Body is now correctly parsed. Not fully tested but let's pretend it works

main.cc

@@ -21,6 +21,13 @@ class MyHandler : public Net::Http::Handler {
 
             }
         }
+        else if (req.resource == "/echo") {
+            if (req.method == Net::Http::Method::Post) {
+                Net::Http::Response response(Net::Http::Code::Ok, req.body);
+
+                response.writeTo(peer);
+            }
+        }
     }
 };
 

src/http.cc

@@ -30,13 +30,20 @@ namespace Private {
         memset(data, sizeof data, 0);
     }
 
+    void
+    Parser::Buffer::reset() {
+        memset(data, sizeof data, 0);
+        len = 0;
+    }
+
     bool
     Parser::Cursor::advance(size_t count)
     {
         if (value + count >= sizeof (buff.data)) {
             //parser->raise("Early EOF");
         }
-        else if (value + count >= buff.len) {
+        // Allowed to advance one past the end
+        else if (value + count > buff.len) {
             return false;
         }
 
@@ -78,8 +85,24 @@ namespace Private {
     }
 
     size_t
-    Parser::Cursor::diff(size_t previous) const {
-        return value - previous;
+    Parser::Cursor::diff(size_t other) const {
+        return value - other;
+    }
+
+    size_t
+    Parser::Cursor::diff(const Cursor& other) const {
+        return value - other.value;
+    }
+
+    size_t
+    Parser::Cursor::remaining() const {
+        // assert(val <= buff.len);
+        return buff.len - value;
+    }
+
+    void
+    Parser::Cursor::reset() {
+        value = 0;
     }
 
     void
@@ -215,19 +238,54 @@ namespace Private {
     Parser::State
     Parser::BodyStep::apply(Cursor& cursor) {
         auto cl = request->headers.tryGet<ContentLength>();
+        if (!cl) return Parser::State::Done;
 
-        if (cl) {
-            // CRLF
+        auto contentLength = cl->value();
+        // We already started to read some bytes but we got an incomplete payload
+        if (bytesRead > 0) {
+            // How many bytes do we still need to read ?
+            const size_t remaining = contentLength - bytesRead;
+            auto start = cursor;
+
+            // Could be refactored in a single function / lambda but I'm too lazy
+            // for that right now
+            if (!cursor.advance(remaining)) {
+                const size_t available = cursor.remaining();
+
+                request->body.append(cursor.offset(start), available);
+                bytesRead += available;
+
+                cursor.advance(available);
+                return State::Again;
+            }
+            else {
+                request->body.append(cursor.offset(), cursor.diff(start));
+            }
+
+        }
+        // This is the first time we are reading the payload
+        else {
             if (!cursor.advance(2)) return State::Again;
 
-            auto len = cl->value();
+            request->body.reserve(contentLength);
+
             auto start = cursor;
 
-            if (!cursor.advance(len)) return State::Again;
+            // We have an incomplete body, read what we can
+            if (!cursor.advance(contentLength)) {
+                const size_t available = cursor.remaining();
+
+                request->body.append(cursor.offset(start), available);
+                bytesRead += available;
+
+                cursor.advance(available);
+                return State::Again;
+            }
 
-            request->body = std::string(cursor.offset(start), cursor.diff(start));
+            request->body.append(cursor.offset(start), cursor.diff(start));
         }
 
+        bytesRead = 0;
         return Parser::State::Done;
     }
 
@@ -254,6 +312,19 @@ namespace Private {
 
         memcpy(buffer.data + buffer.len, data, len);
         buffer.len += len;
+        return true;
+    }
+
+    void
+    Parser::reset() {
+        buffer.reset();
+        cursor.reset();
+
+        currentStep = 0;
+
+        request.headers.clear();
+        request.body.clear();
+        request.resource.clear();
     }
 
     ssize_t
@@ -366,14 +437,19 @@ Response::writeTo(Tcp::Peer& peer)
 
 void
 Handler::onInput(const char* buffer, size_t len, Tcp::Peer& peer) {
-    Private::Parser parser(buffer, len);
-    try {
-        Private::Parser::State state = parser.parse();
-        if (state == Private::Parser::State::Done) {
-            onRequest(parser.request, peer);
+    if (!parser.feed(buffer, len)) {
+        cout << "Could not feed parser bro" << endl;
+    }
+    else {
+        try {
+            auto state = parser.parse();
+            if (state == Private::Parser::State::Done) {
+                onRequest(parser.request, peer);
+                parser.reset();
+            }
+        } catch (const Private::ParsingError &err) {
+            cerr << "Error when parsing HTTP request: " << err.what() << endl;
         }
-    } catch (const Private::ParsingError &err) {
-        cerr << "Error when parsing HTTP request: " << err.what() << endl;
     }
 }
 

src/http.h

@@ -135,6 +135,8 @@ namespace Private {
 
             char data[Const::MaxBuffer];
             size_t len;
+
+            void reset();
         };
 
         struct Cursor {
@@ -182,8 +184,13 @@ namespace Private {
             const char *offset() const;
             const char *offset(size_t off) const;
 
-            size_t diff(size_t before) const;
+            size_t diff(size_t other) const;
+            size_t diff(const Cursor& other) const;
+            size_t remaining() const;
+
+            void reset();
 
+        private:
             const Buffer& buff;
             size_t value;
         };
@@ -221,11 +228,25 @@ namespace Private {
         struct BodyStep : public Step {
             BodyStep(Request* request)
                 : Step(request)
+                , bytesRead(0)
             { }
 
             State apply(Cursor& cursor);
+
+        private:
+            size_t bytesRead;
         };
 
+        Parser()
+            : contentLength(-1)
+            , currentStep(0)
+            , cursor(buffer)
+        {
+            allSteps[0].reset(new RequestLineStep(&request));
+            allSteps[1].reset(new HeadersStep(&request));
+            allSteps[2].reset(new BodyStep(&request));
+        }
+
         Parser(const char* data, size_t len)
             : contentLength(-1)
             , currentStep(0)
@@ -239,6 +260,7 @@ namespace Private {
         }
 
         bool feed(const char* data, size_t len);
+        void reset();
 
         State parse();
 
@@ -305,6 +327,9 @@ public:
     void onOutput();
 
     virtual void onRequest(const Request& request, Tcp::Peer& peer) = 0;
+
+private:
+    Private::Parser parser;
 };
 
 class Endpoint {

src/http_headers.cc

@@ -116,6 +116,11 @@ Headers::list() const {
     return ret;
 }
 
+void
+Headers::clear() {
+    headers.clear();
+}
+
 std::pair<bool, std::shared_ptr<Header>>
 Headers::getImpl(const std::string& name) const {
     auto it = headers.find(name);

src/http_headers.h

@@ -67,6 +67,8 @@ public:
 
     std::vector<std::shared_ptr<Header>> list() const;
 
+    void clear();
+
 private:
     std::pair<bool, std::shared_ptr<Header>> getImpl(const std::string& name) const;