor: failure"};
+        }
+        void init(
+            int level,
+            int windowBits,
+            int memLevel,
+            int strategy) override
+        {
+            deflateEnd(&zs);
+            zs = {};
+            const auto res = deflateInit2(&zs, level, Z_DEFLATED, -windowBits, memLevel, strategy);
+            if(res != Z_OK)
+               BOOST_THROW_EXCEPTION(std::invalid_argument{"zlib compressor: bad arg"});
+        }
+
+        virtual std::size_t avail_in() const noexcept override  { return zs.avail_in; }
+        virtual void avail_in(std::size_t n) noexcept override { zs.avail_in = n; }
+        virtual void const* next_in() const noexcept override { return zs.next_in; }
+        virtual void next_in(const void* ptr) noexcept override { zs.next_in = const_cast<Bytef*>(static_cast<const Bytef*>(ptr)); }
+        virtual std::size_t avail_out() const noexcept override { return zs.avail_out; }
+        virtual void avail_out(std::size_t n_out) noexcept override { zs.avail_out = n_out; }
+        virtual void* next_out() const noexcept override { return zs.next_out; }
+        virtual void next_out(void* ptr) noexcept override { zs.next_out = (Bytef*)ptr; }
+        virtual std::size_t total_out() const noexcept override { return zs.total_out; }
+
+        std::size_t bound(std::size_t src_size) override {
+           return deflateBound(&zs, static_cast<uLong>(src_size));
+        }
+        error_code write(Flush flush) override {
+            constexpr static int zlib_flushes[] = {0, Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, Z_FULL_FLUSH, Z_FINISH, Z_TREES};
+            const auto zlib_flush = zlib_flushes[static_cast<int>(flush)];
+            if(zs.next_in == nullptr && zs.avail_in != 0)
+              BOOST_THROW_EXCEPTION(std::invalid_argument{"zlib compressor: invalid input"});
+            const auto res = deflate(&zs, zlib_flush);
+            switch(res){
+            case Z_OK:
+                return {};
+            case Z_STREAM_END:
+                return error::end_of_stream;
+            case Z_STREAM_ERROR:
+                return error::stream_error;
+            case Z_BUF_ERROR:
+                return error::need_buffers;
+            default:
+                throw;
+            }
+        }
+
+        ~ZlibCompressor() override {
+            deflateEnd(&zs);
+        }
+    } zlib_compressor;
+    class BeastCompressor : public ICompressor {
+        z_params zp;
+        deflate_stream ds;
+
+    public:
+        BeastCompressor() = default;
+        void init() override {
+          zp = {};
+          ds.clear();
+          ds.reset();
+        }
+        void init(
+            int level,
+            int windowBits,
+            int memLevel,
+            int strategy) override
+        {
+            zp = {};
+            ds.clear();
+            ds.reset(
+                level,
+                windowBits,
+                memLevel,
+                toStrategy(strategy));
+        }
+
+        virtual std::size_t avail_in() const noexcept override  { return zp.avail_in; }
+        virtual void avail_in(std::size_t n) noexcept override { zp.avail_in = n; }
+        virtual void const* next_in() const noexcept override { return zp.next_in; }
+        virtual void next_in(const void* ptr) noexcept override { zp.next_in = ptr; }
+        virtual std::size_t avail_out() const noexcept override { return zp.avail_out; }
+        virtual void avail_out(std::size_t n_out) noexcept override { zp.avail_out = n_out; }
+        virtual void* next_out() const noexcept override { return zp.next_out; }
+        virtual void next_out(void* ptr) noexcept override { zp.next_out = (Bytef*)ptr; }
+        virtual std::size_t total_out() const noexcept override { return zp.total_out; }
+
+        std::size_t bound(std::size_t src_size) override {
+            return ds.upper_bound(src_size);
+        }
+        error_code write(Flush flush) override {
+          error_code ec{};
+          ds.write(zp, flush, ec);
+          return ec;
+        }
+
+        ~BeastCompressor() override = default;
+    } beast_compressor;
+
 public:
     // Lots of repeats, limited char range
     static
@@ -151,6 +283,7 @@ public:
 
     using self = deflate_stream_test;
     typedef void(self::*pmf_t)(
+        ICompressor& c,
         int level, int windowBits, int memLevel,
         int strategy, std::string const&);
 
