decoder/sndfile: use decoder_read()

NEWS

@@ -6,6 +6,7 @@ ver 0.18.12 (not yet released)
   - audiofile: improve responsiveness
   - audiofile: fix WAV stream playback
   - dsdiff, dsf: fix stream playback
+  - sndfile: improve responsiveness
 * randomize next song when enabling "random" mode while not playing
 * randomize next song when adding to single-song queue
 

src/decoder/SndfileDecoderPlugin.cxx

@@ -31,10 +31,20 @@
 
 static constexpr Domain sndfile_domain("sndfile");
 
+struct SndfileInputStream {
+	Decoder *const decoder;
+	InputStream &is;
+
+	size_t Read(void *buffer, size_t size) {
+		return decoder_read(decoder, is, buffer, size);
+	}
+};
+
 static sf_count_t
 sndfile_vio_get_filelen(void *user_data)
 {
-	const InputStream &is = *(const InputStream *)user_data;
+	SndfileInputStream &sis = *(SndfileInputStream *)user_data;
+	const InputStream &is = sis.is;
 
 	return is.GetSize();
 }
@@ -42,7 +52,8 @@ sndfile_vio_get_filelen(void *user_data)
 static sf_count_t
 sndfile_vio_seek(sf_count_t offset, int whence, void *user_data)
 {
-	InputStream &is = *(InputStream *)user_data;
+	SndfileInputStream &sis = *(SndfileInputStream *)user_data;
+	InputStream &is = sis.is;
 
 	Error error;
 	if (!is.LockSeek(offset, whence, error)) {
@@ -56,25 +67,18 @@ sndfile_vio_seek(sf_count_t offset, int whence, void *user_data)
 static sf_count_t
 sndfile_vio_read(void *ptr, sf_count_t count, void *user_data)
 {
-	InputStream &is = *(InputStream *)user_data;
+	SndfileInputStream &sis = *(SndfileInputStream *)user_data;
 
 	sf_count_t total_bytes = 0;
-	Error error;
 
 	/* this loop is necessary because libsndfile chokes on partial
 	   reads */
 
 	do {
-		size_t nbytes = is.LockRead((char *)ptr + total_bytes,
-					    count - total_bytes, error);
-		if (nbytes == 0) {
-			if (error.IsDefined()) {
-				LogError(error);
+		size_t nbytes = sis.Read((char *)ptr + total_bytes,
+					 count - total_bytes);
+		if (nbytes == 0)
 			return -1;
-			}
-
-			break;
-		}
 
 		total_bytes += nbytes;
 	} while (total_bytes < count);
@@ -94,7 +98,8 @@ sndfile_vio_write(gcc_unused const void *ptr,
 static sf_count_t
 sndfile_vio_tell(void *user_data)
 {
-	const InputStream &is = *(const InputStream *)user_data;
+	SndfileInputStream &sis = *(SndfileInputStream *)user_data;
+	const InputStream &is = sis.is;
 
 	return is.GetOffset();
 }
@@ -140,7 +145,8 @@ sndfile_stream_decode(Decoder &decoder, InputStream &is)
 
 	info.format = 0;
 
-	sf = sf_open_virtual(&vio, SFM_READ, &info, &is);
+	SndfileInputStream sis{&decoder, is};
+	sf = sf_open_virtual(&vio, SFM_READ, &info, &sis);
 	if (sf == nullptr) {
 		LogWarning(sndfile_domain, "sf_open_virtual() failed");
 		return;