fix(Extractor): move extraction decoding to AbstractExtractor #3396

Data/ODBC/include/Poco/Data/ODBC/Extractor.h

@@ -33,7 +33,6 @@
 #include "Poco/Nullable.h"
 #include "Poco/UTFString.h"
 #include "Poco/TextEncoding.h"
-#include "Poco/TextConverter.h"
 #include "Poco/Exception.h"
 #include <map>
 #ifdef POCO_OS_FAMILY_WINDOWS
@@ -592,11 +591,10 @@ private:
 		val.clear();
 		if (ret)
 		{
-			Poco::TextConverter conv(*_pDBEncoding, *_pToEncoding);
 			val.resize(res.size());
 			typename C::iterator vIt = val.begin();
 			typename C::iterator it = res.begin();
-			for (; it != res.end(); ++it, ++vIt) conv.convert(*it, *vIt);
+			for (; it != res.end(); ++it, ++vIt) transcode(*it, *vIt);
 		}
 		return ret;
 	}
@@ -607,7 +605,7 @@ private:
 		bool ret = false;
 		if (Preparator::DE_BOUND == _dataExtraction)
 		{
-			if (!_transcode)
+			if (!transcodeRequired())
 				ret = extractBoundImplContainer(pos, val);
 			else
 				ret = stringContainerExtractConvert(pos, val);
@@ -628,9 +626,6 @@ private:
 	PreparatorPtr              _pPreparator;
 	Preparator::DataExtraction _dataExtraction;
 	std::vector<SQLLEN>        _lengths;
-	Poco::TextEncoding::Ptr    _pDBEncoding;
-	bool                       _transcode;
-	Poco::TextEncoding::Ptr    _pToEncoding;
 };
 
 

Data/ODBC/src/Extractor.cpp

@@ -35,13 +35,10 @@ const std::string Extractor::FLD_SIZE_EXCEEDED_FMT = "Specified data size (%z by
 
 Extractor::Extractor(const StatementHandle& rStmt,
 	Preparator::Ptr pPreparator,
-	TextEncoding::Ptr pDBEncoding):
+	TextEncoding::Ptr pDBEncoding): AbstractExtractor(pDBEncoding),
 	_rStmt(rStmt),
 	_pPreparator(pPreparator),
-	_dataExtraction(pPreparator->getDataExtraction()),
-	_pDBEncoding(pDBEncoding),
-	_transcode(_pDBEncoding && !_pDBEncoding->isA("UTF-8")),
-	_pToEncoding(_transcode ? Poco::TextEncoding::find("UTF-8") : nullptr)
+	_dataExtraction(pPreparator->getDataExtraction())
 {
 }
 
@@ -707,7 +704,7 @@ bool Extractor::extract(std::size_t pos, std::string& val)
 {
 	bool ret = false;
 
-	if (!_transcode)
+	if (!transcodeRequired())
 	{
 		if (Preparator::DE_MANUAL == _dataExtraction)
 			ret = extractManualImpl(pos, val, SQL_C_CHAR);
@@ -721,8 +718,7 @@ bool Extractor::extract(std::size_t pos, std::string& val)
 			ret = extractManualImpl(pos, result, SQL_C_CHAR);
 		else
 			ret = extractBoundImpl(pos, result);
-		Poco::TextConverter converter(*_pDBEncoding, *_pToEncoding);
-		converter.convert(result, val);
+		transcode(result, val);
 	}
 
 	return ret;

Data/include/Poco/Data/AbstractExtractor.h

@@ -23,6 +23,9 @@
 #include "Poco/Data/LOB.h"
 #include "Poco/UUID.h"
 #include "Poco/UTFString.h"
+#include "Poco/TextConverter.h"
+#include "Poco/TextEncoding.h"
+#include <memory>
 #include <vector>
 #include <deque>
 #include <list>
@@ -54,7 +57,8 @@ class Data_API AbstractExtractor
 public:
 	using Ptr = SharedPtr<AbstractExtractor>;
 
-	AbstractExtractor();
+	AbstractExtractor(Poco::TextEncoding::Ptr pDBEncoding = nullptr,
+		Poco::TextEncoding::Ptr pToEncoding = nullptr);
 		/// Creates the AbstractExtractor.
 
 	virtual ~AbstractExtractor();
@@ -346,6 +350,15 @@ public:
 
 	virtual void reset();
 		/// Resets any information internally cached by the extractor.
+
+protected:
+	bool transcodeRequired() const;
+	void transcode(const std::string& val1, std::string& val2);
+
+private:
+	Poco::TextEncoding::Ptr _pDBEncoding;
+	Poco::TextEncoding::Ptr _pToEncoding;
+	std::unique_ptr<Poco::TextConverter> _pConverter;
 };
 
 
@@ -358,6 +371,22 @@ inline void AbstractExtractor::reset()
 }
 
 
+inline bool AbstractExtractor::transcodeRequired() const
+{
+	return _pConverter.operator bool();
+}
+
+
+inline void AbstractExtractor::transcode(const std::string& val1, std::string& val2)
+{
+	if (_pConverter)
+	{
+		val2.clear();
+		_pConverter->convert(val1, val2);
+	}
+}
+
+
 } } // namespace Poco::Data
 
 

