apache_application.h

/*
 * apache_application.h
 * This file is part of dbPager Classes Library (DCL)
 *
 * Copyright (c) 2008 Dennis Prochko <wolfsoft@mail.ru>
 *
 * DCL is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation version 3.
 *
 * DCL is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with DCL; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

#ifndef _APACHE_APPLICATION_H_
#define _APACHE_APPLICATION_H_

#include <string>

#include <httpd.h>
#include <http_config.h>
#include <http_core.h>
#include <http_protocol.h>

#include "dcl/delegate.h"
#include "dcl/http_header.h"
#include "dcl/web_application.h"

namespace dbp {

namespace local {

// Apache helper class interface
class apache_helper {
public:
        virtual const char* get_server_banner() = 0;
        virtual void set_content_type(const char*, request_rec*) = 0;
        virtual void input(size_t*, char**, request_rec*) = 0;
        virtual void output(int, const char*, request_rec*) = 0;
};

#ifndef _LIBRARY_
// Apache helper class implementation
class apache_helper_impl: public apache_helper {
public:
        virtual const char* get_server_banner() {
                return ap_get_server_banner();
        };
        virtual void set_content_type(const char *type, request_rec *r) {
                ap_set_content_type(r, type);
        };
        virtual void input(size_t *len, char **str, request_rec *r) {
                *len = 0;
                apr_bucket_brigade *bb_in = apr_brigade_create(r->pool,
                  r->connection->bucket_alloc);
                if (!bb_in) return;
                bool seen_eos = false;
                do {
                        apr_status_t rc = ap_get_brigade(r->input_filters, bb_in,
                          AP_MODE_READBYTES, APR_BLOCK_READ, HUGE_STRING_LEN);
                        if (rc != APR_SUCCESS) {
                                return;
                        }
                        for (apr_bucket *bucket = APR_BRIGADE_FIRST(bb_in);
                          bucket != APR_BRIGADE_SENTINEL(bb_in);
                          bucket = APR_BUCKET_NEXT(bucket)) {
                                const char *buf;
                                apr_size_t buflen;
                                rc = apr_bucket_read(bucket, &buf, &buflen, APR_BLOCK_READ);
                                if (rc != APR_SUCCESS) {
                        return;
                                }
                                if (APR_BUCKET_IS_EOS(bucket))
                                        seen_eos = true;
                                *len += buflen;
                                *str = (char*)realloc(*str, *len);
                                memcpy(*str + *len - buflen, buf, buflen);
                        }
                        apr_brigade_cleanup(bb_in);
                } while (!seen_eos);
        };
        virtual void output(int len, const char *str, request_rec *r) {
                ap_rwrite(str, len, r);
        };
};
#endif

} // namespace local


class apache_application: public web_application_int {
public:
        apache_application(): apache(NULL), apache_req(NULL) { };
        virtual void on_handle_request(on_request_handler handler) {
                request_handler = handler;
        };
        virtual void on_exception(on_exception_handler handler) {
                exception_handler = handler;
        };
        static void apache_register_hooks(apr_pool_t*);
protected:
        virtual http_request get_request();
        virtual void send_response(const http_response &response);
private:
        local::apache_helper *apache;
        request_rec *apache_req;
        on_request_handler request_handler;
        on_exception_handler exception_handler;
        static int apache_handler(request_rec *r);
        int handle_request();
};

} //namespace

#undef IMPLEMENT_APP

#define IMPLEMENT_APP(module_name, app_class)                                                           \
                                                                                                                                                        \
int dbp::apache_application::apache_handler(request_rec *r) {                           \
        if (strcmp(r->handler, #module_name) != 0) return DECLINED;                             \
        dbp::local::apache_helper_impl apache;                                                                  \
        app_class app;                                                                                                                  \
        dbp::apache_application &_app = app.application_impl();                                 \
        _app.apache = &apache;                                                                                                  \
        _app.apache_req = r;                                                                                                    \
        return _app.handle_request();                                                                                   \
}                                                                                                                                                       \
                                                                                                                                                        \
void dbp::apache_application::apache_register_hooks(apr_pool_t*) {                      \
        ap_hook_handler(dbp::apache_application::apache_handler, NULL, NULL,    \
          APR_HOOK_LAST);                                                                                                               \
}                                                                                                                                                       \
                                                                                                                                                        \
extern "C" {                                                                                                                            \
                                                                                                                                                        \
module AP_MODULE_DECLARE_DATA module_name = {                                                           \
        STANDARD20_MODULE_STUFF,                                                                                                \
        NULL,                                           /* create per-dir config structures             */      \
        NULL,                                           /* merge  per-dir config structures             */      \
        NULL,                                           /* create per-server config structures  */      \
        NULL,                                           /* merge  per-server config structures  */      \
        NULL,                                           /* table of config file commands                */      \
        dbp::apache_application::apache_register_hooks /* register hooks        */      \
};                                                                                                                                                      \
                                                                                                                                                        \
}

#endif /*_APACHE_APPLICATION_H_*/