[folks] core: Support lazy initialisation of properties

[Philip Withnall <pwithnall src gnome org>]

commit 4a59af5c74f84932c8da90f6ac996a4a2f69e17c
Author: Philip Withnall <philip tecnocode co uk>
Date:   Mon Aug 27 10:05:35 2012 +0100

    core: Support lazy initialisation of properties
    
    Creating several HashSets and HashMultiMaps for every Individual turns
    out to be quite wasteful, especially when most of them will typically be
    empty (as address books are generally quite sparse on properties) and never
    accessed (since most clients donât need local IDs or web service addresses).
    
    This commit delays initialisation of various multi-valued Individual
    properties to the first time theyâre accessed, giving them a null value
    before that time. It preserves the existing API for Individual, i.e. the
    properties themselves remain non-nullable, and only the object members
    backing them become nullable.
    
    This does introduce a slight behaviour change, in that an Individual will
    now emit change notifications for a non-initialised multi-valued property if
    *any* of the Personas in the Individual emit a notification for that
    property. This is because the Individual canât compare the current value of
    its property to the new one resulting from the change in the Personaâs
    property value to determine if a change has really occurred. Therefore the
    Individual makes a safe over-estimate and emits notifications which might
    be false positives.
    
    This shouldnât be a problem: if a client is interested in the property,
    they will have already queried it and caused it to be initialised.
    Initialised properties have the same notification behaviour as before.
    If a client isnât interested in the property, it wonât be connected to the
    property notifications anyway.
    
    This change roughly quarters the number of GObjects being created when
    opening folks-inspect with the Telepathy, key-file and EDS backends enabled
    and ~115 personas in the system.

 NEWS                  |    1 +
 folks/individual.vala |  385 +++++++++++++++++++++++++++++++++++++------------
 2 files changed, 290 insertions(+), 96 deletions(-)
---
diff --git a/NEWS b/NEWS
index 8d988e1..908251e 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,7 @@ Bugs fixed:
   errors
 â Bug 682572 â Build failures due to accessing static members
 â Bug 682346 â build: Make telepathy backend optional
+â Bug 682809 â Lazy instantiation of multi-valued properties
 
 Overview of changes from libfolks 0.7.2 to libfolks 0.7.3
 =========================================================
diff --git a/folks/individual.vala b/folks/individual.vala
index e087b25..2e38325 100644
--- a/folks/individual.vala
+++ b/folks/individual.vala
@@ -470,10 +470,8 @@ public class Folks.Individual : Object,
       set { this.change_gender.begin (value); } /* not writeable */
     }
 
-  private HashSet<UrlFieldDetails> _urls = new HashSet<UrlFieldDetails> (
-      (GLib.HashFunc) UrlFieldDetails.hash,
-      (GLib.EqualFunc) UrlFieldDetails.equal);
-  private Set<UrlFieldDetails> _urls_ro;
+  private HashSet<UrlFieldDetails>? _urls = null;
+  private Set<UrlFieldDetails>? _urls_ro = null;
 
   /**
    * { inheritDoc}
@@ -481,15 +479,16 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public Set<UrlFieldDetails> urls
     {
-      get { return this._urls_ro; }
+      get
+        {
+          this._update_urls (true);
+          return this._urls_ro;
+        }
       set { this.change_urls.begin (value); } /* not writeable */
     }
 
-  private HashSet<PhoneFieldDetails> _phone_numbers =
-      new HashSet<PhoneFieldDetails> (
-          (GLib.HashFunc) PhoneFieldDetails.hash,
-          (GLib.EqualFunc) PhoneFieldDetails.equal);
-  private Set<PhoneFieldDetails> _phone_numbers_ro;
+  private HashSet<PhoneFieldDetails>? _phone_numbers = null;
+  private Set<PhoneFieldDetails>? _phone_numbers_ro = null;
 
   /**
    * { inheritDoc}
@@ -497,15 +496,16 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public Set<PhoneFieldDetails> phone_numbers
     {
-      get { return this._phone_numbers_ro; }
+      get
+        {
+          this._update_phone_numbers (true);
+          return this._phone_numbers_ro;
+        }
       set { this.change_phone_numbers.begin (value); } /* not writeable */
     }
 
-  private HashSet<EmailFieldDetails> _email_addresses =
-      new HashSet<EmailFieldDetails> (
-          (GLib.HashFunc) EmailFieldDetails.hash,
-          (GLib.EqualFunc) EmailFieldDetails.equal);
-  private Set<EmailFieldDetails> _email_addresses_ro;
+  private HashSet<EmailFieldDetails>? _email_addresses = null;
+  private Set<EmailFieldDetails>? _email_addresses_ro = null;
 
