Improve performance of http::string_to_verb

`operator==` performs better than the hand-written comparison routine.

fix #1636

Signed-off-by: Damian Jarek <damian.jarek93@gmail.com>

CHANGELOG.md

@@ -9,6 +9,7 @@ Version 259:
 * Remove unused includes from `test::stream`
 * Move `char_buffer` into a separate file
 * Fix coverage collection in AzP CI
+* Improve performance of `http::string_to_verb`
 
 --------------------------------------------------------------------------------
 

include/boost/beast/core/detail/string.hpp

@@ -0,0 +1,57 @@
+//
+// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// 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/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_DETAIL_STRING_HPP
+#define BOOST_BEAST_DETAIL_STRING_HPP
+
+#include <boost/beast/core/detail/config.hpp>
+#include <boost/version.hpp>
+
+#if defined(BOOST_BEAST_USE_STD_STRING_VIEW)
+#include <string_view>
+#else
+#include <boost/utility/string_view.hpp>
+#endif
+
+namespace boost {
+namespace beast {
+
+namespace detail {
+
+#if defined(BOOST_BEAST_USE_STD_STRING_VIEW)
+  using string_view = std::string_view;
+
+  template<class CharT, class Traits>
+  using basic_string_view =
+      std::basic_string_view<CharT, Traits>;
+#else
+  using string_view = boost::string_view;
+
+  template<class CharT, class Traits>
+  using basic_string_view =
+      boost::basic_string_view<CharT, Traits>;
+#endif
+
+inline string_view operator "" _sv(char const* p, std::size_t n)
+{
+    return string_view{p, n};
+}
+
+inline
+char
+ascii_tolower(char c)
+{
+    return ((static_cast<unsigned>(c) - 65U) < 26) ?
+        c + 'a' - 'A' : c;
+}
+} // detail
+} // beast
+} // boost
+
+#endif

include/boost/beast/core/impl/string.ipp

@@ -0,0 +1,71 @@
+//
+// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// 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/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_IMPL_STRING_IPP
+#define BOOST_BEAST_IMPL_STRING_IPP
+
+#include <boost/beast/core/string.hpp>
+
+#include <algorithm>
+
+namespace boost {
+namespace beast {
+
+bool
+iequals(
+    beast::string_view lhs,
+    beast::string_view rhs)
+{
+    auto n = lhs.size();
+    if(rhs.size() != n)
+        return false;
+    auto p1 = lhs.data();
+    auto p2 = rhs.data();
+    char a, b;
+    // fast loop
+    while(n--)
+    {
+        a = *p1++;
+        b = *p2++;
+        if(a != b)
+            goto slow;
+    }
+    return true;
+slow:
+    do
+    {
+        if(detail::ascii_tolower(a) != detail::ascii_tolower(b))
+            return false;
+        a = *p1++;
+        b = *p2++;
+    }
+    while(n--);
+    return true;
+}
+
+bool
+iless::operator()(
+        string_view lhs,
+        string_view rhs) const
+{
+    using std::begin;
+    using std::end;
+    return std::lexicographical_compare(
+        begin(lhs), end(lhs), begin(rhs), end(rhs),
+        [](char c1, char c2)
+        {
+            return detail::ascii_tolower(c1) < detail::ascii_tolower(c2);
+        }
+    );
+}
+
+} // beast
+} // boost
+
+#endif

include/boost/beast/core/string.hpp

@@ -10,82 +10,17 @@
 #ifndef BOOST_BEAST_STRING_HPP
 #define BOOST_BEAST_STRING_HPP
 
-#include <boost/beast/core/detail/config.hpp>
+#include <boost/beast/core/detail/string.hpp>
-#include <boost/version.hpp>
-
-#if defined(BOOST_BEAST_USE_STD_STRING_VIEW)
-#include <string_view>
-#else
-#include <boost/utility/string_view.hpp>
-#endif
-
-#include <algorithm>
 
 namespace boost {
 namespace beast {
 
-#if defined(BOOST_BEAST_USE_STD_STRING_VIEW)
+/// The type of string view used by the library
-  /// The type of string view used by the library
+using detail::string_view;
-  using string_view = std::string_view;
 
