/*
This file is part of GNUnet.
- (C) 2012 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2012-2013 Christian Grothoff (and other contributing authors)
GNUnet 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; either version 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
* @author Florian Dold
- * @file set/mq.h
- * @brief general purpose request queue
+ * @file include/gnunet_mq_lib.h
+ * @brief general purpose message queue
+ * @defgroup mq general purpose message queue
+ * @{
*/
#ifndef GNUNET_MQ_H
#define GNUNET_MQ_H
-#include "gnunet_common.h"
-
/**
- * Allocate a GNUNET_MQ_Message, with extra space allocated after the space needed
+ * Allocate an envelope, with extra space allocated after the space needed
* by the message struct.
* The allocated message will already have the type and size field set.
*
* @param type type of the message
* @return the MQ message
*/
-#define GNUNET_MQ_msg_extra(mvar, esize, type) GNUNET_MQ_msg_((((void)(mvar)->header), (struct GNUNET_MessageHeader**) &(mvar)), (esize) + sizeof *(mvar), (type))
+#define GNUNET_MQ_msg_extra(mvar, esize, type) GNUNET_MQ_msg_(((struct GNUNET_MessageHeader**) &(mvar)), (esize) + sizeof *(mvar), (type))
/**
- * Allocate a GNUNET_MQ_Message.
- * The allocated message will already have the type and size field set.
+ * Allocate a GNUNET_MQ_Envelope.
+ * The contained message will already have the type and size field set.
*
* @param mvar variable to store the allocated message in;
* must have a header field
* @param type type of the message
- * @return the MQ message
+ * @return the allocated envelope
*/
#define GNUNET_MQ_msg(mvar, type) GNUNET_MQ_msg_extra(mvar, 0, type)
/**
- * Allocate a GNUNET_MQ_Message, where the message only consists of a header.
+ * Allocate a GNUNET_MQ_Envelope, where the message only consists of a header.
* The allocated message will already have the type and size field set.
*
* @param type type of the message
/**
- * Allocate a GNUNET_MQ_Message, where the message only consists of a header and extra space.
+ * Allocate a GNUNET_MQ_Envelope, where the message only consists of a header and extra space.
* The allocated message will already have the type and size field set.
*
* @param mh pointer that will changed to point at to the allocated message header
/**
- * Allocate a GNUNET_MQ_Message, and append a payload message after the given
+ * Allocate a GNUNET_MQ_Envelope, and append a payload message after the given
* message struct.
*
* @param mvar pointer to a message struct, will be changed to point at the newly allocated message,
* whose size is 'sizeof(*mvar) + ntohs (mh->size)'
* @param type message type of the allocated message, has no effect on the nested message
* @param mh message to nest
- * @return a newly allocated 'struct GNUNET_MQ_Message *'
+ * @return a newly allocated 'struct GNUNET_MQ_Envelope *'
*/
#define GNUNET_MQ_msg_nested_mh(mvar, type, mh) GNUNET_MQ_msg_nested_mh_((((void)(mvar)->header), (struct GNUNET_MessageHeader**) &(mvar)), sizeof (*(mvar)), (type), mh)
* @param var pointer to a message struct, the type of the expression determines the base size,
* the space after the base size is the nested message
* @return a 'struct GNUNET_MessageHeader *' that points at the nested message of the given message,
- * or NULL if the given message in 'var' does not have any space after the message struct
+ * or NULL if the given message in @a var does not have any space after the message struct
*/
#define GNUNET_MQ_extract_nested_mh(var) GNUNET_MQ_extract_nested_mh_ ((struct GNUNET_MessageHeader *) (var), sizeof (*(var)))
-struct GNUNET_MessageHeader *
-GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh, uint16_t base_size);
+/**
+ * Implementation of the GNUNET_MQ_extract_nexted_mh macro.
+ *
+ * @param mh message header to extract nested message header from
+ * @param base_size size of the message before the nested message's header appears
+ * @return pointer to the nested message, does not copy the message
+ */
+const struct GNUNET_MessageHeader *
+GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh,
+ uint16_t base_size);
-struct GNUNET_MQ_Message *
-GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp, uint16_t base_size, uint16_t type,
+/**
+ * Implementation of the GNUNET_MQ_msg_nested_mh macro.
+ *
+ * @param mhp pointer to the message header pointer that will be changed to allocate at
+ * the newly allocated space for the message.
+ * @param base_size size of the data before the nested message
+ * @param type type of the message in the envelope
+ * @param nested_mh the message to append to the message after base_size
+ */
+struct GNUNET_MQ_Envelope *
+GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp,
+ uint16_t base_size,
+ uint16_t type,
const struct GNUNET_MessageHeader *nested_mh);
#define GNUNET_MQ_HANDLERS_END {NULL, 0, 0}
-struct GNUNET_MQ_MessageQueue;
+/**
+ * Opaque handle to a message queue.
