social: separate host/guest/place API; add missing method cb params; improve docs

1 files changed, 229 insertions, 193 deletions

diff --git a/src/include/gnunet_social_service.h b/src/include/gnunet_social_service.h
index ba698aee6..e68d84d2f 100644
--- a/src/include/gnunet_social_service.h
+++ b/src/include/gnunet_social_service.h
@@ -20,7 +20,7 @@
 
 /**
  * @file include/gnunet_social_service.h
- * @brief Social service; implements social functionality using the PSYC service.
+ * @brief Social service; implements social interactions using the PSYC service.
  * @author Gabor X Toth
  * @author Christian Grothoff
  */
@@ -48,7 +48,7 @@ extern "C"
 
 
 /**
- * Handle for another user (who is likely pseudonymous) in the network.
+ * Handle for a pseudonym of another user in the network.
  */
 struct GNUNET_SOCIAL_Nym;
 
@@ -58,9 +58,14 @@ struct GNUNET_SOCIAL_Nym;
 struct GNUNET_SOCIAL_Place;
 
 /**
- * Handle for a place that one of our egos hosts.
+ * Host handle for a place that we entered.
  */
-struct GNUNET_SOCIAL_Home;
+struct GNUNET_SOCIAL_Host;
+
+/**
+ * Guest handle for place that we entered.
+ */
+struct GNUNET_SOCIAL_Guest;
 
 /**
  * Handle to an implementation of try-and-slice.
@@ -69,36 +74,45 @@ struct GNUNET_SOCIAL_Slicer;
 
 
 /**
- * Method called from SOCIAL upon receiving a message indicating a call
- * to a @e method.
+ * Function called upon receiving a message indicating a call to a @e method.
  *
- * @param cls Closure.
- * @param nym The sender of the message. NULL for the ego's own messages to the home.
- * @param full_method_name Original method name from PSYC (may be more
- *        specific than the registered method name due to try-and-slice matching).
-
- * @param message_id Unique message counter for this message
- *                   (unique only in combination with the given sender for
- *                    this channel).
- * @param modifier_count Number of elements in the @a modifiers array.
- * @param modifiers Modifiers present in the message. FIXME: use environment instead?
- * @param data_offset Byte offset of @a data in the overall data of the method.
- * @param data Data stream given to the method (might not be zero-terminated
- *             if data is binary).
- * @param data_size Number of bytes in @a data.
- * @param flags Message flags indicating fragmentation status.
+ * This function is called one or more times for each message until all data
+ * fragments arrive from the network.
+ *
+ * @param cls  Closure.
+ * @param message_id  Message counter, monotonically increasing from 1.
+ * @param nym  The sender of the message.  Can be NULL if the message is not
+ *          connected to a pseudonym.
+ * @param flags  OR'ed GNUNET_PSYC_MessageFlags
+ * @param method_name  Original method name from PSYC (may be more specific
+ *          than the registered method name due to try-and-slice matching).
+ * @param env  Environment containing variables for the message and operations
+ *          on objects of the place, or NULL.
+ *          Only set for the first call of this function for each @a message_id,
+ *          NULL when notifying about further data fragments.
+ * @param data_offset  Byte offset of @a data in the overall data of the method.
+ * @param data_size  Number of bytes in @a data.
+ * @param data  Data stream given to the method (might not be zero-terminated
+ *          if data is binary).
+ * @param end  End of message?
+ *          #GNUNET_NO  if there are further fragments,
+ *          #GNUNET_YES if this is the last fragment,
+ *          #GNUNET_SYSERR indicates the message was cancelled by the sender.
+ *
+ * @return #GNUNET_YES the application keeps @a env for further use,
+ *         #GNUNET_NO  @a env is free()'d after the function returns.
  */
 typedef int
-(*GNUNET_SOCIAL_Method) (void *cls,
-                         struct GNUNET_SOCIAL_Nym *nym,
-                         const char *full_method_name,
-                         uint64_t message_id,
-                         size_t modifier_count,
-                         struct GNUNET_ENV_Modifier *modifiers,
-                         uint64_t data_offset,
-                         const void *data,
-                         size_t data_size,
-                         enum GNUNET_PSYC_MessageFlags flags);
+(*GNUNET_SOCIAL_MethodCallback) (void *cls,
+                                 uint64_t message_id,
+                                 uint32_t flags,
+                                 const struct GNUNET_SOCIAL_Nym *nym,
+                                 const char *method_name,
+                                 struct GNUNET_ENV_Environment *env,
+                                 uint64_t data_offset,
+                                 size_t data_size,
+                                 const void *data,
+                                 int end);
 