-  /// The type of basic string view used by the library
+/// The type of basic string view used by the library
-  template<class CharT, class Traits>
+template<class CharT, class Traits>
-  using basic_string_view =
+using basic_string_view = detail::basic_string_view<CharT, Traits>;
-      std::basic_string_view<CharT, Traits>;
-#else
-  /// The type of string view used by the library
-  using string_view = boost::string_view;
-
-  /// The type of basic string view used by the library
-  template<class CharT, class Traits>
-  using basic_string_view =
-      boost::basic_string_view<CharT, Traits>;
-#endif
-
-namespace detail {
-
-inline
-char
-ascii_tolower(char c)
-{
-    return ((static_cast<unsigned>(c) - 65U) < 26) ?
-        c + 'a' - 'A' : c;
-}
-
-template<class = void>
-bool
-iequals(
-    beast::string_view lhs,
-    beast::string_view rhs)
-{
-    auto n = lhs.size();
-    if(rhs.size() != n)
-        return false;
-    auto p1 = lhs.data();
-    auto p2 = rhs.data();
-    char a, b;
-    // fast loop
-    while(n--)
-    {
-        a = *p1++;
-        b = *p2++;
-        if(a != b)
-            goto slow;
-    }
-    return true;
-slow:
-    do
-    {
-        if(ascii_tolower(a) != ascii_tolower(b))
-            return false;
-        a = *p1++;
-        b = *p2++;
-    }
-    while(n--);
-    return true;
-}
-
-} // detail
 
 /** Returns `true` if two strings are equal, using a case-insensitive comparison.
 
@@ -95,14 +30,11 @@ slow:
 
     @param rhs The string on the right side of the equality
 */
-inline
+BOOST_BEAST_DECL
 bool
 iequals(
     beast::string_view lhs,
-    beast::string_view rhs)
+    beast::string_view rhs);
-{
-    return detail::iequals(lhs, rhs);
-}
 
 /** A case-insensitive less predicate for strings.
 
@@ -110,21 +42,11 @@ iequals(
 */
 struct iless
 {
+    BOOST_BEAST_DECL
     bool
     operator()(
         string_view lhs,
-        string_view rhs) const
+        string_view rhs) const;
-    {
-        using std::begin;
-        using std::end;
-        return std::lexicographical_compare(
-            begin(lhs), end(lhs), begin(rhs), end(rhs),
-            [](char c1, char c2)
-            {
-                return detail::ascii_tolower(c1) < detail::ascii_tolower(c2);
-            }
-        );
-    }
 };
 
 /** A case-insensitive equality predicate for strings.
@@ -145,4 +67,8 @@ struct iequal
 } // beast
 } // boost
 
+#ifdef BOOST_BEAST_HEADER_ONLY
+#include <boost/beast/core/impl/string.ipp>
+#endif
+
 #endif

include/boost/beast/http/impl/verb.ipp

@@ -21,50 +21,51 @@ namespace http {
 string_view
 to_string(verb v)
 {
+    using beast::detail::operator "" _sv;
     switch(v)
     {
-    case verb::delete_:       return "DELETE";
+    case verb::delete_:       return "DELETE"_sv;
-    case verb::get:           return "GET";
+    case verb::get:           return "GET"_sv;
-    case verb::head:          return "HEAD";
+    case verb::head:          return "HEAD"_sv;
-    case verb::post:          return "POST";
+    case verb::post:          return "POST"_sv;
-    case verb::put:           return "PUT";
+    case verb::put:           return "PUT"_sv;
-    case verb::connect:       return "CONNECT";
+    case verb::connect:       return "CONNECT"_sv;
-    case verb::options:       return "OPTIONS";
+    case verb::options:       return "OPTIONS"_sv;
-    case verb::trace:         return "TRACE";
+    case verb::trace:         return "TRACE"_sv;
 
-    case verb::copy:          return "COPY";
+    case verb::copy:          return "COPY"_sv;
-    case verb::lock:          return "LOCK";
+    case verb::lock:          return "LOCK"_sv;
-    case verb::mkcol:         return "MKCOL";
+    case verb::mkcol:         return "MKCOL"_sv;
-    case verb::move:          return "MOVE";
+    case verb::move:          return "MOVE"_sv;
-    case verb::propfind:      return "PROPFIND";
+    case verb::propfind:      return "PROPFIND"_sv;
-    case verb::proppatch:     return "PROPPATCH";
+    case verb::proppatch:     return "PROPPATCH"_sv;
-    case verb::search:        return "SEARCH";
+    case verb::search:        return "SEARCH"_sv;
-    case verb::unlock:        return "UNLOCK";
+    case verb::unlock:        return "UNLOCK"_sv;
-    case verb::bind:          return "BIND";
+    case verb::bind:          return "BIND"_sv;
-    case verb::rebind:        return "REBIND";
+    case verb::rebind:        return "REBIND"_sv;
-    case verb::unbind:        return "UNBIND";
+    case verb::unbind:        return "UNBIND"_sv;
-    case verb::acl:           return "ACL";
+    case verb::acl:           return "ACL"_sv;
 