   /**
    * { inheritDoc}
@@ -513,14 +513,16 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public Set<EmailFieldDetails> email_addresses
     {
-      get { return this._email_addresses_ro; }
+      get
+        {
+          this._update_email_addresses (true);
+          return this._email_addresses_ro;
+        }
       set { this.change_email_addresses.begin (value); } /* not writeable */
     }
 
-  private HashSet<RoleFieldDetails> _roles = new HashSet<RoleFieldDetails> (
-      (GLib.HashFunc) RoleFieldDetails.hash,
-      (GLib.EqualFunc) RoleFieldDetails.equal);
-  private Set<RoleFieldDetails> _roles_ro;
+  private HashSet<RoleFieldDetails>? _roles = null;
+  private Set<RoleFieldDetails>? _roles_ro = null;
 
   /**
    * { inheritDoc}
@@ -528,12 +530,16 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public Set<RoleFieldDetails> roles
     {
-      get { return this._roles_ro; }
+      get
+        {
+          this._update_roles (true);
+          return this._roles_ro;
+        }
       set { this.change_roles.begin (value); } /* not writeable */
     }
 
-  private HashSet<string> _local_ids = new HashSet<string> ();
-  private Set<string> _local_ids_ro;
+  private HashSet<string>? _local_ids = null;
+  private Set<string>? _local_ids_ro = null;
 
   /**
    * { inheritDoc}
@@ -541,7 +547,11 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public Set<string> local_ids
     {
-      get { return this._local_ids_ro; }
+      get
+        {
+          this._update_local_ids (true);
+          return this._local_ids_ro;
+        }
       set { this.change_local_ids.begin (value); } /* not writeable */
     }
 
@@ -569,10 +579,8 @@ public class Folks.Individual : Object,
       set { this.change_calendar_event_id.begin (value); } /* not writeable */
     }
 
-  private HashSet<NoteFieldDetails> _notes = new HashSet<NoteFieldDetails> (
-      (GLib.HashFunc) NoteFieldDetails.hash,
-      (GLib.EqualFunc) NoteFieldDetails.equal);
-  private Set<NoteFieldDetails> _notes_ro;
+  private HashSet<NoteFieldDetails>? _notes = null;
+  private Set<NoteFieldDetails>? _notes_ro = null;
 
   /**
    * { inheritDoc}
@@ -580,15 +588,16 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public Set<NoteFieldDetails> notes
     {
-      get { return this._notes_ro; }
+      get
+        {
+          this._update_notes (true);
+          return this._notes_ro;
+        }
       set { this.change_notes.begin (value); } /* not writeable */
     }
 
-  private HashSet<PostalAddressFieldDetails> _postal_addresses =
-      new HashSet<PostalAddressFieldDetails> (
-          (GLib.HashFunc) PostalAddressFieldDetails.hash,
-          (GLib.EqualFunc) PostalAddressFieldDetails.equal);
-  private Set<PostalAddressFieldDetails> _postal_addresses_ro;
+  private HashSet<PostalAddressFieldDetails>? _postal_addresses = null;
+  private Set<PostalAddressFieldDetails>? _postal_addresses_ro = null;
 
   /**
    * { inheritDoc}
@@ -596,7 +605,11 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public Set<PostalAddressFieldDetails> postal_addresses
     {
-      get { return this._postal_addresses_ro; }
+      get
+        {
+          this._update_postal_addresses (true);
+          return this._postal_addresses_ro;
+        }
       set { this.change_postal_addresses.begin (value); } /* not writeable */
     }
 
@@ -680,8 +693,8 @@ public class Folks.Individual : Object,
       this.notify_property ("is-favourite");
     }
 
-  private HashSet<string> _groups = new HashSet<string> ();
-  private Set<string> _groups_ro;
+  private HashSet<string>? _groups = null;
+  private Set<string>? _groups_ro = null;
 
   /**
    * { inheritDoc}
@@ -689,7 +702,11 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public Set<string> groups
     {
-      get { return this._groups_ro; }
+      get
+        {
+          this._update_groups (true);
+          return this._groups_ro;
+        }
       set { this.change_groups.begin (value); }
     }
 
@@ -742,14 +759,9 @@ public class Folks.Individual : Object,
           assert (persona_error != null);
           throw persona_error;
         }
-
-      /* Update our copy of the property. */
-      this._update_groups ();
     }
 