 
 /**
@@ -125,8 +139,8 @@ GNUNET_SOCIAL_slicer_create (void);
 void
 GNUNET_SOCIAL_slicer_add (struct GNUNET_SOCIAL_Slicer *slicer,
                           const char *method_name,
-                          GNUNET_SOCIAL_Method method,
-                          void *method_cls);
+                          GNUNET_SOCIAL_MethodCallback method_cb,
+                          void *cls);
 
 
 /**
@@ -139,7 +153,7 @@ GNUNET_SOCIAL_slicer_add (struct GNUNET_SOCIAL_Slicer *slicer,
 void
 GNUNET_SOCIAL_slicer_remove (struct GNUNET_SOCIAL_Slicer *slicer,
                              const char *method_name,
-                             GNUNET_SOCIAL_Method method);
+                             GNUNET_SOCIAL_MethodCallback method_cb);
 
 /**
  * Destroy a given try-and-slice instance.
@@ -153,10 +167,10 @@ GNUNET_SOCIAL_slicer_destroy (struct GNUNET_SOCIAL_Slicer *slicer);
 /**
  * Function called asking for nym to be admitted to the place.
  *
- * Should call either GNUNET_SOCIAL_home_admit() or
- * GNUNET_SOCIAL_home_reject_entry() (possibly asynchronously).  If this owner
+ * Should call either GNUNET_SOCIAL_host_admit() or
+ * GNUNET_SOCIAL_host_reject_entry() (possibly asynchronously).  If this host
  * cannot decide, it is fine to call neither function, in which case hopefully
- * some other owner of the home exists that will make the decision. The @a nym
+ * some other host of the place exists that will make the decision.  The @a nym
  * reference remains valid until the #GNUNET_SOCIAL_FarewellCallback is invoked
  * for it.
  *
@@ -197,26 +211,26 @@ typedef void
 
 
 /**
- * Enter a home where guests (nyms) can be hosted.
+ * Enter a place as host.
  *
- * A home is created upon first entering, and exists until
- * GNUNET_SOCIAL_home_destroy() is called. It can also be left temporarily using
- * GNUNET_SOCIAL_home_leave().
+ * A place is created upon first entering, and it is active until permanently
+ * left using GNUNET_SOCIAL_host_leave().
  *
- * @param cfg Configuration to contact the social service.
- * @param home_keyfile File with the private-public key pair of the home,
- *        created if the file does not exist; pass NULL for ephemeral homes.
- * @param policy Policy specifying entry and history restrictions of the home.
- * @param ego Owner of the home (host).
- * @param slicer Slicer to handle guests talking.
- * @param listener_cb Function to handle new nyms that want to enter.
- * @param farewell_cb Function to handle departing nyms.
- * @param cls Closure for @a listener_cb and @a farewell_cb.
- * @return Handle for a new home.
- */
-struct GNUNET_SOCIAL_Home *
-GNUNET_SOCIAL_home_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
-                          const char *home_keyfile,
+ * @param cfg  Configuration to contact the social service.
+ * @param place_keyfile  File with the private-public key pair of the place,
+ *        created if the file does not exist; pass NULL for ephemeral places.
+ * @param policy  Policy specifying entry and history restrictions of the place.
+ * @param ego  Identity of the host.
+ * @param slicer  Slicer to handle incoming messages.
+ * @param listener_cb  Function to handle new nyms that want to enter.
+ * @param farewell_cb  Function to handle departing nyms.
+ * @param cls  Closure for @a listener_cb and @a farewell_cb.
+ *
+ * @return Handle for the host.
+ */
+struct GNUNET_SOCIAL_Host *
+GNUNET_SOCIAL_host_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                          const char *place_keyfile,
                           enum GNUNET_PSYC_Policy policy,
                           struct GNUNET_IDENTITY_Ego *ego,
                           struct GNUNET_SOCIAL_Slicer *slicer,
@@ -226,38 +240,38 @@ GNUNET_SOCIAL_home_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
 
