-hacking up new regex client library

1 files changed, 333 insertions, 0 deletions

diff --git a/src/regex/regex_api.c b/src/regex/regex_api.c
new file mode 100644
index 0000000000..ec9ee0de83
--- /dev/null
+++ b/src/regex/regex_api.c
@@ -0,0 +1,333 @@
+/*
+     This file is part of GNUnet
+     (C) 2012, 2013 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 3, 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 include/gnunet_regex_service.h
+ * @brief access regex service to advertise capabilities via regex and discover
+ *        respective peers using matching strings
+ * @author Maximilian Szengel
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_protocols.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_regex_service.h"
+#include "regex_ipc.h"
+
+/**
+ * Handle to store cached data about a regex announce.
+ */
+struct GNUNET_REGEX_Announcement
+{
+  /**
+   * Connection to the regex service.
+   */
+  struct GNUNET_CLIENT_Connection *client;
+
+  /** 
+   * Our configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+  
+  /**
+   * Message we're sending to the service.
+   */
+  struct AnnounceMessage msg;
+};
+
+
+/**
+ * We got a response (!?) or disconnect after asking regex
+ * to do the announcement.  Retry.
+ * 
+ * @param cls the 'struct GNUNET_REGEX_Announcement' to retry
+ * @param msg NULL on disconnect
+ */
+static void
+handle_a_reconnect (void *cls,
+		    const struct GNUNET_MessageHeader *msg);
+
+
+/**
+ * Try sending the announcement request to regex.  On 
+ * errors (i.e. regex died), try again.
+ *
+ * @param a the announcement to retry
+ */
+static void
+retry_announcement (struct GNUNET_REGEX_Announcement *a)
+{
+  GNUNET_assert (NULL != a->client);
+  GNUNET_assert (GNUNET_OK ==
+		 GNUNET_CLIENT_transmit_and_get_response (a->client,
+							  &a->msg.header,
+							  GNUNET_TIME_UNIT_FOREVER_REL,
+							  GNUNET_YES,
+							  &handle_a_reconnect,
+							  a));
+}
+
+
+/**
+ * We got a response (!?) or disconnect after asking regex
+ * to do the announcement.  Retry.
+ * 
+ * @param cls the 'struct GNUNET_REGEX_Announcement' to retry
+ * @param msg NULL on disconnect
+ */
+static void
+handle_a_reconnect (void *cls,
+		    const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_REGEX_Announcement *a = cls;
+
+  GNUNET_CLIENT_disconnect (a->client);
+  a->client = GNUNET_CLIENT_connect ("regex", a->cfg);
+  retry_announcement (a);
+}
+
+
+/**
+ * Announce the given peer under the given regular expression.  Does
+ * not free resources, must call GNUNET_REGEX_announce_cancel for
+ * that.
+ * 
+ * @param cfg configuration to use
+ * @param id ID to announce as provider of regex. Own ID in most cases.
+ * @param regex Regular expression to announce.
+ * @param refresh_delay after what delay should the announcement be repeated?
+ * @param compression How many characters per edge can we squeeze?
+ * @return Handle to reuse o free cached resources.
+ *         Must be freed by calling GNUNET_REGEX_announce_cancel.
+ */
+struct GNUNET_REGEX_Announcement *
+GNUNET_REGEX_announce (const struct GNUNET_CONFIGURATION_Handle *cfg,
+		       const struct GNUNET_PeerIdentity *id,
+                       const char *regex,
+		       struct GNUNET_TIME_Relative refresh_delay,
+                       uint16_t compression)
+{
+  struct GNUNET_REGEX_Announcement *a;
+  size_t slen;
+
+  slen = strlen (regex) + 1;
+  if (slen + sizeof (struct AnnounceMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  a = GNUNET_malloc (sizeof (struct GNUNET_REGEX_Announcement) + slen);
+  a->cfg = cfg;
+  a->client = GNUNET_CLIENT_connect ("regex", cfg);
+  if (NULL == a->client)
+    return NULL;
+  a->msg.header.type = htons (GNUNET_MESSAGE_TYPE_REGEX_ANNOUNCE);
+  a->msg.header.size = htons (slen + sizeof (struct AnnounceMessage));
+  a->msg.compression = htons (compression);
+  a->msg.reserved = htons (0);
+  a->msg.refresh_delay = GNUNET_TIME_relative_hton (refresh_delay);
+  a->msg.pid = *id;
+  memcpy (&a[1], regex, slen);
+  retry_announcement (a);
+  return a;
+}
+
+
+/**
+ * Stop announcing the regex specified by the given handle.
+ * 
+ * @param a handle returned by a previous GNUNET_REGEX_announce call.
+ */
+void
+GNUNET_REGEX_announce_cancel (struct GNUNET_REGEX_Announcement *a)
+{
+  GNUNET_CLIENT_disconnect (a->client);
+  GNUNET_free (a);
+}
+
+
+/**
+ * Handle to store data about a regex search.
+ */
+struct GNUNET_REGEX_Search
+{
+  /**
+   * Connection to the regex service.
