dbms: IO: fixed error [#CONV-2546].

dbms/include/DB/IO/CompressedReadBuffer.h

@@ -26,13 +26,6 @@ private:
 	std::vector<char> compressed_buffer;
 	char scratch[QLZ_SCRATCH_DECOMPRESS];
 
-public:
-	CompressedReadBuffer(ReadBuffer & in_)
-		: in(in_),
-		compressed_buffer(QUICKLZ_HEADER_SIZE)
-	{
-	}
-
 	bool nextImpl()
 	{
 		if (in.eof())
@@ -63,6 +56,13 @@ public:
 
 		return true;
 	}
+
+public:
+	CompressedReadBuffer(ReadBuffer & in_)
+		: in(in_),
+		compressed_buffer(QUICKLZ_HEADER_SIZE)
+	{
+	}
 };
 
 }

dbms/include/DB/IO/CompressedWriteBuffer.h

@@ -23,9 +23,6 @@ private:
 
 	size_t compressed_bytes;
 
-public:
-	CompressedWriteBuffer(WriteBuffer & out_) : out(out_), compressed_bytes(0) {}
-
 	void nextImpl()
 	{
 		size_t uncompressed_size = pos - working_buffer.begin();
@@ -44,6 +41,9 @@ public:
 		compressed_bytes += compressed_size;
 	}
 
+public:
+	CompressedWriteBuffer(WriteBuffer & out_) : out(out_), compressed_bytes(0) {}
+
 	/// Объём сжатых данных
 	size_t getCompressedBytes()
 	{

dbms/include/DB/IO/ReadBuffer.h

@@ -57,6 +57,9 @@ public:
 	{
 		bytes_read += pos - working_buffer.begin();
 		bool res = nextImpl();
+		if (!res)
+			working_buffer = Buffer(working_buffer.begin(), working_buffer.begin());
+		
 		pos = working_buffer.begin();
 		return res;
 	}

dbms/include/DB/IO/ReadBufferFromIStream.h

@@ -17,25 +17,26 @@ class ReadBufferFromIStream : public ReadBuffer
 private:
 	std::istream & istr;
 
-public:
-	ReadBufferFromIStream(std::istream & istr_) : istr(istr_) {}
-
 	bool nextImpl()
 	{
 		istr.read(working_buffer.begin(), DEFAULT_READ_BUFFER_SIZE);
+		size_t gcount = istr.gcount();
 
-		working_buffer = Buffer(working_buffer.begin(), working_buffer.begin() + istr.gcount());
-
-		if (working_buffer.end() == working_buffer.begin())
+		if (!gcount)
 		{
 			if (istr.eof())
 				return false;
-			if (!istr.good())
+			else
 				throw Exception("Cannot read from istream", ErrorCodes::CANNOT_READ_FROM_ISTREAM);
 		}
+		else
+			working_buffer = Buffer(working_buffer.begin(), working_buffer.begin() + gcount);
 
 		return true;
 	}
+
+public:
+	ReadBufferFromIStream(std::istream & istr_) : istr(istr_) {}
 };
 
 }

dbms/include/DB/IO/WriteBufferFromOStream.h

@@ -17,9 +17,6 @@ class WriteBufferFromOStream : public WriteBuffer
 private:
 	std::ostream & ostr;
 
-public:
-	WriteBufferFromOStream(std::ostream & ostr_) : ostr(ostr_) {}
-
 	void nextImpl()
 	{
 		ostr.write(working_buffer.begin(), pos - working_buffer.begin());
@@ -29,6 +26,9 @@ public:
 			throw Exception("Cannot write to ostream", ErrorCodes::CANNOT_WRITE_TO_OSTREAM);
 	}
 
+public:
+	WriteBufferFromOStream(std::ostream & ostr_) : ostr(ostr_) {}
+
 	~WriteBufferFromOStream()
 	{
 		next();