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Diffstat (limited to 'sca-cpp/branches/cpp-contrib/modules/server/mod-wiring.cpp')
| -rw-r--r-- | sca-cpp/branches/cpp-contrib/modules/server/mod-wiring.cpp | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/sca-cpp/branches/cpp-contrib/modules/server/mod-wiring.cpp b/sca-cpp/branches/cpp-contrib/modules/server/mod-wiring.cpp new file mode 100644 index 0000000000..c21b0fe254 --- /dev/null +++ b/sca-cpp/branches/cpp-contrib/modules/server/mod-wiring.cpp @@ -0,0 +1,383 @@ +/* + * 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 component references and route requests to + * target service components. + */ + +#include <sys/stat.h> + +#include "string.hpp" +#include "stream.hpp" +#include "list.hpp" +#include "tree.hpp" +#include "value.hpp" +#include "monad.hpp" +#include "../scdl/scdl.hpp" +#include "../http/httpd.hpp" + +extern "C" { +extern module AP_MODULE_DECLARE_DATA mod_tuscany_wiring; +} + +namespace tuscany { +namespace server { +namespace modwiring { + +/** + * Server configuration. + */ +class ServerConf { +public: + ServerConf(server_rec* s) : s(s), start(false), home(""), wiringServerName(""), contributionPath(""), compositeName("") { + } + const server_rec* s; + bool start; + string home; + string wiringServerName; + string contributionPath; + string compositeName; + list<value> references; + list<value> services; +}; + +/** + * Set to true to wire using mod_proxy, false to wire using HTTP client redirects. + */ +const bool useModProxy = true; + +/** + * Returns true if a URI is absolute. + */ +const bool isAbsolute(const string& uri) { + return contains(uri, "://"); +} + +/** + * Route a /references/component-name/reference-name request, + * to the target of the component reference. + */ +int translateReference(request_rec *r) { + httpdDebugRequest(r, "modwiring::translateReference::input"); + debug(r->uri, "modwiring::translateReference::uri"); + + // Find the requested component + const ServerConf& sc = httpd::serverConf<ServerConf>(r, &mod_tuscany_wiring); + const list<value> rpath(pathValues(r->uri)); + const list<value> comp(assoctree(cadr(rpath), sc.references)); + if (isNil(comp)) + return HTTP_NOT_FOUND; + + // Find the requested reference and target configuration + const list<value> ref(assoctree<value>(caddr(rpath), cadr(comp))); + if (isNil(ref)) + return HTTP_NOT_FOUND; + const string target(cadr(ref)); + debug(target, "modwiring::translateReference::target"); + + // Route to an absolute target URI using mod_proxy or an HTTP client redirect + if (isAbsolute(target)) { + if (useModProxy) { + r->filename = apr_pstrdup(r->pool, c_str(string("proxy:") + target)); + r->proxyreq = PROXYREQ_REVERSE; + r->handler = "proxy-server"; + return OK; + } + + r->status = HTTP_MOVED_TEMPORARILY; + apr_table_setn(r->headers_out, "Location", apr_pstrdup(r->pool, c_str(target))); + r->handler = "mod_tuscany_wiring"; + return OK; + } + + // Route to a relative target URI using a local internal redirect + r->filename = apr_pstrdup(r->pool, c_str(string("/redirect:/components/") + target)); + r->handler = "mod_tuscany_wiring"; + return OK; +} + +/** + * Find a leaf matching a request path in a tree of URI paths. + */ +const int matchPath(const list<value>& k, const list<value>& p) { + if (isNil(p)) + return true; + if (isNil(k)) + return false; + if (car(k) != car(p)) + return false; + return matchPath(cdr(k), cdr(p)); +} + +const list<value> assocPath(const value& k, const list<value>& tree) { + if (isNil(tree)) + return tree; + if (matchPath(k, car<value>(car(tree)))) + return car(tree); + if (k < car<value>(car(tree))) + return assocPath(k, cadr(tree)); + return assocPath(k, caddr(tree)); +} + +/** + * Route a service request to the component providing the requested service. + */ +int translateService(request_rec *r) { + httpdDebugRequest(r, "modwiring::translateService::input"); + debug(r->uri, "modwiring::translateService::uri"); + + // Find the requested component + const ServerConf& sc = httpd::serverConf<ServerConf>(r, &mod_tuscany_wiring); + const