/*
This file is part of GNUnet.
- (C) 2012-2013 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2012-2016 GNUnet e.V.
- 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 3, or (at your
- option) any later version.
+ 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
- General Public License for more details.
+ Affero General Public License for more details.
- 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.
+ 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/>.
+
+ SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @author Florian Dold
- * @file include/gnunet_mq_lib.h
- * @brief general purpose message queue
- * @defgroup mq general purpose message queue
+ * @author Christian Grothoff
+ *
+ * @file
+ * General-purpose message queue
+ *
+ * @defgroup mq MQ library
+ * General-purpose message queue
+ *
+ * @see [Documentation](https://gnunet.org/message-queue-api)
+ *
* @{
*/
-#ifndef GNUNET_MQ_H
-#define GNUNET_MQ_H
+#ifndef GNUNET_MQ_LIB_H
+#define GNUNET_MQ_LIB_H
+#include "gnunet_scheduler_lib.h"
/**
* Allocate an envelope, with extra space allocated after the space needed
* The allocated message will already have the type and size field set.
*
* @param mvar variable to store the allocated message in;
- * must have a header field
+ * must have a header field;
+ * can be NULL
* @param esize extra space to allocate after the message
* @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_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
+ * must have a header field;
+ * can be NULL
* @param type type of the message
* @return the allocated envelope
*/
-#define GNUNET_MQ_msg(mvar, type) GNUNET_MQ_msg_extra(mvar, 0, type)
+#define GNUNET_MQ_msg(mvar, type) GNUNET_MQ_msg_extra (mvar, 0, type)
/**
*
* @param type type of the message
*/
-#define GNUNET_MQ_msg_header(type) GNUNET_MQ_msg_ (NULL, sizeof (struct GNUNET_MessageHeader), type)
+#define GNUNET_MQ_msg_header(type) \
+ GNUNET_MQ_msg_ (NULL, sizeof (struct GNUNET_MessageHeader), type)
/**
* @param esize extra space to allocate after the message header
* @param type type of the message
*/
-#define GNUNET_MQ_msg_header_extra(mh, esize, type) GNUNET_MQ_msg_ (&mh, (esize) + sizeof (struct GNUNET_MessageHeader), type)
+#define GNUNET_MQ_msg_header_extra(mh, esize, type) \
+ GNUNET_MQ_msg_ (&mh, (esize) + sizeof (struct GNUNET_MessageHeader), type)
/**
* @param mh message to nest
* @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)
+#define GNUNET_MQ_msg_nested_mh(mvar, type, mh) \
+ ({ \
+ struct GNUNET_MQ_Envelope *_ev; \
+ _ev = GNUNET_MQ_msg_nested_mh_ ((struct GNUNET_MessageHeader **) &(mvar), \
+ sizeof (*(mvar)), \
+ (type), \
+ (mh)); \
+ (void) (mvar)->header; /* type check */ \
+ _ev; \
+ })
/**
* @return a 'struct GNUNET_MessageHeader *' that points at the nested message of the given message,
* 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)))
+#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.
+ * 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
+ * OR NULL in case of a malformed message.
+ */
+const struct GNUNET_MessageHeader *
+GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh,
+ uint16_t base_size);
+
+
+/**
+ * Opaque handle to an envelope.
+ */
+struct GNUNET_MQ_Envelope;
+
+
+/**
+ * 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 next envelope in queue.
+ *
+ * @param env a queued envelope
+ * @return next one, or NULL
*/
-struct GNUNET_MessageHeader *
-GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh, uint16_t base_size);
+const struct GNUNET_MQ_Envelope *
+GNUNET_MQ_env_next (const struct GNUNET_MQ_Envelope *env);
/**
- * Implementation of the GNUNET_MQ_msg_nested_mh macro.
+ * 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 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,
+GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp,
+ uint16_t base_size,
+ uint16_t type,
const struct GNUNET_MessageHeader *nested_mh);
-
-/**
- * End-marker for the handlers array
- */
-#define GNUNET_MQ_HANDLERS_END {NULL, 0, 0}
-
-
/**
* Opaque handle to a message queue.
*/
struct GNUNET_MQ_Handle;
-/**
- * Opaque handle to an envelope.