 
 /**
- * Admit @a nym to the @a home.
+ * Admit @a nym to the place.
  *
- * The @a nym reference will remain valid until either the home is destroyed or
- * @a nym leaves.
+ * The @a nym reference will remain valid until either the @a host or @a nym
+ * leaves the place.
  *
- * @param home Home to allow @a nym to enter.
- * @param nym Handle for the entity that wants to enter.
+ * @param host  Host of the place.
+ * @param nym  Handle for the entity that wants to enter.
  */
 void
-GNUNET_SOCIAL_home_admit (struct GNUNET_SOCIAL_Home *home,
+GNUNET_SOCIAL_host_admit (struct GNUNET_SOCIAL_Host *host,
                           struct GNUNET_SOCIAL_Nym *nym);
 
 
 /**
- * Throw @a nym out of the @a home.
+ * Throw @a nym out of the place.
  *
  * The @a nym reference will remain valid until the
  * #GNUNET_SOCIAL_FarewellCallback is invoked,
  * which should be very soon after this call.
  *
- * @param home Home to eject @a nym from.
- * @param nym Handle for the entity to be ejected.
+ * @param host  Host of the place.
+ * @param nym  Handle for the entity to be ejected.
  */
 void
-GNUNET_SOCIAL_home_eject (struct GNUNET_SOCIAL_Home *home,
+GNUNET_SOCIAL_host_eject (struct GNUNET_SOCIAL_Host *host,
                           struct GNUNET_SOCIAL_Nym *nym);
 
 
 /**
- * Refuse @a nym entry into the @a home.
+ * Refuse @a nym entry into the place.
  *
- * @param home Home to disallow @a nym to enter.
+ * @param host  Host of the place.
  * @param nym Handle for the entity that wanted to enter.
  * @param method_name Method name for the rejection message.
  * @param env Environment containing variables for the message, or NULL.
@@ -265,7 +279,7 @@ GNUNET_SOCIAL_home_eject (struct GNUNET_SOCIAL_Home *home,
  * @param data_size Number of bytes in @a data for method.
  */
 void
-GNUNET_SOCIAL_home_reject_entry (struct GNUNET_SOCIAL_Home *home,
+GNUNET_SOCIAL_host_refuse_entry (struct GNUNET_SOCIAL_Host *host,
                                  struct GNUNET_SOCIAL_Nym *nym,
                                  const char *method_name,
                                  const struct GNUNET_ENV_Environment *env,
@@ -274,7 +288,7 @@ GNUNET_SOCIAL_home_reject_entry (struct GNUNET_SOCIAL_Home *home,
 
 
 /**
- * Get the public key of a nym.
+ * Get the public key of a @a nym.
  *
  * Suitable, for example, to be used with GNUNET_NAMESTORE_zone_to_name().
  *
@@ -287,20 +301,22 @@ GNUNET_SOCIAL_nym_get_key (struct GNUNET_SOCIAL_Nym *nym,
 
 
 /**
- * Obtain the private-public key pair of the home.
+ * Obtain the private-public key pair of the host.
  *
- * @param home Home to get the key of.
- * @param[out] home_key Set to the private-public key pair of the home.  The public part is suitable for storing in GNS within a "PLACE" record, along with peer IDs to join at.
+ * @param host  Host to get the key of.
+ * @param[out] host_key  Set to the private-public key pair of the host.  The
+ *                 public part is suitable for storing in GNS within a "PLACE"
+ *                 record, along with peer IDs to join at.
  */
 void
-GNUNET_SOCIAL_home_get_key (struct GNUNET_SOCIAL_Home *home,
-                            struct GNUNET_CRYPTO_EddsaPrivateKey *home_key);
+GNUNET_SOCIAL_host_get_key (struct GNUNET_SOCIAL_Host *host,
+                            struct GNUNET_CRYPTO_EddsaPrivateKey *host_key);
 