@@ -171,29 +304,26 @@ public:
 
     void
     doDeflate1_beast(
+        ICompressor& c,
         int level, int windowBits, int memLevel,
         int strategy, std::string const& check)
     {
         std::string out;
-        z_params zs;
+        c.init(
-        deflate_stream ds;
-        ds.reset(
             level,
             windowBits,
             memLevel,
-            toStrategy(strategy));
+            strategy);
-        out.resize(ds.upper_bound(
+        out.resize(c.bound(check.size()));
-            static_cast<uLong>(check.size())));
+        c.next_in(check.data());
-        zs.next_in = (Bytef*)check.data();
+        c.avail_in(check.size());
-        zs.avail_in = static_cast<uInt>(check.size());
+        c.next_out((void*)out.data());
-        zs.next_out = (Bytef*)out.data();
+        c.avail_out(out.size());
-        zs.avail_out = static_cast<uInt>(out.size());
         {
             bool progress = true;
             for(;;)
             {
-                error_code ec;
+                error_code ec = c.write(Flush::full);
-                ds.write(zs, Flush::full, ec);
                 if( ec == error::need_buffers ||
                     ec == error::end_of_stream) // per zlib FAQ
                     goto fin;
@@ -206,7 +336,7 @@ public:
         }
 
     fin:
-        out.resize(zs.total_out);
+        out.resize(c.total_out());
         BEAST_EXPECT(decompress(out) == check);
 
     err:
@@ -217,6 +347,7 @@ public:
 
     void
     doDeflate2_beast(
+        ICompressor& c,
         int level, int windowBits, int memLevel,
         int strategy, std::string const& check)
     {
@@ -224,50 +355,44 @@ public:
         {
             for(std::size_t j = 1;; ++j)
             {
-                z_params zs;
+                c.init(
-                deflate_stream ds;
-                ds.reset(
                     level,
                     windowBits,
                     memLevel,
-                    toStrategy(strategy));
+                    strategy);
                 std::string out;
-                out.resize(ds.upper_bound(
+                out.resize(c.bound(check.size()));
-                    static_cast<uLong>(check.size())));
                 if(j >= out.size())
                     break;
-                zs.next_in = (Bytef*)check.data();
+                c.next_in((void*)check.data());
-                zs.avail_in = static_cast<uInt>(i);
+                c.avail_in(i);
-                zs.next_out = (Bytef*)out.data();
+                c.next_out((void*)out.data());
-                zs.avail_out = static_cast<uInt>(j);
+                c.avail_out(j);
                 bool bi = false;
                 bool bo = false;
                 for(;;)
                 {
-                    error_code ec;
+                    error_code ec = c.write(
-                    ds.write(zs,
+                        bi ? Flush::full : Flush::none);
-                        bi ? Flush::full : Flush::none, ec);
                     if( ec == error::need_buffers ||
                         ec == error::end_of_stream) // per zlib FAQ
                         goto fin;
                     if(! BEAST_EXPECTS(! ec, ec.message()))
                         goto err;
-                    if(zs.avail_in == 0 && ! bi)
+                    if(c.avail_in() == 0 && ! bi)
                     {
                         bi = true;
-                        zs.avail_in =
+                        c.avail_in(check.size() - i);
-                            static_cast<uInt>(check.size() - i);
                     }
-                    if(zs.avail_out == 0 && ! bo)
+                    if(c.avail_out() == 0 && ! bo)
                     {
                         bo = true;
-                        zs.avail_out =
+                        c.avail_out(out.size() - j);
-                            static_cast<uInt>(out.size() - j);
                     }
                 }
 
             fin:
-                out.resize(zs.total_out);
+                out.resize(c.total_out());
                 BEAST_EXPECT(decompress(out) == check);
 
             err:
@@ -279,7 +404,7 @@ public:
     //--------------------------------------------------------------------------
 
     void
-    doMatrix(std::string const& check, pmf_t pmf)
+    doMatrix(ICompressor& c, std::string const& check, pmf_t pmf)
     {
         for(int level = 0; level <= 9; ++level)
         {
@@ -293,127 +418,115 @@ public:
                     for (int memLevel = 8; memLevel <= 9; ++memLevel)
                     {
                         (this->*pmf)(
-                                level, windowBits, memLevel, strategy, check);
+                            c, level, windowBits, memLevel, strategy, check);
                     }
                 }
             }
         }
 