- */
-struct GNUNET_MQ_Envelope;
-
/**
* Error codes for the queue.
- */
+ */
enum GNUNET_MQ_Error
{
/**
- * FIXME: document!
- */
+ * Failed to read message from the network.
+ * FIXME: Likely not properly distinguished
+ * from TIMEOUT case in the code!
+ */
GNUNET_MQ_ERROR_READ = 1,
/**
* FIXME: document!
- */
+ */
GNUNET_MQ_ERROR_WRITE = 2,
/**
* FIXME: document!
- */
- GNUNET_MQ_ERROR_TIMEOUT = 4
+ */
+ GNUNET_MQ_ERROR_TIMEOUT = 4,
+
+ /**
+ * We received a message that was malformed and thus
+ * could not be passed to its handler.
+ */
+ GNUNET_MQ_ERROR_MALFORMED = 8,
+
+ /**
+ * We received a message for which we have no matching
+ * handler.
+ */
+ GNUNET_MQ_ERROR_NO_MATCH = 16
+};
+
+
+/**
+ * Per envelope preferences and priorities.
+ */
+enum GNUNET_MQ_PriorityPreferences
+{
+
+ /**
+ * Lowest priority, i.e. background traffic (i.e. NSE, FS).
+ * This is the default!
+ */
+ GNUNET_MQ_PRIO_BACKGROUND = 0,
+
+ /**
+ * Best-effort traffic (i.e. CADET relay, DHT)
+ */
+ GNUNET_MQ_PRIO_BEST_EFFORT = 1,
+
+ /**
+ * Urgent traffic (local peer, i.e. Conversation).
+ */
+ GNUNET_MQ_PRIO_URGENT = 2,
+
+ /**
+ * Highest priority, control traffic (i.e. CORE/CADET KX).
+ */
+ GNUNET_MQ_PRIO_CRITICAL_CONTROL = 3,
+
+ /**
+ * Bit mask to apply to extract the priority bits.
+ */
+ GNUNET_MQ_PRIORITY_MASK = 3,
+
+ /**
+ * Flag to indicate that unreliable delivery is acceptable. This
+ * means TRANSPORT will not attempt to receive an
+ * acknowledgment. CORE will just pass this flag through. CADET
+ * will use unreliable delivery if this flag is set.
+ *
+ * Note that even without this flag, messages may be lost by
+ * TRANSPORT and CORE.
+ *
+ * Thus, how "strong" the semantics of reliable delivery are depends
+ * on the layer!
+ */
+ GNUNET_MQ_PREF_UNRELIABLE = 16,
+
+ /**
+ * Flag to indicate that low latency is important. This flag must
+ * generally not be used in combination with
+ * #GNUNET_MQ_PREF_CORKING_ALLOWED as it would be a contradiction.
+ * When this flags is set, the envelope may skip forward in the
+ * queue (depending on priority) and also TRANSPORT should attempt
+ * to pick a communicator with particularly low latency.
+ */
+ GNUNET_MQ_PREF_LOW_LATENCY = 32,
+
+ /**
+ * Flag to indicate that CORKing is acceptable. This allows the
+ * receiver to delay transmission in hope of combining this message
+ * with other messages into a larger transmission with less
+ * per-message overhead.
+ */
+ GNUNET_MQ_PREF_CORK_ALLOWED = 64,
+
+ /**
+ * Flag to indicate that high bandwidth is desired. This flag
+ * indicates that the method chosen for transmission should focus on
+ * overall goodput. It rarely makes sense to combine this flag with
+ * #GNUNET_MQ_PREF_LOW_LATENCY.
+ */
+ GNUNET_MQ_PREF_GOODPUT = 128,
+
+ /**
+ * Flag to indicate that out-of-order delivery is OK.
+ */
+ GNUNET_MQ_PREF_OUT_OF_ORDER = 256,
+
+ /**
+ * Flag to indicate no buffering.
