Refactored httpd server integration, split http support and server logic in two modules. Added functions to load component implementations packaged as dynamic libraries. Minor monad code cleanup, converted cast operators to separate functions.

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@883249 13f79535-47bb-0310-9956-ffa450edef68

sca-cpp/trunk/modules/server/mod-cpp.hpp

@@ -0,0 +1,91 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/* $Rev$ $Date$ */
+
+#ifndef tuscany_modcpp_hpp
+#define tuscany_modcpp_hpp
+
+/**
+ * Evaluation functions used by mod-eval to evaluate implementation.cpp
+ * component implementations.
+ */
+
+#include <string>
+#include <iostream>
+#include <fstream>
+
+#include "function.hpp"
+#include "list.hpp"
+#include "value.hpp"
+#include "monad.hpp"
+#include "dynlib.hpp"
+#include "cache.hpp"
+#include "../eval/driver.hpp"
+#include "../http/httpd.hpp"
+#include "mod-eval.hpp"
+
+namespace tuscany {
+namespace server {
+namespace modeval {
+namespace cpp {
+
+/**
+ * Evaluate a C++ component implementation function.
+ */
+struct evalImplementation {
+    const lib ilib;
+    const ilambda impl;
+    evalImplementation(const lib& ilib, const ilambda& impl) : ilib(ilib), impl(impl) {
+    }
+    const failable<value, std::string> operator()(const value& func, const list<value>& params) const {
+        httpd::logValue(cons<value>(func, params), "expr");
+        const failable<value, std::string> val = impl(func, params);
+        httpd::logValue(content(val), "val");
+        return val;
+    }
+};
+
+/**
+ * Read a C++ component implementation.
+ */
+const failable<ilambda, std::string> readLatestImplementation(const std::string path) {
+    const failable<lib, std::string> ilib(dynlib(path));
+    if (!hasContent(ilib))
+        return mkfailure<ilambda, std::string>(reason(ilib));
+
+    const failable<ilambda, std::string> impl(dynlambda<failable<value, std::string>(value, list<value>)>("eval", content(ilib)));
+    if (!hasContent(impl))
+        return impl;
+    return ilambda(evalImplementation(content(ilib), content(impl)));
+}
+
+const cached<failable<ilambda, std::string> > readImplementation(const std::string& path) {
+    const lambda<failable<ilambda, std::string>(std::string)> ri(readLatestImplementation);
+    const lambda<unsigned long(std::string)> ft(latestFileTime);
+    const std::string p(path + dynlibExt);
+    return cached<failable<ilambda, std::string> >(curry(ri, p), curry(ft, p));
+}
+
+}
+}
+}
+}
+
+#endif /* tuscany_modcpp_hpp */