1 files changed, 162 insertions, 147 deletions

diff --git a/src/include/gnunet_mq_lib.h b/src/include/gnunet_mq_lib.h
index 54ea806a5..b73cab8d8 100644
--- a/src/include/gnunet_mq_lib.h
+++ b/src/include/gnunet_mq_lib.h
@@ -21,7 +21,7 @@
 /**
  * @author Florian Dold
  * @file set/mq.h
- * @brief general purpose request queue
+ * @brief general purpose message queue
  */
 #ifndef GNUNET_MQ_H
 #define GNUNET_MQ_H
@@ -30,7 +30,7 @@
 
 
 /**
- * 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.
  *
@@ -43,19 +43,19 @@
 #define GNUNET_MQ_msg_extra(mvar, esize, type) GNUNET_MQ_msg_((((void)(mvar)->header), (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
@@ -64,7 +64,7 @@
 
 
 /**
- * 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
@@ -75,14 +75,14 @@
 
 
 /**
- * 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)
 
@@ -98,11 +98,24 @@
 #define GNUNET_MQ_extract_nested_mh(var) GNUNET_MQ_extract_nested_mh_ ((struct GNUNET_MessageHeader *) (var), sizeof (*(var)))
 
 
+/**
+ * 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
+ */
 struct GNUNET_MessageHeader *
 GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh, uint16_t base_size);
 
 
-struct GNUNET_MQ_Message *
+/**
+ * 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.
+ */
+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);
 
@@ -114,9 +127,15 @@ GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp, uint16_t base_size,
 #define GNUNET_MQ_HANDLERS_END {NULL, 0, 0}
 
 
-struct GNUNET_MQ_MessageQueue;
+/**
+ * Opaque handle to a message queue.
+ */
+struct GNUNET_MQ_Handle;
 
-struct GNUNET_MQ_Message;
+/**
+ * Opaque handle to an envelope.
+ */
+struct GNUNET_MQ_Envelope;
 
 enum GNUNET_MQ_Error
 {
@@ -133,22 +152,45 @@ enum GNUNET_MQ_Error
  * @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_Handle *mq,
+                       const struct GNUNET_MessageHeader *msg,
+                       void *impl_state);
+
+
+/**
+ * Signature of functions implementing the
+ * destruction of a message queue.
+ * Implementations must not free 'mq', but should
+ * take care of 'impl_state'.
+ * 
+ * @param mq the message queue to destroy
+ * @param impl_state state of the implementation
  */
 typedef void
-(*GNUNET_MQ_SendImpl) (struct GNUNET_MQ_MessageQueue *q, struct GNUNET_MQ_Message *m);
+(*GNUNET_MQ_DestroyImpl) (struct GNUNET_MQ_Handle *mq, void *impl_state);
 
 
+/**
+ * Implementation function that cancels the currently sent message.
+ * 
+ * @param mq message queue
+ * @param impl_state state specific to the implementation
+ */
 typedef void
-(*GNUNET_MQ_DestroyImpl) (struct GNUNET_MQ_MessageQueue *q);
+(*GNUNET_MQ_CancelImpl) (struct GNUNET_MQ_Handle *mq, void *impl_state);
 
 
 /**
@@ -160,117 +202,23 @@ typedef void
 (*GNUNET_MQ_NotifyCallback) (void *cls);
 
 
-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;
-};
-
-
 /**
- * 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 
@@ -296,14 +244,14 @@ struct GNUNET_MQ_Handler
 
 
 /**
- * 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 *
+struct GNUNET_MQ_Envelope *
 GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type);
 
 
@@ -315,7 +263,7 @@ 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);
 
 
 /**
@@ -326,7 +274,7 @@ GNUNET_MQ_discard (struct GNUNET_MQ_Message *mqm);
  * @param mqm 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);
 
 
 /**
@@ -336,7 +284,7 @@ GNUNET_MQ_send (struct GNUNET_MQ_MessageQueue *mq, struct GNUNET_MQ_Message *mqm
  * @param mqm queued message to cancel
  */
 void
-GNUNET_MQ_send_cancel (struct GNUNET_MQ_Message *mqm);
+GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev);
 
 
 /**
@@ -347,9 +295,7 @@ GNUNET_MQ_send_cancel (struct GNUNET_MQ_Message *mqm);
  * @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
@@ -359,7 +305,7 @@ GNUNET_MQ_assoc_add (struct GNUNET_MQ_MessageQueue *mq,
  * @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);
 
 
 /**
@@ -370,7 +316,7 @@ GNUNET_MQ_assoc_get (struct GNUNET_MQ_MessageQueue *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);
 
 
 
@@ -383,9 +329,9 @@ GNUNET_MQ_assoc_remove (struct GNUNET_MQ_MessageQueue *mq, uint32_t request_id);
  * @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,
                                        void *cls);
 
 
@@ -395,7 +341,7 @@ GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connecti
  * @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);
 
 
@@ -404,16 +350,19 @@ 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 destroy function that implements canceling a message
  * @param state for the queue, passed to 'send' and 'destroy'
  * @param handlers array of message handlers
  * @param error_handler handler for read and write errors
+ * @param cls closure for handlers
  * @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);
                                
@@ -424,27 +373,30 @@ GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
  * 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);
 
@@ -455,7 +407,7 @@ GNUNET_MQ_notify_sent (struct GNUNET_MQ_Message *mqm,
  * @param mq message queue to destroy
  */
 void
-GNUNET_MQ_destroy (struct GNUNET_MQ_MessageQueue *mq);
+GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq);
 
 
 /**
@@ -465,7 +417,70 @@ GNUNET_MQ_destroy (struct GNUNET_MQ_MessageQueue *mq);
  * @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 right callback for an error condition.
+ *
+ * @param mq message queue
+ */
+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.
+ * 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
+ * @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);
+
+/**
+ * Mark the current message as irrevocably sent, but do not
+ * proceed with sending the next message.
+ * Will call the appropriate GNUNET_MQ_NotifyCallback, if any.
+ *
+ * @param mq message queue
+ */
+void
+GNUNET_MQ_impl_send_commit (struct GNUNET_MQ_Handle *mq);
 
 #endif