/*
This file is part of GNUnet.
Copyright (C) 2012-2017 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet 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
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @author Florian Dold
* @file util/mq.c
* @brief general purpose request queue
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#define LOG(kind,...) GNUNET_log_from (kind, "util-mq",__VA_ARGS__)
struct GNUNET_MQ_Envelope
{
/**
* Messages are stored in a linked list.
* Each queue has its own list of envelopes.
*/
struct GNUNET_MQ_Envelope *next;
/**
* Messages are stored in a linked list
* Each queue has its own list of envelopes.
*/
struct GNUNET_MQ_Envelope *prev;
/**
* Actual allocated message header.
* The GNUNET_MQ_Envelope header is allocated at
* the end of the message.
*/
struct GNUNET_MessageHeader *mh;
/**
* Queue the message is queued in, NULL if message is not queued.
*/
struct GNUNET_MQ_Handle *parent_queue;
/**
* Called after the message was sent irrevocably.
*/
GNUNET_SCHEDULER_TaskCallback sent_cb;
/**
* Closure for @e send_cb
*/
void *sent_cls;
/**
* Flags that were set for this envelope by
* #GNUNET_MQ_env_set_options(). Only valid if
* @e have_custom_options is set.
*/
uint64_t flags;
/**
* Additional options buffer set for this envelope by
* #GNUNET_MQ_env_set_options(). Only valid if
* @e have_custom_options is set.
*/
const void *extra;
/**
* Did the application call #GNUNET_MQ_env_set_options()?
*/
int have_custom_options;
};
/**
* Handle to a message queue.
*/
struct GNUNET_MQ_Handle
{
/**
* Handlers array, or NULL if the queue should not receive messages
*/
struct GNUNET_MQ_MessageHandler *handlers;
/**
* 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-dependent send cancel function
*/
GNUNET_MQ_CancelImpl cancel_impl;
/**
* Implementation-specific state
*/
void *impl_state;
/**
* Callback will be called when an error occurs.
*/
GNUNET_MQ_ErrorHandler error_handler;
/**
* Closure for the error handler.
*/
void *error_handler_cls;
/**
* Task to asynchronously run #impl_send_continue().
*/
struct GNUNET_SCHEDULER_Task *send_task;
/**
* Linked list of messages pending to be sent
*/
struct GNUNET_MQ_Envelope *envelope_head;
/**
* Linked list of messages pending to be sent
*/
struct GNUNET_MQ_Envelope *envelope_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_Envelope *current_envelope;
/**
* Map of associations, lazily allocated
*/
struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map;
/**
* Functions to call on queue destruction; kept in a DLL.
*/
struct GNUNET_MQ_DestroyNotificationHandle *dnh_head;
/**
* Functions to call on queue destruction; kept in a DLL.
*/
struct GNUNET_MQ_DestroyNotificationHandle *dnh_tail;
/**
* Additional options buffer set for this queue by
* #GNUNET_MQ_set_options(). Default is 0.
*/
const void *default_extra;
/**
* Flags that were set for this queue by
* #GNUNET_MQ_set_options(). Default is 0.
*/
uint64_t default_flags;
/**
* Next id that should be used for the @e assoc_map,
* initialized lazily to a random value together with
* @e assoc_map
*/
uint32_t assoc_id;
/**
* Number of entries we have in the envelope-DLL.
*/
unsigned int queue_length;
/**
* #GNUNET_YES if GNUNET_MQ_impl_evacuate was called.
* FIXME: is this dead?
*/
int evacuate_called;
/**
* #GNUNET_YES if GNUNET_MQ_impl_send_in_flight() was called.