         // Check default settings
-        (this->*pmf)(compression::default_size, 15, 8, 0, check);
+        (this->*pmf)(c, compression::default_size, 15, 8, 0, check);
     }
 
     void
-    testDeflate()
+    testDeflate(ICompressor& c)
     {
-        doMatrix("Hello, world!", &self::doDeflate1_beast);
+        doMatrix(c, "Hello, world!", &self::doDeflate1_beast);
-        doMatrix("Hello, world!", &self::doDeflate2_beast);
+        doMatrix(c, "Hello, world!", &self::doDeflate2_beast);
-        doMatrix(corpus1(56), &self::doDeflate2_beast);
+        log << "no-silence keepalive" << std::endl;
-        doMatrix(corpus1(1024), &self::doDeflate1_beast);
+        doMatrix(c, corpus1(56), &self::doDeflate2_beast);
+        doMatrix(c, corpus1(1024), &self::doDeflate1_beast);
     }
 
-    void testInvalidSettings()
+    void testInvalidSettings(ICompressor& c)
     {
         except<std::invalid_argument>(
-            []()
+            [&]()
             {
-                deflate_stream ds;
+                c.init(-42, 15, 8, static_cast<int>(Strategy::normal));
-                ds.reset(-42, 15, 8, Strategy::normal);
             });
         except<std::invalid_argument>(
-            []()
+            [&]()
             {
-                deflate_stream ds;
+                c.init(compression::default_size, -1, 8, static_cast<int>(Strategy::normal));
-                ds.reset(compression::default_size, -1, 8, Strategy::normal);
             });
         except<std::invalid_argument>(
-            []()
+            [&]()
             {
-                deflate_stream ds;
+                c.init(compression::default_size, 15, -1, static_cast<int>(Strategy::normal));
-                ds.reset(compression::default_size, 15, -1, Strategy::normal);
             });
         except<std::invalid_argument>(
-            []()
+            [&]()
             {
-                deflate_stream ds;
+                c.init();
-                ds.reset();
+                c.avail_in(1);
-                z_params zp{};
+                c.next_in(nullptr);
-                zp.avail_in = 1;
+                c.write(Flush::full);
-                zp.next_in = nullptr;
-                error_code ec;
-                ds.write(zp, Flush::full, ec);
             });
     }
 
     void
-    testWriteAfterFinish()
+    testWriteAfterFinish(ICompressor& c)
     {
-        z_params zp;
+        c.init();
-        deflate_stream ds;
-        ds.reset();
         std::string out;
         out.resize(1024);
         string_view s = "Hello";
-        zp.next_in = s.data();
+        c.next_in(s.data());
-        zp.avail_in = s.size();
+        c.avail_in(s.size());
-        zp.next_out = &out.front();
+        c.next_out(&out.front());
-        zp.avail_out = out.size();
+        c.avail_out(out.size());
-        error_code ec;
+        error_code ec = c.write(Flush::sync);
-        ds.write(zp, Flush::sync, ec);
         BEAST_EXPECT(!ec);
-        zp.next_in = nullptr;
+        c.next_in(nullptr);
-        zp.avail_in = 0;
+        c.avail_in(0);
-        ds.write(zp, Flush::finish, ec);
+        ec = c.write(Flush::finish);
         BEAST_EXPECT(ec == error::end_of_stream);
-        zp.next_in = s.data();
+        c.next_in(s.data());
-        zp.avail_in = s.size();
+        c.avail_in(s.size());
-        zp.next_out = &out.front();
+        c.next_out(&out.front());
-        zp.avail_out = out.size();
+        c.avail_out(out.size());
-        ds.write(zp, Flush::sync, ec);
+        ec = c.write(Flush::sync);
         BEAST_EXPECT(ec == error::stream_error);
-        ds.write(zp, Flush::finish, ec);
+        ec = c.write(Flush::finish);
         BEAST_EXPECT(ec == error::need_buffers);
     }
 