list<value> p(pathValues(r->uri)); + const list<value> svc(assocPath(p, sc.services)); + if (isNil(svc)) + return DECLINED; + debug(svc, "modwiring::translateService::service"); + + // Build a component-name + path-info URI + const list<value> target(cons<value>(cadr(svc), httpd::pathInfo(p, car(svc)))); + debug(target, "modwiring::translateService::target"); + + // Dispatch to the target component using a local internal redirect + const string tp(path(target)); + debug(tp, "modwiring::translateService::path"); + const string redir(string("/redirect:/components") + tp); + debug(redir, "modwiring::translateService::redirect"); + r->filename = apr_pstrdup(r->pool, c_str(redir)); + r->handler = "mod_tuscany_wiring"; + return OK; +} + +/** + * Translate an HTTP service or reference request and route it + * to the target component. + */ +int translate(request_rec *r) { + gc_scoped_pool pool(r->pool); + if (!strncmp(r->uri, "/components/", 12) != 0) + return DECLINED; + + // Translate a component reference request + if (!strncmp(r->uri, "/references/", 12) != 0) + return translateReference(r); + + // Translate a service request + return translateService(r); +} + +/** + * HTTP request handler, redirect to a target component. + */ +int handler(request_rec *r) { + gc_scoped_pool pool(r->pool); + if(strcmp(r->handler, "mod_tuscany_wiring")) + return DECLINED; + httpdDebugRequest(r, "modwiring::handler::input"); + + // Do an internal redirect + if (r->filename == NULL || strncmp(r->filename, "/redirect:", 10) != 0) + return DECLINED; + debug(r->uri, "modwiring::handler::uri"); + debug(r->filename, "modwiring::handler::filename"); + debug(r->path_info, "modwiring::handler::path info"); + + if (r->args == NULL) + return httpd::internalRedirect(httpd::redirectURI(string(r->filename + 10), string(r->path_info)), r); + return httpd::internalRedirect(httpd::redirectURI(string(r->filename + 10), string(r->path_info), string(r->args)), r); +} + +/** + * Read the components declared in a composite. + */ +const failable<list<value> > readComponents(const string& path) { + ifstream is(path); + if (fail(is)) + return mkfailure<list<value> >(string("Could not read composite: ") + path); + return scdl::components(readXML(streamList(is))); +} + +/** + * Return a list of component-name + references pairs. The references are + * arranged in trees of reference-name + reference-target pairs. + */ +const list<value> componentReferenceToTargetTree(const value& c) { + return mklist<value>(scdl::name(c), mkbtree(sort(scdl::referenceToTargetAssoc(scdl::references(c))))); +} + +const list<value> componentReferenceToTargetAssoc(const list<value>& c) { + if (isNil(c)) + return c; + return cons<value>(componentReferenceToTargetTree(car(c)), componentReferenceToTargetAssoc(cdr(c))); +} + +/** + * Return a list of service-URI-path + component-name pairs. Service-URI-paths are + * represented as lists of URI path fragments. + */ +const list<value> defaultBindingURI(const string& cn, const string& sn) { + return mklist<value>(cn, sn); +} + +const list<value> bindingToComponentAssoc(const string& cn, const string& sn, const list<value>& b) { + if (isNil(b)) + return b; + const value uri(scdl::uri(car(b))); + if (isNil(uri)) + return cons<value>(mklist<value>(defaultBindingURI(cn, sn), cn), bindingToComponentAssoc(cn, sn, cdr(b))); + return cons<value>(mklist<value>(pathValues(c_str(string(uri))), cn), bindingToComponentAssoc(cn, sn, cdr(b))); +} + +const list<value> serviceToComponentAssoc(const string& cn, const list<value>& s) { + if (isNil(s)) + return s; + const string sn(scdl::name(car(s))); + const list<value> btoc(bindingToComponentAssoc(cn, sn, scdl::bindings(car(s)))); + if (isNil(btoc)) + return cons<value>(mklist<value>(defaultBindingURI(cn, sn), cn), serviceToComponentAssoc(cn, cdr(s))); + return append<value>(btoc, serviceToComponentAssoc(cn, cdr(s))); +} + +const list<value> uriToComponentAssoc(const list<value>& c) { + if (isNil(c)) + return c; + return