-    case verb::report:        return "REPORT";
+    case verb::report:        return "REPORT"_sv;
-    case verb::mkactivity:    return "MKACTIVITY";
+    case verb::mkactivity:    return "MKACTIVITY"_sv;
-    case verb::checkout:      return "CHECKOUT";
+    case verb::checkout:      return "CHECKOUT"_sv;
-    case verb::merge:         return "MERGE";
+    case verb::merge:         return "MERGE"_sv;
 
-    case verb::msearch:       return "M-SEARCH";
+    case verb::msearch:       return "M-SEARCH"_sv;
-    case verb::notify:        return "NOTIFY";
+    case verb::notify:        return "NOTIFY"_sv;
-    case verb::subscribe:     return "SUBSCRIBE";
+    case verb::subscribe:     return "SUBSCRIBE"_sv;
-    case verb::unsubscribe:   return "UNSUBSCRIBE";
+    case verb::unsubscribe:   return "UNSUBSCRIBE"_sv;
 
-    case verb::patch:         return "PATCH";
+    case verb::patch:         return "PATCH"_sv;
-    case verb::purge:         return "PURGE";
+    case verb::purge:         return "PURGE"_sv;
 
-    case verb::mkcalendar:    return "MKCALENDAR";
+    case verb::mkcalendar:    return "MKCALENDAR"_sv;
+
+    case verb::link:          return "LINK"_sv;
+    case verb::unlink:        return "UNLINK"_sv;
 
-    case verb::link:          return "LINK";
-    case verb::unlink:        return "UNLINK";
-    
     case verb::unknown:
-        return "<unknown>";
+        return "<unknown>"_sv;
     }
 
     BOOST_THROW_EXCEPTION(std::invalid_argument{"unknown verb"});
@@ -108,34 +109,20 @@ string_to_verb(string_view v)
     UNLOCK
     UNSUBSCRIBE
 */
+    using beast::detail::operator "" _sv;
     if(v.size() < 3)
         return verb::unknown;
-    // s must be null terminated
-    auto const eq =
-        [](string_view sv, char const* s)
-        {
-            auto p = sv.data();
-            for(;;)
-            {
-                if(*s != *p)
-                    return false;
-                ++s;
-                ++p;
-                if(! *s)
-                    return p == (sv.data() + sv.size());
-            }
-        };
     auto c = v[0];
     v.remove_prefix(1);
     switch(c)
     {
     case 'A':
-        if(v == "CL")
+        if(v == "CL"_sv)
             return verb::acl;
         break;
 
     case 'B':
-        if(v == "IND")
+        if(v == "IND"_sv)
             return verb::bind;
         break;
 
@@ -145,14 +132,14 @@ string_to_verb(string_view v)
         switch(c)
         {
         case 'H':
-            if(eq(v, "ECKOUT"))
+            if(v == "ECKOUT"_sv)
                 return verb::checkout;
             break;
 
         case 'O':
-            if(eq(v, "NNECT"))
+            if(v == "NNECT"_sv)
                 return verb::connect;
-            if(eq(v, "PY"))
+            if(v == "PY"_sv)
                 return verb::copy;
             BOOST_FALLTHROUGH;
 
@@ -162,24 +149,24 @@ string_to_verb(string_view v)
         break;
 
     case 'D':
-        if(eq(v, "ELETE"))
+        if(v == "ELETE"_sv)
             return verb::delete_;
         break;
 
     case 'G':
-        if(eq(v, "ET"))
+        if(v == "ET"_sv)
             return verb::get;
         break;
 
     case 'H':
-        if(eq(v, "EAD"))
+        if(v == "EAD"_sv)
             return verb::head;
         break;
 
     case 'L':
-        if(eq(v, "INK"))
+        if(v == "INK"_sv)
             return verb::link;
-        if(eq(v, "OCK"))
+        if(v == "OCK"_sv)
             return verb::lock;
         break;
 
