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Diffstat (limited to 'web/apache/service')
| -rw-r--r-- | web/apache/service | 330 |
1 files changed, 0 insertions, 330 deletions
diff --git a/web/apache/service b/web/apache/service deleted file mode 100644 index 45cf39b..0000000 --- a/web/apache/service +++ /dev/null @@ -1,330 +0,0 @@ -// file : web/apache/service -*- C++ -*- -// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd -// license : MIT; see accompanying LICENSE file - -#ifndef WEB_APACHE_SERVICE -#define WEB_APACHE_SERVICE - -#include <apr_pools.h> // apr_pool_t -#include <apr_hooks.h> // APR_HOOK_* - -#include <httpd.h> // request_rec, server_rec, HTTP_*, DECLINED -#include <http_config.h> // module, cmd_parms, ap_hook_*() - -#include <map> -#include <memory> // unique_ptr -#include <string> -#include <cassert> - -#include <web/module> -#include <web/apache/log> -#include <web/apache/request> - -namespace web -{ - namespace apache - { - // Apache has 3 configuration scopes: main server, virtual server, and - // directory (location). It provides configuration scope-aware modules - // with the ability to build a hierarchy of configuration contexts. Later, - // when processing a request, Apache passes the appropriate directory - // configuration context to the request handler. - // - // This Apache service implementation first makes a copy of the provided - // (in the constructor below) module exemplar for each directory context. - // It then initializes each of these "context exemplars" with the (merged) - // set of configuration options. Finally, when handling a request, it - // copies the corresponding "context exemplar" to create the "handling - // instance". Note that the "context exemplars" are created as a copy of - // the provided exemplar, which is never initialized. As a result, it is - // possible to detect if the module's copy constructor is used to create a - // "context exemplar" or a "handling instance". - // - class service: ::module - { - public: - // Note that the module exemplar is stored by-reference. - // - template <typename M> - service (const std::string& name, M& exemplar) - : ::module - { - STANDARD20_MODULE_STUFF, - nullptr, - nullptr, - nullptr, - nullptr, - nullptr, - ®ister_hooks<M> - }, - name_ (name), - exemplar_ (exemplar) - { - init_directives (); - - // Set configuration context management hooks. - // - // The overall process of building the configuration hierarchy for a - // module is as follows: - // - // 1. Apache creates directory and server configuration contexts for - // scopes containing module-defined directives by calling the - // create_{server,dir}_context() callback functions. For directives - // at the server scope the special directory context is created as - // well. - // - // 2. Apache calls parse_option() function for each module-defined - // directive. The function parses the directives and places the - // resulting options into the corresponding configuration context. - // It also establishes the directory-server contexts relations. - // - // 3. Apache calls merge_server_context() function for each virtual - // server. The function complements virtual server context options - // with the ones from the main server. - // - // 4. Apache calls config_finalizer() which complements the directory - // contexts options with the ones from the enclosing servers. - // - // 5. Apache calls worker_initializer() which creates module exemplar - // for each directory configuration context that have - // 'SetHandler <mod_name>' directive in effect for it. - // - // References: - // http://www.apachetutor.org/dev/config - // http://httpd.apache.org/docs/2.4/developer/modguide.html - // http://wiki.apache.org/httpd/ModuleLife - // - create_server_config = &create_server_context; - create_dir_config = &create_dir_context; - merge_server_config = &merge_server_context<M>; - - // instance<M> () is invented to delegate processing from apache - // request handler C function to the service non static member - // function. This appoach resticts number of service objects per - // specific module implementation class with just one instance. - // - service*& srv (instance<M> ()); - assert (srv == nullptr); - srv = this; - } - - ~service () - { - delete [] cmds; - } - - private: - template <typename M> - static service*& - instance () noexcept - { - static service* instance; - return instance; - } - - template <typename M> - static void - register_hooks (apr_pool_t*) noexcept - { - // The config_finalizer() function is called at the end of Apache - // server configuration parsing. - // - ap_hook_post_config (&config_finalizer<M>, NULL, NULL, APR_HOOK_LAST); - - // The worker_initializer() function is called right after Apache - // worker process is started. Called for every new process spawned. - // - ap_hook_child_init ( - &worker_initializer<M>, NULL, NULL, APR_HOOK_LAST); - - // The request_handler () function is called for each client request. - // - ap_hook_handler (&request_handler<M>, NULL, NULL, APR_HOOK_LAST); - } - - template <typename M> - static int - config_finalizer (apr_pool_t*, apr_pool_t*, apr_pool_t*, server_rec* s) - noexcept - { - instance<M> ()->finalize_config (s); - return OK; - } - - template <typename M> - static void - worker_initializer (apr_pool_t*, server_rec* s) noexcept - { - auto srv (instance<M> ()); - log l (s, srv); - srv->template init_worker<M> (l); - } - - template <typename M> - static int - request_handler (request_rec* r) noexcept; - - private: - - // Reflects the allowability of the request handling in the specific - // configuration scope. - // - enum class request_handling - { - // Configuration scope has 'SetHandler <mod_name>' directive - // specified. The module is allowed to handle a request in the scope. - // - allowed, - - // Configuration scope has 'SetHandler <other_mod_name>|None' - // directive specified. The module is disallowed to handle a request - // in the scope. - // - disallowed, - - // - // Note that if there are several SetHandler directives specified - // in the specific scope, then the latest one takes the precedence. - - // Configuration scope has no SetHandler directive specified. The - // request handling allowability is established by the enclosing - // scopes. - // - inherit - }; - - // Our representation of the Apache configuration context. - // - // The lifetime of this object is under the control of the Apache API, - // which treats it as a raw sequence of bytes. In order not to tinker - // with the C-style structures and APR memory pools, we will keep it a - // (C++11) POD type with just the members required to maintain the - // context hierarchy. - // - // We will then use the pointers to these context objects as keys in - // maps to (1) the corresponding application-level option lists during - // the configuration cycle and to (2) the corresponding module exemplar - // during the HTTP request handling phase. We will also use the same - // type for both directory and server configuration contexts. - // - struct context - { - // Outer (server) configuration context for the directory - // configuration context, NULL otherwise. - // - context* server = nullptr; - - // If module directives appear directly in the server configuration - // scope, Apache creates a special directory context for them. This - // context appears at the same hierarchy level as the user-defined - // directory contexts of the same server scope. - // - bool special; - - // Request handling allowability for the corresponding configuration - // scope. - // - request_handling handling = request_handling::inherit; - - // Create the server configuration context. - // - context (): special (false) {} - - // Create the directory configuration context. Due to the Apache API - // implementation details it is not possible to detect the enclosing - // server configuration context at the time of directory context - // creation. As a result, the server member is set by the module's - // parse_option() function. - // - context (bool s): special (s) {} - - // Ensure the object is only destroyed by Apache. - // - ~context () = delete; - }; - - static context* - context_cast (void* config) noexcept - {return static_cast<context*> (config);} - - private: - void - init_directives (); - - // Create the server configuration context. Called by the Apache API - // whenever a new object of that type is required. - // - static void* - create_server_context (apr_pool_t*, server_rec*) noexcept; - - // Create the server directory configuration context. Called by the - // Apache API whenever a new object of that type is required. - // - static void* - create_dir_context (apr_pool_t*, char* dir) noexcept; - - template <typename M> - static void* - merge_server_context (apr_pool_t*, void* enclosing, void* enclosed) - noexcept - { - instance<M> ()->complement ( - context_cast (enclosed), context_cast (enclosing)); - - return enclosed; - } - - static const char* - parse_option (cmd_parms* parms, void* conf, const char* args) noexcept; - - const char* - add_option (context*, const char* name, optional<std::string> value); - - void - finalize_config (server_rec*); - - void - clear_config (); - - // Complement the enclosed context with options of the enclosing one. - // If the 'handling' member of the enclosed context is set to - // request_handling::inherit value, assign it a value from the enclosing - // context. - // - void - complement (context* enclosed, context* enclosing); - - template <typename M> - void - init_worker (log&); - - template <typename M> - int - handle (request&, const context*, log&) const; - - private: - std::string name_; - module& exemplar_; - option_descriptions option_descriptions_; - - // The context objects pointed to by the key can change during the - // configuration phase. - // - using options = std::map<context*, name_values>; - options options_; - - // The context objects pointed to by the key can not change during the - // request handling phase. - // - using exemplars = std::map<const context*, std::unique_ptr<module>>; - exemplars exemplars_; - - bool options_parsed_ = false; - bool version_logged_ = false; - }; - } -} - -#include <web/apache/service.txx> - -#endif // WEB_APACHE_SERVICE |