-  private HashMultiMap<string, ImFieldDetails> _im_addresses =
-      new HashMultiMap<string, ImFieldDetails> (
-          null, null, ImFieldDetails.hash, (EqualFunc) ImFieldDetails.equal);
+  private HashMultiMap<string, ImFieldDetails>? _im_addresses = null;
 
   /**
    * { inheritDoc}
@@ -757,14 +769,16 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public MultiMap<string, ImFieldDetails> im_addresses
     {
-      get { return this._im_addresses; }
+      get
+        {
+          this._update_im_addresses (true);
+          return this._im_addresses;
+        }
       set { this.change_im_addresses.begin (value); } /* not writeable */
     }
 
-  private HashMultiMap<string, WebServiceFieldDetails> _web_service_addresses =
-      new HashMultiMap<string, WebServiceFieldDetails> (null, null,
-          (GLib.HashFunc) WebServiceFieldDetails.hash,
-          (GLib.EqualFunc) WebServiceFieldDetails.equal);
+  private HashMultiMap<string, WebServiceFieldDetails>? _web_service_addresses =
+      null;
 
   /**
    * { inheritDoc}
@@ -772,7 +786,11 @@ public class Folks.Individual : Object,
   [CCode (notify = false)]
   public MultiMap<string, WebServiceFieldDetails> web_service_addresses
     {
-      get { return this._web_service_addresses; }
+      get
+        {
+          this._update_web_service_addresses (true);
+          return this._web_service_addresses;
+        }
       /* Not writeable: */
       set { this.change_web_service_addresses.begin (value); }
     }
@@ -945,7 +963,7 @@ public class Folks.Individual : Object,
 
   private void _persona_group_changed_cb (string group, bool is_member)
     {
-      this._update_groups ();
+      this._update_groups (false);
     }
 
   private void _notify_gender_cb ()
@@ -955,27 +973,27 @@ public class Folks.Individual : Object,
 
   private void _notify_urls_cb ()
     {
-      this._update_urls ();
+      this._update_urls (false);
     }
 
   private void _notify_phone_numbers_cb ()
     {
-      this._update_phone_numbers ();
+      this._update_phone_numbers (false);
     }
 
   private void _notify_postal_addresses_cb ()
     {
-      this._update_postal_addresses ();
+      this._update_postal_addresses (false);
     }
 
   private void _notify_email_addresses_cb ()
     {
-      this._update_email_addresses ();
+      this._update_email_addresses (false);
     }
 
   private void _notify_roles_cb ()
     {
-      this._update_roles ();
+      this._update_roles (false);
     }
 
   private void _notify_birthday_cb ()
@@ -985,12 +1003,12 @@ public class Folks.Individual : Object,
 
   private void _notify_notes_cb ()
     {
-      this._update_notes ();
+      this._update_notes (false);
     }
 
   private void _notify_local_ids_cb ()
     {
-      this._update_local_ids ();
+      this._update_local_ids (false);
     }
 
   /**
@@ -1025,12 +1043,12 @@ public class Folks.Individual : Object,
 
   private void _notify_im_addresses_cb (Object obj, ParamSpec ps)
     {
-      this._update_im_addresses ();
+      this._update_im_addresses (false);
     }
 
   private void _notify_web_service_addresses_cb (Object obj, ParamSpec ps)
     {
-      this._update_web_service_addresses ();
+      this._update_web_service_addresses (false);
     }
 
   private void _notify_is_favourite_cb (Object obj, ParamSpec ps)
@@ -1100,14 +1118,6 @@ public class Folks.Individual : Object,
           this._persona_set.size, this);
 
       this._persona_set_ro = this._persona_set.read_only_view;
-      this._urls_ro = this._urls.read_only_view;
-      this._phone_numbers_ro = this._phone_numbers.read_only_view;
-      this._email_addresses_ro = this._email_addresses.read_only_view;
-      this._roles_ro = this._roles.read_only_view;
-      this._local_ids_ro = this._local_ids.read_only_view;
-      this._postal_addresses_ro = this._postal_addresses.read_only_view;
-      this._notes_ro = this._notes.read_only_view;
-      this._groups_ro = this._groups.read_only_view;
     }
 
