1 files changed, 688 insertions, 0 deletions

diff --git a/src/statistics/statistics_api.c b/src/statistics/statistics_api.c
new file mode 100644
index 000000000..f68cf9396
--- /dev/null
+++ b/src/statistics/statistics_api.c
@@ -0,0 +1,688 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009 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.
+*/
+
+/**
+ * @file statistics/statistics_api.c
+ * @brief API of the statistics service
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_client_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_server_lib.h"
+#include "gnunet_statistics_service.h"
+#include "gnunet_strings_lib.h"
+#include "statistics.h"
+
+#define SET_TRANSMIT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
+
+
+/**
+ * Types of actions.
+ */
+enum ActionType
+{
+  ACTION_GET,
+  ACTION_SET,
+  ACTION_UPDATE
+};
+
+
+/**
+ * Linked list of things we still need to do.
+ */
+struct ActionItem
+{
+  /**
+   * This is a linked list.
+   */
+  struct ActionItem *next;
+
+  /**
+   * What subsystem is this action about? (can be NULL)
+   */
+  char *subsystem;
+
+  /**
+   * What value is this action about? (can be NULL)
+   */
+  char *name;
+
+  /**
+   * Continuation to call once action is complete.
+   */
+  GNUNET_STATISTICS_Callback cont;
+
+  /**
+   * Function to call (for GET actions only).
+   */
+  GNUNET_STATISTICS_Iterator proc;
+
+  /**
+   * Closure for proc and cont.
+   */
+  void *cls;
+
+  /**
+   * Timeout for this action.
+   */
+  struct GNUNET_TIME_Absolute timeout;
+
+  /**
+   * Associated value.
+   */
+  unsigned long long value;
+
+  /**
+   * Flag for SET/UPDATE actions.
+   */
+  int make_persistent;
+
+  /**
+   * Has the current iteration been aborted; for GET actions.
+   */
+  int aborted;
+
+  /**
+   * Is this a GET, SET or UPDATE?
+   */
+  enum ActionType type;
+
+  /**
+   * Size of the message that we will be transmitting.
+   */
+  uint16_t msize;
+
+};
+
+
+/**
+ * Handle for the service.
+ */
+struct GNUNET_STATISTICS_Handle
+{
+  /**
+   * Our scheduler.
+   */
+  struct GNUNET_SCHEDULER_Handle *sched;
+
+  /**
+   * Name of our subsystem.
+   */
+  char *subsystem;
+
+  /**
+   * Configuration to use.
+   */
+  struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Socket (if available).
+   */
+  struct GNUNET_CLIENT_Connection *client;
+
+  /**
+   * Head of the linked list of pending actions (first action
+   * to be performed).
+   */
+  struct ActionItem *action_head;
+
+  /**
+   * Tail of the linked list of actions (for fast append).
+   */
+  struct ActionItem *action_tail;
+
+  /**
+   * Action we are currently busy with (action request has been
+   * transmitted, we're now receiving the response from the
+   * service).
+   */
+  struct ActionItem *current;
+
+  /**
+   * Should this handle be destroyed once we've processed
+   * all actions?
+   */
+  int do_destroy;
+
+};
+
+
+/**
+ * Try to (re)connect to the statistics service.
+ *
+ * @return GNUNET_YES on success, GNUNET_NO on failure.
+ */
+static int
+try_connect (struct GNUNET_STATISTICS_Handle *ret)
+{
+  if (ret->client != NULL)
+    return GNUNET_OK;
+  ret->client = GNUNET_CLIENT_connect (ret->sched, "statistics", ret->cfg);
+  if (ret->client != NULL)
+    return GNUNET_YES;
+  GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+              _("Failed to connect to statistics service!\n"));
+  return GNUNET_NO;
+}
+
+
+/**
+ * Free memory associated with the given action item.
