Fix calling multiple ZlibDecompressor in parallel causes adler32 chec…

…ksum failure (GH weidai11#596, weidai11#600)
StrataSource · Mar 25, 2018 · b0f7170 · b0f7170
1 parent b42d728
commit b0f7170
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Showing 2 changed files with 40 additions and 29 deletions.
diff --git a/zinflate.cpp b/zinflate.cpp
@@ -612,41 +612,51 @@ void Inflator::FlushOutput()
 	}
 }
 
-struct NewFixedLiteralDecoder
+void Inflator::CreateFixedLiteralDecoder()
 {
-	HuffmanDecoder * operator()() const
-	{
-		unsigned int codeLengths[288];
-		std::fill(codeLengths + 0, codeLengths + 144, 8);
-		std::fill(codeLengths + 144, codeLengths + 256, 9);
-		std::fill(codeLengths + 256, codeLengths + 280, 7);
-		std::fill(codeLengths + 280, codeLengths + 288, 8);
-		member_ptr<HuffmanDecoder> pDecoder(new HuffmanDecoder);
-		pDecoder->Initialize(codeLengths, 288);
-		return pDecoder.release();
-	}
+	unsigned int codeLengths[288];
+	std::fill(codeLengths + 0, codeLengths + 144, 8);
+	std::fill(codeLengths + 144, codeLengths + 256, 9);
+	std::fill(codeLengths + 256, codeLengths + 280, 7);
+	std::fill(codeLengths + 280, codeLengths + 288, 8);
+	m_fixedLiteralDecoder.reset(new HuffmanDecoder);
+	m_fixedLiteralDecoder->Initialize(codeLengths, 288);
 };
 
-struct NewFixedDistanceDecoder
+void Inflator::CreateFixedDistanceDecoder()
 {
-	HuffmanDecoder * operator()() const
-	{
-		unsigned int codeLengths[32];
-		std::fill(codeLengths + 0, codeLengths + 32, 5);
-		member_ptr<HuffmanDecoder> pDecoder(new HuffmanDecoder);
-		pDecoder->Initialize(codeLengths, 32);
-		return pDecoder.release();
-	}
+	unsigned int codeLengths[32];
+	std::fill(codeLengths + 0, codeLengths + 32, 5);
+	m_fixedDistanceDecoder.reset(new HuffmanDecoder);
+	m_fixedDistanceDecoder->Initialize(codeLengths, 32);
 };
 
-const HuffmanDecoder& Inflator::GetLiteralDecoder() const
+const HuffmanDecoder& Inflator::GetLiteralDecoder()
 {
-	return m_blockType == 1 ? Singleton<HuffmanDecoder, NewFixedLiteralDecoder>().Ref() : m_dynamicLiteralDecoder;
+	if (m_blockType == 1)
+	{
+		if (m_fixedLiteralDecoder.get() == NULLPTR)
+			CreateFixedLiteralDecoder();
+		return *m_fixedLiteralDecoder;
+	}
+	else
+	{
+		return m_dynamicLiteralDecoder;
+	}
 }
 
-const HuffmanDecoder& Inflator::GetDistanceDecoder() const
+const HuffmanDecoder& Inflator::GetDistanceDecoder()
 {
-	return m_blockType == 1 ? Singleton<HuffmanDecoder, NewFixedDistanceDecoder>().Ref() : m_dynamicDistanceDecoder;
+	if (m_blockType == 1)
+	{
+		if (m_fixedDistanceDecoder.get() == NULLPTR)
+			CreateFixedDistanceDecoder();
+		return *m_fixedDistanceDecoder;
+	}
+	else
+	{
+		return m_dynamicDistanceDecoder;
+	}
 }
 
 NAMESPACE_END
diff --git a/zinflate.h b/zinflate.h
@@ -133,11 +133,11 @@ class Inflator : public AutoSignaling<Filter>
 	void OutputString(const byte *string, size_t length);
 	void OutputPast(unsigned int length, unsigned int distance);
 
-	static const HuffmanDecoder *FixedLiteralDecoder();
-	static const HuffmanDecoder *FixedDistanceDecoder();
+	void CreateFixedDistanceDecoder();
+	void CreateFixedLiteralDecoder();
 
-	const HuffmanDecoder& GetLiteralDecoder() const;
-	const HuffmanDecoder& GetDistanceDecoder() const;
+	const HuffmanDecoder& GetLiteralDecoder();
+	const HuffmanDecoder& GetDistanceDecoder();
 
 	enum State {PRE_STREAM, WAIT_HEADER, DECODING_BODY, POST_STREAM, AFTER_END};
 	State m_state;
@@ -148,6 +148,7 @@ class Inflator : public AutoSignaling<Filter>
 	NextDecode m_nextDecode;
 	unsigned int m_literal, m_distance;	// for LENGTH_BITS or DISTANCE_BITS
 	HuffmanDecoder m_dynamicLiteralDecoder, m_dynamicDistanceDecoder;
+	member_ptr<HuffmanDecoder> m_fixedLiteralDecoder, m_fixedDistanceDecoder;
 	LowFirstBitReader m_reader;
 	SecByteBlock m_window;
 	size_t m_current, m_lastFlush;