*/
int in_flight;
};
/**
* 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_inject_message (struct GNUNET_MQ_Handle *mq,
const struct GNUNET_MessageHeader *mh)
{
const struct GNUNET_MQ_MessageHandler *handler;
int handled = GNUNET_NO;
uint16_t msize = ntohs (mh->size);
uint16_t mtype = ntohs (mh->type);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Received message of type %u and size %u\n",
mtype, msize);
if (NULL == mq->handlers)
goto done;
for (handler = mq->handlers; NULL != handler->cb; handler++)
{
if (handler->type == mtype)
{
handled = GNUNET_YES;
if ( (handler->expected_size > msize) ||
( (handler->expected_size != msize) &&
(NULL == handler->mv) ) )
{
/* Too small, or not an exact size and
no 'mv' handler to check rest */
LOG (GNUNET_ERROR_TYPE_ERROR,
"Received malformed message of type %u\n",
(unsigned int) handler->type);
GNUNET_MQ_inject_error (mq,
GNUNET_MQ_ERROR_MALFORMED);
break;
}
if ( (NULL == handler->mv) ||
(GNUNET_OK ==
handler->mv (handler->cls, mh)) )
{
/* message well-formed, pass to handler */
handler->cb (handler->cls, mh);
}
else
{
/* Message rejected by check routine */
LOG (GNUNET_ERROR_TYPE_ERROR,
"Received malformed message of type %u\n",
(unsigned int) handler->type);
GNUNET_MQ_inject_error (mq,
GNUNET_MQ_ERROR_MALFORMED);
}
break;
}
}
done:
if (GNUNET_NO == handled)
LOG (GNUNET_ERROR_TYPE_INFO,
"No handler for message of type %u and size %u\n",
mtype, msize);
}
/**
* 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 by 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)
{
if (NULL == mq->error_handler)
{
LOG (GNUNET_ERROR_TYPE_WARNING,
"Got error %d, but no handler installed\n",
(int) error);
return;
}
mq->error_handler (mq->error_handler_cls,
error);
}
/**
* Discard the message queue message, free all
* allocated resources. Must be called in the event
* that a message is created but should not actually be sent.
*
* @param mqm the message to discard
*/
void
GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *ev)
{
GNUNET_assert (NULL == ev->parent_queue);
GNUNET_free (ev);
}
/**
* Obtain the current length of the message queue.
*
* @param mq queue to inspect
* @return number of queued, non-transmitted messages
*/
unsigned int
GNUNET_MQ_get_length (struct GNUNET_MQ_Handle *mq)
{
if (GNUNET_YES != mq->in_flight)
{
return mq->queue_length;
}
return mq->queue_length - 1;
}
/**
* Send a message with the given message queue.
* May only be called once per message.
*
* @param mq message queue
* @param ev the envelope with the message to send.
*/
void
GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq,
struct GNUNET_MQ_Envelope *ev)
{
GNUNET_assert (NULL != mq);
GNUNET_assert (NULL == ev->parent_queue);
mq->queue_length++;
GNUNET_break (mq->queue_length < 10000); /* This would seem like a bug... */
ev->parent_queue = mq;
/* is the implementation busy? queue it! */
if ( (NULL != mq->current_envelope) ||
(NULL != mq->send_task) )
{
GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head,
mq->envelope_tail,
ev);
return;
}
GNUNET_assert (NULL == mq->envelope_head);
mq->current_envelope = ev;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"sending message of type %u, queue empty (MQ: %p)\n",
ntohs(ev->mh->type),
mq);
mq->send_impl (mq,
ev->mh,
mq->impl_state);
}
/**
* Remove the first envelope that has not yet been sent from the message
* queue and return it.
*
* @param mq queue to remove envelope from
* @return NULL if queue is empty (or has no envelope that is not under transmission)
*/
struct GNUNET_MQ_Envelope *
GNUNET_MQ_unsent_head (struct GNUNET_MQ_Handle *mq)
{
struct GNUNET_MQ_Envelope *env;
env = mq->envelope_head;
GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
mq->envelope_tail,
env);
mq->queue_length--;
env->parent_queue = NULL;
return env;
}
/**
* Function to copy an envelope. The envelope must not yet
* be in any queue or have any options or callbacks set.
*
* @param env envelope to copy
* @return copy of @a env
*/
struct GNUNET_MQ_Envelope *
GNUNET_MQ_env_copy (struct GNUNET_MQ_Envelope *env)
{
GNUNET_assert (NULL == env->next);
GNUNET_assert (NULL == env->parent_queue);
GNUNET_assert (NULL == env->sent_cb);
GNUNET_assert (GNUNET_NO == env->have_custom_options);
return GNUNET_MQ_msg_copy (env->mh);
}
/**
* Send a copy of a message with the given message queue.