+ */
+struct GNUNET_MQ_Handle;
+
+/**
+ * Opaque handle to an envelope.
+ */
+struct GNUNET_MQ_Envelope;
-struct GNUNET_MQ_Message;
+/**
+ * Error codes for the queue.
+ */
enum GNUNET_MQ_Error
{
+ /**
+ * FIXME: document!
+ */
GNUNET_MQ_ERROR_READ = 1,
+
+ /**
+ * FIXME: document!
+ */
GNUNET_MQ_ERROR_WRITE = 2,
+
+ /**
+ * FIXME: document!
+ */
GNUNET_MQ_ERROR_TIMEOUT = 4
};
* @param msg the received message
*/
typedef void
-(*GNUNET_MQ_MessageCallback) (void *cls, const struct GNUNET_MessageHeader *msg);
+(*GNUNET_MQ_MessageCallback) (void *cls,
+ const struct GNUNET_MessageHeader *msg);
/**
* Signature of functions implementing the
- * sending part of a message queue
+ * sending functionality of a message queue.
*
- * @param q the message queue
- * @param m the message
+ * @param mq the message queue
+ * @param msg the message to send
+ * @param impl_state state of the implementation
*/
typedef void
-(*GNUNET_MQ_SendImpl) (struct GNUNET_MQ_MessageQueue *q, struct GNUNET_MQ_Message *m);
+(*GNUNET_MQ_SendImpl) (struct GNUNET_MQ_Handle *mq,
+ const struct GNUNET_MessageHeader *msg,
+ void *impl_state);
+/**
+ * Signature of functions implementing the
+ * destruction of a message queue.
+ * Implementations must not free @a mq, but should
+ * take care of @a impl_state.
+ *
+ * @param mq the message queue to destroy
+ * @param impl_state state of the implementation
+ */
typedef void
-(*GNUNET_MQ_DestroyImpl) (struct GNUNET_MQ_MessageQueue *q);
+(*GNUNET_MQ_DestroyImpl) (struct GNUNET_MQ_Handle *mq,
+ void *impl_state);
/**
- * Callback used for notifications
+ * Implementation function that cancels the currently sent message.
*
- * @param cls closure
+ * @param mq message queue
+ * @param impl_state state specific to the implementation
*/
typedef void
-(*GNUNET_MQ_NotifyCallback) (void *cls);
+(*GNUNET_MQ_CancelImpl) (struct GNUNET_MQ_Handle *mq,
+ void *impl_state);
+/**
+ * Callback used for notifications
+ *
+ * @param cls closure
+ */
typedef void
-(*GNUNET_MQ_ErrorHandler) (void *cls, enum GNUNET_MQ_Error error);
-
-
-struct GNUNET_MQ_Message
-{
- /**
- * Messages are stored in a linked list
- */
- struct GNUNET_MQ_Message *next;
-
- /**
- * Messages are stored in a linked list
- */
- struct GNUNET_MQ_Message *prev;
-
- /**
- * Actual allocated message header,
- * usually points to the end of the containing GNUNET_MQ_Message
- */
- struct GNUNET_MessageHeader *mh;
-
- /**
- * Queue the message is queued in, NULL if message is not queued.
- */
- struct GNUNET_MQ_MessageQueue *parent_queue;
-
- /**
- * Called after the message was sent irrevokably
- */
- GNUNET_MQ_NotifyCallback sent_cb;
-
- /**
- * Closure for send_cb
- */
- void *sent_cls;
-};
+(*GNUNET_MQ_NotifyCallback) (void *cls);
/**
- * Handle to a message queue.
+ * Generic error handler, called with the appropriate
+ * error code and the same closure specified at the creation of
+ * the message queue.
+ * Not every message queue implementation supports an error handler.
+ *
+ * @param cls closure, same closure as for the message handlers
+ * @param error error code
*/
-struct GNUNET_MQ_MessageQueue
-{
- /**
- * Handlers array, or NULL if the queue should not receive messages
- */
- const struct GNUNET_MQ_Handler *handlers;
-
- /**
- * Closure for the handler callbacks,
- * as well as for the error handler.
- */
- void *handlers_cls;
-
- /**
- * Actual implementation of message sending,
- * called when a message is added
- */
- GNUNET_MQ_SendImpl send_impl;
-
- /**
- * Implementation-dependent queue destruction function
- */
- GNUNET_MQ_DestroyImpl destroy_impl;
-
- /**
- * Implementation-specific state
- */
- void *impl_state;
-
- /**
- * Callback will be called when an error occurs.