     void
-    testFlushPartial()
+    testFlushPartial(ICompressor& c)
     {
-        z_params zp;
+        c.init();
-        deflate_stream ds;
-        ds.reset();
         std::string out;
         out.resize(1024);
         string_view s = "Hello";
-        zp.next_in = s.data();
+        c.next_in(s.data());
-        zp.avail_in = s.size();
+        c.avail_in(s.size());
-        zp.next_out = &out.front();
+        c.next_out(&out.front());
-        zp.avail_out = out.size();
+        c.avail_out(out.size());
         error_code ec;
-        ds.write(zp, Flush::none, ec);
+        ec = c.write(Flush::none);
         BEAST_EXPECT(!ec);
-        ds.write(zp, Flush::partial, ec);
+        ec = c.write(Flush::partial);
         BEAST_EXPECT(!ec);
     }
 
     void
-    testFlushAtLiteralBufferFull()
+    testFlushAtLiteralBufferFull(ICompressor& c)
     {
         struct fixture
         {
-            explicit fixture(std::size_t n, Strategy s)
+            ICompressor& c;
+            explicit fixture(ICompressor&c, std::size_t n, Strategy s) : c(c)
             {
-                ds.reset(8, 15, 1, s);
+                c.init(8, 15, 1, static_cast<int>(s));
-                std::iota(in.begin(), in.end(),
+                std::iota(in.begin(), in.end(), std::uint8_t{0});
-                    static_cast<std::uint8_t>(0));
                 out.resize(n);
-                zp.next_in = in.data();
+                c.next_in(in.data());
-                zp.avail_in = in.size();
+                c.avail_in(in.size());
-                zp.next_out = &out.front();
+                c.next_out(&out.front());
-                zp.avail_out = out.size();
+                c.avail_out(out.size());
             }
 
-            z_params zp;
-            deflate_stream ds;
             std::array<std::uint8_t, 255> in;
             std::string out;
         };
@@ -421,25 +534,22 @@ public:
         for (auto s : {Strategy::huffman, Strategy::rle, Strategy::normal})
         {
             {
-                fixture f{264, s};
+                fixture f{c, 264, s};
-                error_code ec;
+                error_code ec = c.write(Flush::finish);
-                f.ds.write(f.zp, Flush::finish, ec);
                 BEAST_EXPECT(ec == error::end_of_stream);
-                BEAST_EXPECT(f.zp.avail_out == 1);
+                BEAST_EXPECT(c.avail_out() == 1);
             }
 
             {
-                fixture f{263, s};
+                fixture f{c,263, s};
-                error_code ec;
+                error_code ec = c.write(Flush::finish);
-                f.ds.write(f.zp, Flush::finish, ec);
                 BEAST_EXPECT(!ec);
-                BEAST_EXPECT(f.zp.avail_out == 0);
+                BEAST_EXPECT(c.avail_out() == 0);
             }
 
             {
-                fixture f{20, s};
+                fixture f{c, 20, s};
-                error_code ec;
+                error_code ec = c.write(Flush::sync);
-                f.ds.write(f.zp, Flush::sync, ec);
                 BEAST_EXPECT(!ec);
             }
 
@@ -447,35 +557,30 @@ public:
     }
 
     void
-    testRLEMatchLengthExceedLookahead()
+    testRLEMatchLengthExceedLookahead(ICompressor& c)
     {
-        z_params zp;
-        deflate_stream ds;
         std::vector<std::uint8_t> in;
         in.resize(300);
 
-
+        c.init(8, 15, 1, static_cast<int>(Strategy::rle));
-        ds.reset(8, 15, 1, Strategy::rle);
         std::fill_n(in.begin(), 4, 'a');
         std::string out;
         out.resize(in.size() * 2);
-        zp.next_in = in.data();
+        c.next_in(in.data());
-        zp.avail_in = in.size();
+        c.avail_in(in.size());
-        zp.next_out = &out.front();
+        c.next_out(&out.front());
-        zp.avail_out = out.size();
+        c.avail_out(out.size());
 
         error_code ec;
-        ds.write(zp, Flush::sync, ec);
+        ec = c.write(Flush::sync);
         BEAST_EXPECT(!ec);
     }
 
     void
-    testFlushAfterDistMatch()
+    testFlushAfterDistMatch(ICompressor& c)
     {
         for (auto out_size : {144, 129})
         {
-            z_params zp;
-            deflate_stream ds;
             std::array<std::uint8_t, 256> in{};
             // 125 will mostly fill the lit buffer, so emitting a distance code
             // results in a flush.
@@ -485,16 +590,16 @@ public:
             std::iota(in.begin() + n, in.end(),
                 static_cast<std::uint8_t>(0));
 