* Can be called repeatedly on the same envelope.
*
* @param mq message queue
* @param ev the envelope with the message to send.
*/
void
GNUNET_MQ_send_copy (struct GNUNET_MQ_Handle *mq,
const struct GNUNET_MQ_Envelope *ev)
{
struct GNUNET_MQ_Envelope *env;
uint16_t msize;
msize = ntohs (ev->mh->size);
env = GNUNET_malloc (sizeof (struct GNUNET_MQ_Envelope) +
msize);
env->mh = (struct GNUNET_MessageHeader *) &env[1];
env->sent_cb = ev->sent_cb;
env->sent_cls = ev->sent_cls;
GNUNET_memcpy (&env[1],
ev->mh,
msize);
GNUNET_MQ_send (mq,
env);
}
/**
* Task run to 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 cls message queue to send the next message with
*/
static void
impl_send_continue (void *cls)
{
struct GNUNET_MQ_Handle *mq = cls;
mq->send_task = NULL;
/* call is only valid if we're actually currently sending
* a message */
if (NULL == mq->envelope_head)
return;
mq->current_envelope = mq->envelope_head;
GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
mq->envelope_tail,
mq->current_envelope);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"sending message of type %u from queue\n",
ntohs(mq->current_envelope->mh->type));
mq->send_impl (mq,
mq->current_envelope->mh,
mq->impl_state);
}
/**
* 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)
{
struct GNUNET_MQ_Envelope *current_envelope;
GNUNET_SCHEDULER_TaskCallback cb;
GNUNET_assert (0 < mq->queue_length);
mq->queue_length--;
mq->in_flight = GNUNET_NO;
current_envelope = mq->current_envelope;
current_envelope->parent_queue = NULL;
mq->current_envelope = NULL;
GNUNET_assert (NULL == mq->send_task);
mq->send_task = GNUNET_SCHEDULER_add_now (&impl_send_continue,
mq);
if (NULL != (cb = current_envelope->sent_cb))
{
current_envelope->sent_cb = NULL;
cb (current_envelope->sent_cls);
}
GNUNET_free (current_envelope);
}
/**
* Call the send notification for the current message, but do not
* try to send the next message until #GNUNET_MQ_impl_send_continue
* is called.
*
* 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_in_flight (struct GNUNET_MQ_Handle *mq)
{
struct GNUNET_MQ_Envelope *current_envelope;
GNUNET_SCHEDULER_TaskCallback cb;
mq->in_flight = GNUNET_YES;
/* call is only valid if we're actually currently sending
* a message */
current_envelope = mq->current_envelope;
GNUNET_assert (NULL != current_envelope);
/* can't call cancel from now on anymore */
current_envelope->parent_queue = NULL;
if (NULL != (cb = current_envelope->sent_cb))
{
current_envelope->sent_cb = NULL;
cb (current_envelope->sent_cls);
}
}
/**
* Create a message queue for the specified handlers.
*
* @param send function the implements sending messages
* @param destroy function that implements destroying the queue
* @param cancel function that implements canceling a message
* @param impl_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 error_handler_cls closure for @a error_handler
* @return a new message queue
*/
struct GNUNET_MQ_Handle *
GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
GNUNET_MQ_DestroyImpl destroy,
GNUNET_MQ_CancelImpl cancel,
void *impl_state,
const struct GNUNET_MQ_MessageHandler *handlers,
GNUNET_MQ_ErrorHandler error_handler,
void *error_handler_cls)
{
struct GNUNET_MQ_Handle *mq;
mq = GNUNET_new (struct GNUNET_MQ_Handle);
mq->send_impl = send;
mq->destroy_impl = destroy;
mq->cancel_impl = cancel;
mq->handlers = GNUNET_MQ_copy_handlers (handlers);
mq->error_handler = error_handler;
mq->error_handler_cls = error_handler_cls;
mq->impl_state = impl_state;
return mq;
}
/**
* Change the closure argument in all of the `handlers` of the
* @a mq.
