Preserve compatibility with ABI v1 output plugins

VladislavGrudinin · Dec 24, 2021 · 5ecc3ad · 5ecc3ad
1 parent 4f46f27
commit 5ecc3ad
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Showing 5 changed files with 29 additions and 16 deletions.
diff --git a/mixer.h b/mixer.h
@@ -35,7 +35,10 @@ struct mixer_plugin_ops {
 	int (*exit)(void);
 	int (*open)(int *volume_max);
 	int (*close)(void);
-	int (*get_fds)(int what, int *fds);
+	union {
+	    int (*abi_1)(int *fds); // MIXER_FDS_VOLUME
+	    int (*abi_2)(int what, int *fds);
+	} get_fds;
 	int (*set_volume)(int l, int r);
 	int (*get_volume)(int *l, int *r);
 };

diff --git a/op/coreaudio.c b/op/coreaudio.c
@@ -957,13 +957,13 @@ const struct output_plugin_ops op_pcm_ops = {
 
 
 const struct mixer_plugin_ops op_mixer_ops = {
-	.init       = coreaudio_mixer_dummy,
-	.exit       = coreaudio_mixer_dummy,
-	.open       = coreaudio_mixer_open,
-	.close      = coreaudio_mixer_close,
-	.get_fds    = coreaudio_mixer_get_fds,
-	.set_volume = coreaudio_mixer_set_volume,
-	.get_volume = coreaudio_mixer_get_volume,
+	.init          = coreaudio_mixer_dummy,
+	.exit          = coreaudio_mixer_dummy,
+	.open          = coreaudio_mixer_open,
+	.close         = coreaudio_mixer_close,
+	.get_fds.abi_2 = coreaudio_mixer_get_fds,
+	.set_volume    = coreaudio_mixer_set_volume,
+	.get_volume    = coreaudio_mixer_get_volume,
 };
 
 const struct output_plugin_opt op_pcm_options[] = {

diff --git a/op/mixer_alsa.c b/op/mixer_alsa.c
@@ -218,7 +218,7 @@ const struct mixer_plugin_ops op_mixer_ops = {
 	.exit = alsa_mixer_exit,
 	.open = alsa_mixer_open,
 	.close = alsa_mixer_close,
-	.get_fds = alsa_mixer_get_fds,
+	.get_fds.abi_2 = alsa_mixer_get_fds,
 	.set_volume = alsa_mixer_set_volume,
 	.get_volume = alsa_mixer_get_volume,
 };

diff --git a/op/pulse.c b/op/pulse.c
@@ -606,7 +606,7 @@ const struct mixer_plugin_ops op_mixer_ops = {
 	.exit		= op_pulse_mixer_exit,
 	.open		= op_pulse_mixer_open,
 	.close		= op_pulse_mixer_close,
-	.get_fds	= op_pulse_mixer_get_fds,
+	.get_fds.abi_2	= op_pulse_mixer_get_fds,
 	.set_volume	= op_pulse_mixer_set_volume,
 	.get_volume	= op_pulse_mixer_get_volume,
 };

diff --git a/output.c b/output.c
@@ -43,6 +43,7 @@ struct output_plugin {
 	char *name;
 	void *handle;
 
+	const unsigned *abi_version_ptr;
 	const struct output_plugin_ops *pcm_ops;
 	const struct mixer_plugin_ops *mixer_ops;
 	const struct output_plugin_opt *pcm_options;
@@ -95,7 +96,6 @@ void op_load_plugins(void)
 		struct output_plugin *plug;
 		void *so, *symptr;
 		char *ext;
-		const unsigned *abi_version_ptr;
 		bool err = false;
 
 		if (d->d_name[0] == '.')
@@ -119,12 +119,13 @@ void op_load_plugins(void)
 		plug->pcm_ops = dlsym(so, "op_pcm_ops");
 		plug->pcm_options = dlsym(so, "op_pcm_options");
 		symptr = dlsym(so, "op_priority");
-		abi_version_ptr = dlsym(so, "op_abi_version");
+		plug->abi_version_ptr = dlsym(so, "op_abi_version");
 		if (!plug->pcm_ops || !plug->pcm_options || !symptr) {
 			error_msg("%s: missing symbol", filename);
 			err = true;
 		}
-		if (!abi_version_ptr || *abi_version_ptr != OP_ABI_VERSION) {
+		STATIC_ASSERT(OP_ABI_VERSION == 2);
+		if (!plug->abi_version_ptr || (*plug->abi_version_ptr != 1 && *plug->abi_version_ptr != 2)) {
 			error_msg("%s: incompatible plugin version", filename);
 			err = true;
 		}
@@ -322,9 +323,18 @@ int mixer_get_fds(int what, int *fds)
 		return -OP_ERROR_NOT_INITIALIZED;
 	if (!op->mixer_open)
 		return -OP_ERROR_NOT_OPEN;
-	if (!op->mixer_ops->get_fds)
-		return -OP_ERROR_NOT_SUPPORTED;
-	return op->mixer_ops->get_fds(what, fds);
+	switch (*op->abi_version_ptr) {
+	case 1:
+		if (!op->mixer_ops->get_fds.abi_1)
+			return -OP_ERROR_NOT_SUPPORTED;
+		if (what != MIXER_FDS_VOLUME)
+			return 0;
+		return op->mixer_ops->get_fds.abi_1(fds);
+	default:
+		if (!op->mixer_ops->get_fds.abi_2)
+			return -OP_ERROR_NOT_SUPPORTED;
+		return op->mixer_ops->get_fds.abi_2(what, fds);
+	}
 }
 
 extern int soft_vol;