From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 18 Dec 2017 20:52:50 +0000 (+0100)
Subject: sd-bus: add new API sd_bus_match_signal() + sd_bus_match_signal_asnyc()
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=fcf57ffefc702c6edc9c6fc5e18270247f4f9abe;p=elogind.git

sd-bus: add new API sd_bus_match_signal() + sd_bus_match_signal_asnyc()

These are convenience helpers that hide the match string logic (which we
probably should never have exposed), and instead just takes regular C
arguments.
---

diff --git a/src/libelogind/libelogind.sym b/src/libelogind/libelogind.sym
index 8bd8107d2..84b7ef406 100644
--- a/src/libelogind/libelogind.sym
+++ b/src/libelogind/libelogind.sym
@@ -544,4 +544,6 @@ global:
         sd_bus_request_name_async;
         sd_bus_release_name_async;
         sd_bus_add_match_async;
+        sd_bus_match_signal;
+        sd_bus_match_signal_async;
 } LIBSYSTEMD_236;
diff --git a/src/libelogind/sd-bus/bus-convenience.c b/src/libelogind/sd-bus/bus-convenience.c
index 9d3b59642..7d702e637 100644
--- a/src/libelogind/sd-bus/bus-convenience.c
+++ b/src/libelogind/sd-bus/bus-convenience.c
@@ -615,3 +615,69 @@ _public_ int sd_bus_query_sender_privilege(sd_bus_message *call, int capability)
 
         return 0;
 }
+
+#define make_expression(sender, path, interface, member)        \
+        strjoina(                                               \
+                "type='signal'",                                \
+                sender ? ",sender='" : "",                      \
+                sender ?: "",                                   \
+                sender ? "'" : "",                              \
+                path ? ",path='" : "",                          \
+                path ?: "",                                     \
+                path ? "'" : "",                                \
+                interface ? ",interface='" : "",                \
+                interface ?: "",                                \
+                interface ? "'" : "",                           \
+                member ? ",member='" : "",                      \
+                member ?: "",                                   \
+                member ? "'" : ""                               \
+        )
+
+_public_ int sd_bus_match_signal(
+                sd_bus *bus,
+                sd_bus_slot **ret,
+                const char *sender,
+                const char *path,
+                const char *interface,
+                const char *member,
+                sd_bus_message_handler_t callback,
+                void *userdata) {
+
+        const char *expression;
+
+        assert_return(bus, -EINVAL);
+        assert_return(!bus_pid_changed(bus), -ECHILD);
+        assert_return(!sender || service_name_is_valid(sender), -EINVAL);
+        assert_return(!path || object_path_is_valid(path), -EINVAL);
+        assert_return(!interface || interface_name_is_valid(interface), -EINVAL);
+        assert_return(!member || member_name_is_valid(member), -EINVAL);
+
+        expression = make_expression(sender, path, interface, member);
+
+        return sd_bus_add_match(bus, ret, expression, callback, userdata);
+}
+
+_public_ int sd_bus_match_signal_async(
+                sd_bus *bus,
+                sd_bus_slot **ret,
+                const char *sender,
+                const char *path,
+                const char *interface,
+                const char *member,
+                sd_bus_message_handler_t callback,
+                sd_bus_message_handler_t install_callback,
+                void *userdata) {
+
+        const char *expression;
+
+        assert_return(bus, -EINVAL);
+        assert_return(!bus_pid_changed(bus), -ECHILD);
+        assert_return(!sender || service_name_is_valid(sender), -EINVAL);
+        assert_return(!path || object_path_is_valid(path), -EINVAL);
+        assert_return(!interface || interface_name_is_valid(interface), -EINVAL);
+        assert_return(!member || member_name_is_valid(member), -EINVAL);
+
+        expression = make_expression(sender, path, interface, member);
+
+        return sd_bus_add_match_async(bus, ret, expression, callback, install_callback, userdata);
+}
diff --git a/src/systemd/sd-bus.h b/src/systemd/sd-bus.h
index d5e519d98..60e9d06df 100644
--- a/src/systemd/sd-bus.h
+++ b/src/systemd/sd-bus.h
@@ -341,6 +341,9 @@ int sd_bus_emit_interfaces_removed(sd_bus *bus, const char *path, const char *in
 int sd_bus_query_sender_creds(sd_bus_message *call, uint64_t mask, sd_bus_creds **creds);
 int sd_bus_query_sender_privilege(sd_bus_message *call, int capability);
 
+int sd_bus_match_signal(sd_bus *bus, sd_bus_slot **ret, const char *sender, const char *path, const char *interface, const char *member, sd_bus_message_handler_t callback, void *userdata);
+int sd_bus_match_signal_async(sd_bus *bus, sd_bus_slot **ret, const char *sender, const char *path, const char *interface, const char *member, sd_bus_message_handler_t match_callback, sd_bus_message_handler_t add_callback, void *userdata);
+
 /* Credential handling */
 
 int sd_bus_creds_new_from_pid(sd_bus_creds **ret, pid_t pid, uint64_t creds_mask);