+ */
+ GNUNET_MQ_PREF_NO_BUFFER = 512,
+
+ /**
+ * Flag to indicate default
+ */
+ GNUNET_MQ_PREF_DEFAULT = 1024,
+
+ /**
+ * Flag to indicate reliable
+ */
+ GNUNET_MQ_PREF_RELIABLE = 2048
+
};
* @param cls closure
* @param msg the received message
*/
-typedef void
-(*GNUNET_MQ_MessageCallback) (void *cls,
- const struct GNUNET_MessageHeader *msg);
+typedef void (*GNUNET_MQ_MessageCallback) (
+ void *cls,
+ const struct GNUNET_MessageHeader *msg);
+
+
+/**
+ * Called when a message needs to be validated.
+ *
+ * @param cls closure
+ * @param msg the received message
+ * @return #GNUNET_OK if the message is well-formed,
+ * #GNUNET_SYSERR if not
+ */
+typedef int (*GNUNET_MQ_MessageValidationCallback) (
+ void *cls,
+ const struct GNUNET_MessageHeader *msg);
/**
* @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);
+typedef void (*GNUNET_MQ_SendImpl) (struct GNUNET_MQ_Handle *mq,
+ const struct GNUNET_MessageHeader *msg,
+ void *impl_state);
/**
* 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_Handle *mq, void *impl_state);
+typedef void (*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_CancelImpl) (struct GNUNET_MQ_Handle *mq, void *impl_state);
+typedef void (*GNUNET_MQ_CancelImpl) (struct GNUNET_MQ_Handle *mq,
+ void *impl_state);
/**
- * Callback used for notifications
+ * 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
+ * @param error error code
*/
-typedef void
-(*GNUNET_MQ_NotifyCallback) (void *cls);
+typedef void (*GNUNET_MQ_ErrorHandler) (void *cls, enum GNUNET_MQ_Error error);
/**
- * 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.
+ * 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 cls closure, same closure as for the message handlers
- * @param error error code
+ * @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);
+
+
+/**
+ * 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);
+
+
+/**
+ * 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.
+ * @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);
+
+
+/**
+ * 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.
*/
-typedef void
-(*GNUNET_MQ_ErrorHandler) (void *cls, enum GNUNET_MQ_Error error);
+struct GNUNET_MQ_MessageHandler *
+GNUNET_MQ_copy_handlers2 (const struct GNUNET_MQ_MessageHandler *handlers,
+ GNUNET_MQ_MessageCallback agpl_handler,
+ void *agpl_cls);
+
+
+/**
+ * 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);
/**
struct GNUNET_MQ_MessageHandler
{
/**
- * Callback, called every time a new message of
- * the specified type has been receied.
+ * Callback to validate a message of the specified @e type.
+ * The closure given to @e mv will be this struct (not @e ctx).
+ * Using NULL means only size-validation using
+ * @e expected_size. In this case, @e expected_size must
+ * be non-zero.
+ */
+ GNUNET_MQ_MessageValidationCallback mv;
+
+ /**
+ * Callback, called every time a new message of
+ * the specified @e type has been receied.
+ * The closure given to @e mv will be this struct (not @e ctx).
*/
GNUNET_MQ_MessageCallback cb;
/**
- * Type of the message this handler covers.
+ * Closure for @e mv and @e cb.
+ */
+ void *cls;
+
+ /**
+ * Type of the message this handler covers, in host byte order.
*/
uint16_t type;
/**
- * Expected size of messages of this type. Use 0 for
- * variable-size. If non-zero, messages of the given
- * type will be discarded (and the connection closed)
- * if they do not have the right size.
+ * Expected size of messages of this type. Minimum size of the
+ * message if @e mv is non-NULL. Messages of the given type will be
+ * discarded (and the connection closed with an error reported to
+ * the application) if they do not have the right size.
*/
uint16_t expected_size;
};
+/**
+ * End-marker for the handlers array
+ */
+#define GNUNET_MQ_handler_end() \
+ { \
+ NULL, NULL, NULL, 0, 0 \
+ }
+
+
+/**
+ * Defines a static function @a name which takes as a single argument
+ * a message handler for fixed-sized messages of type @a code and with
+ * a message type argument of @a str. Given such an argument, the
+ * function @name will return a `struct GNUNET_MQ_MessageHandler`
+ * for the given message type.
