1 files changed, 276 insertions, 0 deletions
diff --git a/cpp/sca/modules/http/mod-wiring.cpp b/cpp/sca/modules/http/mod-wiring.cpp
new file mode 100644
index 0000000000..965d5a87fb
--- /dev/null
+++ b/cpp/sca/modules/http/mod-wiring.cpp
@@ -0,0 +1,276 @@
+/*
+ * 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.
+ */
+
+/* $Rev$ $Date$ */
+
+/**
+ * HTTPD module used to wire components.
+ */
+
+#include <sys/stat.h>
+
+#include <string>
+#include <iostream>
+#include <sstream>
+#include <fstream>
+
+#include "list.hpp"
+#include "slist.hpp"
+#include "value.hpp"
+#include "monad.hpp"
+#include "../scdl/scdl.hpp"
+#include "../cache/cache.hpp"
+#include "httpd.hpp"
+
+extern "C" {
+extern module AP_MODULE_DECLARE_DATA mod_tuscany_wiring;
+}
+
+namespace tuscany {
+namespace httpd {
+namespace modwiring {
+
+/**
+ * Server configuration.
+ */
+class ServerConf {
+public:
+    std::string home;
+    ServerConf() : home("") {
+    }
+};
+
+const ServerConf& serverConf(const request_rec* r) {
+    return *(ServerConf*)ap_get_module_config(r->server->module_config, &mod_tuscany_wiring);
+}
+
+/**
+ * Set to true to wire using mod_proxy, false to wire using HTTP client redirects.
+ */
+const bool useModProxy = true;
+
+/**
+ * Directory configuration.
+ */
+class DirConf {
+public:
+    DirConf() : contributionPath(""), compositeName("") {
+    }
+    std::string contributionPath;
+    std::string compositeName;
+    cache::cached<failable<list<value>, std::string> > components;
+};
+
+DirConf& dirConf(const request_rec* r) {
+    return *(DirConf*)ap_get_module_config(r->per_dir_config, &mod_tuscany_wiring);
+}
+
+/**
+ * Read the SCDL configuration of the deployed components.
+ */
+const failable<list<value>, std::string> readComponents(const std::string& path) {
+    std::ifstream is(path);
+    if (is.fail() || is.bad())
+        return mkfailure<list<value>, std::string>("Could not read composite: " + path);
+    return scdl::components(readXML(streamList(is)));
+}
+
+const cache::cached<failable<list<value>, std::string> > components(DirConf* conf) {
+    const std::string path(conf->contributionPath + conf->compositeName);
+    const lambda<failable<list<value>, std::string>(std::string)> rc(readComponents);
+    const lambda<unsigned long(std::string)> ft(cache::latestFileTime);
+    return cache::cached<failable<list<value>, std::string> >(curry(rc, path), curry(ft, path));
+}
+
+/**
+ * Returns true if a URI is absolute.
+ */
+const bool isAbsolute(const std::string& uri) {
+    return uri.find("://") != std::string::npos;
+}
+
+/**
+ * Translate an HTTP request URI. Wire a URI in the form /references/component-name/reference-name
+ * to the target of the reference.
+ */
+int translate(request_rec *r) {
+    if (strncmp(r->uri, "/references/", 12) != 0)
+        return DECLINED;
+    const list<value> rpath(path(r->uri));
+
+    // Log the request
+    if(logRequests)
+        logRequest(r, "mod_tuscany_wiring::translate");
+
+    // Find the requested component, reference and its target configuration
+    DirConf&  conf = dirConf(r);
+    conf.components = cache::latest(conf.components);
+    const failable<list<value>, std::string> comps(conf.components);
+    if (!hasValue(comps))
+        return HTTP_INTERNAL_SERVER_ERROR;
+    const value comp(scdl::named(cadr(rpath), list<value>(comps)));
+    if (isNil(comp))
+        return HTTP_NOT_FOUND;
+    const value ref(scdl::named(caddr(rpath), scdl::references(comp)));
+    if (isNil(ref))
+        return HTTP_NOT_FOUND;
+    const std::string target(scdl::target(ref));
+
+    // Absolute target URI
+    if (isAbsolute(target)) {
+
+        // Wire using mod_proxy
+        if (useModProxy) {
+            r->filename = apr_pstrdup(r->pool, std::string("proxy:" + target).c_str());
+            r->proxyreq = PROXYREQ_REVERSE;
+            r->handler = "proxy-server";
+            return OK;
+        }
+
+        // Wire using an HTTP client redirect
+        r->status = HTTP_MOVED_TEMPORARILY;
+        apr_table_setn(r->headers_out, "Location", apr_pstrdup(r->pool, target.c_str()));
+        r->handler = "mod_tuscany_wiring";
+        return OK;
+
+    }
+
+    // Local internal redirect
+    r->filename = apr_pstrdup(r->pool, std::string("/redirect:/" + target).c_str());
+    r->handler = "mod_tuscany_wiring";
+    return OK;
+}
+
+/**
+ * Construct a redirect URI.