 
 /**
- * Advertise @a home under @a name in the GNS zone of the @e ego.
+ * Advertise the place in the GNS zone of the @e ego of the @a host.
  *
- * @param home The home to advertise.
+ * @param host  Host of the place.
  * @param name The name for the PLACE record to put in the zone.
  * @param peer_count Number of elements in the @a peers array.
  * @param peers List of peers in the PLACE record that can be used to send join
@@ -309,7 +325,7 @@ GNUNET_SOCIAL_home_get_key (struct GNUNET_SOCIAL_Home *home,
  * @param password Password used to encrypt the record.
  */
 void
-GNUNET_SOCIAL_home_advertise (struct GNUNET_SOCIAL_Home *home,
+GNUNET_SOCIAL_host_advertise (struct GNUNET_SOCIAL_Host *host,
                               const char *name,
                               size_t peer_count,
                               const struct GNUNET_PeerIdentity *peers,
@@ -318,16 +334,16 @@ GNUNET_SOCIAL_home_advertise (struct GNUNET_SOCIAL_Home *home,
 
 
 /**
- * Flags for announcements in a home.
+ * Flags for announcements by a host.
  */
 enum GNUNET_SOCIAL_AnnounceFlags
 {
   GNUNET_SOCIAL_ANNOUNCE_NONE = 0,
 
   /**
-   * Whether this announcement removes all objects from the home.
+   * Whether this announcement removes all objects from the place.
    *
-   * New objects can be still added to the now empty home using the @e env
+   * New objects can be still added to the now empty place using the @e env
    * parameter of the same announcement.
    */
   GNUNET_SOCIAL_ANNOUNCE_CLEAR_OBJECTS = 1 << 0
@@ -341,22 +357,23 @@ struct GNUNET_SOCIAL_Announcement;
 
 
 /**
- * Send a message to all nyms that are present in the home.
+ * Send a message to all nyms that are present in the place.
  *
- * This function is restricted to the home owner.  Nyms can only send requests
- * to the home owner who can decide to relay it to other guests.
+ * This function is restricted to the host.  Nyms can only send requests
+ * to the host who can decide to relay it to everyone in the place.
  *
- * @param home Home to address the announcement to.
+ * @param host  Host of the place.
  * @param method_name Method to use for the announcement.
- * @param env Environment containing variables for the message and operations on
- *        objects of the home, or NULL.
+ * @param env  Environment containing variables for the message and operations
+ *          on objects of the place.  Can be NULL.
  * @param notify Function to call to get the payload of the announcement.
  * @param notify_cls Closure for @a notify.
  * @param flags Flags for this announcement.
+ *
  * @return NULL on error (announcement already in progress?).
  */
 struct GNUNET_SOCIAL_Announcement *
-GNUNET_SOCIAL_home_announce (struct GNUNET_SOCIAL_Home *home,
+GNUNET_SOCIAL_host_announce (struct GNUNET_SOCIAL_Host *host,
                              const char *method_name,
                              const struct GNUNET_ENV_Environment *env,
                              GNUNET_CONNECTION_TransmitReadyNotify notify,
@@ -370,37 +387,39 @@ GNUNET_SOCIAL_home_announce (struct GNUNET_SOCIAL_Home *home,
  * @param a The announcement to cancel.
  */
 void
-GNUNET_SOCIAL_home_announce_cancel (struct GNUNET_SOCIAL_Announcement *a);
+GNUNET_SOCIAL_host_announce_cancel (struct GNUNET_SOCIAL_Announcement *a);
 
