audio_format: added audio_format_clear() and audio_format_defined()

audio_format_clear() sets an audio_format struct to an cleared (undefined) state, which is both faster and smaller than memset(0). audio_format_defined() checks if the audio_format struct actually has a defined value (i.e. non-zero). Both can be used to avoid pointers to audio_format, replacing the "NULL" value with an "undefined" audio_format.

audio_format: added audio_format_clear() and audio_format_defined()
d9254369 · Max Kellermann · 9ceadb05 · d9254369 · d9254369
Commit d9254369 authored Sep 10, 2008 by Max Kellermann
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Showing with 13 additions and 1 deletion

audio.c src/audio.c +1 -1

audio_format.h src/audio_format.h +12 -0

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--- a/src/audio.c
+++ b/src/audio.c
@@ -231,7 +231,7 @@ static void syncAudioDeviceStates(void)
 	struct audio_output *audioOutput;
 	unsigned int i;
-	if (!audio_format.channels)
+	if (!audio_format_defined(&audio_format))
 		return;
 	for (i = 0; i < audioOutputArraySize; ++i) {

--- a/src/audio_format.h
+++ b/src/audio_format.h
@@ -27,6 +27,18 @@ struct audio_format {
 	mpd_sint8 channels;
 };
+static inline void audio_format_clear(struct audio_format *af)
+{
+	af->sampleRate = 0;
+	af->bits = 0;
+	af->channels = 0;
+}
+static inline int audio_format_defined(const struct audio_format *af)
+{
+	return af->sampleRate != 0;
+}
 static inline int audio_format_equals(const struct audio_format *a,
 				      const struct audio_format *b)
 {