+ *
+ * The macro is to be used as follows:
+ * <code>
+ * struct GNUNET_MessageTest { ... }; // must be fixed size
+ * static void
+ * handle_test_message (void *cls,
+ * const struct GNUNET_MessageTest *msg)
+ * { ... }
+ *
+ * struct GNUNET_MQ_MessageHandler handlers[] = {
+ * GNUNET_MQ_hd_fixed_size(test_message,
+ * GNUNET_MESSAGE_TYPE_TEST,
+ * struct GNUNET_MessageTest,
+ * "context"),
+ * GNUNET_MQ_handler_end()
+ * };
+ *
+ * @param name unique basename for the functions
+ * @param code message type constant
+ * @param str type of the message (a struct)
+ * @param ctx context for the callbacks
+ */
+#define GNUNET_MQ_hd_fixed_size(name, code, str, ctx) \
+ ({ \
+ void (*_cb) (void *cls, const str *msg) = &handle_##name; \
+ ((struct GNUNET_MQ_MessageHandler){NULL, \
+ (GNUNET_MQ_MessageCallback) _cb, \
+ (ctx), \
+ (code), \
+ sizeof (str)}); \
+ })
+
+
+/**
+ * Defines a static function @a name which takes two arguments and a
+ * context-pointer for validating and handling variable-sized messages
+ * of type @a code and with a message type argument of @a str. Given
+ * such arguments, the function @name will return a `struct
+ * GNUNET_MQ_MessageHandler` for the given message type.
+ *
+ * The macro is to be used as follows:
+ * <code>
+ * struct GNUNET_MessageTest { ... }; // can be variable size
+ * static int
+ * check_test (void *cls,
+ * const struct GNUNET_MessageTest *msg)
+ * {
+ * const char *ctx = cls;
+ * GNUNET_assert (0 == strcmp ("context", ctx));
+ * // ...
+ * }
+ * static void
+ * handle_test (void *cls,
+ * const struct GNUNET_MessageTest *msg)
+ * {
+ * const char *ctx = cls;
+ * GNUNET_assert (0 == strcmp ("context", ctx));
+ * // ...
+ * }
+ *
+ * struct GNUNET_MQ_MessageHandler handlers[] = {
+ * GNUNET_MQ_hd_var_size(test_message,
+ * GNUNET_MESSAGE_TYPE_TEST,
+ * struct GNUNET_MessageTest,
+ * "context"),
+ * GNUNET_MQ_handler_end()
+ * };
+ *
+ * @param name unique basename for the functions
+ * @param code message type constant
+ * @param str type of the message (a struct)
+ * @param ctx context for the callbacks
+ */
+#define GNUNET_MQ_hd_var_size(name, code, str, ctx) \
+ __extension__({ \
+ int (*_mv) (void *cls, const str *msg) = &check_##name; \
+ void (*_cb) (void *cls, const str *msg) = &handle_##name; \
+ ((struct GNUNET_MQ_MessageHandler){(GNUNET_MQ_MessageValidationCallback) \
+ _mv, \
+ (GNUNET_MQ_MessageCallback) _cb, \
+ (ctx), \
+ (code), \
+ sizeof (str)}); \
+ })
+
+
+/**
+ * Insert code for a "check_" function that verifies that
+ * a given variable-length message received over the network
+ * is followed by a 0-terminated string. If the message @a m
+ * is not followed by a 0-terminated string, an error is logged
+ * and the function is returned with #GNUNET_NO.
+ *
+ * @param an IPC message with proper type to determine
+ * the size, starting with a `struct GNUNET_MessageHeader`
+ */
+#define GNUNET_MQ_check_zero_termination(m) \
+ { \
+ const char *str = (const char *) &m[1]; \
+ const struct GNUNET_MessageHeader *hdr = \
+ (const struct GNUNET_MessageHeader *) m; \
+ uint16_t slen = ntohs (hdr->size) - sizeof (*m); \
+ if ((0 == slen) || (memchr (str, 0, slen) != &str[slen - 1])) \
+ { \
+ GNUNET_break (0); \
+ return GNUNET_NO; \
+ } \
+ }
+
+
+/**
+ * Insert code for a "check_" function that verifies that
+ * a given variable-length message received over the network
+ * is followed by another variable-length message that fits
+ * exactly with the given size. If the message @a m
+ * is not followed by another `struct GNUNET_MessageHeader`
+ * with a size that adds up to the total size, an error is logged
+ * and the function is returned with #GNUNET_NO.
