/* 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.

 */

/**

 * @file  http_connection.h

 * @brief Apache connection library

 *

 * @defgroup APACHE_CORE_CONNECTION Connection Library

 * @ingroup  APACHE_CORE

 * @{

 */

#ifndef APACHE_HTTP_CONNECTION_H

#define APACHE_HTTP_CONNECTION_H

#include "apr_network_io.h"

#include "apr_buckets.h"

#ifdef __cplusplus

extern "C" {

#endif

/**

 * This is the protocol module driver.  This calls all of the

 * pre-connection and connection hooks for all protocol modules.

 * @param c The connection on which the request is read

 * @param csd The mechanism on which this connection is to be read.

 *            Most times this will be a socket, but it is up to the module

 *            that accepts the request to determine the exact type.

 */

AP_CORE_DECLARE(void) ap_process_connection(conn_rec *c, void *csd);

/**

 * Shutdown the connection for writing.

 * @param c The connection to shutdown

 * @param flush Whether or not to flush pending data before

 * @return APR_SUCCESS or the underlying error

 */

AP_CORE_DECLARE(apr_status_t) ap_shutdown_conn(conn_rec *c, int flush);

/**

 * Flushes all remain data in the client send buffer

 * @param c The connection to flush

 * @remark calls ap_shutdown_conn(c, 1)

 */

AP_CORE_DECLARE(void) ap_flush_conn(conn_rec *c);

/**

 * This function is responsible for the following cases:

 * 

 * we now proceed to read from the client until we get EOF, or until

 * MAX_SECS_TO_LINGER has passed.  The reasons for doing this are

 * documented in a draft:

 *

 * http://tools.ietf.org/html/draft-ietf-http-connection-00.txt

 *

 * in a nutshell -- if we don't make this effort we risk causing

 * TCP RST packets to be sent which can tear down a connection before

 * all the response data has been sent to the client.

 * 

 * @param c The connection we are closing

 */

AP_DECLARE(void) ap_lingering_close(conn_rec *c);

AP_DECLARE(int) ap_prep_lingering_close(conn_rec *c);

AP_DECLARE(int) ap_start_lingering_close(conn_rec *c);

/* Hooks */

/**

 * create_connection is a RUN_FIRST hook which allows modules to create

 * connections. In general, you should not install filters with the

 * create_connection hook. If you require vhost configuration information

 * to make filter installation decisions, you must use the pre_connection

 * or install_network_transport hook. This hook should close the connection

 * if it encounters a fatal error condition.

 *

 * @param p The pool from which to allocate the connection record

 * @param server The server record to create the connection too.

 * @param csd The socket that has been accepted

 * @param conn_id A unique identifier for this connection.  The ID only

 *                needs to be unique at that time, not forever.

 * @param sbh A handle to scoreboard information for this connection.

 * @param alloc The bucket allocator to use for all bucket/brigade creations

 * @return An allocated connection record or NULL.

 */

AP_DECLARE_HOOK(conn_rec *, create_connection,

                (apr_pool_t *p, server_rec *server, apr_socket_t *csd,

                 long conn_id, void *sbh, apr_bucket_alloc_t *alloc))

/**

 * This hook gives protocol modules an opportunity to set everything up

 * before calling the protocol handler.  All pre-connection hooks are

 * run until one returns something other than ok or decline

 * @param c The connection on which the request has been received.

 * @param csd The mechanism on which this connection is to be read.

 *            Most times this will be a socket, but it is up to the module

 *            that accepts the request to determine the exact type.

 * @return OK or DECLINED

 */

AP_DECLARE_HOOK(int,pre_connection,(conn_rec *c, void *csd))

/**

 * This hook implements different protocols.  After a connection has been

 * established, the protocol module must read and serve the request.  This

 * function does that for each protocol module.  The first protocol module

 * to handle the request is the last module run.

 * @param c The connection on which the request has been received.

 * @return OK or DECLINED

 */

AP_DECLARE_HOOK(int,process_connection,(conn_rec *c))

/**

 * This hook implements different protocols.  Before a connection is closed,

 * protocols might have to perform some housekeeping actions, such as 

 * sending one last goodbye packet. The connection is, unless some other

 * error already happened before, still open and operational.

 * All pre-close-connection hooks are run until one returns something 

 * other than ok or decline

 * @param c The connection on which the request has been received.

 * @return OK or DECLINED

 */

AP_DECLARE_HOOK(int,pre_close_connection,(conn_rec *c))

/** End Of Connection (EOC) bucket */

AP_DECLARE_DATA extern const apr_bucket_type_t ap_bucket_type_eoc;

/**

 * Determine if a bucket is an End Of Connection (EOC) bucket

 * @param e The bucket to inspect

 * @return true or false

 */

#define AP_BUCKET_IS_EOC(e)         (e->type == &ap_bucket_type_eoc)

/**

 * Make the bucket passed in an End Of Connection (EOC) bucket

 * @param b The bucket to make into an EOC bucket

 * @return The new bucket, or NULL if allocation failed

 */

AP_DECLARE(apr_bucket *) ap_bucket_eoc_make(apr_bucket *b);

/**

 * Create a bucket referring to an End Of Connection (EOC). This indicates

 * that the connection will be closed.

 * @param list The freelist from which this bucket should be allocated

 * @return The new bucket, or NULL if allocation failed

 */

AP_DECLARE(apr_bucket *) ap_bucket_eoc_create(apr_bucket_alloc_t *list);

#ifdef __cplusplus

}

#endif

#endif  /* !APACHE_HTTP_CONNECTION_H */

/** @} */