-            ds.reset(8, 15, 1, Strategy::normal);
+            c.init(8, 15, 1, static_cast<int>(Strategy::normal));
             std::string out;
             out.resize(out_size);
-            zp.next_in = in.data();
+            c.next_in(in.data());
-            zp.avail_in = in.size();
+            c.avail_in(in.size());
-            zp.next_out = &out.front();
+            c.next_out(&out.front());
-            zp.avail_out = out.size();
+            c.avail_out(out.size());
 
             error_code ec;
-            ds.write(zp, Flush::sync, ec);
+            ec = c.write(Flush::sync);
             BEAST_EXPECT(!ec);
         }
     }
@@ -506,13 +611,20 @@ public:
             "sizeof(deflate_stream) == " <<
             sizeof(deflate_stream) << std::endl;
 
-        testDeflate();
+        testDeflate(zlib_compressor);
-        testInvalidSettings();
+        testDeflate(beast_compressor);
-        testWriteAfterFinish();
+        testInvalidSettings(zlib_compressor);
-        testFlushPartial();
+        testInvalidSettings(beast_compressor);
-        testFlushAtLiteralBufferFull();
+        testWriteAfterFinish(zlib_compressor);
-        testRLEMatchLengthExceedLookahead();
+        testWriteAfterFinish(beast_compressor);
-        testFlushAfterDistMatch();
+        testFlushPartial(zlib_compressor);
+        testFlushPartial(beast_compressor);
+        testFlushAtLiteralBufferFull(zlib_compressor);
+        testFlushAtLiteralBufferFull(beast_compressor);
+        testRLEMatchLengthExceedLookahead(zlib_compressor);
+        testRLEMatchLengthExceedLookahead(beast_compressor);
+        testFlushAfterDistMatch(zlib_compressor);
+        testFlushAfterDistMatch(beast_compressor);
     }
 };
 

test/beast/zlib/error.cpp

@@ -41,12 +41,13 @@ public:
     {
         check("boost.beast.zlib", error::need_buffers);
         check("boost.beast.zlib", error::end_of_stream);
+        check("boost.beast.zlib", error::need_dict);
         check("boost.beast.zlib", error::stream_error);
 
         check("boost.beast.zlib", error::invalid_block_type);
         check("boost.beast.zlib", error::invalid_stored_length);
         check("boost.beast.zlib", error::too_many_symbols);
-        check("boost.beast.zlib", error::invalid_code_lenths);
+        check("boost.beast.zlib", error::invalid_code_lengths);
         check("boost.beast.zlib", error::invalid_bit_length_repeat);
         check("boost.beast.zlib", error::missing_eob);
         check("boost.beast.zlib", error::invalid_literal_length);

