From 0ad2eb34c74dc128e7884552ef1f930f3f495066 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@duempel.org>
Date: Mon, 28 Oct 2013 23:29:23 +0100
Subject: [PATCH] decoder/dsdlib: add class DsdUint64

Merge lots of duplicate code.
---
 src/decoder/DsdLib.hxx              | 12 ++++++++++++
 src/decoder/DsdiffDecoderPlugin.cxx |  9 ++++-----
 src/decoder/DsfDecoderPlugin.cxx    | 30 ++++++++++-------------------
 3 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/src/decoder/DsdLib.hxx b/src/decoder/DsdLib.hxx
index 6b7498df1..25329e650 100644
--- a/src/decoder/DsdLib.hxx
+++ b/src/decoder/DsdLib.hxx
@@ -20,6 +20,7 @@
 #ifndef MPD_DECODER_DSDLIB_HXX
 #define MPD_DECODER_DSDLIB_HXX
 
+#include "system/ByteOrder.hxx"
 #include "Compiler.h"
 
 #include <stddef.h>
@@ -35,6 +36,17 @@ struct DsdId {
 	bool Equals(const char *s) const;
 };
 
+class DsdUint64 {
+	uint32_t lo;
+	uint32_t hi;
+
+public:
+	constexpr uint64_t Read() const {
+		return (uint64_t(FromLE32(hi)) << 32) |
+			uint64_t(FromLE32(lo));
+	}
+};
+
 bool
 dsdlib_read(Decoder *decoder, InputStream &is,
 	    void *data, size_t length);
diff --git a/src/decoder/DsdiffDecoderPlugin.cxx b/src/decoder/DsdiffDecoderPlugin.cxx
index 939904d11..1dc7c7c6a 100644
--- a/src/decoder/DsdiffDecoderPlugin.cxx
+++ b/src/decoder/DsdiffDecoderPlugin.cxx
@@ -43,22 +43,21 @@
 
 struct DsdiffHeader {
 	DsdId id;
-	uint32_t size_high, size_low;
+	DsdUint64 size;
 	DsdId format;
 };
 
 struct DsdiffChunkHeader {
 	DsdId id;
-	uint32_t size_high, size_low;
+	DsdUint64 size;
 
 	/**
 	 * Read the "size" attribute from the specified header, converting it
 	 * to the host byte order if needed.
 	 */
-	gcc_const
+	constexpr
 	uint64_t GetSize() const {
-		return (uint64_t(FromBE32(size_high)) << 32) |
-			uint64_t(FromBE32(size_low));
+		return size.Read();
 	}
 };
 
diff --git a/src/decoder/DsfDecoderPlugin.cxx b/src/decoder/DsfDecoderPlugin.cxx
index 5b1044455..a9eaebcbc 100644
--- a/src/decoder/DsfDecoderPlugin.cxx
+++ b/src/decoder/DsfDecoderPlugin.cxx
@@ -56,11 +56,11 @@ struct DsfHeader {
 	/** DSF header id: "DSD " */
 	DsdId id;
 	/** DSD chunk size, including id = 28 */
-	uint32_t size_low, size_high;
+	DsdUint64 size;
 	/** total file size */
-	uint32_t fsize_low, fsize_high;
+	DsdUint64 fsize;
 	/** pointer to id3v2 metadata, should be at the end of the file */
-	uint32_t pmeta_low, pmeta_high;
+	DsdUint64 pmeta;
 };
 
 /** DSF file fmt chunk */
@@ -68,7 +68,7 @@ struct DsfFmtChunk {
 	/** id: "fmt " */
 	DsdId id;
 	/** fmt chunk size, including id, normally 52 */
-	uint32_t size_low, size_high;
+	DsdUint64 size;
 	/** version of this format = 1 */
 	uint32_t version;
 	/** 0: DSD raw */
@@ -82,7 +82,7 @@ struct DsfFmtChunk {
 	/** bits per sample 1 or 8 */
 	uint32_t bitssample;
 	/** Sample count per channel in bytes */
-	uint32_t scnt_low, scnt_high;
+	DsdUint64 scnt;
 	/** block size per channel = 4096 */
 	uint32_t block_size;
 	/** reserved, should be all zero */
@@ -92,7 +92,7 @@ struct DsfFmtChunk {
 struct DsfDataChunk {
 	DsdId id;
 	/** "data" chunk size, includes header (id+size) */
-	uint32_t size_low, size_high;
+	DsdUint64 size;
 };
 
 /**
@@ -102,22 +102,17 @@ static bool
 dsf_read_metadata(Decoder *decoder, InputStream &is,
 		  DsfMetaData *metadata)
 {
-	uint64_t chunk_size;
 	DsfHeader dsf_header;
 	if (!dsdlib_read(decoder, is, &dsf_header, sizeof(dsf_header)) ||
 	    !dsf_header.id.Equals("DSD "))
 		return false;
 
-	chunk_size = (uint64_t(FromLE32(dsf_header.size_high)) << 32) |
-		uint64_t(FromLE32(dsf_header.size_low));
-
+	const uint64_t chunk_size = dsf_header.size.Read();
 	if (sizeof(dsf_header) != chunk_size)
 		return false;
 
 #ifdef HAVE_ID3TAG
-	uint64_t metadata_offset;
-	metadata_offset = (uint64_t(FromLE32(dsf_header.pmeta_high)) << 32) |
-		uint64_t(FromLE32(dsf_header.pmeta_low));
+	const uint64_t metadata_offset = dsf_header.pmeta.Read();
 #endif
 
 	/* read the 'fmt ' chunk of the DSF file */
@@ -126,10 +121,7 @@ dsf_read_metadata(Decoder *decoder, InputStream &is,
 	    !dsf_fmt_chunk.id.Equals("fmt "))
 		return false;
 
-	uint64_t fmt_chunk_size;
-	fmt_chunk_size = (uint64_t(FromLE32(dsf_fmt_chunk.size_high)) << 32) |
-		uint64_t(FromLE32(dsf_fmt_chunk.size_low));
-
+	const uint64_t fmt_chunk_size = dsf_fmt_chunk.size.Read();
 	if (fmt_chunk_size != sizeof(dsf_fmt_chunk))
 		return false;
 
@@ -158,9 +150,7 @@ dsf_read_metadata(Decoder *decoder, InputStream &is,
 	/* data size of DSF files are padded to multiple of 4096,
 	   we use the actual data size as chunk size */
 
-	uint64_t data_size;
-	data_size = (uint64_t(FromLE32(data_chunk.size_high)) << 32) |
-		uint64_t(FromLE32(data_chunk.size_low));
+	uint64_t data_size = data_chunk.size.Read();
 	data_size -= sizeof(data_chunk);
 
 	metadata->chunk_size = data_size;