1 files changed, 481 insertions, 0 deletions

diff --git a/src/util/mq.c b/src/util/mq.c
new file mode 100644
index 000000000..36cacd30b
--- /dev/null
+++ b/src/util/mq.c
@@ -0,0 +1,481 @@
+/*
+     This file is part of GNUnet.
+     (C) 2012 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
+     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.
+
+     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.
+*/
+
+/**
+ * @author Florian Dold
+ * @file util/mq.c
+ * @brief general purpose request queue
+ */
+
+#include "platform.h"
+#include "gnunet_common.h"
+#include "gnunet_util_lib.h"
+
+#define LOG(kind,...) GNUNET_log_from (kind, "mq",__VA_ARGS__)
+
+
+
+struct ServerClientSocketState
+{
+  struct GNUNET_SERVER_Client *client;
+  struct GNUNET_SERVER_TransmitHandle* th;
+};
+
+
+struct ClientConnectionState
+{
+  /**
+   * Did we call receive?
+   */
+  int receive_active;
+  struct GNUNET_CLIENT_Connection *connection;
+  struct GNUNET_CLIENT_TransmitHandle *th;
+};
+
+
+
+
+/**
+ * Call the right callback for a message.
+ *
+ * @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)
+{
+  const struct GNUNET_MQ_Handler *handler;
+  int handled = GNUNET_NO;
+
+  handler = mq->handlers;
+  if (NULL == handler)
+    return;
+  for (; NULL != handler->cb; handler++)
+  {
+    if (handler->type == ntohs (mh->type))
+    {
+      handler->cb (mq->handlers_cls, mh);
+      handled = GNUNET_YES;
+    }
+  }
+  
+  if (GNUNET_NO == handled)
+    LOG (GNUNET_ERROR_TYPE_WARNING, "no handler for message of type %d\n", ntohs (mh->type));
+}
+
+
+void
+GNUNET_MQ_discard (struct GNUNET_MQ_Message *mqm)
+{
+  GNUNET_assert (NULL == mqm->parent_queue);
+  GNUNET_free (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.
+ */
+void
+GNUNET_MQ_send (struct GNUNET_MQ_MessageQueue *mq, struct GNUNET_MQ_Message *mqm)
+{
+  GNUNET_assert (NULL != mq);
+  mq->send_impl (mq, mqm);
+}
+
+
+struct GNUNET_MQ_Message *
+GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp, uint16_t size, uint16_t type)
+{
+  struct GNUNET_MQ_Message *mqm;
+
+  mqm = GNUNET_malloc (sizeof *mqm + size);
+  mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
+  mqm->mh->size = htons (size);
+  mqm->mh->type = htons (type);
+  if (NULL != mhp)
+    *mhp = mqm->mh;
+  return mqm;
+}
+
+
+int
+GNUNET_MQ_nest_ (struct GNUNET_MQ_Message **mqmp,
+                 const void *data, uint16_t len)
+{
+  size_t new_size;
+  size_t old_size;
+
+  GNUNET_assert (NULL != mqmp);
+  /* there's no data to append => do nothing */
+  if (NULL == data)
+    return GNUNET_OK;
+  old_size = ntohs ((*mqmp)->mh->size);
+  /* message too large to concatenate? */
+  if (((uint16_t) (old_size + len)) < len)
+    return GNUNET_SYSERR;
+  new_size = old_size + len;
+  *mqmp = GNUNET_realloc (*mqmp, sizeof (struct GNUNET_MQ_Message) + new_size);
+  (*mqmp)->mh = (struct GNUNET_MessageHeader *) &(*mqmp)[1];
+  memcpy (((void *) (*mqmp)->mh) + old_size, data, new_size - old_size);
+  (*mqmp)->mh->size = htons (new_size);
+  return GNUNET_OK;
+}
+
+
+
+
+/*** Transmit a queued message to the session's client.