+ */
+static void
+free_action_item (struct ActionItem *ai)
+{
+  GNUNET_free_non_null (ai->subsystem);
+  GNUNET_free_non_null (ai->name);
+  GNUNET_free (ai);
+}
+
+
+/**
+ * Get handle for the statistics service.
+ *
+ * @param subsystem name of subsystem using the service
+ * @param cfg services configuration in use
+ * @return handle to use
+ */
+struct GNUNET_STATISTICS_Handle *
+GNUNET_STATISTICS_create (struct GNUNET_SCHEDULER_Handle *sched,
+                          const char *subsystem,
+                          struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_STATISTICS_Handle *ret;
+
+  GNUNET_assert (subsystem != NULL);
+  GNUNET_assert (sched != NULL);
+  GNUNET_assert (cfg != NULL);
+  ret = GNUNET_malloc (sizeof (struct GNUNET_STATISTICS_Handle));
+  ret->sched = sched;
+  ret->cfg = cfg;
+  ret->subsystem = GNUNET_strdup (subsystem);
+  try_connect (ret);
+  return ret;
+}
+
+
+/**
+ * Actually free the handle.
+ */
+static void
+do_destroy (struct GNUNET_STATISTICS_Handle *h)
+{
+  GNUNET_assert (h->action_head == NULL);
+  GNUNET_assert (h->current == NULL);
+  if (h->client != NULL)
+    {
+      GNUNET_CLIENT_disconnect (h->client);
+      h->client = NULL;
+    }
+  GNUNET_free (h->subsystem);
+  GNUNET_free (h);
+}
+
+
+/**
+ * Destroy a handle (free all state associated with
+ * it).
+ */
+void
+GNUNET_STATISTICS_destroy (struct GNUNET_STATISTICS_Handle *handle)
+{
+  GNUNET_assert (handle->do_destroy == GNUNET_NO);
+  if ((handle->action_head != NULL) || (handle->current != NULL))
+    {
+      handle->do_destroy = GNUNET_YES;
+      return;
+    }
+  do_destroy (handle);
+}
+
+
+/**
+ * Process the message.
+ *
+ * @return GNUNET_OK if the message was well-formed
+ */
+static int
+process_message (struct GNUNET_STATISTICS_Handle *h,
+                 const struct GNUNET_MessageHeader *msg)
+{
+  char *service;
+  char *name;
+  const struct GNUNET_STATISTICS_ReplyMessage *smsg;
+  uint16_t size;
+
+  if (h->current->aborted)
+    return GNUNET_OK;           /* don't bother */
+  size = ntohs (msg->size);
+  if (size < sizeof (struct GNUNET_STATISTICS_ReplyMessage))
+    {
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+  smsg = (const struct GNUNET_STATISTICS_ReplyMessage *) msg;
+  size -= sizeof (struct GNUNET_STATISTICS_ReplyMessage);
+  if (size != GNUNET_STRINGS_buffer_tokenize ((const char *) &smsg[1],
+                                              size, 2, &service, &name))
+    {
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+#if DEBUG_STATISTICS
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received valid statistic on `%s:%s': %llu\n",
+              service, name, GNUNET_ntohll (smsg->value));
+#endif
+  if (GNUNET_OK !=
+      h->current->proc (h->current->cls,
+                        service,
+                        name,
+                        GNUNET_ntohll (smsg->value),
+                        0 !=
+                        (ntohl (smsg->uid) & GNUNET_STATISTICS_PERSIST_BIT)))
+    {
+#if DEBUG_STATISTICS
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Processing of remaining statistics aborted by client.\n");
+#endif
+      h->current->aborted = GNUNET_YES;
+    }
+  return GNUNET_OK;
+}
+
+
+
+/**
+ * Schedule the next action to be performed.
+ */
+static void schedule_action (struct GNUNET_STATISTICS_Handle *h);
+
+
+/**
+ * GET processing is complete, tell client about it.