+   */
+  struct GNUNET_CLIENT_Connection *client;
+
+  /** 
+   * Our configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+  
+  /**
+   * Function to call with results.
+   */
+  GNUNET_REGEX_Found callback;
+
+  /**
+   * Closure for 'callback'.
+   */
+  void *callback_cls;
+  
+  /**
+   * Search message to transmit to the service.
+   */
+  struct SearchMessage msg;
+};
+
+
+/**
+ * We got a response or disconnect after asking regex
+ * to do the search.  Handle it.
+ * 
+ * @param cls the 'struct GNUNET_REGEX_Search' to retry
+ * @param msg NULL on disconnect
+ */
+static void
+handle_search_response (void *cls,
+			const struct GNUNET_MessageHeader *msg);
+
+
+/**
+ * Try sending the search request to regex.  On 
+ * errors (i.e. regex died), try again.
+ *
+ * @param s the search to retry
+ */
+static void
+retry_search (struct GNUNET_REGEX_Search *s)
+{
+  GNUNET_assert (NULL != s->client);
+  GNUNET_assert (GNUNET_OK ==
+		 GNUNET_CLIENT_transmit_and_get_response (s->client,
+							  &s->msg.header,
+							  GNUNET_TIME_UNIT_FOREVER_REL,
+							  GNUNET_YES,
+							  &handle_search_response,
+							  s));
+}
+
+
+/**
+ * We got a response or disconnect after asking regex
+ * to do the search.  Handle it.
+ * 
+ * @param cls the 'struct GNUNET_REGEX_Search' to retry
+ * @param msg NULL on disconnect, otherwise presumably a response
+ */
+static void
+handle_search_response (void *cls,
+			const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_REGEX_Search *s = cls;
+  const struct ResultMessage *result;
+  uint16_t size;
+  uint16_t gpl;
+  uint16_t ppl;
+
+  if (NULL == msg)
+  {
+    GNUNET_CLIENT_disconnect (s->client);
+    s->client = GNUNET_CLIENT_connect ("regex", s->cfg);
+    retry_search (s);
+    return;
+  }
+  size = ntohs (msg->size);
+  if ( (GNUNET_MESSAGE_TYPE_REGEX_RESULT == ntohs (msg->type)) &&
+       (size >= sizeof (struct ResultMessage)) )
+  {
+    result = (const struct ResultMessage *) msg;
+    gpl = ntohs (result->get_path_length);
+    ppl = ntohs (result->put_path_length);
+    if (size == (sizeof (struct ResultMessage) + 
+		 (gpl + ppl) * sizeof (struct GNUNET_PeerIdentity)))
+    {
+      const struct GNUNET_PeerIdentity *pid;
+
+      GNUNET_CLIENT_receive (s->client,
+			     &handle_search_response, s,
+			     GNUNET_TIME_UNIT_FOREVER_REL);
+      pid = &result->id;
+      s->callback (s->callback_cls,
+		   pid,
+		   &pid[1], gpl,
+		   &pid[1 + gpl], ppl);		   
+      return;
+    }
+  }
+  GNUNET_break (0);
+  GNUNET_CLIENT_disconnect (s->client);
+  s->client = GNUNET_CLIENT_connect ("regex", s->cfg);
+  retry_search (s);
+}
+
+
+/**
+ * Search for a peer offering a regex matching certain string in the DHT.
+ * The search runs until GNUNET_REGEX_search_cancel is called, even if results
+ * are returned.
+ *
+ * @param cfg configuration to use
+ * @param string String to match against the regexes in the DHT.
+ * @param callback Callback for found peers.
+ * @param callback_cls Closure for @c callback.
+ * @return Handle to stop search and free resources.
+ *         Must be freed by calling GNUNET_REGEX_search_cancel.
+ */
+struct GNUNET_REGEX_Search *
+GNUNET_REGEX_search (const struct GNUNET_CONFIGURATION_Handle *cfg,
+		     const char *string,
+                     GNUNET_REGEX_Found callback,
+                     void *callback_cls)
+{
+  struct GNUNET_REGEX_Search *s;
+  size_t slen;
+
+  slen = strlen (string) + 1;
+  s = GNUNET_malloc (sizeof (struct GNUNET_REGEX_Announcement) + slen);
+  s->cfg = cfg;
+  s->client = GNUNET_CLIENT_connect ("regex", cfg);
+  if (NULL == s->client)
+    return NULL;
+  s->callback = callback;
+  s->callback_cls = callback_cls;
+  s->msg.header.type = htons (GNUNET_MESSAGE_TYPE_REGEX_SEARCH);
+  s->msg.header.size = htons (sizeof (struct SearchMessage) + slen);
+  memcpy (&s[1], string, slen);
+  retry_search (s);
+  return s;
+}
+
+
+/**
+ * Stop search and free all data used by a GNUNET_REGEX_search call.
+ * 
+ * @param s Handle returned by a previous GNUNET_REGEX_search call.
+ */
+void
+GNUNET_REGEX_search_cancel (struct GNUNET_REGEX_Search *s)
+{
+  GNUNET_CLIENT_disconnect (s->client);
+  GNUNET_free (s);
+}
+
+
+/* end of regex_api.c */