@@ -189,31 +176,31 @@ string_to_verb(string_view v)
         switch(c)
         {
         case '-':
-            if(eq(v, "SEARCH"))
+            if(v == "SEARCH"_sv)
                 return verb::msearch;
             break;
 
         case 'E':
-            if(eq(v, "RGE"))
+            if(v == "RGE"_sv)
                 return verb::merge;
             break;
 
         case 'K':
-            if(eq(v, "ACTIVITY"))
+            if(v == "ACTIVITY"_sv)
                 return verb::mkactivity;
             if(v[0] == 'C')
             {
                 v.remove_prefix(1);
-                if(eq(v, "ALENDAR"))
+                if(v == "ALENDAR"_sv)
                     return verb::mkcalendar;
-                if(eq(v, "OL"))
+                if(v == "OL"_sv)
                     return verb::mkcol;
                 break;
             }
             break;
-        
+
         case 'O':
-            if(eq(v, "VE"))
+            if(v == "VE"_sv)
                 return verb::move;
             BOOST_FALLTHROUGH;
 
@@ -223,12 +210,12 @@ string_to_verb(string_view v)
         break;
 
     case 'N':
-        if(eq(v, "OTIFY"))
+        if(v == "OTIFY"_sv)
             return verb::notify;
         break;
 
     case 'O':
-        if(eq(v, "PTIONS"))
+        if(v == "PTIONS"_sv)
             return verb::options;
         break;
 
@@ -238,26 +225,26 @@ string_to_verb(string_view v)
         switch(c)
         {
         case 'A':
-            if(eq(v, "TCH"))
+            if(v == "TCH"_sv)
                 return verb::patch;
             break;
 
         case 'O':
-            if(eq(v, "ST"))
+            if(v == "ST"_sv)
                 return verb::post;
             break;
 
         case 'R':
-            if(eq(v, "OPFIND"))
+            if(v == "OPFIND"_sv)
                 return verb::propfind;
-            if(eq(v, "OPPATCH"))
+            if(v == "OPPATCH"_sv)
                 return verb::proppatch;
             break;
 
         case 'U':
-            if(eq(v, "RGE"))
+            if(v == "RGE"_sv)
                 return verb::purge;
-            if(eq(v, "T"))
+            if(v == "T"_sv)
                 return verb::put;
             BOOST_FALLTHROUGH;
 
@@ -270,21 +257,21 @@ string_to_verb(string_view v)
         if(v[0] != 'E')
             break;
         v.remove_prefix(1);
-        if(eq(v, "BIND"))
+        if(v == "BIND"_sv)
             return verb::rebind;
-        if(eq(v, "PORT"))
+        if(v == "PORT"_sv)
             return verb::report;
         break;
 
     case 'S':
-        if(eq(v, "EARCH"))
+        if(v == "EARCH"_sv)
             return verb::search;
-        if(eq(v, "UBSCRIBE"))
+        if(v == "UBSCRIBE"_sv)
             return verb::subscribe;
         break;
 
     case 'T':
-        if(eq(v, "RACE"))
+        if(v == "RACE"_sv)
             return verb::trace;
         break;
 
@@ -292,13 +279,13 @@ string_to_verb(string_view v)
         if(v[0] != 'N')
             break;
         v.remove_prefix(1);
-        if(eq(v, "BIND"))
+        if(v == "BIND"_sv)
             return verb::unbind;
-        if(eq(v, "LINK"))
+        if(v == "LINK"_sv)
             return verb::unlink;
-        if(eq(v, "LOCK"))
+        if(v == "LOCK"_sv)
             return verb::unlock;
-        if(eq(v, "SUBSCRIBE"))
+        if(v == "SUBSCRIBE"_sv)
             return verb::unsubscribe;
         break;
 

include/boost/beast/src.hpp

@@ -39,6 +39,7 @@ the program, with the macro BOOST_BEAST_SEPARATE_COMPILATION defined.
 #include <boost/beast/core/impl/flat_static_buffer.ipp>
 #include <boost/beast/core/impl/saved_handler.ipp>
 #include <boost/beast/core/impl/static_buffer.ipp>
+#include <boost/beast/core/impl/string.ipp>
 
 #include <boost/beast/http/detail/basic_parser.ipp>
 #include <boost/beast/http/detail/rfc7230.ipp>

include/boost/beast/websocket/detail/hybi13.ipp

@@ -47,11 +47,12 @@ make_sec_ws_accept(
     string_view key)
 {
     BOOST_ASSERT(key.size() <= sec_ws_key_type::max_size_n);
-    auto const& guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
+    using beast::detail::operator "" _sv;
+    auto const guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"_sv;
     beast::detail::sha1_context ctx;
     beast::detail::init(ctx);
     beast::detail::update(ctx, key.data(), key.size());
-    beast::detail::update(ctx, guid, sizeof(guid) - 1);
+    beast::detail::update(ctx, guid.data(), guid.size());
     char digest[beast::detail::sha1_context::digest_size];
     beast::detail::finish(ctx, &digest[0]);
     accept.resize(accept.max_size());