MXS-1220: Rename and reorganize HttpParser

The HttpParser class was renamed to HttpRequest as it parses and processes
only HTTP requests. A second class that creates a HTTP response needs to
be created to handle the response generation.

Moved some of the HTTP constants and helper functions to a separate
http.hh header.

server/core/httprequest.cc

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2019-07-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+#include "maxscale/httprequest.hh"
+
+#include <ctype.h>
+
+/** TODO: Move this to a C++ string utility header */
+namespace maxscale
+{
+static inline string& trim(string& str)
+{
+    while (isspace(*str.begin()))
+    {
+        str.erase(str.begin());
+    }
+
+    while (isspace(*str.rbegin()))
+    {
+        str.erase(str.rbegin().base());
+    }
+
+    return str;
+}
+}
+
+HttpRequest* HttpRequest::parse(string data)
+{
+    size_t pos = data.find("\r\n");
+    string request_line = data.substr(0, pos);
+    data.erase(0, pos + 2);
+
+    pos = request_line.find(" ");
+    string verb = request_line.substr(0, pos);
+    request_line.erase(0, pos + 1);
+
+    pos = request_line.find(" ");
+    string uri = request_line.substr(0, pos);
+    request_line.erase(0, pos + 1);
+
+    pos = request_line.find("\r\n");
+    string http_version = request_line.substr(0, pos);
+    request_line.erase(0, pos + 2);
+
+    map<string, string> headers;
+
+    while ((pos = data.find("\r\n")) != string::npos)
+    {
+        string header_line = data.substr(0, pos);
+        data.erase(0, pos + 2);
+
+        if (header_line.length() == 0)
+        {
+            /** End of headers */
+            break;
+        }
+
+        if ((pos = header_line.find(":")) != string::npos)
+        {
+            string key = header_line.substr(0, pos);
+            header_line.erase(0, pos + 1);
+            headers[key] = mxs::trim(header_line);
+        }
+    }
+
+    /** The headers are now processed and consumed. The message body is
+     * the only thing left in the request string. */
+
+    HttpRequest* request = NULL;
+    enum http_verb verb_value = string_to_http_verb(verb);
+
+    if (http_version == "HTTP/1.1" && verb_value != HTTP_UNKNOWN)
+    {
+        request = new HttpRequest();
+        request->m_verb = verb_value;
+        request->m_resource = uri;
+        request->m_headers = headers;
+        request->m_body = data;
+    }
+
+    return request;
+}
+
+HttpRequest::HttpRequest()
+{
+
+}
+
+HttpRequest::~HttpRequest()
+{
+
+}