contacts-cache: return most relevant contacts

Return in the contacts in *reverse* rank order, i.e. the most relevant come first.
This is useful since we only want the first maxnum contacts, and those should of
course be the most relevant.

Update mu cfind/server as well.

cfind

lib/mu-contacts-cache.cc

@@ -304,7 +304,7 @@ using ContactSet = std::set<std::reference_wrapper<const Contact>,
 			    ContactLessThan>;
 
 void
-ContactsCache::for_each(const EachContactFunc& each_contact, size_t max_num) const
+ContactsCache::for_each(const EachContactFunc& each_contact) const
 {
 	std::lock_guard<std::mutex> l_{priv_->mtx_};
 
@@ -316,12 +316,10 @@ ContactsCache::for_each(const EachContactFunc& each_contact, size_t max_num) con
 	for (const auto& item : priv_->contacts_)
 		sorted.emplace(item.second);
 
-	// sadly, there's no set::resize
+	// return in _reverse_ order, so we get the most relevant ones first.
-	size_t n{};
+	for (auto it = sorted.rbegin(); it != sorted.rend(); ++it) {
-	for (const auto& ci : sorted) {
+		if (!each_contact(*it))
-		if (max_num > 0 && n++ >= max_num)
 			break;
-		each_contact(ci);
 	}
 }
 
@@ -424,6 +422,7 @@ test_mu_contacts_cache_sort()
 			if (g_test_verbose())
 				g_print("\t- %s\n", contact.display_name().c_str());
 			str += contact.name;
+			return true;
 		});
 		return str;
 	};
@@ -431,38 +430,38 @@ test_mu_contacts_cache_sort()
 
 	const auto now{std::time({})};
 
-	// "first" means less relevant
+	// "first" means more relevant
 
-	{ /* recent messages, older comes first */
+	{ /* recent messages, newer comes first */
 
 		Mu::ContactsCache ccache("");
 		ccache.add(Mu::Contact{"a@example.com", "a", now, true, 1000, 0});
 		ccache.add(Mu::Contact{"b@example.com", "b", now-1, true, 1000, 0});
-		assert_equal(result_chars(ccache), "ba");
+		assert_equal(result_chars(ccache), "ab");
 	}
 
-	{ /* non-recent messages, less frequent comes first */
+	{ /* non-recent messages, more frequent comes first */
 
 		Mu::ContactsCache ccache("");
 		ccache.add(Mu::Contact{"a@example.com", "a", now-2*RecentOffset, true, 1000, 0});
 		ccache.add(Mu::Contact{"b@example.com", "b", now-3*RecentOffset, true, 2000, 0});
-		assert_equal(result_chars(ccache), "ab");
+		assert_equal(result_chars(ccache), "ba");
 	}
 
-	{ /* non-personal comes first */
+	{ /* personal comes first */
 
 		Mu::ContactsCache ccache("");
 		ccache.add(Mu::Contact{"a@example.com", "a", now-5*RecentOffset, true, 1000, 0});
 		ccache.add(Mu::Contact{"b@example.com", "b", now, false, 8000, 0});
-		assert_equal(result_chars(ccache), "ba");
+		assert_equal(result_chars(ccache), "ab");
 	}
 
-	{ /* if all else fails, alphabetically */
+	{ /* if all else fails, reverse-alphabetically */
 		Mu::ContactsCache ccache("");
 		ccache.add(Mu::Contact{"a@example.com", "a", now, false, 1000, 0});
 		ccache.add(Mu::Contact{"b@example.com", "b", now, false, 1000, 0});
 		g_assert_cmpuint(ccache.size(),==,2);
-		assert_equal(result_chars(ccache), "ab");
+		assert_equal(result_chars(ccache), "ba");
 	}
 }
 

lib/mu-contacts-cache.hh

@@ -136,16 +136,18 @@ public:
 	 * Prototype for a callable that receives a contact
 	 *
 	 * @param contact some contact
+	 *
+	 * @return to get more contacts; false otherwise
 	 */
-	using EachContactFunc = std::function<void(const Contact& contact_info)>;
+	using EachContactFunc = std::function<bool(const Contact& contact_info)>;
 
 	/**
-	 * Invoke some callable for each contact, in order of rank.
+	 * Invoke some callable for each contact, in _descending_ order of rank (i.e., the
+	 * highest ranked contacts come first).
 	 *
 	 * @param each_contact function invoked for each contact
-	 * @param max_num stop after at most so many contacts, or 0 for no limit
 	 */
-	void for_each(const EachContactFunc& each_contact, size_t max_num=0) const;
+	void for_each(const EachContactFunc& each_contact) const;
 
 private:
 	struct Private;

lib/mu-server.cc

@@ -532,30 +532,25 @@ Server::Private::contacts_handler(const Parameters& params)
 		time_to_string("%c", after).c_str(),
 		static_cast<size_t>(tstamp));
 
-	auto       rank{0};
+	auto       n{0};
 	Sexp::List contacts;
 	store().contacts_cache().for_each([&](const Contact& ci) {
 