 
 /**
- * Convert our home to a place so we can access it via the place API.
+ * Obtain handle for a hosted place.
+ *
+ * The returned handle can be used to access the place API.
  *
- * @param home Handle for the home.
- * @return Place handle for the same home, valid as long as @a home is valid;
- *         do NOT try to GNUNET_SOCIAL_place_leave() this place, it's your home!
+ * @param host  Handle for the host.
+ *
+ * @return Handle for the hosted place, valid as long as @a host is valid.
  */
 struct GNUNET_SOCIAL_Place *
-GNUNET_SOCIAL_home_get_place (struct GNUNET_SOCIAL_Home *home);
+GNUNET_SOCIAL_host_get_place (struct GNUNET_SOCIAL_Host *host);
 
 
 /**
- * Leave a home.
-
- * Invalidates home handle.
- * Guests will be disconnected until the home is restarted.
+ * Stop hosting a place.
+ *
+ * Invalidates host handle.
  *
- * @param home Home to leave.
- * @param keep_active Keep home active after last application disconnected.
+ * @param host  Host leaving the place.
+ * @param keep_active  Keep the place active after last host disconnected.
  */
 void
-GNUNET_SOCIAL_home_leave (struct GNUNET_SOCIAL_Home *home, int keep_active);
+GNUNET_SOCIAL_host_leave (struct GNUNET_SOCIAL_Host *host, int keep_active);
+
 
 /**
- * Request entry to a place (home hosted by someone else).
+ * Request entry to a place as a guest.
  *
- * @param cfg Configuration to contact the social service.
- * @param ego Owner of the home (host).
+ * @param cfg  Configuration to contact the social service.
+ * @param ego  Identity of the guest.
  * @param address GNS name of the place to enter.  Either in the form of
  *        'room.friend.gnu', or 'NYMPUBKEY.zkey'.  This latter case refers to
  *        the 'PLACE' record of the empty label ("+") in the GNS zone with the
@@ -411,10 +430,11 @@ GNUNET_SOCIAL_home_leave (struct GNUNET_SOCIAL_Home *home, int keep_active);
  * @param data Payload for the message to give to the enter callback.
  * @param data_size Number of bytes in @a data.
  * @param slicer Slicer to use for processing incoming requests from guests.
- * @return NULL on errors, otherwise handle to the place.
+ *
+ * @return NULL on errors, otherwise handle for the guest.
  */
-struct GNUNET_SOCIAL_Place *
-GNUNET_SOCIAL_place_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
+struct GNUNET_SOCIAL_Guest *
+GNUNET_SOCIAL_guest_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
                            struct GNUNET_IDENTITY_Ego *ego,
                            char *address,
                            const char *method_name,
@@ -424,10 +444,10 @@ GNUNET_SOCIAL_place_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
                            struct GNUNET_SOCIAL_Slicer *slicer);
 
 /**
- * Request entry to a place (home hosted by someone else).
+ * Request entry to a place as a guest.
  *
  * @param cfg Configuration to contact the social service.
- * @param ego Owner of the home (host).
+ * @param ego  Identity of the guest.
  * @param crypto_address Public key of the place to enter.
  * @param origin Peer identity of the origin of the underlying multicast group.
  * @param relay_count Number of elements in the @a relays array.
@@ -437,10 +457,11 @@ GNUNET_SOCIAL_place_enter (const struct GNUNET_CONFIGURATION_Handle *cfg,
  * @param data Payload for the message to give to the enter callback.
  * @param data_size Number of bytes in @a data.
  * @param slicer Slicer to use for processing incoming requests from guests.
- * @return NULL on errors, otherwise handle to the place.
+ *
+ * @return NULL on errors, otherwise handle for the guest.
  */
-struct GNUNET_SOCIAL_Place *
-GNUNET_SOCIAL_place_enter2 (const struct GNUNET_CONFIGURATION_Handle *cfg,
+struct GNUNET_SOCIAL_Guest *
+GNUNET_SOCIAL_guest_enter2 (const struct GNUNET_CONFIGURATION_Handle *cfg,
                             struct GNUNET_IDENTITY_Ego *ego,
                             struct GNUNET_CRYPTO_EddsaPublicKey *crypto_address,
                             struct GNUNET_PeerIdentity *origin,
@@ -453,81 +474,6 @@ GNUNET_SOCIAL_place_enter2 (const struct GNUNET_CONFIGURATION_Handle *cfg,
                             struct GNUNET_SOCIAL_Slicer *slicer);
 