*
* @param mq to modify
* @param handlers_cls new closure to use
*/
void
GNUNET_MQ_set_handlers_closure (struct GNUNET_MQ_Handle *mq,
void *handlers_cls)
{
if (NULL == mq->handlers)
return;
for (unsigned int i=0;NULL != mq->handlers[i].cb; i++)
mq->handlers[i].cls = handlers_cls;
}
/**
* 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)
{
GNUNET_assert (NULL != mq->current_envelope);
GNUNET_assert (NULL != mq->current_envelope->mh);
return mq->current_envelope->mh;
}
/**
* 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)
{
return mq->impl_state;
}
struct GNUNET_MQ_Envelope *
GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp,
uint16_t size,
uint16_t type)
{
struct GNUNET_MQ_Envelope *ev;
ev = GNUNET_malloc (size + sizeof (struct GNUNET_MQ_Envelope));
ev->mh = (struct GNUNET_MessageHeader *) &ev[1];
ev->mh->size = htons (size);
ev->mh->type = htons (type);
if (NULL != mhp)
*mhp = ev->mh;
return ev;
}
/**
* Create a new envelope by copying an existing message.
*
* @param hdr header of the message to copy
* @return envelope containing @a hdr
*/
struct GNUNET_MQ_Envelope *
GNUNET_MQ_msg_copy (const struct GNUNET_MessageHeader *hdr)
{
struct GNUNET_MQ_Envelope *mqm;
uint16_t size = ntohs (hdr->size);
mqm = GNUNET_malloc (sizeof (*mqm) + size);
mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
GNUNET_memcpy (mqm->mh,
hdr,
size);
return mqm;
}
/**
* 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)
{
struct GNUNET_MQ_Envelope *mqm;
uint16_t size;
if (NULL == nested_mh)
return GNUNET_MQ_msg_ (mhp, base_size, type);
size = base_size + ntohs (nested_mh->size);
/* check for uint16_t overflow */
if (size < base_size)
return NULL;
mqm = GNUNET_MQ_msg_ (mhp, size, type);
GNUNET_memcpy ((char *) mqm->mh + base_size,
nested_mh,
ntohs (nested_mh->size));
return mqm;
}
/**
* Associate the assoc_data in mq with a unique request id.
*
* @param mq message queue, id will be unique for the queue
* @param assoc_data to associate
*/
uint32_t
GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq,
void *assoc_data)
{
uint32_t id;
if (NULL == mq->assoc_map)
{
mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8);
mq->assoc_id = 1;
}
id = mq->assoc_id++;
GNUNET_assert (GNUNET_OK ==
GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map,
id,
assoc_data,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
return id;
}
/**
* Get the data associated with a @a request_id in a queue
*
* @param mq the message queue with the association
* @param request_id the request id we are interested in
* @return the associated data
*/
void *
GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq,
uint32_t request_id)
{
if (NULL == mq->assoc_map)
return NULL;
return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map,
request_id);
}
/**
* Remove the association for a @a request_id
*
* @param mq the message queue with the association
* @param request_id the request id we want to remove
* @return the associated data
*/
void *
GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq,
uint32_t request_id)
{
void *val;
if (NULL == mq->assoc_map)
return NULL;
val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map,
request_id);
GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map,
request_id);
return val;
}
/**
* 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 ev message to call the notify callback for
* @param cb the notify callback
* @param cb_cls closure for the callback
*/
void
GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *ev,
GNUNET_SCHEDULER_TaskCallback cb,
void *cb_cls)
{
/* allow setting *OR* clearing callback */
GNUNET_assert ( (NULL == ev->sent_cb) ||
(NULL == cb) );
ev->sent_cb = cb;
ev->sent_cls = cb_cls;
}
/**
* Handle we return for callbacks registered to be
* notified when #GNUNET_MQ_destroy() is called on a queue.
*/
struct GNUNET_MQ_DestroyNotificationHandle
{
/**
* Kept in a DLL.
*/
struct GNUNET_MQ_DestroyNotificationHandle *prev;
/**
* Kept in a DLL.