test/beast/zlib/inflate_stream.cpp

@@ -23,6 +23,127 @@ namespace zlib {
 
 class inflate_stream_test : public beast::unit_test::suite
 {
+    struct IDecompressor {
+        virtual void init() = 0;
+        virtual void init(int windowBits) = 0;
+
+        virtual std::size_t avail_in() const noexcept = 0;
+        virtual void avail_in(std::size_t) noexcept = 0;
+        virtual void const* next_in() const noexcept = 0;
+        virtual void next_in(const void*) noexcept = 0;
+        virtual std::size_t avail_out() const noexcept = 0;
+        virtual void avail_out(std::size_t) noexcept = 0;
+        virtual void* next_out() const noexcept = 0;
+        virtual void next_out(void*) noexcept = 0;
+
+        virtual error_code write(Flush) = 0;
+        virtual ~IDecompressor() = default;
+    };
+    class ZlibDecompressor : public IDecompressor {
+       z_stream zs;
+
+    public:
+        ZlibDecompressor() = default;
+        void init(int windowBits) override
+        {
+            inflateEnd(&zs);
+            zs = {};
+            const auto res = inflateInit2(&zs, windowBits);
+            switch(res){
+            case Z_OK:
+               break;
+            case Z_MEM_ERROR:
+               BOOST_THROW_EXCEPTION(std::runtime_error{"zlib decompressor: no memory"});
+            case Z_STREAM_ERROR:
+               BOOST_THROW_EXCEPTION(std::domain_error{"zlib decompressor: bad arg"});
+            }
+        }
+        void init() override {
+            inflateEnd(&zs);
+            zs = {};
+            const auto res = inflateInit2(&zs, -15);
+            switch(res){
+            case Z_OK:
+                break;
+            case Z_MEM_ERROR:
+                BOOST_THROW_EXCEPTION(std::runtime_error{"zlib decompressor: no memory"});
+            case Z_STREAM_ERROR:
+               BOOST_THROW_EXCEPTION(std::domain_error{"zlib decompressor: bad arg"});
+            }
+        }
+
+        virtual std::size_t avail_in() const noexcept override  { return zs.avail_in; }
+        virtual void avail_in(std::size_t n) noexcept override { zs.avail_in = n; }
+        virtual void const* next_in() const noexcept override { return zs.next_in; }
+        virtual void next_in(const void* ptr) noexcept override { zs.next_in = const_cast<Bytef*>(static_cast<const Bytef*>(ptr)); }
+        virtual std::size_t avail_out() const noexcept override { return zs.avail_out; }
+        virtual void avail_out(std::size_t n_out) noexcept override { zs.avail_out = n_out; }
+        virtual void* next_out() const noexcept override { return zs.next_out; }
+        virtual void next_out(void* ptr) noexcept override { zs.next_out = (Bytef*)ptr; }
+
+        error_code write(Flush flush) override {
+            constexpr static int zlib_flushes[] = {0, Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, Z_FULL_FLUSH, Z_FINISH, Z_TREES};
+            const auto zlib_flush = zlib_flushes[static_cast<int>(flush)];
+            const auto res = inflate(&zs, zlib_flush);
+            switch(res){
+            case Z_OK:
+              return {};
+            case Z_STREAM_END:
+              return error::end_of_stream;
+            case Z_NEED_DICT:
+              return error::need_dict;
+            case Z_DATA_ERROR:
+            case Z_STREAM_ERROR:
+              return error::stream_error;
+            case Z_MEM_ERROR:
+              BOOST_THROW_EXCEPTION(std::bad_alloc{});
+            case Z_BUF_ERROR:
+              return error::need_buffers;
+            default:
+              BOOST_THROW_EXCEPTION(std::runtime_error{"zlib decompressor: impossible value"});
+            }
+        }
+
+        ~ZlibDecompressor() override {
+          inflateEnd(&zs);
+        }
+    } zlib_decompressor{};
+    class BeastCompressor : public IDecompressor {
+        z_params zp;
+        inflate_stream is;
+
+    public:
+        BeastCompressor() = default;
+
+        void init(int windowBits) override
+        {
+            zp = {};
+            is.clear();
+            is.reset(windowBits);
+        }
+        void init() override {
+          zp = {};
+          is.clear();
+          is.reset();
+        }
+
+        virtual std::size_t avail_in() const noexcept override  { return zp.avail_in; }
+        virtual void avail_in(std::size_t n) noexcept override { zp.avail_in = n; }
+        virtual void const* next_in() const noexcept override { return zp.next_in; }
+        virtual void next_in(const void* ptr) noexcept override { zp.next_in = ptr; }
+        virtual std::size_t avail_out() const noexcept override { return zp.avail_out; }
+        virtual void avail_out(std::size_t n_out) noexcept override { zp.avail_out = n_out; }
+        virtual void* next_out() const noexcept override { return zp.next_out; }
+        virtual void next_out(void* ptr) noexcept override { zp.next_out = (Bytef*)ptr; }
+
+        error_code write(Flush flush) override {
+            error_code ec{};
+            is.write(zp, flush, ec);
+            return ec;
+        }
+
+        ~BeastCompressor() override = default;
+    } beast_decompressor{};
 public:
     // Lots of repeats, limited char range
     static
@@ -283,7 +404,7 @@ public:
     };
 
     void
-    testInflate()
+    testInflate(IDecompressor& d)
     {
         {
             Matrix m{*this};
@@ -381,8 +502,8 @@ public:
         }
 #endif
 