- */
- GNUNET_MQ_ErrorHandler error_handler;
-
- /**
- * Linked list of messages pending to be sent
- */
- struct GNUNET_MQ_Message *msg_head;
-
- /**
- * Linked list of messages pending to be sent
- */
- struct GNUNET_MQ_Message *msg_tail;
-
- /**
- * Message that is currently scheduled to be
- * sent. Not the head of the message queue, as the implementation
- * needs to know if sending has been already scheduled or not.
- */
- struct GNUNET_MQ_Message *current_msg;
-
- /**
- * Map of associations, lazily allocated
- */
- struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map;
-
- /**
- * Next id that should be used for the assoc_map,
- * initialized lazily to a random value together with
- * assoc_map
- */
- uint32_t assoc_id;
-};
+typedef void
+(*GNUNET_MQ_ErrorHandler) (void *cls,
+ enum GNUNET_MQ_Error error);
/**
* Message handler for a specific message type.
*/
-struct GNUNET_MQ_Handler
+struct GNUNET_MQ_MessageHandler
{
/**
- * Callback, called every time a new message of
+ * Callback, called every time a new message of
* the specified type has been receied.
*/
GNUNET_MQ_MessageCallback cb;
-
/**
* Type of the message this handler covers.
*/
/**
- * Create a new message for MQ.
- *
+ * Create a new envelope.
+ *
* @param mhp message header to store the allocated message header in, can be NULL
* @param size size of the message to allocate
* @param type type of the message, will be set in the allocated message
* @return the allocated MQ message
*/
-struct GNUNET_MQ_Message *
-GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type);
+struct GNUNET_MQ_Envelope *
+GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp,
+ uint16_t size,
+ uint16_t type);
/**
* @param mqm the message to discard
*/
void
-GNUNET_MQ_discard (struct GNUNET_MQ_Message *mqm);
+GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *mqm);
/**
* Send a message with the give message queue.
* May only be called once per message.
- *
+ *
* @param mq message queue
- * @param mqm the message to send.
+ * @param ev the envelope with the message to send.
*/
void
-GNUNET_MQ_send (struct GNUNET_MQ_MessageQueue *mq, struct GNUNET_MQ_Message *mqm);
+GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq,
+ struct GNUNET_MQ_Envelope *ev);
/**
- * Cancel sending the message. Message must have been sent with GNUNET_MQ_send before.
- * May not be called after the notify sent callback has been called
+ * Cancel sending the message. Message must have been sent with
+ * #GNUNET_MQ_send before. May not be called after the notify sent
+ * callback has been called
*
- * @param mqm queued message to cancel
+ * @param ev queued envelope to cancel
*/
void
-GNUNET_MQ_send_cancel (struct GNUNET_MQ_Message *mqm);
+GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev);
/**
* Associate the assoc_data in mq with a unique request id.
*
* @param mq message queue, id will be unique for the queue
- * @param mqm message to associate
* @param assoc_data to associate
*/
uint32_t
-GNUNET_MQ_assoc_add (struct GNUNET_MQ_MessageQueue *mq,
- struct GNUNET_MQ_Message *mqm,
- void *assoc_data);
+GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq, void *assoc_data);
+
/**
* Get the data associated with a request id in a queue
* @return the associated data
*/
void *
-GNUNET_MQ_assoc_get (struct GNUNET_MQ_MessageQueue *mq, uint32_t request_id);
+GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq,
+ uint32_t request_id);
/**
* @return the associated data
*/
void *
-GNUNET_MQ_assoc_remove (struct GNUNET_MQ_MessageQueue *mq, uint32_t request_id);
-
+GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq,
+ uint32_t request_id);
/**
*
* @param connection the client connection
* @param handlers handlers for receiving messages
+ * @param error_handler error handler
* @param cls closure for the handlers
* @return the message queue
*/
-struct GNUNET_MQ_MessageQueue *
+struct GNUNET_MQ_Handle *
GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection,
- const struct GNUNET_MQ_Handler *handlers,
+ const struct GNUNET_MQ_MessageHandler *handlers,
+ GNUNET_MQ_ErrorHandler error_handler,
void *cls);
/**
- * Create a message queue for a GNUNET_STREAM_Socket.
+ * Create a message queue for a GNUNET_SERVER_Client.