   ~Individual ()
@@ -1185,26 +1195,26 @@ public class Folks.Individual : Object,
 
   private void _update_fields ()
     {
-      this._update_groups ();
+      this._update_groups (false);
       this._update_presence ();
       this._update_is_favourite ();
       this._update_avatar ();
       this._update_alias ();
       this._update_trust_level ();
-      this._update_im_addresses ();
-      this._update_web_service_addresses ();
+      this._update_im_addresses (false);
+      this._update_web_service_addresses (false);
       this._update_structured_name ();
       this._update_full_name ();
       this._update_nickname ();
       this._update_gender ();
-      this._update_urls ();
-      this._update_phone_numbers ();
-      this._update_email_addresses ();
-      this._update_roles ();
+      this._update_urls (false);
+      this._update_phone_numbers (false);
+      this._update_email_addresses (false);
+      this._update_roles (false);
       this._update_birthday ();
-      this._update_notes ();
-      this._update_postal_addresses ();
-      this._update_local_ids ();
+      this._update_notes (false);
+      this._update_postal_addresses (false);
+      this._update_local_ids (false);
     }
 
   /* Delegate to update the value of a property on this individual from the
@@ -1325,8 +1335,25 @@ public class Folks.Individual : Object,
       setter (candidate_p);
     }
 
-  private void _update_groups ()
+  private void _update_groups (bool create_if_not_exist)
     {
+      /* If the set of groups doesn't exist, and we're not meant to lazily
+       * create it, then simply emit a notification (since the set might've
+       * changed â we can't be sure, but emitting is a safe over-estimate) and
+       * return. */
+      if (this._groups == null && create_if_not_exist == false)
+        {
+          this.notify_property ("groups");
+          return;
+        }
+
+      /* Lazily instantiate the set of groups. */
+      else if (this._groups == null)
+        {
+          this._groups = new HashSet<string> ();
+          this._groups_ro = this._groups.read_only_view;
+        }
+
       var new_groups = new HashSet<string> ();
 
       /* FIXME: this should partition the personas by store (maybe we should
@@ -1535,8 +1562,26 @@ public class Folks.Individual : Object,
         this.trust_level = trust_level;
     }
 
-  private void _update_im_addresses ()
+  private void _update_im_addresses (bool create_if_not_exist)
     {
+      /* If the set of IM addresses doesn't exist, and we're not meant to lazily
+       * create it, then simply emit a notification (since the set might've
+       * changed â we can't be sure, but emitting is a safe over-estimate) and
+       * return. */
+      if (this._im_addresses == null && create_if_not_exist == false)
+        {
+          this.notify_property ("im-addresses");
+          return;
+        }
+
+      /* Lazily instantiate the set of IM addresses. */
+      else if (this._im_addresses == null)
+        {
+          this._im_addresses = new HashMultiMap<string, ImFieldDetails> (
+              null, null, ImFieldDetails.hash,
+              (EqualFunc) ImFieldDetails.equal);
+        }
+
       /* populate the IM addresses as the union of our Personas' addresses */
       this._im_addresses.clear ();
 
@@ -1560,8 +1605,27 @@ public class Folks.Individual : Object,
       this.notify_property ("im-addresses");
     }
 
-  private void _update_web_service_addresses ()
+  private void _update_web_service_addresses (bool create_if_not_exist)
     {
+      /* If the set of web service addresses doesn't exist, and we're not meant
+       * to lazily create it, then simply emit a notification (since the set
+       * might've changed â we can't be sure, but emitting is a safe
+       * over-estimate) and return. */
+      if (this._web_service_addresses == null && create_if_not_exist == false)
+        {
+          this.notify_property ("web-service-addresses");
+          return;
+        }
+
+      /* Lazily instantiate the set of web service addresses. */
+      else if (this._web_service_addresses == null)
+        {
+          this._web_service_addresses =
+              new HashMultiMap<string, WebServiceFieldDetails> (null, null,
+                  (GLib.HashFunc) WebServiceFieldDetails.hash,
+                  (GLib.EqualFunc) WebServiceFieldDetails.equal);;
+        }
+
       /* populate the web service addresses as the union of our Personas' addresses */
       this._web_service_addresses.clear ();
 
@@ -1825,11 +1889,29 @@ public class Folks.Individual : Object,
         });
     }
 