-        check({0x63, 0x18, 0x05, 0x40, 0x0c, 0x00}, {}, 8,  3);
+        check(d, {0x63, 0x18, 0x05, 0x40, 0x0c, 0x00}, {}, 8,  3);
-        check({0xed, 0xc0, 0x81, 0x00, 0x00, 0x00, 0x00, 0x80,
+        check(d, {0xed, 0xc0, 0x81, 0x00, 0x00, 0x00, 0x00, 0x80,
                0xa0, 0xfd, 0xa9, 0x17, 0xa9, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -390,7 +511,7 @@ public:
                0x00, 0x00, 0x00, 0x00, 0x00, 0x06}, {});
     }
 
-    std::string check(
+    std::string check(IDecompressor& d,
         std::initializer_list<std::uint8_t> const& in,
         error_code expected,
         std::size_t window_size = 15,
@@ -419,103 +540,97 @@ public:
         return out;
     }
 
-    void testInflateErrors()
+    void testInflateErrors(IDecompressor& d)
     {
-        check({0x00, 0x00, 0x00, 0x00, 0x00},
+        check(d, {0x00, 0x00, 0x00, 0x00, 0x00},
             error::invalid_stored_length);
-        check({0x03, 0x00},
+        check(d, {0x03, 0x00},
             error::end_of_stream);
-        check({0x06},
+        check(d, {0x06},
             error::invalid_block_type);
-        check({0xfc, 0x00, 0x00},
+        check(d, {0xfc, 0x00, 0x00},
             error::too_many_symbols);
-        check({0x04, 0x00, 0xfe, 0xff},
+        check(d, {0x04, 0x00, 0xfe, 0xff},
             error::incomplete_length_set);
-        check({0x04, 0x00, 0x24, 0x49, 0x00},
+        check(d, {0x04, 0x00, 0x24, 0x49, 0x00},
             error::invalid_bit_length_repeat);
-        check({0x04, 0x00, 0x24, 0xe9, 0xff, 0xff},
+        check(d, {0x04, 0x00, 0x24, 0xe9, 0xff, 0xff},
             error::invalid_bit_length_repeat);
-        check({0x04, 0x00, 0x24, 0xe9, 0xff, 0x6d},
+        check(d, {0x04, 0x00, 0x24, 0xe9, 0xff, 0x6d},
             error::missing_eob);
-        check({0x04, 0x80, 0x49, 0x92, 0x24, 0x49, 0x92, 0x24,
+        check(d, {0x04, 0x80, 0x49, 0x92, 0x24, 0x49, 0x92, 0x24,
                0x71, 0xff, 0xff, 0x93, 0x11, 0x00},
             error::over_subscribed_length);
-        check({0x04, 0x80, 0x49, 0x92, 0x24, 0x0f, 0xb4, 0xff,
+        check(d, {0x04, 0x80, 0x49, 0x92, 0x24, 0x0f, 0xb4, 0xff,
                0xff, 0xc3, 0x84},
             error::incomplete_length_set);
-        check({0x04, 0xc0, 0x81, 0x08, 0x00, 0x00, 0x00, 0x00,
+        check(d, {0x04, 0xc0, 0x81, 0x08, 0x00, 0x00, 0x00, 0x00,
                0x20, 0x7f, 0xeb, 0x0b, 0x00, 0x00},
             error::invalid_literal_length);
-        check({0x02, 0x7e, 0xff, 0xff},
+        check(d, {0x02, 0x7e, 0xff, 0xff},
             error::invalid_distance_code);
-        check({0x0c, 0xc0, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00,
+        check(d, {0x0c, 0xc0, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x90, 0xff, 0x6b, 0x04, 0x00},
             error::invalid_distance);
-        check({0x05,0xe0, 0x81, 0x91, 0x24, 0xcb, 0xb2, 0x2c,
+        check(d, {0x05,0xe0, 0x81, 0x91, 0x24, 0xcb, 0xb2, 0x2c,
                0x49, 0xe2, 0x0f, 0x2e, 0x8b, 0x9a, 0x47, 0x56,
                0x9f, 0xfb, 0xfe, 0xec, 0xd2, 0xff, 0x1f},
             error::end_of_stream);
-        check({0xed, 0xc0, 0x01, 0x01, 0x00, 0x00, 0x00, 0x40,
+        check(d, {0xed, 0xc0, 0x01, 0x01, 0x00, 0x00, 0x00, 0x40,
                0x20, 0xff, 0x57, 0x1b, 0x42, 0x2c, 0x4f},
             error::end_of_stream);
-        check({0x02, 0x08, 0x20, 0x80, 0x00, 0x03, 0x00},
+        check(d, {0x02, 0x08, 0x20, 0x80, 0x00, 0x03, 0x00},
             error::end_of_stream);
-        // TODO: Excess data (from golang test inflate suite), should this be an error?
+        check(d, {0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01, 0x78, 0x9c, 0xff},
-        check({0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01, 0x78, 0x9c, 0xff},
             error::invalid_stored_length);
     }
 