*
* @param client the client
* @return the message queue
*/
-struct GNUNET_MQ_MessageQueue *
+struct GNUNET_MQ_Handle *
GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client);
*
* @param send function the implements sending messages
* @param destroy function that implements destroying the queue
- * @param state for the queue, passed to 'send' and 'destroy'
+ * @param cancel function that implements canceling a message
+ * @param impl_state for the queue, passed to @a send, @a destroy and @a cancel
* @param handlers array of message handlers
* @param error_handler handler for read and write errors
+ * @param cls closure for message handlers and error handler
* @return a new message queue
*/
-struct GNUNET_MQ_MessageQueue *
+struct GNUNET_MQ_Handle *
GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
GNUNET_MQ_DestroyImpl destroy,
+ GNUNET_MQ_CancelImpl cancel,
void *impl_state,
- struct GNUNET_MQ_Handler *handlers,
+ const struct GNUNET_MQ_MessageHandler *handlers,
GNUNET_MQ_ErrorHandler error_handler,
void *cls);
-
/**
- * Replace the handlers of a message queue with new handlers.
- * Takes effect immediately, even for messages that already have been received, but for
- * with the handler has not been called.
+ * Replace the handlers of a message queue with new handlers. Takes
+ * effect immediately, even for messages that already have been
+ * received, but for with the handler has not been called.
+ *
+ * If the message queue does not support receiving messages,
+ * this function has no effect.
*
* @param mq message queue
* @param new_handlers new handlers
* @param cls new closure for the handlers
*/
void
-GNUNET_MQ_replace_handlers (struct GNUNET_MQ_MessageQueue *mq,
- const struct GNUNET_MQ_Handler *new_handlers,
+GNUNET_MQ_replace_handlers (struct GNUNET_MQ_Handle *mq,
+ const struct GNUNET_MQ_MessageHandler *new_handlers,
void *cls);
/**
- * Call a callback once the message has been sent, that is, the message
- * can not be canceled anymore.
- * There can be only one notify sent callback per message.
+ * Call a callback once the envelope has been sent, that is,
+ * sending it can not be canceled anymore.
+ * There can be only one notify sent callback per envelope.
*
- * @param mqm message to call the notify callback for
+ * @param ev message to call the notify callback for
* @param cb the notify callback
* @param cls closure for the callback
*/
void
-GNUNET_MQ_notify_sent (struct GNUNET_MQ_Message *mqm,
+GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *ev,
GNUNET_MQ_NotifyCallback cb,
void *cls);
* @param mq message queue to destroy
*/
void
-GNUNET_MQ_destroy (struct GNUNET_MQ_MessageQueue *mq);
+GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq);
/**
- * Call the right callback for a message.
+ * Call the message message handler that was registered
+ * for the type of the given message in the given message queue.
+ *
+ * This function is indended to be used for the implementation
+ * of message queues.
*
* @param mq message queue with the handlers
* @param mh message to dispatch
*/
void
-GNUNET_MQ_dispatch (struct GNUNET_MQ_MessageQueue *mq,
- const struct GNUNET_MessageHeader *mh);
+GNUNET_MQ_inject_message (struct GNUNET_MQ_Handle *mq,
+ const struct GNUNET_MessageHeader *mh);
+
+
+/**
+ * Call the error handler of a message queue with the given
+ * error code. If there is no error handler, log a warning.
+ *
+ * This function is intended to be used for the implementation
+ * of message queues.
+ *
+ * @param mq message queue
+ * @param error the error type
+ */
+void
+GNUNET_MQ_inject_error (struct GNUNET_MQ_Handle *mq,
+ enum GNUNET_MQ_Error error);
+
+
+/**
+ * Call the send implementation for the next queued message,
+ * if any.
+ * Only useful for implementing message queues,
+ * results in undefined behavior if not used carefully.
+ *
+ * @param mq message queue to send the next message with
+ */
+void
+GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq);
+
+
+/**
+ * Get the message that should currently be sent.
+ * The returned message is only valid until #GNUNET_MQ_impl_send_continue
+ * is called.
+ * Fails if there is no current message.
+ * Only useful for implementing message queues,
+ * results in undefined behavior if not used carefully.
+ *
+ * @param mq message queue with the current message, only valid
+ * until #GNUNET_MQ_impl_send_continue is called
+ * @return message to send, never NULL
+ */
+const struct GNUNET_MessageHeader *
+GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq);
+
+
+/**
+ * Get the implementation state associated with the
+ * message queue.
+ *
+ * While the GNUNET_MQ_Impl* callbacks receive the
+ * implementation state, continuations that are scheduled
+ * by the implementation function often only have one closure
+ * argument, with this function it is possible to get at the
+ * implementation state when only passing the GNUNET_MQ_Handle
+ * as closure.
+ *
+ * @param mq message queue with the current message
+ * @return message to send, never NULL
+ */
+void *
+GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq);
+
+
+/** @} */ /* end of group mq */
#endif
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