+ */
+const std::string redirect(const std::string& file, const std::string& pi) {
+    return file + pi;
+}
+
+const std::string redirect(const std::string& file, const std::string& pi, const std::string& args) {
+    return file + pi + "?" + args;
+}
+
+/**
+ * HTTP request internal redirect handler.
+ */
+int handler(request_rec *r) {
+    if(strcmp(r->handler, "mod_tuscany_wiring"))
+        return DECLINED;
+
+    // Log the request
+    if(logRequests)
+        logRequest(r, "mod_tuscany_wiring::handler");
+
+    // Do an internal redirect
+    if (r->filename == NULL || strncmp(r->filename, "/redirect:", 10) != 0)
+        return DECLINED;
+    if (r->args == NULL) {
+        ap_internal_redirect(apr_pstrdup(r->pool, redirect(r->filename + 10, r->path_info).c_str()), r);
+        return OK;
+    }
+    ap_internal_redirect(apr_pstrdup(r->pool, redirect(r->filename + 10, r->path_info, r->args).c_str()), r);
+    return OK;
+}
+
+/**
+ * Configuration commands.
+ */
+const char *confHome(cmd_parms *cmd, void *dummy, const char *arg) {
+    ServerConf *c = (ServerConf*)ap_get_module_config(cmd->server->module_config, &mod_tuscany_wiring);
+    c->home = arg;
+    return NULL;
+}
+const char *confContribution(cmd_parms *cmd, void *c, const char *arg) {
+    DirConf* conf = (DirConf*)c;
+    conf->contributionPath = arg;
+    conf->components = components(conf);
+    return NULL;
+}
+const char *confComposite(cmd_parms *cmd, void *c, const char *arg) {
+    DirConf* conf = (DirConf*)c;
+    conf->compositeName = arg;
+    conf->components = components(conf);
+    return NULL;
+}
+
+void *makeDirConf(apr_pool_t *p, char *dirspec) {
+    DirConf* c = new (apr_palloc(p, sizeof(DirConf))) DirConf();
+    apr_pool_cleanup_register(p, c, gc_pool_cleanupCallback<DirConf>, apr_pool_cleanup_null) ;
+    return c;
+}
+void* makeServerConf(apr_pool_t *p, server_rec *s) {
+    ServerConf* c = new (apr_palloc(p, sizeof(ServerConf))) ServerConf();
+    apr_pool_cleanup_register(p, c, gc_pool_cleanupCallback<ServerConf>, apr_pool_cleanup_null) ;
+    return c;
+}
+
+/**
+ * HTTP server module declaration.
+ */
+const command_rec commands[] = {
+    AP_INIT_TAKE1("TuscanyHome", (const char*(*)())confHome, NULL, RSRC_CONF, "Tuscany home directory"),
+    AP_INIT_TAKE1("SCAContribution", (const char*(*)())confContribution, NULL, ACCESS_CONF, "SCA contribution location"),
+    AP_INIT_TAKE1("SCAComposite", (const char*(*)())confComposite, NULL, ACCESS_CONF, "SCA composite location"),
+    {NULL}
+};
+
+int postConfig(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *ptemp, server_rec *s) {
+   return OK;
+}
+
+void childInit(apr_pool_t* p, server_rec* svr_rec) {
+    ServerConf *conf = (ServerConf*)ap_get_module_config(svr_rec->module_config, &mod_tuscany_wiring);
+    if(conf == NULL) {
+        std::cerr << "[Tuscany] Due to one or more errors mod_tuscany_wiring loading failed. Causing apache to stop loading." << std::endl;
+        exit(APEXIT_CHILDFATAL);
+    }
+}
+
+void registerHooks(apr_pool_t *p) {
+    ap_hook_post_config(postConfig, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_child_init(childInit, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_handler(handler, NULL, NULL, APR_HOOK_MIDDLE);
+    ap_hook_translate_name(translate, NULL, NULL, APR_HOOK_FIRST);
+}
+
+}
+}
+}
+
+extern "C" {
+
+module AP_MODULE_DECLARE_DATA mod_tuscany_wiring = {
+    STANDARD20_MODULE_STUFF,
+    // dir config
+    tuscany::httpd::modwiring::makeDirConf,
+    // dir merger, default is to override
+    NULL,
+    // server config
+    tuscany::httpd::modwiring::makeServerConf,
+    // merge server config
+    NULL,
+    // command table
+    tuscany::httpd::modwiring::commands,
+    // register hooks
+    tuscany::httpd::modwiring::registerHooks
+};
+
+}