+ *
+ * @param cls consensus session
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t
+transmit_queued (void *cls, size_t size,
+                 void *buf)
+{
+  struct GNUNET_MQ_MessageQueue *mq = cls;
+  struct GNUNET_MQ_Message *mqm = mq->current_msg;
+  struct ServerClientSocketState *state = mq->impl_state;
+  size_t msg_size;
+
+  GNUNET_assert (NULL != buf);
+
+  if (NULL != mqm->sent_cb)
+  {
+    mqm->sent_cb (mqm->sent_cls);
+  }
+
+  mq->current_msg = NULL;
+  GNUNET_assert (NULL != mqm);
+  msg_size = ntohs (mqm->mh->size);
+  GNUNET_assert (size >= msg_size);
+  memcpy (buf, mqm->mh, msg_size);
+  GNUNET_free (mqm);
+  state->th = NULL;
+
+  if (NULL != mq->msg_head)
+  {
+    mq->current_msg = mq->msg_head;
+    GNUNET_CONTAINER_DLL_remove (mq->msg_head, mq->msg_tail, mq->current_msg);
+    state->th = 
+        GNUNET_SERVER_notify_transmit_ready (state->client, msg_size, 
+                                             GNUNET_TIME_UNIT_FOREVER_REL,
+                                             &transmit_queued, mq);
+  }
+  return msg_size;
+}
+
+
+
+static void
+server_client_destroy_impl (struct GNUNET_MQ_MessageQueue *mq)
+{
+  struct ServerClientSocketState *state;
+  
+  GNUNET_assert (NULL != mq);
+  state = mq->impl_state;
+  GNUNET_assert (NULL != state);
+  GNUNET_SERVER_client_drop (state->client);
+  GNUNET_free (state);
+}
+
+static void
+server_client_send_impl (struct GNUNET_MQ_MessageQueue *mq, struct GNUNET_MQ_Message *mqm)
+{
+  struct ServerClientSocketState *state;
+  int msize;
+
+  GNUNET_assert (NULL != mq);
+  state = mq->impl_state;
+  GNUNET_assert (NULL != state);
+
+  if (NULL != state->th)
+  {
+    GNUNET_CONTAINER_DLL_insert_tail (mq->msg_head, mq->msg_tail, mqm);
+    return;
+  }
+  GNUNET_assert (NULL == mq->msg_head);
+  GNUNET_assert (NULL == mq->current_msg);
+  msize = ntohs (mqm->mh->size);
+  mq->current_msg = mqm;
+  state->th = 
+      GNUNET_SERVER_notify_transmit_ready (state->client, msize, 
+                                           GNUNET_TIME_UNIT_FOREVER_REL,
+                                           &transmit_queued, mq);
+}
+
+
+struct GNUNET_MQ_MessageQueue *
+GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client)
+{
+  struct GNUNET_MQ_MessageQueue *mq;
+  struct ServerClientSocketState *scss;
+
+  mq = GNUNET_new (struct GNUNET_MQ_MessageQueue);
+  scss = GNUNET_new (struct ServerClientSocketState);
+  mq->impl_state = scss;
+  scss->client = client;
+  GNUNET_SERVER_client_keep (client);
+  mq->send_impl = server_client_send_impl;
+  mq->destroy_impl = server_client_destroy_impl;
+  return mq;
+}
+
+
+/**
+ * Type of a function to call when we receive a message
+ * from the service.
+ *
+ * @param cls closure
+ * @param msg message received, NULL on timeout or fatal error
+ */
+static void
+handle_client_message (void *cls,
+                       const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_MQ_MessageQueue *mq = cls;
+  struct ClientConnectionState *state;
+
+  state = mq->impl_state;
+  
+  if (NULL == msg)
+  {
+    if (NULL == mq->error_handler)
+      LOG (GNUNET_ERROR_TYPE_WARNING, "ignoring read error (no handler installed)\n");
+    mq->error_handler (mq->handlers_cls, GNUNET_MQ_ERROR_READ);
+    return;
+  }
+
+  GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
+                         GNUNET_TIME_UNIT_FOREVER_REL);
+
+  GNUNET_MQ_dispatch (mq, msg);
+}
+
+
+/**
+ * Transmit a queued message to the session's client.