+ */
+static void
+finish (struct GNUNET_STATISTICS_Handle *h, int code)
+{
+  struct ActionItem *pos = h->current;
+  h->current = NULL;
+  schedule_action (h);
+  if (pos->cont != NULL)
+    pos->cont (pos->cls, code);
+  free_action_item (pos);
+}
+
+
+/**
+ * Function called with messages from stats service.
+ *
+ * @param cls closure
+ * @param msg message received, NULL on timeout or fatal error
+ */
+static void
+receive_stats (void *cls, const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_STATISTICS_Handle *h = cls;
+
+  if (msg == NULL)
+    {
+      GNUNET_CLIENT_disconnect (h->client);
+      h->client = NULL;
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                  _
+                  ("Error receiving statistics from service, is the service running?\n"));
+      finish (h, GNUNET_SYSERR);
+      return;
+    }
+  switch (ntohs (msg->type))
+    {
+    case GNUNET_MESSAGE_TYPE_STATISTICS_END:
+#if DEBUG_STATISTICS
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Received end of statistics marker\n");
+#endif
+      finish (h, GNUNET_OK);
+      return;
+    case GNUNET_MESSAGE_TYPE_STATISTICS_VALUE:
+      if (GNUNET_OK == process_message (h, msg))
+        {
+          /* finally, look for more! */
+          GNUNET_CLIENT_receive (h->client,
+                                 &receive_stats,
+                                 h,
+                                 GNUNET_TIME_absolute_get_remaining (h->
+                                                                     current->
+                                                                     timeout));
+          return;
+        }
+      GNUNET_break (0);
+      break;
+    default:
+      GNUNET_break (0);
+      break;
+    }
+  GNUNET_CLIENT_disconnect (h->client);
+  h->client = NULL;
+  finish (h, GNUNET_SYSERR);
+}
+
+
+/**
+ * Transmit a GET request (and if successful, start to receive
+ * the response).
+ */
+static size_t
+transmit_get (struct GNUNET_STATISTICS_Handle *handle, size_t size, void *buf)
+{
+  struct GNUNET_MessageHeader *hdr;
+  size_t slen1;
+  size_t slen2;
+  uint16_t msize;
+
+  if (buf == NULL)
+    {
+      /* timeout / error */
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  _("Transmission of request for statistics failed!\n"));
+      finish (handle, GNUNET_SYSERR);
+      return 0;
+    }
+  slen1 = strlen (handle->current->subsystem) + 1;
+  slen2 = strlen (handle->current->name) + 1;
+  msize = slen1 + slen2 + sizeof (struct GNUNET_MessageHeader);
+  GNUNET_assert (msize <= size);
+  hdr = (struct GNUNET_MessageHeader *) buf;
+  hdr->size = htons (msize);
+  hdr->type = htons (GNUNET_MESSAGE_TYPE_STATISTICS_GET);
+  GNUNET_assert (slen1 + slen2 ==
+                 GNUNET_STRINGS_buffer_fill ((char *) &hdr[1],
+                                             slen1 + slen2,
+                                             2,
+                                             handle->current->subsystem,
+                                             handle->current->name));
+  GNUNET_CLIENT_receive (handle->client,
+                         &receive_stats,
+                         handle,
+                         GNUNET_TIME_absolute_get_remaining (handle->current->
+                                                             timeout));
+  return msize;
+}
+
+
+
+/**
+ * Transmit a SET/UPDATE request.