 
-struct GNUNET_SOCIAL_WatchHandle;
-
-/**
- * Watch a place for changed objects.
- *
- * @param place Place to watch.
- * @param object_filter Object prefix to match.
- * @param state_cb Function to call when an object/state changes.
- * @param state_cb_cls Closure for callback.
- *
- * @return Handle that can be used to cancel watching.
- */
-struct GNUNET_SOCIAL_WatchHandle *
-GNUNET_SOCIAL_place_watch (struct GNUNET_SOCIAL_Place *place,
-                           const char *object_filter,
-                           GNUNET_PSYC_StateCallback state_cb,
-                           void *state_cb_cls);
-
-
-/**
- * Cancel watching a place for changed objects.
- *
- * @param wh Watch handle to cancel.
- */
-void
-GNUNET_SOCIAL_place_watch_cancel (struct GNUNET_SOCIAL_WatchHandle *wh);
-
-
-struct GNUNET_SOCIAL_LookHandle;
-
-
-/**
- * Look at objects in the place with a matching name prefix.
- *
- * @param place The place to look its objects at.
- * @param name_prefix Look at objects with names beginning with this value.
- * @param state_cb Function to call for each object found.
- * @param state_cb_cls Closure for callback function.
- *
- * @return Handle that can be used to stop looking at objects.
- */
-struct GNUNET_SOCIAL_LookHandle *
-GNUNET_SOCIAL_place_look (struct GNUNET_SOCIAL_Place *place,
-                          const char *name_prefix,
-                          GNUNET_PSYC_StateCallback state_cb,
-                          void *state_cb_cls);
-
-
-/**
- * Stop looking at objects.
- *
- * @param lh Look handle to stop.
- */
-void
-GNUNET_SOCIAL_place_look_cancel (struct GNUNET_SOCIAL_LookHandle *lh);
-
-
-
-/**
- * Look at a particular object in the place.
- *
- * The best matching object is returned (its name might be less specific than
- * what was requested).
- *
- * @param place The place to look the object at.
- * @param full_name Full name of the object.
- * @param value_size Set to the size of the returned value.
- * @return NULL if there is no such object at this place.
- */
-const void *
-GNUNET_SOCIAL_place_look_at (struct GNUNET_SOCIAL_Place *place,
-                             const char *full_name,
-                             size_t *value_size);
-
-
 /**
  * Flags for talking to the host of a place.
  */
@@ -542,6 +488,7 @@ enum GNUNET_SOCIAL_TalkFlags
  */
 struct GNUNET_SOCIAL_TalkRequest;
 
+
 /**
  * Talk to the host of the place.
  *
@@ -551,11 +498,12 @@ struct GNUNET_SOCIAL_TalkRequest;
  * @param notify Function to use to get the payload for the method.
  * @param notify_cls Closure for @a notify.
  * @param flags Flags for the message being sent.
+ *
  * @return NULL if we are already trying to talk to the host,
  *         otherwise handle to cancel the request.
  */
 struct GNUNET_SOCIAL_TalkRequest *
-GNUNET_SOCIAL_place_talk (struct GNUNET_SOCIAL_Place *place,
+GNUNET_SOCIAL_guest_talk (struct GNUNET_SOCIAL_Place *place,
                           const char *method_name,
                           const struct GNUNET_ENV_Environment *env,
                           GNUNET_CONNECTION_TransmitReadyNotify notify,
@@ -569,7 +517,32 @@ GNUNET_SOCIAL_place_talk (struct GNUNET_SOCIAL_Place *place,
  * @param tr Talk request to cancel.
  */
 void
-GNUNET_SOCIAL_place_talk_cancel (struct GNUNET_SOCIAL_TalkRequest *tr);
+GNUNET_SOCIAL_guest_talk_cancel (struct GNUNET_SOCIAL_TalkRequest *tr);
+
+
+/**
+ * Leave a place permanently.
+ *
+ * Notifies the owner of the place about leaving, and destroys the place handle.
+ *
+ * @param place Place to leave permanently.
+ * @param keep_active Keep place active after last application disconnected.
+ */
+void
+GNUNET_SOCIAL_guest_leave (struct GNUNET_SOCIAL_Place *place, int keep_active);
+
+
+/**
+ * Obtain handle for a place entered as guest.
+ *
+ * The returned handle can be used to access the place API.
+ *
+ * @param guest  Handle for the guest.
+ *
+ * @return Handle for the place, valid as long as @a guest is valid.
+ */
+struct GNUNET_SOCIAL_Place *
+GNUNET_SOCIAL_guest_get_place (struct GNUNET_SOCIAL_Host *guest);
 