+ *
+ * @param an IPC message with proper type to determine
+ * the size, starting with a `struct GNUNET_MessageHeader`
+ */
+#define GNUNET_MQ_check_boxed_message(m) \
+ { \
+ const struct GNUNET_MessageHeader *inbox = \
+ (const struct GNUNET_MessageHeader *) &m[1]; \
+ const struct GNUNET_MessageHeader *hdr = \
+ (const struct GNUNET_MessageHeader *) m; \
+ uint16_t slen = ntohs (hdr->size) - sizeof (*m); \
+ if ((slen < sizeof (struct GNUNET_MessageHeader)) || \
+ (slen != ntohs (inbox->size))) \
+ { \
+ GNUNET_break (0); \
+ return GNUNET_NO; \
+ } \
+ }
+
+
+/**
+ * Call the message message handler that was registered
+ * for the type of the given message in the given @a handlers list.
+ *
+ * This function is indended to be used for the implementation
+ * of message queues.
+ *
+ * @param handlers a set of handlers
+ * @param mh message to dispatch
+ * @return #GNUNET_OK on success, #GNUNET_NO if no handler matched,
+ * #GNUNET_SYSERR if message was rejected by check function
+ */
+int
+GNUNET_MQ_handle_message (const struct GNUNET_MQ_MessageHandler *handlers,
+ const struct GNUNET_MessageHeader *mh);
+
/**
* 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_Envelope *
-GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type);
+GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp,
+ uint16_t size,
+ uint16_t type);
+
+
+/**
+ * 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);
/**
/**
- * Send a message with the give message queue.
+ * 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);
+
+
+/**
+ * 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);
+
+
+/**
+ * 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);
+
+
+/**
+ * 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 pp priority and preferences to set for @a env
+ */
+void
+GNUNET_MQ_env_set_options (struct GNUNET_MQ_Envelope *env,
+ enum GNUNET_MQ_PriorityPreferences pp);
+
+
+/**
+ * Get performance preferences set for this envelope.
+ *
+ * @param env message to set options for
+ * @return priority and preferences to use
+ */
+enum GNUNET_MQ_PriorityPreferences
+GNUNET_MQ_env_get_options (struct GNUNET_MQ_Envelope *env);
+
+
+/**
+ * Combine performance preferences set for different
+ * envelopes that are being combined into one larger envelope.
+ *
+ * @param p1 one set of preferences
+ * @param p2 second set of preferences
+ * @return combined priority and preferences to use
+ */
+enum GNUNET_MQ_PriorityPreferences
+GNUNET_MQ_env_combine_options (enum GNUNET_MQ_PriorityPreferences p1,
+ enum GNUNET_MQ_PriorityPreferences p2);
+
+
+/**
+ * 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);
+
+
+/**
+ * Set application-specific options for this queue.
+ *
+ * @param mq message queue to set options for
+ * @param pp priority and preferences to use by default
+ */
+void
+GNUNET_MQ_set_options (struct GNUNET_MQ_Handle *mq,
+ enum GNUNET_MQ_PriorityPreferences pp);
+
+
+/**
+ * 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);
+
+
+/**
+ * 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_MQ_send (struct GNUNET_MQ_Handle *mq, struct GNUNET_MQ_Envelope *ev);
+
+
+/**
+ * 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);
/**
/**
- * Associate the assoc_data in mq with a unique request id.
+ * Associate the assoc_data in @a mq with a unique request id.
*
* @param mq message queue, id will be unique for the queue
* @param assoc_data to associate
/**
- * Get the data associated with a request id in a queue
+ * 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
/**
- * Remove the association for a 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
GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq, uint32_t request_id);
-/**
- * Create a message queue for a GNUNET_CLIENT_Connection.
- * If handlers are specfied, receive messages from the connection.
- *
- * @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_Handle *
-GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection,
- const struct GNUNET_MQ_MessageHandler *handlers,
- GNUNET_MQ_ErrorHandler error_handler,
- void *cls);
-
-
-/**
- * Create a message queue for a GNUNET_SERVER_Client.