+ */
+static size_t
+transmit_set (struct GNUNET_STATISTICS_Handle *handle, size_t size, void *buf)
+{
+  struct GNUNET_STATISTICS_SetMessage *r;
+  size_t slen;
+  size_t nlen;
+  size_t nsize;
+
+  if (NULL == buf)
+    {
+      finish (handle, GNUNET_SYSERR);
+      return 0;
+    }
+
+  slen = strlen (handle->current->subsystem) + 1;
+  nlen = strlen (handle->current->name) + 1;
+  nsize = sizeof (struct GNUNET_STATISTICS_SetMessage) + slen + nlen;
+  if (size < nsize)
+    {
+      GNUNET_break (0);
+      finish (handle, GNUNET_SYSERR);
+      return 0;
+    }
+  r = buf;
+  r->header.size = htons (nsize);
+  r->header.type = htons (GNUNET_MESSAGE_TYPE_STATISTICS_SET);
+  r->flags = 0;
+  r->value = GNUNET_htonll (handle->current->value);
+  if (handle->current->make_persistent)
+    r->flags |= htonl (GNUNET_STATISTICS_SETFLAG_PERSISTENT);
+  if (handle->current->type == ACTION_UPDATE)
+    r->flags |= htonl (GNUNET_STATISTICS_SETFLAG_RELATIVE);
+  GNUNET_assert (slen + nlen ==
+                 GNUNET_STRINGS_buffer_fill ((char *) &r[1],
+                                             slen + nlen,
+                                             2,
+                                             handle->current->subsystem,
+                                             handle->current->name));
+  finish (handle, GNUNET_OK);
+  return nsize;
+}
+
+
+static size_t
+transmit_action (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_STATISTICS_Handle *handle = cls;
+  size_t ret;
+
+  switch (handle->current->type)
+    {
+    case ACTION_GET:
+      ret = transmit_get (handle, size, buf);
+      break;
+    case ACTION_SET:
+    case ACTION_UPDATE:
+      ret = transmit_set (handle, size, buf);
+      break;
+    }
+  return ret;
+}
+
+
+/**
+ * Schedule the next action to be performed.
+ */
+static void
+schedule_action (struct GNUNET_STATISTICS_Handle *h)
+{
+  struct GNUNET_TIME_Relative timeout;
+
+  if (h->current != NULL)
+    return;                     /* action already pending */
+  if (GNUNET_YES != try_connect (h))
+    {
+      finish (h, GNUNET_SYSERR);
+      return;
+    }
+
+  /* schedule next action */
+  h->current = h->action_head;
+  if (NULL == h->current)
+    {
+      /* no pending network action, check destroy! */
+      if (h->do_destroy != GNUNET_YES)
+        return;
+      do_destroy (h);
+      return;
+    }
+  h->action_head = h->action_head->next;
+  if (NULL == h->action_head)
+    h->action_tail = NULL;
+  h->current->next = NULL;
+
+  timeout = GNUNET_TIME_absolute_get_remaining (h->current->timeout);
+  if (NULL ==
+      GNUNET_CLIENT_notify_transmit_ready (h->client,
+                                           h->current->msize,
+                                           timeout, &transmit_action, h))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  "Failed to transmit request to statistics service.\n");
+      finish (h, GNUNET_SYSERR);
+    }
+}
+
+
+static void
+insert_ai (struct GNUNET_STATISTICS_Handle *h, struct ActionItem *ai)
+{
+  if (h->action_tail == NULL)
+    {
+      h->action_head = ai;
+      h->action_tail = ai;
+      schedule_action (h);
+    }
+  else
+    {
+      h->action_tail->next = ai;
+      h->action_tail = ai;
+    }
+}
+
+
+/**
+ * Get statistic from the peer.
+ *
+ * @param handle identification of the statistics service
+ * @param subsystem limit to the specified subsystem, NULL for our subsystem
+ * @param name name of the statistic value, NULL for all values
+ * @param timeout after how long should we give up (and call
+ *        cont with an error code)?
