constexpr + noexcept sqz

Author: mrotteveel

src/jrd/sqz.cpp

@@ -50,15 +50,15 @@ using namespace Jrd;
 
 namespace
 {
-	const unsigned MIN_COMPRESS_RUN = 8; // minimal length of compressable run
+	constexpr unsigned MIN_COMPRESS_RUN = 8; // minimal length of compressable run
 
-	const int MAX_NONCOMP_RUN = MAX_SCHAR;	// 127
+	constexpr int MAX_NONCOMP_RUN = MAX_SCHAR;	// 127
 
-	const int MAX_SHORT_RUN = -MIN_SCHAR;	// 128
-	const int MAX_MEDIUM_RUN = MAX_USHORT;	// 2^16
-	const int MAX_LONG_RUN = MAX_SLONG;		// 2^31
+	constexpr int MAX_SHORT_RUN = -MIN_SCHAR;	// 128
+	constexpr int MAX_MEDIUM_RUN = MAX_USHORT;	// 2^16
+	constexpr int MAX_LONG_RUN = MAX_SLONG;		// 2^31
 
-	inline int adjustRunLength(unsigned length)
+	inline int adjustRunLength(unsigned length) noexcept
 	{
 		return (length <= MAX_SHORT_RUN) ? 0 :
 			(length <= MAX_MEDIUM_RUN) ? sizeof(USHORT) : sizeof(ULONG);
@@ -469,7 +469,7 @@ UCHAR* Compressor::unpack(ULONG inLength, const UCHAR* input,
  *
  **************************************/
 	const auto end = input + inLength;
-	const auto output_end = output + outLength;
+	const auto* const output_end = output + outLength;
 
 	while (input < end)
 	{
@@ -526,9 +526,9 @@ ULONG Difference::apply(ULONG diffLength, ULONG outLength, UCHAR* const output)
 		BUGCHECK(176);	// msg 176 bad difference record
 
 	auto differences = m_differences;
-	const auto end = differences + diffLength;
+	const auto* const end = differences + diffLength;
 	auto p = output;
-	const auto p_end = output + outLength;
+	const auto* const p_end = output + outLength;
 
 	while (differences < end && p < p_end)
 	{
@@ -566,15 +566,15 @@ ULONG Difference::apply(ULONG diffLength, ULONG outLength, UCHAR* const output)
 	return length;
 }
 
-ULONG Difference::makeNoDiff(ULONG length)
+ULONG Difference::makeNoDiff(ULONG length) noexcept
 {
 /**************************************
  *
  *  Generates differences record marking that there are no differences.
  *
  **************************************/
 	auto output = m_differences;
-	const auto end = output + MAX_DIFFERENCES;
+	const auto* const end = output + MAX_DIFFERENCES;
 
 	while (length)
 	{
@@ -593,7 +593,7 @@ ULONG Difference::makeNoDiff(ULONG length)
 }
 
 ULONG Difference::make(ULONG length1, const UCHAR* rec1,
-					   ULONG length2, const UCHAR* rec2)
+					   ULONG length2, const UCHAR* rec2) noexcept
 {
 /**************************************
  *
@@ -611,7 +611,7 @@ ULONG Difference::make(ULONG length1, const UCHAR* rec1,
  *
  **************************************/
 	auto output = m_differences;
-	const auto end = output + MAX_DIFFERENCES;
+	const auto* const end = output + MAX_DIFFERENCES;
 	const auto end1 = rec1 + MIN(length1, length2);
 	const auto end2 = rec2 + length2;
 
@@ -621,7 +621,7 @@ ULONG Difference::make(ULONG length1, const UCHAR* rec1,
 		{
 			auto p = output++;
 
-			const auto yellow = (UCHAR*) MIN((U_IPTR) end1, ((U_IPTR) rec1 + 127)) - 1;
+			const auto* const yellow = (UCHAR*) MIN((U_IPTR) end1, ((U_IPTR) rec1 + 127)) - 1;
 			while (rec1 <= yellow && (rec1[0] != rec2[0] || (rec1 < yellow && rec1[1] != rec2[1])))
 			{
 				if (output >= end)
@@ -654,7 +654,7 @@ ULONG Difference::make(ULONG length1, const UCHAR* rec1,
 	{
 		auto p = output++;
 
-		const auto yellow = (UCHAR*) MIN((U_IPTR) end2, ((U_IPTR) rec2 + 127));
+		const auto* const yellow = (UCHAR*) MIN((U_IPTR) end2, ((U_IPTR) rec2 + 127));
 		while (rec2 < yellow)
 		{
 			if (output >= end)

src/jrd/sqz.h

@@ -37,12 +37,12 @@ namespace Jrd
 		Compressor(thread_db* tdbb, ULONG length, const UCHAR* data);
 		Compressor(MemoryPool& pool, bool allowLongRuns, bool allowUnpacked, ULONG length, const UCHAR* data);
 
-		ULONG getPackedLength() const
+		ULONG getPackedLength() const noexcept
 		{
 			return m_length;
 		}
 
-		bool isPacked() const
+		bool isPacked() const noexcept
 		{
 			return m_runs.hasData();
 		}
@@ -69,28 +69,28 @@ namespace Jrd
 	class Difference
 	{
 		// Max length of generated differences string between two records
-		static const unsigned MAX_DIFFERENCES = 1024;
+		static constexpr unsigned MAX_DIFFERENCES = 1024;
 
 	public:
-		UCHAR* getData()
+		UCHAR* getData() noexcept
 		{
 			return m_differences;
 		}
 
-		const UCHAR* getData() const
+		const UCHAR* getData() const noexcept
 		{
 			return m_differences;
 		}
 
-		ULONG getCapacity() const
+		ULONG getCapacity() const noexcept
 		{
 			return MAX_DIFFERENCES;
 		}
 
 		ULONG apply(ULONG diffLength, ULONG outLength, UCHAR* output);
 		ULONG make(ULONG length1, const UCHAR* rec1,
-				   ULONG length2, const UCHAR* rec2);
-		ULONG makeNoDiff(ULONG length);
+				   ULONG length2, const UCHAR* rec2) noexcept;
+		ULONG makeNoDiff(ULONG length) noexcept;
 
 	private:
 		UCHAR m_differences[MAX_DIFFERENCES];