From 3cd391daa620cf1ca8d72c0f1588f37e4bc38445 Mon Sep 17 00:00:00 2001
From: Vinnie Falco <vinnie.falco@gmail.com>
Date: Sun, 12 Oct 2014 19:10:33 -0700
Subject: [PATCH] Return error_code from beast::http::basic_parser: This
 changes the HTTP parser interface to return an error_code instead of a bool.
 This eliminates the need for the error() member function and simplifies
 calling code.

---
 beast/http/basic_parser.h        | 49 ++++++++++++++++----------------
 beast/http/impl/basic_parser.cpp | 25 +++++++---------
 beast/http/tests/parser.test.cpp | 10 +++----
 3 files changed, 41 insertions(+), 43 deletions(-)

diff --git a/beast/http/basic_parser.h b/beast/http/basic_parser.h
index 208ed3c09f..769bfbf9d6 100644
--- a/beast/http/basic_parser.h
+++ b/beast/http/basic_parser.h
@@ -111,16 +111,12 @@ public:
         return complete_;
     }
 
-    /** Returns the error if write or write_eof returned false. */
-    error_code
-    error() const noexcept;
-
     /** Write data to the parser.
         @param data A buffer containing the data to write
         @param bytes The size of the buffer pointed to by data.
         @return A pair with bool success, and the number of bytes consumed.
     */
-    std::pair <bool, std::size_t>
+    std::pair <error_code, std::size_t>
     write (void const* data, std::size_t bytes);
 
     /** Write a set of buffer data to the parser.
@@ -131,24 +127,8 @@ public:
         @return A pair with bool success, and the number of bytes consumed.
     */
     template <class ConstBufferSequence>
-    std::pair <bool, std::size_t>
-    write (ConstBufferSequence const& buffers)
-    {
-        std::pair <bool, std::size_t> result (true, 0);
-        for (auto const& buffer : buffers)
-        {
-            std::size_t bytes_consumed;
-            std::tie (result.first, bytes_consumed) =
-                write (boost::asio::buffer_cast <void const*> (buffer),
-                    boost::asio::buffer_size (buffer));
-            if (! result.first)
-                break;
-            result.second += bytes_consumed;
-            if (complete())
-                break;
-        }
-        return result;
-    }
+    std::pair <error_code, std::size_t>
+    write (ConstBufferSequence const& buffers);
 
     /** Called to indicate the end of file.
         HTTP needs to know where the end of the stream is. For example,
@@ -158,7 +138,7 @@ public:
         @note This is typically called when a socket read returns eof.
         @return `true` if the message is complete.
     */
-    bool
+    error_code
     write_eof();
 
 protected:
@@ -253,6 +233,27 @@ private:
     static int cb_message_complete (joyent::http_parser*);
 };
 
+template <class ConstBufferSequence>
+auto
+basic_parser::write (ConstBufferSequence const& buffers) ->
+    std::pair <error_code, std::size_t>
+{
+    std::pair <error_code, std::size_t> result ({}, 0);
+    for (auto const& buffer : buffers)
+    {
+        std::size_t bytes_consumed;
+        std::tie (result.first, bytes_consumed) =
+            write (boost::asio::buffer_cast <void const*> (buffer),
+                boost::asio::buffer_size (buffer));
+        if (result.first)
+            break;
+        result.second += bytes_consumed;
+        if (complete())
+            break;
+    }
+    return result;
+}
+
 } // http
 } // beast
 
diff --git a/beast/http/impl/basic_parser.cpp b/beast/http/impl/basic_parser.cpp
index e34992bc5b..8d9aefac79 100644
--- a/beast/http/impl/basic_parser.cpp
+++ b/beast/http/impl/basic_parser.cpp
@@ -114,32 +114,29 @@ basic_parser::operator= (basic_parser&& other)
     return *this;
 }
 
-basic_parser::error_code
-basic_parser::error() const noexcept
+auto
+basic_parser::write (void const* data, std::size_t bytes) ->
+    std::pair <error_code, std::size_t>
 {
-    auto s (reinterpret_cast <joyent::http_parser const*> (&state_));
-    return error_code{static_cast<int>(s->http_errno), message_category()};
-}
-
-std::pair <bool, std::size_t>
-basic_parser::write (void const* data, std::size_t bytes)
-{
-    std::pair <bool, std::size_t> result (false, 0);
+    std::pair <error_code, std::size_t> result ({}, 0);
     auto s (reinterpret_cast <joyent::http_parser*> (&state_));
     auto h (reinterpret_cast <joyent::http_parser_settings const*> (&hooks_));
     result.second = joyent::http_parser_execute (s, h,
         static_cast <const char*> (data), bytes);
-    result.first = s->http_errno == 0;
+    result.first = error_code{static_cast<int>(s->http_errno),
+        message_category()};
     return result;
 }
 
-bool
-basic_parser::write_eof()
+auto
+basic_parser::write_eof() ->
+    error_code
 {
     auto s (reinterpret_cast <joyent::http_parser*> (&state_));
     auto h (reinterpret_cast <joyent::http_parser_settings const*> (&hooks_));
     joyent::http_parser_execute (s, h, nullptr, 0);
-    return s->http_errno == 0;
+    return error_code{static_cast<int>(s->http_errno),
+        message_category()};
 }
 
 //------------------------------------------------------------------------------
diff --git a/beast/http/tests/parser.test.cpp b/beast/http/tests/parser.test.cpp
index d9e53e4639..d81946383f 100644
--- a/beast/http/tests/parser.test.cpp
+++ b/beast/http/tests/parser.test.cpp
@@ -67,9 +67,9 @@ public:
             message m;
             parser p (m, true);
             auto result (p.write (boost::asio::buffer(text)));
-            expect (result.first);
+            expect (! result.first);
             auto result2 (p.write_eof());
-            expect (result2);
+            expect (! result2);
             expect (p.complete());
         }
 
@@ -81,9 +81,9 @@ public:
                 ;
             message m;
             parser p (m, true);
-            auto result (p.write (boost::asio::buffer(text)));
-            if (expect (! result.first))
-                expect (p.error().message() == "invalid HTTP method");
+            auto result = p.write (boost::asio::buffer(text));
+            if (expect (result.first))
+                expect (result.first.message() == "invalid HTTP method");
         }
     }
 };