*/
struct GNUNET_MQ_DestroyNotificationHandle *next;
/**
* Queue to notify about.
*/
struct GNUNET_MQ_Handle *mq;
/**
* Function to call.
*/
GNUNET_SCHEDULER_TaskCallback cb;
/**
* Closure for @e cb.
*/
void *cb_cls;
};
/**
* Destroy the message queue.
*
* @param mq message queue to destroy
*/
void
GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq)
{
struct GNUNET_MQ_DestroyNotificationHandle *dnh;
if (NULL != mq->destroy_impl)
{
mq->destroy_impl (mq, mq->impl_state);
}
if (NULL != mq->send_task)
{
GNUNET_SCHEDULER_cancel (mq->send_task);
mq->send_task = NULL;
}
while (NULL != mq->envelope_head)
{
struct GNUNET_MQ_Envelope *ev;
ev = mq->envelope_head;
ev->parent_queue = NULL;
GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
mq->envelope_tail,
ev);
GNUNET_assert (0 < mq->queue_length);
mq->queue_length--;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"MQ destroy drops message of type %u\n",
ntohs (ev->mh->type));
GNUNET_MQ_discard (ev);
}
if (NULL != mq->current_envelope)
{
/* we can only discard envelopes that
* are not queued! */
mq->current_envelope->parent_queue = NULL;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"MQ destroy drops current message of type %u\n",
ntohs (mq->current_envelope->mh->type));
GNUNET_MQ_discard (mq->current_envelope);
mq->current_envelope = NULL;
GNUNET_assert (0 < mq->queue_length);
mq->queue_length--;
}
GNUNET_assert (0 == mq->queue_length);
while (NULL != (dnh = mq->dnh_head))
{
dnh->cb (dnh->cb_cls);
GNUNET_MQ_destroy_notify_cancel (dnh);
}
if (NULL != mq->assoc_map)
{
GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map);
mq->assoc_map = NULL;
}
GNUNET_free_non_null (mq->handlers);
GNUNET_free (mq);
}
const struct GNUNET_MessageHeader *
GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh,
uint16_t base_size)
{
uint16_t whole_size;
uint16_t nested_size;
const struct GNUNET_MessageHeader *nested_msg;
whole_size = ntohs (mh->size);
GNUNET_assert (whole_size >= base_size);
nested_size = whole_size - base_size;
if (0 == nested_size)
return NULL;
if (nested_size < sizeof (struct GNUNET_MessageHeader))
{
GNUNET_break_op (0);
return NULL;
}
nested_msg = (const struct GNUNET_MessageHeader *) ((char *) mh + base_size);
if (ntohs (nested_msg->size) != nested_size)
{
GNUNET_break_op (0);
return NULL;
}
return nested_msg;
}
/**
* 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 ev queued envelope to cancel
*/
void
GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev)
{
struct GNUNET_MQ_Handle *mq = ev->parent_queue;
GNUNET_assert (NULL != mq);
GNUNET_assert (NULL != mq->cancel_impl);
mq->evacuate_called = GNUNET_NO;
if (mq->current_envelope == ev)
{
/* complex case, we already started with transmitting
the message using the callbacks. */
GNUNET_assert (0 < mq->queue_length);
mq->queue_length--;
mq->cancel_impl (mq,
mq->impl_state);
/* continue sending the next message, if any */
mq->current_envelope = mq->envelope_head;
if (NULL != mq->current_envelope)
{
GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
mq->envelope_tail,
mq->current_envelope);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"sending canceled message of type %u queue\n",
ntohs(ev->mh->type));
mq->send_impl (mq,
mq->current_envelope->mh,
mq->impl_state);
}
}
else
{
/* simple case, message is still waiting in the queue */
GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
mq->envelope_tail,
ev);
GNUNET_assert (0 < mq->queue_length);
mq->queue_length--;
}
if (GNUNET_YES != mq->evacuate_called)
{
ev->parent_queue = NULL;
ev->mh = NULL;
/* also frees ev */
GNUNET_free (ev);
}
}
/**
* Function to obtain the current envelope
* from within #GNUNET_MQ_SendImpl implementations.