-  private void _update_urls ()
+  private void _update_urls (bool create_if_not_exist)
     {
+      /* If the set of URIs doesn't exist, and we're not meant to lazily create
+       * it, then simply emit a notification (since the set might've changed â
+       * we can't be sure, but emitting is a safe over-estimate) and return. */
+      if (this._urls == null && create_if_not_exist == false)
+        {
+          this.notify_property ("urls");
+          return;
+        }
+
+      /* Lazily instantiate the set of URIs. */
+      else if (this._urls == null)
+        {
+          this._urls = new HashSet<UrlFieldDetails> (
+              (GLib.HashFunc) UrlFieldDetails.hash,
+              (GLib.EqualFunc) UrlFieldDetails.equal);
+          this._urls_ro = this._urls.read_only_view;
+        }
+
       /* Populate the URLs as the union of our Personas' URLs.
        * If the same URL exists multiple times we merge the parameters. */
-      var urls_set = new HashMap<unowned string, unowned UrlFieldDetails> (
+      var urls_set = new HashMap<string, UrlFieldDetails> (
           null, null, (GLib.EqualFunc) UrlFieldDetails.equal);
 
       this._urls.clear ();
@@ -1848,7 +1930,7 @@ public class Folks.Individual : Object,
                     {
                       var new_url_fd = new UrlFieldDetails (url_fd.value);
                       new_url_fd.extend_parameters (url_fd.parameters);
-                      urls_set.set (url_fd.value, new_url_fd);
+                      urls_set.set (new_url_fd.value, new_url_fd);
                       this._urls.add (new_url_fd);
                     }
                 }
@@ -1858,12 +1940,30 @@ public class Folks.Individual : Object,
       this.notify_property ("urls");
     }
 
-  private void _update_phone_numbers ()
+  private void _update_phone_numbers (bool create_if_not_exist)
     {
+      /* If the set of phone numbers doesn't exist, and we're not meant to
+       * lazily create it, then simply emit a notification (since the set
+       * might've changed â we can't be sure, but emitting is a safe
+       * over-estimate) and return. */
+      if (this._phone_numbers == null && create_if_not_exist == false)
+        {
+          this.notify_property ("phone-numbers");
+          return;
+        }
+
+      /* Lazily instantiate the set of phone numbers. */
+      else if (this._phone_numbers == null)
+        {
+          this._phone_numbers = new HashSet<PhoneFieldDetails> (
+              (GLib.HashFunc) PhoneFieldDetails.hash,
+              (GLib.EqualFunc) PhoneFieldDetails.equal);
+          this._phone_numbers_ro = this._phone_numbers.read_only_view;
+        }
+
       /* Populate the phone numbers as the union of our Personas' numbers
        * If the same number exists multiple times we merge the parameters. */
-      var phone_numbers_set =
-          new HashMap<unowned string, unowned PhoneFieldDetails> (
+      var phone_numbers_set = new HashMap<string, PhoneFieldDetails> (
               null, null, (GLib.EqualFunc) PhoneFieldDetails.equal);
 
       this._phone_numbers.clear ();
@@ -1882,7 +1982,7 @@ public class Folks.Individual : Object,
                     {
                       var new_fd = new PhoneFieldDetails (phone_fd.value);
                       new_fd.extend_parameters (phone_fd.parameters);
-                      phone_numbers_set.set (phone_fd.value, new_fd);
+                      phone_numbers_set.set (new_fd.value, new_fd);
                       this._phone_numbers.add (new_fd);
                     }
                 }
@@ -1892,11 +1992,30 @@ public class Folks.Individual : Object,
       this.notify_property ("phone-numbers");
     }
 
-  private void _update_email_addresses ()
+  private void _update_email_addresses (bool create_if_not_exist)
     {
+      /* If the set of e-mail addresses doesn't exist, and we're not meant to
+       * lazily create it, then simply emit a notification (since the set
+       * might've changed â we can't be sure, but emitting is a safe
+       * over-estimate) and return. */
+      if (this._email_addresses == null && create_if_not_exist == false)
+        {
+          this.notify_property ("email-addresses");
+          return;
+        }
+
+      /* Lazily instantiate the set of e-mail addresses. */
+      else if (this._email_addresses == null)
+        {
+          this._email_addresses = new HashSet<EmailFieldDetails> (
+              (GLib.HashFunc) EmailFieldDetails.hash,
+              (GLib.EqualFunc) EmailFieldDetails.equal);
+          this._email_addresses_ro = this._email_addresses.read_only_view;
+        }
+
       /* Populate the email addresses as the union of our Personas' addresses.
        * If the same address exists multiple times we merge the parameters. */
-      var emails_set = new HashMap<unowned string, unowned EmailFieldDetails> (
+      var emails_set = new HashMap<string, EmailFieldDetails> (
           null, null, (GLib.EqualFunc) EmailFieldDetails.equal);
 
       this._email_addresses.clear ();
@@ -1915,7 +2034,7 @@ public class Folks.Individual : Object,
                     {
                       var new_email_fd = new EmailFieldDetails (email_fd.value,
                           email_fd.parameters);
-                      emails_set.set (email_fd.value, new_email_fd);
+                      emails_set.set (new_email_fd.value, new_email_fd);
                       this._email_addresses.add (new_email_fd);
                     }
                 }
@@ -1925,8 +2044,27 @@ public class Folks.Individual : Object,
       this.notify_property ("email-addresses");
     }
 