 		/* since the last time we got some contacts */
 		if (tstamp > ci.tstamp)
-			return;
+			return true;
 		/* (maybe) only include 'personal' contacts */
 		if (personal && !ci.personal)
-			return;
+			return true;
 		/* only include newer-than-x contacts */
 		if (after > ci.message_date)
-			return;
+			return true;
 
-		rank++;
+		n++;
 
-		Sexp::List contact;
+		contacts.add(Sexp::make_string(ci.display_name(true/*encode-if-needed*/)));
-		contact.add_prop(":address",
+		return maxnum == 0 || n < maxnum;
-				 Sexp::make_string(ci.display_name(true/*encode-if-needed*/)));
+	});
-		contact.add_prop(":rank", Sexp::make_number(rank));
-		auto contacts_sexp{Sexp::make_list(std::move(contact))};
-		contacts_sexp.formatting_opts |= Sexp::FormattingOptions::SplitList;
-		contacts.add(std::move(contacts_sexp));
-	}, static_cast<size_t>(maxnum));
 
 	Sexp::List seq;
 	seq.add_prop(":contacts", Sexp::make_list(std::move(contacts)));
@@ -564,7 +559,7 @@ Server::Private::contacts_handler(const Parameters& params)
 					      g_get_monotonic_time())));
 
 	/* dump the contacts cache as a giant sexp */
-	g_debug("sending %d of %zu contact(s)", rank, store().contacts_cache().size());
+	g_debug("sending %d of %zu contact(s)", n, store().contacts_cache().size());
 	output_sexp(std::move(seq), Server::OutputFlags::SplitList);
 }
 

mu/mu-cmd-cfind.cc

@@ -265,18 +265,19 @@ print_plain(const std::string& email, const std::string& name, bool color)
 }
 
 struct ECData {
-	MuConfigFormat format;
+	MuConfigFormat	format;
-	gboolean       color, personal;
+	gboolean	color, personal;
-	time_t         after;
+	time_t		after;
-	GRegex*        rx;
+	GRegex*		rx;
-	GHashTable*    nicks;
+	GHashTable*	nicks;
-	size_t         n;
+	size_t		maxnum;
+	size_t		n;
 };
 
 static void
 each_contact(const Mu::Contact& ci, ECData& ecdata)
 {
-	if (ecdata.personal && ci.personal)
+	if (ecdata.personal && !ci.personal)
 		return;
 
 	if (ci.message_date < ecdata.after)
@@ -334,13 +335,14 @@ each_contact(const Mu::Contact& ci, ECData& ecdata)
 }
 
 static MuError
-run_cmd_cfind(const Mu::Store&     store,
+run_cmd_cfind(const Mu::Store&		store,
-	      const char*          pattern,
+	      const char*		pattern,
-	      gboolean             personal,
+	      gboolean			personal,
-	      time_t               after,
+	      time_t			after,
-	      const MuConfigFormat format,
+	      int			maxnum,
-	      gboolean             color,
+	      const MuConfigFormat	format,
-	      GError**             err)
+	      gboolean			color,
+	      GError**			err)
 {
 	ECData ecdata{};
 
@@ -360,14 +362,17 @@ run_cmd_cfind(const Mu::Store&     store,
 	ecdata.personal = personal;
 	ecdata.n        = 0;
 	ecdata.after    = after;
+	ecdata.maxnum   = maxnum;
 	ecdata.format   = format;
 	ecdata.color    = color;
 	ecdata.nicks    = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
 
 	print_header(format);
 
-	store.contacts_cache().for_each([&](const auto& ci) { each_contact(ci, ecdata); });
+	store.contacts_cache().for_each([&](const auto& ci) {
-
+		each_contact(ci, ecdata);
+		return ecdata.maxnum == 0 || ecdata.n < ecdata.maxnum;
+	});
 	g_hash_table_unref(ecdata.nicks);
 
 	if (ecdata.rx)
@@ -422,6 +427,7 @@ Mu::mu_cmd_cfind(const Mu::Store& store, const MuConfig* opts, GError** err)
 				 opts->params[1],
 				 opts->personal,
 				 opts->after,
+				 opts->maxnum,
 				 opts->format,
 				 !opts->nocolor,
 				 err);

mu/mu-config.cc

@@ -296,6 +296,8 @@ config_options_group_cfind()
 	     "whether to only get 'personal' contacts", NULL},
 	    {"after", 0, 0, G_OPTION_ARG_INT, &MU_CONFIG.after,
 	     "only get addresses last seen after T", "<timestamp>"},
+	    {"maxnum", 'n', 0, G_OPTION_ARG_INT, &MU_CONFIG.maxnum,
+	     "maximum number of contacts", "<number>"},
 	    {NULL, 0, 0, G_OPTION_ARG_NONE, NULL, NULL, NULL}};
 
 	og = g_option_group_new("cfind", "Options for the 'cfind' command", "", NULL,