append<value>(serviceToComponentAssoc(scdl::name(car(c)), scdl::services(car(c))), uriToComponentAssoc(cdr(c))); +} + +/** + * Configure the components declared in the server's deployment composite. + */ +const bool confComponents(ServerConf& sc) { + if (sc.contributionPath == "" || sc.compositeName == "") + return true; + + // Read the component configuration and store the references and service URIs + // in trees for fast retrieval later + const failable<list<value> > comps = readComponents(sc.contributionPath + sc.compositeName); + if (!hasContent(comps)) + return true; + const list<value> refs = componentReferenceToTargetAssoc(content(comps)); + debug(refs, "modwiring::confComponents::references"); + sc.references = mkbtree(sort(refs)); + + const list<value> svcs = uriToComponentAssoc(content(comps)); + debug(svcs, "modwiring::confComponents::services"); + sc.services = mkbtree(sort(svcs)); + return true; +} + +/** + * Called after all the configuration commands have been run. + * Process the server configuration and configure the wiring for the deployed components. + */ +int postConfig(unused apr_pool_t *p, unused apr_pool_t *plog, unused apr_pool_t *ptemp, server_rec *s) { + // Count the calls to post config, skip the first one as + // postConfig is always called twice + const string k("tuscany::modwiring::postConfig"); + const int count = (int)httpd::userData(k, s); + httpd::putUserData(k, (void*)(count + 1), s); + if (count == 0) + return OK; + + // Configure the wiring for the deployed components + ServerConf& sc = httpd::serverConf<ServerConf>(s, &mod_tuscany_wiring); + debug(sc.wiringServerName, "modwiring::postConfig::wiringServerName"); + debug(sc.contributionPath, "modwiring::postConfig::contributionPath"); + debug(sc.compositeName, "modwiring::postConfig::compositeName"); + confComponents(sc); + return OK; +} + +/** + * Child process initialization. + */ +void childInit(apr_pool_t* p, server_rec* svr_rec) { + gc_scoped_pool pool(p); + ServerConf *conf = (ServerConf*)ap_get_module_config(svr_rec->module_config, &mod_tuscany_wiring); + if(conf == NULL) { + cerr << "[Tuscany] Due to one or more errors mod_tuscany_wiring loading failed. Causing apache to stop loading." << endl; + exit(APEXIT_CHILDFATAL); + } +} + +/** + * Configuration commands. + */ +const char *confHome(cmd_parms *cmd, unused void *c, const char *arg) { + gc_scoped_pool pool(cmd->pool); + ServerConf& sc = httpd::serverConf<ServerConf>(cmd, &mod_tuscany_wiring); + sc.home = arg; + return NULL; +} +const char *confWiringServerName(cmd_parms *cmd, unused void *c, const char *arg) { + gc_scoped_pool pool(cmd->pool); + ServerConf& sc = httpd::serverConf<ServerConf>(cmd, &mod_tuscany_wiring); + sc.wiringServerName = arg; + return NULL; +} +const char *confContribution(cmd_parms *cmd, unused void *c, const char *arg) { + gc_scoped_pool pool(cmd->pool); + ServerConf& sc = httpd::serverConf<ServerConf>(cmd, &mod_tuscany_wiring); + sc.contributionPath = arg; + return NULL; +} +const char *confComposite(cmd_parms *cmd, unused void *c, const char *arg) { + gc_scoped_pool pool(cmd->pool); + ServerConf& sc = httpd::serverConf<ServerConf>(cmd, &mod_tuscany_wiring); + sc.compositeName = arg; + return NULL; +} + +/** + * HTTP server module declaration. + */ +const command_rec commands[] = { + AP_INIT_TAKE1("TuscanyHome", (const char*(*)())confHome, NULL, RSRC_CONF, "Tuscany home directory"), + AP_INIT_TAKE1("SCAWiringServerName", (const char*(*)())confWiringServerName, NULL, RSRC_CONF, "SCA wiring server name"), + AP_INIT_TAKE1("SCAContribution", (const char*(*)())confContribution, NULL, RSRC_CONF, "SCA contribution location"), + AP_INIT_TAKE1("SCAComposite", (const char*(*)())confComposite, NULL, RSRC_CONF, "SCA composite location"), + {NULL, NULL, NULL, 0, NO_ARGS, NULL} +}; + +void registerHooks(unused 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 and merger + NULL, NULL, + // server config and merger + tuscany::httpd::makeServerConf<tuscany::server::modwiring::ServerConf>, NULL, + // commands and hooks + tuscany::server::modwiring::commands, tuscany::server::modwiring::registerHooks +}; + +} |