-  private void _update_roles ()
+  private void _update_roles (bool create_if_not_exist)
     {
+      /* If the set of roles doesn't exist, and we're not meant to
+       * lazily create it, then simply emit a notification (since the set
+       * might've changed â we can't be sure, but emitting is a safe
+       * over-estimate) and return. */
+      if (this._roles == null && create_if_not_exist == false)
+        {
+          this.notify_property ("roles");
+          return;
+        }
+
+      /* Lazily instantiate the set of roles. */
+      else if (this._roles == null)
+        {
+          this._roles = new HashSet<RoleFieldDetails> (
+              (GLib.HashFunc) RoleFieldDetails.hash,
+              (GLib.EqualFunc) RoleFieldDetails.equal);
+          this._roles_ro = this._roles.read_only_view;
+        }
+
       this._roles.clear ();
 
       foreach (var persona in this._persona_set)
@@ -1944,8 +2082,25 @@ public class Folks.Individual : Object,
       this.notify_property ("roles");
     }
 
-  private void _update_local_ids ()
+  private void _update_local_ids (bool create_if_not_exist)
     {
+      /* If the set of local IDs doesn't exist, and we're not meant to
+       * lazily create it, then simply emit a notification (since the set
+       * might've changed â we can't be sure, but emitting is a safe
+       * over-estimate) and return. */
+      if (this._local_ids == null && create_if_not_exist == false)
+        {
+          this.notify_property ("local-ids");
+          return;
+        }
+
+      /* Lazily instantiate the set of local IDs. */
+      else if (this._local_ids == null)
+        {
+          this._local_ids = new HashSet<string> ();
+          this._local_ids_ro = this._local_ids.read_only_view;
+        }
+
       this._local_ids.clear ();
 
       foreach (var persona in this._persona_set)
@@ -1963,8 +2118,27 @@ public class Folks.Individual : Object,
       this.notify_property ("local-ids");
     }
 
-  private void _update_postal_addresses ()
+  private void _update_postal_addresses (bool create_if_not_exist)
     {
+      /* If the set of addresses doesn't exist, and we're not meant to lazily
+       * create it, then simply emit a notification (since the set might've
+       * changed â we can't be sure, but emitting is a safe over-estimate) and
+       * return. */
+      if (this._postal_addresses == null && create_if_not_exist == false)
+        {
+          this.notify_property ("postal-addresses");
+          return;
+        }
+
+      /* Lazily instantiate the set of addresses. */
+      else if (this._postal_addresses == null)
+        {
+          this._postal_addresses = new HashSet<PostalAddressFieldDetails> (
+              (GLib.HashFunc) PostalAddressFieldDetails.hash,
+              (GLib.EqualFunc) PostalAddressFieldDetails.equal);
+          this._postal_addresses_ro = this._postal_addresses.read_only_view;
+        }
+
       this._postal_addresses.clear ();
 
       /* FIXME: Detect duplicates somehow? */
@@ -2033,8 +2207,27 @@ public class Folks.Individual : Object,
         });
     }
 
-  private void _update_notes ()
+  private void _update_notes (bool create_if_not_exist)
     {
+      /* If the set of notes doesn't exist, and we're not meant to lazily
+       * create it, then simply emit a notification (since the set might've
+       * changed â we can't be sure, but emitting is a safe over-estimate) and
+       * return. */
+      if (this._notes == null && create_if_not_exist == false)
+        {
+          this.notify_property ("notes");
+          return;
+        }
+
+      /* Lazily instantiate the set of notes. */
+      else if (this._notes == null)
+        {
+          this._notes = new HashSet<NoteFieldDetails> (
+              (GLib.HashFunc) NoteFieldDetails.hash,
+              (GLib.EqualFunc) NoteFieldDetails.equal);
+          this._notes_ro = this._notes.read_only_view;
+        }
+
       this._notes.clear ();
 
       foreach (var persona in this._persona_set)