- *
- * @param client the client
- * @return the message queue
- */
-struct GNUNET_MQ_Handle *
-GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client);
-
-
/**
* Create a message queue for the specified 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.
- *
- * If the message queue does not support receiving messages,
- * this function has no effect.
+ * Change the closure argument in all of the `handlers` of the
+ * @a mq.
*
- * @param mq message queue
- * @param new_handlers new handlers
- * @param cls new closure for the handlers
+ * @param mq to modify
+ * @param handlers_cls new closure to use
*/
void
-GNUNET_MQ_replace_handlers (struct GNUNET_MQ_Handle *mq,
- const struct GNUNET_MQ_MessageHandler *new_handlers,
- void *cls);
+GNUNET_MQ_set_handlers_closure (struct GNUNET_MQ_Handle *mq,
+ void *handlers_cls);
/**
*
* @param ev message to call the notify callback for
* @param cb the notify callback
- * @param cls closure for the callback
+ * @param cb_cls closure for the callback
*/
void
GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *ev,
- GNUNET_MQ_NotifyCallback cb,
- void *cls);
+ GNUNET_SCHEDULER_TaskCallback cb,
+ void *cb_cls);
/**
GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq);
+/**
+ * Handle we return for callbacks registered to be
+ * notified when #GNUNET_MQ_destroy() is called on a queue.
+ */
+struct GNUNET_MQ_DestroyNotificationHandle;
+
+
+/**
+ * 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);
+
+/**
+ * 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);
+
+
/**
* Call the message message handler that was registered
* for the type of the given message in the given message queue.
/**
- * 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.
+ * Call the send implementation for the next queued message, if any.
+ * Calls the send notification for the current message unless
+ * #GNUNET_MQ_impl_send_in_flight was called for this envelope.
+ *
+ * Only useful for implementing message queues, results in undefined
+ * behavior if not used carefully.
*
* @param mq message queue to send the next message with
*/
/**
- * 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.
+ * 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.
*
- * @param mq message queue with the current message
- * @return message to send, never NULL
+ * Only useful for implementing message queues, results in undefined
+ * behavior if not used carefully.
+ *
+ * @param mq message queue to send the next message with
*/
-const struct GNUNET_MessageHeader *
-GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq);
+void
+GNUNET_MQ_impl_send_in_flight (struct GNUNET_MQ_Handle *mq);
/**
* 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
+ * implementation state when only passing the `struct GNUNET_MQ_Handle`
* as closure.
*
* @param mq message queue with the current message
/**
- * 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.
+ * 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);
+
+
+/**
+ * Enum defining all known preference categories.
*
- * @param mq message queue
+ * @deprecated will be replaced by `enum GNUNET_MQ_PriorityPreference`
*/
-void
-GNUNET_MQ_impl_send_commit (struct GNUNET_MQ_Handle *mq);
+enum GNUNET_MQ_PreferenceKind
+{
+
+ /**
+ * No preference was expressed.
+ */
+ GNUNET_MQ_PREFERENCE_NONE = 0,
+
+ /**
+ * The preferred transmission for this envelope focuses on
+ * maximizing bandwidth.
+ */
+ GNUNET_MQ_PREFERENCE_BANDWIDTH = 1,
+
+ /**
+ * The preferred transmission for this envelope foces on
+ * minimizing latency.
+ */
+ GNUNET_MQ_PREFERENCE_LATENCY = 2,
+
+ /**
+ * The preferred transmission for this envelope foces on
+ * reliability.
+ */
+ GNUNET_MQ_PREFERENCE_RELIABILITY = 3
+
+/**
+ * Number of preference values allowed.
+ */
+#define GNUNET_MQ_PREFERENCE_COUNT 4
+
+};
+
+
+/**
+ * Convert an `enum GNUNET_MQ_PreferenceType` to a string
+ *
+ * @param type the preference type
+ * @return a string or NULL if invalid
+ *
+ * @deprecated will be replaced by `enum GNUNET_MQ_PriorityPreference`
+ */
+const char *
+GNUNET_MQ_preference_to_string (enum GNUNET_MQ_PreferenceKind type);
-/** @} */ /* end of group mq */
#endif
+
+/** @} */ /* end of group mq */
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