 
 /**
@@ -618,16 +591,79 @@ void
 GNUNET_SOCIAL_place_get_history_cancel (struct GNUNET_SOCIAL_HistoryLesson *hist);
 
 
+struct GNUNET_SOCIAL_WatchHandle;
+
 /**
- * Leave a place permanently.
+ * Watch a place for changed objects.
  *
- * Notifies the owner of the place about leaving, and destroys the place handle.
+ * @param place Place to watch.
+ * @param object_filter Object prefix to match.
+ * @param state_cb Function to call when an object/state changes.
+ * @param state_cb_cls Closure for callback.
  *
- * @param place Place to leave permanently.
- * @param keep_active Keep place active after last application disconnected.
+ * @return Handle that can be used to cancel watching.
+ */
+struct GNUNET_SOCIAL_WatchHandle *
+GNUNET_SOCIAL_place_watch (struct GNUNET_SOCIAL_Place *place,
+                           const char *object_filter,
+                           GNUNET_PSYC_StateCallback state_cb,
+                           void *state_cb_cls);
+
+
+/**
+ * Cancel watching a place for changed objects.
+ *
+ * @param wh Watch handle to cancel.
  */
 void
-GNUNET_SOCIAL_place_leave (struct GNUNET_SOCIAL_Place *place, int keep_active);
+GNUNET_SOCIAL_place_watch_cancel (struct GNUNET_SOCIAL_WatchHandle *wh);
+
+
+struct GNUNET_SOCIAL_LookHandle;
+
+
+/**
+ * Look at objects in the place with a matching name prefix.
+ *
+ * @param place The place to look its objects at.
+ * @param name_prefix Look at objects with names beginning with this value.
+ * @param state_cb Function to call for each object found.
+ * @param state_cb_cls Closure for callback function.
+ *
+ * @return Handle that can be used to stop looking at objects.
+ */
+struct GNUNET_SOCIAL_LookHandle *
+GNUNET_SOCIAL_place_look (struct GNUNET_SOCIAL_Place *place,
+                          const char *name_prefix,
+                          GNUNET_PSYC_StateCallback state_cb,
+                          void *state_cb_cls);
+
+
+/**
+ * Stop looking at objects.
+ *
+ * @param lh Look handle to stop.
+ */
+void
+GNUNET_SOCIAL_place_look_cancel (struct GNUNET_SOCIAL_LookHandle *lh);
+
+
+
+/**
+ * Look at a particular object in the place.
+ *
+ * The best matching object is returned (its name might be less specific than
+ * what was requested).
+ *
+ * @param place The place to look the object at.
+ * @param full_name Full name of the object.
+ * @param value_size Set to the size of the returned value.
+ * @return NULL if there is no such object at this place.
+ */
+const void *
+GNUNET_SOCIAL_place_look_at (struct GNUNET_SOCIAL_Place *place,
+                             const char *full_name,
+                             size_t *value_size);
 
 
 #if 0                           /* keep Emacsens' auto-indent happy */