-    void testInvalidSettings()
+    void testInvalidSettings(IDecompressor& d)
     {
         except<std::domain_error>(
-            []()
+            [&]()
             {
-                inflate_stream is;
+                d.init(7);
-                is.reset(7);
             });
     }
 
-    void testFixedHuffmanFlushTrees()
+    void testFixedHuffmanFlushTrees(IDecompressor& d)
     {
         std::string out(5, 0);
-        z_params zs;
+        d.init();
-        inflate_stream is;
-        is.reset();
         boost::system::error_code ec;
         std::initializer_list<std::uint8_t> in = {
             0xf2, 0x48, 0xcd, 0xc9, 0xc9, 0x07, 0x00, 0x00,
             0x00, 0xff, 0xff};
-        zs.next_in = &*in.begin();
+        d.next_in(&*in.begin());
-        zs.next_out = &out[0];
+        d.next_out(&out[0]);
-        zs.avail_in = in.size();
+        d.avail_in(in.size());
-        zs.avail_out = out.size();
+        d.avail_out(out.size());
-        is.write(zs, Flush::trees, ec);
+        ec = d.write(Flush::trees);
         BEAST_EXPECT(!ec);
-        is.write(zs, Flush::sync, ec);
+        ec = d.write(Flush::sync);
         BEAST_EXPECT(!ec);
-        BEAST_EXPECT(zs.avail_out == 0);
+        BEAST_EXPECT(d.avail_out() == 0);
         BEAST_EXPECT(out == "Hello");
     }
 
-    void testUncompressedFlushTrees()
+    void testUncompressedFlushTrees(IDecompressor& d)
     {
         std::string out(5, 0);
-        z_params zs;
+        d.init();
-        inflate_stream is;
-        is.reset();
         boost::system::error_code ec;
         std::initializer_list<std::uint8_t> in = {
             0x00, 0x05, 0x00, 0xfa, 0xff, 0x48, 0x65, 0x6c,
             0x6c, 0x6f, 0x00, 0x00};
-        zs.next_in = &*in.begin();
+        d.next_in(&*in.begin());
-        zs.next_out = &out[0];
+        d.next_out(&out[0]);
-        zs.avail_in = in.size();
+        d.avail_in(in.size());
-        zs.avail_out = out.size();
+        d.avail_out(out.size());
-        is.write(zs, Flush::trees, ec);
+        ec = d.write(Flush::trees);
         BEAST_EXPECT(!ec);
-        is.write(zs, Flush::sync, ec);
+        ec = d.write(Flush::sync);
         BEAST_EXPECT(!ec);
-        BEAST_EXPECT(zs.avail_out == 0);
+        BEAST_EXPECT(d.avail_out() == 0);
         BEAST_EXPECT(out == "Hello");
     }
 
@@ -525,11 +640,16 @@ public:
         log <<
             "sizeof(inflate_stream) == " <<
             sizeof(inflate_stream) << std::endl;
-        testInflate();
+        testInflate(zlib_decompressor);
-        testInflateErrors();
+        testInflate(beast_decompressor);
-        testInvalidSettings();
+        testInflateErrors(zlib_decompressor);
-        testFixedHuffmanFlushTrees();
+        testInflateErrors(beast_decompressor);
-        testUncompressedFlushTrees();
+        testInvalidSettings(zlib_decompressor);
+        testInvalidSettings(beast_decompressor);
+        testFixedHuffmanFlushTrees(zlib_decompressor);
+        testFixedHuffmanFlushTrees(beast_decompressor);
+        testUncompressedFlushTrees(zlib_decompressor);
+        testUncompressedFlushTrees(beast_decompressor);
     }
 };