*
* @param mq message queue to interrogate
* @return the current envelope
*/
struct GNUNET_MQ_Envelope *
GNUNET_MQ_get_current_envelope (struct GNUNET_MQ_Handle *mq)
{
return mq->current_envelope;
}
/**
* Function to obtain the last envelope in the queue.
*
* @param mq message queue to interrogate
* @return the last envelope in the queue
*/
struct GNUNET_MQ_Envelope *
GNUNET_MQ_get_last_envelope (struct GNUNET_MQ_Handle *mq)
{
if (NULL != mq->envelope_tail)
return mq->envelope_tail;
return mq->current_envelope;
}
/**
* Set application-specific options for this envelope.
* Overrides the options set for the queue with
* #GNUNET_MQ_set_options() for this message only.
*
* @param env message to set options for
* @param flags flags to use (meaning is queue-specific)
* @param extra additional buffer for further data (also queue-specific)
*/
void
GNUNET_MQ_env_set_options (struct GNUNET_MQ_Envelope *env,
uint64_t flags,
const void *extra)
{
env->flags = flags;
env->extra = extra;
env->have_custom_options = GNUNET_YES;
}
/**
* Get application-specific options for this envelope.
*
* @param env message to set options for
* @param[out] flags set to flags to use (meaning is queue-specific)
* @return extra additional buffer for further data (also queue-specific)
*/
const void *
GNUNET_MQ_env_get_options (struct GNUNET_MQ_Envelope *env,
uint64_t *flags)
{
struct GNUNET_MQ_Handle *mq = env->parent_queue;
if (GNUNET_YES == env->have_custom_options)
{
*flags = env->flags;
return env->extra;
}
if (NULL == mq)
{
*flags = 0;
return NULL;
}
*flags = mq->default_flags;
return mq->default_extra;
}
/**
* Set application-specific options for this queue.
*
* @param mq message queue to set options for
* @param flags flags to use (meaning is queue-specific)
* @param extra additional buffer for further data (also queue-specific)
*/
void
GNUNET_MQ_set_options (struct GNUNET_MQ_Handle *mq,
uint64_t flags,
const void *extra)
{
mq->default_flags = flags;
mq->default_extra = extra;
}
/**
* Obtain message contained in envelope.
*
* @param env the envelope
* @return message contained in the envelope
*/
const struct GNUNET_MessageHeader *
GNUNET_MQ_env_get_msg (const struct GNUNET_MQ_Envelope *env)
{
return env->mh;
}
/**
* Return next envelope in queue.
*
* @param env a queued envelope
* @return next one, or NULL
*/
const struct GNUNET_MQ_Envelope *
GNUNET_MQ_env_next (const struct GNUNET_MQ_Envelope *env)
{
return env->next;
}
/**
* Register function to be called whenever @a mq is being
* destroyed.
*
* @param mq message queue to watch
* @param cb function to call on @a mq destruction
* @param cb_cls closure for @a cb
* @return handle for #GNUNET_MQ_destroy_notify_cancel().
*/
struct GNUNET_MQ_DestroyNotificationHandle *
GNUNET_MQ_destroy_notify (struct GNUNET_MQ_Handle *mq,
GNUNET_SCHEDULER_TaskCallback cb,
void *cb_cls)
{
struct GNUNET_MQ_DestroyNotificationHandle *dnh;
dnh = GNUNET_new (struct GNUNET_MQ_DestroyNotificationHandle);
dnh->mq = mq;
dnh->cb = cb;
dnh->cb_cls = cb_cls;
GNUNET_CONTAINER_DLL_insert (mq->dnh_head,
mq->dnh_tail,
dnh);
return dnh;
}
/**
* Cancel registration from #GNUNET_MQ_destroy_notify().
*
* @param dnh handle for registration to cancel
*/
void
GNUNET_MQ_destroy_notify_cancel (struct GNUNET_MQ_DestroyNotificationHandle *dnh)
{
struct GNUNET_MQ_Handle *mq = dnh->mq;
GNUNET_CONTAINER_DLL_remove (mq->dnh_head,
mq->dnh_tail,
dnh);
GNUNET_free (dnh);
}
/**
* Insert @a env into the envelope DLL starting at @a env_head
* Note that @a env must not be in any MQ while this function
* is used with DLLs defined outside of the MQ module. This
* is just in case some application needs to also manage a
* FIFO of envelopes independent of MQ itself and wants to
* re-use the pointers internal to @a env. Use with caution.