Data/src/AbstractExtractor.cpp

@@ -20,8 +20,18 @@ namespace Poco {
 namespace Data {
 
 
-AbstractExtractor::AbstractExtractor()
+AbstractExtractor::AbstractExtractor(Poco::TextEncoding::Ptr pDBEncoding,
+	Poco::TextEncoding::Ptr pToEncoding):
+	_pDBEncoding(pDBEncoding),
+	_pToEncoding(pToEncoding ?
+		pToEncoding : _pDBEncoding ?
+			Poco::TextEncoding::find("UTF-8") : nullptr),
+	_pConverter(_pDBEncoding ?
+		new Poco::TextConverter(*pDBEncoding, *_pToEncoding) :
+		nullptr)
 {
+	poco_assert_dbg((!_pDBEncoding && !_pToEncoding) ||
+		(_pDBEncoding && _pToEncoding));
 }
 
 

Data/testsuite/src/DataTest.cpp

@@ -9,6 +9,7 @@
 
 
 #include "DataTest.h"
+#include "Extractor.h"
 #include "CppUnit/TestCaller.h"
 #include "CppUnit/TestSuite.h"
 #include "Poco/Data/Session.h"
@@ -29,6 +30,7 @@
 #include "Poco/Dynamic/Var.h"
 #include "Poco/Data/DynamicLOB.h"
 #include "Poco/Data/DynamicDateTime.h"
+#include "Poco/Latin1Encoding.h"
 #include "Poco/Exception.h"
 #include <cstring>
 #include <sstream>
@@ -45,6 +47,7 @@ using Poco::UInt32;
 using Poco::Int64;
 using Poco::UInt64;
 using Poco::DateTime;
+using Poco::Latin1Encoding;
 using Poco::Dynamic::Var;
 using Poco::InvalidAccessException;
 using Poco::IllegalStateException;
@@ -65,6 +68,7 @@ using Poco::Data::Row;
 using Poco::Data::SimpleRowFormatter;
 using Poco::Data::Date;
 using Poco::Data::Time;
+using Poco::Data::AbstractExtractor;
 using Poco::Data::AbstractExtraction;
 using Poco::Data::AbstractExtractionVec;
 using Poco::Data::AbstractExtractionVecVec;
@@ -1358,6 +1362,29 @@ void DataTest::testExternalBindingAndExtraction()
 }
 
 
+void DataTest::testTranscode()
+{
+	Latin1Encoding::Ptr pL2E = new Latin1Encoding();
+
+	const unsigned char latin1Chars[] = { 'g', 252, 'n', 't', 'e', 'r', 0 };
+	const unsigned char utf8Chars[] = { 'g', 195, 188, 'n', 't', 'e', 'r', 0 };
+	std::string latin1Text((const char*)latin1Chars);
+	std::string utf8Text((const char*)utf8Chars);
+
+	Poco::Data::Test::Extractor ext;
+	ext.setString(latin1Text);
+	std::string utf8Out;
+	assertTrue (ext.extract(0, utf8Out));
+	assertTrue(utf8Out == latin1Text);
+
+	Poco::Data::Test::Extractor ext2(new Latin1Encoding());
+	ext2.setString(latin1Text);
+	utf8Out.clear();
+	assertTrue(ext2.extract(0, utf8Out));
+	assertTrue(utf8Out == utf8Text);
+}
+
+
 void DataTest::setUp()
 {
 }
@@ -1388,6 +1415,7 @@ CppUnit::Test* DataTest::suite()
 	CppUnit_addTest(pSuite, DataTest, testRowFormat);
 	CppUnit_addTest(pSuite, DataTest, testDateAndTime);
 	CppUnit_addTest(pSuite, DataTest, testExternalBindingAndExtraction);
+	CppUnit_addTest(pSuite, DataTest, testTranscode);
 
 	return pSuite;
 }

Data/testsuite/src/DataTest.h

@@ -43,6 +43,7 @@ public:
 	void testRowFormat();
 	void testDateAndTime();
 	void testExternalBindingAndExtraction();
+	void testTranscode();
 
 	void setUp();
 	void tearDown();

Data/testsuite/src/Extractor.cpp

@@ -18,7 +18,8 @@ namespace Data {
 namespace Test {
 
 
-Extractor::Extractor()
+Extractor::Extractor(Poco::TextEncoding::Ptr pDBEncoding):
+	AbstractExtractor(pDBEncoding)
 {
 }
 
@@ -130,7 +131,10 @@ bool Extractor::extract(std::size_t pos, char& val)
 
 bool Extractor::extract(std::size_t pos, std::string& val)
 {
-	val = "";
+	if (!transcodeRequired())
+		val = _stringValue;
+	else
+		transcode(_stringValue, val);
 	return true;
 }
 

Data/testsuite/src/Extractor.h

@@ -26,7 +26,7 @@ class Extractor: public Poco::Data::AbstractExtractor
 	/// A no-op implementation of AbstractExtractor for testing.
 {
 public:
-	Extractor();
+	Extractor(Poco::TextEncoding::Ptr pDBEncoding = nullptr);
 		/// Creates the Extractor.
 
 	~Extractor();
@@ -110,6 +110,14 @@ public:
 		/// Returns true if the current row value at pos column is null.
 
 	void reset();
+
+	void setString(const std::string& str)
+	{
+		_stringValue = str;
+	}
+
+private:
+	std::string _stringValue;
 };