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diff --git a/sca-cpp/branches/lightweight-sca/components/cache/datacache.cpp b/sca-cpp/branches/lightweight-sca/components/cache/datacache.cpp
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+/*
+ * 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.
+ */
+
+/* $Rev$ $Date$ */
+
+/**
+ * A data cache component implementation which coordinates access to two
+ * levels of backend read/write caches or stores. Each cache or store is
+ * accessed through two references: a writer reference and a reader reference.
+ *
+ * This is useful if your level2 store is made of a master and slave
+ * replicated databases, you can then wire the writer reference to the master
+ * database and the reader reference to one your slave databases (assuming
+ * that the updates eventually get replicated to the slave database, in the
+ * meantime the updates will be retrieved from the level1 cache).
+ */
+
+#define WANT_HTTPD_LOG 1
+#include "string.hpp"
+#include "function.hpp"
+#include "list.hpp"
+#include "value.hpp"
+#include "monad.hpp"
+
+namespace tuscany {
+namespace datacache {
+
+/**
+ * Get an item from the cache.
+ */
+const failable<value> get(const value& key, const lambda<value(const list<value>&)>& rcache1, const lambda<value(const list<value>&)>& wcache1, const lambda<value(const list<value>&)>& rcache2, unused const lambda<value(const list<value>&)>& wcache2) {
+
+    // Lookup level1 cache
+    const value val1 = rcache1(mklist<value>("get", key));
+    if (!isNil(val1))
+        return val1;
+
+    // Lookup level2 cache
+    const value val2 = rcache2(mklist<value>("get", key));
+    if (isNil(val2)) {
+        ostringstream os;
+        os << "Couldn't get cache entry: " << key;
+        return mkfailure<value>(str(os), 404, false);
+    }
+
+    // Update level1 cache
+    wcache1(mklist<value>("put", key, val2));
+
+    return val2;
+}
+
+/**
+ * Post an item to the cache.
+ */
+const failable<value> post(const value& key, const value& val, unused const lambda<value(const list<value>&)>& rcache1, const lambda<value(const list<value>&)>& wcache1, unused const lambda<value(const list<value>&)>& rcache2, const lambda<value(const list<value>&)>& wcache2) {
+    const value id = append<value>(key, mklist(mkuuid()));
+
+    // Update level1 cache
+    wcache1(mklist<value>("put", id, val));
+
+    // Update level2 cache
+    wcache2(mklist<value>("put", id, val));
+
+    return id;
+}
+
+/**
+ * Put an item into the cache.
+ */
+const failable<value> put(const value& key, const value& val, unused const lambda<value(const list<value>&)>& rcache1, const lambda<value(const list<value>&)>& wcache1, unused const lambda<value(const list<value>&)>& rcache2, const lambda<value(const list<value>&)>& wcache2) {
+
+    // Update level1 cache
+    wcache1(mklist<value>("put", key, val));
+
+    // Update level2 cache
+    wcache2(mklist<value>("put", key, val));
+
+    return value(true);
+}
+
+/**
+ * Delete an item from the cache.
+ */
+const failable<value> del(const value& key, unused const lambda<value(const list<value>&)>& rcache1, const lambda<value(const list<value>&)>& wcache1, unused const lambda<value(const list<value>&)>& rcache2, const lambda<value(const list<value>&)>& wcache2) {
+
+    // Delete from level1 cache
+    wcache1(mklist<value>("delete", key));
+
+    // Delete from level2 cache
+    wcache2(mklist<value>("delete", key));
+
+    return value(true);
+}
+
+}
+}
+
+extern "C" {
+
+const tuscany::value apply(const tuscany::list<tuscany::value>& params) {
+    const tuscany::value func(car(params));
+    if (func == "get")
+        return tuscany::datacache::get(cadr(params), caddr(params), cadddr(params), caddddr(params), cadddddr(params));
+    if (func == "post")
+        return tuscany::datacache::post(cadr(params), caddr(params), cadddr(params), caddddr(params), cadddddr(params), caddddddr(params));
+    if (func == "put")
+        return tuscany::datacache::put(cadr(params), caddr(params), cadddr(params), caddddr(params), cadddddr(params), caddddddr(params));
+    if (func == "delete")
+        return tuscany::datacache::del(cadr(params), caddr(params), cadddr(params), caddddr(params), cadddddr(params));
+    return tuscany::mkfailure<tuscany::value>();
+}
+
+}