*
* @param[in|out] env_head of envelope DLL
* @param[in|out] env_tail tail of envelope DLL
* @param[in|out] env element to insert at the tail
*/
void
GNUNET_MQ_dll_insert_tail (struct GNUNET_MQ_Envelope **env_head,
struct GNUNET_MQ_Envelope **env_tail,
struct GNUNET_MQ_Envelope *env)
{
GNUNET_CONTAINER_DLL_insert_tail (*env_head,
*env_tail,
env);
}
/**
* Remove @a env from the envelope DLL starting at @a env_head.
* Note that @a env must not be in any MQ while this function
* is used with DLLs defined outside of the MQ module. This
* is just in case some application needs to also manage a
* FIFO of envelopes independent of MQ itself and wants to
* re-use the pointers internal to @a env. Use with caution.
*
* @param[in|out] env_head of envelope DLL
* @param[in|out] env_tail tail of envelope DLL
* @param[in|out] env element to remove from the DLL
*/
void
GNUNET_MQ_dll_remove (struct GNUNET_MQ_Envelope **env_head,
struct GNUNET_MQ_Envelope **env_tail,
struct GNUNET_MQ_Envelope *env)
{
GNUNET_CONTAINER_DLL_remove (*env_head,
*env_tail,
env);
}
/**
* Copy an array of handlers.
*
* Useful if the array has been delared in local memory and needs to be
* persisted for future use.
*
* @param handlers Array of handlers to be copied. Can be NULL (nothing done).
* @return A newly allocated array of handlers.
* Needs to be freed with #GNUNET_free.
*/
struct GNUNET_MQ_MessageHandler *
GNUNET_MQ_copy_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
{
struct GNUNET_MQ_MessageHandler *copy;
unsigned int count;
if (NULL == handlers)
return NULL;
count = GNUNET_MQ_count_handlers (handlers);
copy = GNUNET_new_array (count + 1,
struct GNUNET_MQ_MessageHandler);
GNUNET_memcpy (copy,
handlers,
count * sizeof (struct GNUNET_MQ_MessageHandler));
return copy;
}
/**
* Copy an array of handlers, appending AGPL handler.
*
* Useful if the array has been delared in local memory and needs to be
* persisted for future use.
*
* @param handlers Array of handlers to be copied. Can be NULL (nothing done).
* @param agpl_handler function to call for AGPL handling
* @param agpl_cls closure for @a agpl_handler
* @return A newly allocated array of handlers.
* Needs to be freed with #GNUNET_free.
*/
struct GNUNET_MQ_MessageHandler *
GNUNET_MQ_copy_handlers2 (const struct GNUNET_MQ_MessageHandler *handlers,
GNUNET_MQ_MessageCallback agpl_handler,
void *agpl_cls)
{
struct GNUNET_MQ_MessageHandler *copy;
unsigned int count;
if (NULL == handlers)
return NULL;
count = GNUNET_MQ_count_handlers (handlers);
copy = GNUNET_new_array (count + 2,
struct GNUNET_MQ_MessageHandler);
GNUNET_memcpy (copy,
handlers,
count * sizeof (struct GNUNET_MQ_MessageHandler));
copy[count].mv = NULL;
copy[count].cb = agpl_handler;
copy[count].cls = agpl_cls;
copy[count].type = GNUNET_MESSAGE_TYPE_REQUEST_AGPL;
copy[count].expected_size = sizeof (struct GNUNET_MessageHeader);
return copy;
}
/**
* Count the handlers in a handler array.
*
* @param handlers Array of handlers to be counted.
* @return The number of handlers in the array.
*/
unsigned int
GNUNET_MQ_count_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
{
unsigned int i;
if (NULL == handlers)
return 0;
for (i=0; NULL != handlers[i].cb; i++) ;
return i;
}
/* end of mq.c */