+ *
+ * @param cls consensus session
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t
+connection_client_transmit_queued (void *cls, size_t size,
+                 void *buf)
+{
+  struct GNUNET_MQ_MessageQueue *mq = cls;
+  struct GNUNET_MQ_Message *mqm = mq->current_msg;
+  struct ClientConnectionState *state = mq->impl_state;
+  size_t msg_size;
+
+  if (NULL == buf)
+  {
+    if (NULL == mq->error_handler)
+    {
+      LOG (GNUNET_ERROR_TYPE_WARNING, "read error, but no error handler installed\n");
+      return 0;
+    }
+    mq->error_handler (mq->handlers_cls, GNUNET_MQ_ERROR_READ);
+    return 0;
+  }
+
+  if ((NULL != mq->handlers) && (GNUNET_NO == state->receive_active))
+  {
+    state->receive_active = GNUNET_YES;
+    GNUNET_CLIENT_receive (state->connection, handle_client_message, mq,
+                           GNUNET_TIME_UNIT_FOREVER_REL);
+  }
+
+
+  GNUNET_assert (NULL != mqm);
+
+  if (NULL != mqm->sent_cb)
+  {
+    mqm->sent_cb (mqm->sent_cls);
+  }
+
+  mq->current_msg = NULL;
+  GNUNET_assert (NULL != buf);
+  msg_size = ntohs (mqm->mh->size);
+  GNUNET_assert (size >= msg_size);
+  memcpy (buf, mqm->mh, msg_size);
+  GNUNET_free (mqm);
+  state->th = NULL;
+  if (NULL != mq->msg_head)
+  {
+    mq->current_msg = mq->msg_head;
+    GNUNET_CONTAINER_DLL_remove (mq->msg_head, mq->msg_tail, mq->current_msg);
+    state->th = 
+      GNUNET_CLIENT_notify_transmit_ready (state->connection, ntohs (mq->current_msg->mh->size), 
+                                             GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
+                                             &connection_client_transmit_queued, mq);
+  }
+  return msg_size;
+}
+
+
+
+static void
+connection_client_destroy_impl (struct GNUNET_MQ_MessageQueue *mq)
+{
+  GNUNET_free (mq->impl_state);
+}
+
+static void
+connection_client_send_impl (struct GNUNET_MQ_MessageQueue *mq,
+                             struct GNUNET_MQ_Message *mqm)
+{
+  struct ClientConnectionState *state = mq->impl_state;
+  int msize;
+
+  GNUNET_assert (NULL != state);
+
+  if (NULL != state->th)
+  {
+    GNUNET_CONTAINER_DLL_insert_tail (mq->msg_head, mq->msg_tail, mqm);
+    return;
+  }
+  GNUNET_assert (NULL == mq->current_msg);
+  mq->current_msg = mqm;
+  msize = ntohs (mqm->mh->size);
+  state->th = 
+      GNUNET_CLIENT_notify_transmit_ready (state->connection, msize, 
+                                           GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
+                                           &connection_client_transmit_queued, mq);
+}
+
+
+
+
+
+struct GNUNET_MQ_MessageQueue *
+GNUNET_MQ_queue_for_connection_client (struct GNUNET_CLIENT_Connection *connection,
+                                       const struct GNUNET_MQ_Handler *handlers,
+                                       void *cls)
+{
+  struct GNUNET_MQ_MessageQueue *mq;
+  struct ClientConnectionState *state;
+
+  GNUNET_assert (NULL != connection);
+
+  mq = GNUNET_new (struct GNUNET_MQ_MessageQueue);
+  mq->handlers = handlers;
+  mq->handlers_cls = cls;
+  state = GNUNET_new (struct ClientConnectionState);
+  state->connection = connection;
+  mq->impl_state = state;
+  mq->send_impl = connection_client_send_impl;
+  mq->destroy_impl = connection_client_destroy_impl;
+
+  return mq;
+}
+
+
+void
+GNUNET_MQ_replace_handlers (struct GNUNET_MQ_MessageQueue *mq,
+                            const struct GNUNET_MQ_Handler *new_handlers,
+                            void *cls)
+{
+  mq->handlers = new_handlers;
+  mq->handlers_cls = cls;
+}
+
+
+/**
+ * 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)
+{
+  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_CONTAINER_multihashmap32_put (mq->assoc_map, id, assoc_data,
+                                       GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
+  return id;
+}
+
+
+
+void *
+GNUNET_MQ_assoc_get (struct GNUNET_MQ_MessageQueue *mq, uint32_t request_id)
+{
+  if (NULL == mq->assoc_map)
+    return NULL;
+  return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
+}
+
+
+void *
+GNUNET_MQ_assoc_remove (struct GNUNET_MQ_MessageQueue *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_assert (NULL != val);
+  GNUNET_CONTAINER_multihashmap32_remove (mq->assoc_map, request_id, val);
+  return val;
+}
+
+
+void
+GNUNET_MQ_notify_sent (struct GNUNET_MQ_Message *mqm,
+                       GNUNET_MQ_NotifyCallback cb,
+                       void *cls)
+{
+  mqm->sent_cb = cb;
+  mqm->sent_cls = cls;
+}
+
+
+void
+GNUNET_MQ_destroy (struct GNUNET_MQ_MessageQueue *mq)
+{
+  /* FIXME: destroy all pending messages in the queue */
+
+  if (NULL != mq->destroy_impl)
+  {
+    mq->destroy_impl (mq);
+  }
+
+  GNUNET_free (mq);
+}
+