+ * @param cont continuation to call when done (can be NULL)
+ * @param proc function to call on each value
+ * @param cls closure for cont and proc
+ */
+void
+GNUNET_STATISTICS_get (struct GNUNET_STATISTICS_Handle *handle,
+                       const char *subsystem,
+                       const char *name,
+                       struct GNUNET_TIME_Relative timeout,
+                       GNUNET_STATISTICS_Callback cont,
+                       GNUNET_STATISTICS_Iterator proc, void *cls)
+{
+  size_t slen1;
+  size_t slen2;
+  struct ActionItem *ai;
+
+  GNUNET_assert (handle != NULL);
+  GNUNET_assert (proc != NULL);
+  if (GNUNET_YES != try_connect (handle))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  "Failed to connect to statistics service, can not get value `%s:%s'.\n",
+                  strlen (subsystem) ? subsystem : "*",
+                  strlen (name) ? name : "*");
+      cont (cls, GNUNET_SYSERR);
+      return;
+    }
+  if (subsystem == NULL)
+    subsystem = "";
+  if (name == NULL)
+    name = "";
+  slen1 = strlen (subsystem);
+  slen2 = strlen (name);
+  GNUNET_assert (slen1 + slen2 + sizeof (struct GNUNET_MessageHeader) <
+                 GNUNET_SERVER_MAX_MESSAGE_SIZE);
+  ai = GNUNET_malloc (sizeof (struct ActionItem));
+  ai->subsystem = GNUNET_strdup (subsystem);
+  ai->name = GNUNET_strdup (name);
+  ai->cont = cont;
+  ai->proc = proc;
+  ai->cls = cls;
+  ai->timeout = GNUNET_TIME_relative_to_absolute (timeout);
+  ai->type = ACTION_GET;
+  ai->msize = slen1 + slen2 + sizeof (struct GNUNET_MessageHeader);
+  insert_ai (handle, ai);
+}
+
+
+static void
+add_setter_action (struct GNUNET_STATISTICS_Handle *h,
+                   const char *name,
+                   int make_persistent,
+                   unsigned long long value, enum ActionType type)
+{
+  struct ActionItem *ai;
+  size_t slen;
+  size_t nlen;
+  size_t nsize;
+
+  GNUNET_assert (h != NULL);
+  GNUNET_assert (name != NULL);
+  if (GNUNET_YES != try_connect (h))
+    return;
+  slen = strlen (h->subsystem) + 1;
+  nlen = strlen (name) + 1;
+  nsize = sizeof (struct GNUNET_STATISTICS_SetMessage) + slen + nlen;
+  if (nsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
+    {
+      GNUNET_break (0);
+      return;
+    }
+  ai = GNUNET_malloc (sizeof (struct ActionItem));
+  ai->subsystem = GNUNET_strdup (h->subsystem);
+  ai->name = GNUNET_strdup (name);
+  ai->timeout = GNUNET_TIME_relative_to_absolute (SET_TRANSMIT_TIMEOUT);
+  ai->make_persistent = make_persistent;
+  ai->msize = nsize;
+  ai->value = value;
+  ai->type = type;
+  insert_ai (h, ai);
+  schedule_action (h);
+}
+
+
+/**
+ * Set statistic value for the peer.  Will always use our
+ * subsystem (the argument used when "handle" was created).
+ *
+ * @param handle identification of the statistics service
+ * @param name name of the statistic value
+ * @param value new value to set
+ * @param make_persistent should the value be kept across restarts?
+ */
+void
+GNUNET_STATISTICS_set (struct GNUNET_STATISTICS_Handle *handle,
+                       const char *name,
+                       unsigned long long value, int make_persistent)
+{
+  add_setter_action (handle, name, make_persistent, value, ACTION_SET);
+}
+
+
+/**
+ * Set statistic value for the peer.  Will always use our
+ * subsystem (the argument used when "handle" was created).
+ *
+ * @param handle identification of the statistics service
+ * @param name name of the statistic value
+ * @param delta change in value (added to existing value)
+ * @param make_persistent should the value be kept across restarts?
+ */
+void
+GNUNET_STATISTICS_update (struct GNUNET_STATISTICS_Handle *handle,
+                          const char *name,
+                          long long delta, int make_persistent)
+{
+  add_setter_action (handle, name, make_persistent,
+                     (unsigned long long) delta, ACTION_UPDATE);
+}
+
+
+/* end of statistics_api.c */