src/main/cpp/jsonlayout.cpp - logging-log4cxx - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <log4cxx/logstring.h>
 #include <log4cxx/jsonlayout.h>
 #include <log4cxx/spi/loggingevent.h>
 #include <log4cxx/level.h>
 #include <log4cxx/helpers/optionconverter.h>
 #include <log4cxx/helpers/cacheddateformat.h>
 #include <log4cxx/helpers/simpledateformat.h>
 #include <log4cxx/helpers/stringhelper.h>
 #include <log4cxx/helpers/transcoder.h>

 #include <string.h>

 using namespace LOG4CXX_NS;
 using namespace LOG4CXX_NS::helpers;
 using namespace LOG4CXX_NS::spi;

 IMPLEMENT_LOG4CXX_OBJECT(JSONLayout)

 struct JSONLayout::JSONLayoutPrivate
 {
 	JSONLayoutPrivate() :
 		locationInfo(false),
 		prettyPrint(false),
 		ppIndentL1(LOG4CXX_STR("  ")),
 		ppIndentL2(LOG4CXX_STR("    ")),
 		expectedPatternLength(100),
 		threadInfo(false) {}

 	// Print no location info by default
 	bool locationInfo; //= false
 	bool prettyPrint; //= false

 	pattern::CachedDateFormat dateFormat
 		{ std::make_shared<helpers::SimpleDateFormat>(LOG4CXX_STR("yyyy-MM-dd HH:mm:ss,SSS"))
 		, pattern::CachedDateFormat::getMaximumCacheValidity(LOG4CXX_STR("yyyy-MM-dd HH:mm:ss,SSS"))
 		};

 	LogString ppIndentL1;
 	LogString ppIndentL2;

 	// Expected length of a formatted event excluding the message text
 	size_t expectedPatternLength;

 	// Thread info is not included by default
 	bool threadInfo; //= false
 };

 JSONLayout::JSONLayout() :
 	m_priv(std::make_unique<JSONLayoutPrivate>())
 {
 }

 JSONLayout::~JSONLayout(){}

 void JSONLayout::setLocationInfo(bool locationInfoFlag)
 {
 	m_priv->locationInfo = locationInfoFlag;
 }

 bool JSONLayout::getLocationInfo() const
 {
 	return m_priv->locationInfo;
 }

 void JSONLayout::setPrettyPrint(bool prettyPrintFlag)
 {
 	m_priv->prettyPrint = prettyPrintFlag;
 }

 bool JSONLayout::getPrettyPrint() const
 {
 	return m_priv->prettyPrint;
 }

 void JSONLayout::setThreadInfo(bool newValue)
 {
 	m_priv->threadInfo = newValue;
 }

 bool JSONLayout::getThreadInfo() const
 {
 	return m_priv->threadInfo;
 }

 LogString JSONLayout::getContentType() const
 {
 	return LOG4CXX_STR("application/json");
 }

 void JSONLayout::activateOptions(helpers::Pool& /* p */)
 {
 	m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 }

 void JSONLayout::setOption(const LogString& option, const LogString& value)
 {
 	if (StringHelper::equalsIgnoreCase(option,
 			LOG4CXX_STR("LOCATIONINFO"), LOG4CXX_STR("locationinfo")))
 	{
 		setLocationInfo(OptionConverter::toBoolean(value, false));
 	}
 	else if (StringHelper::equalsIgnoreCase(option,
 			LOG4CXX_STR("THREADINFO"), LOG4CXX_STR("threadinfo")))
 	{
 		setThreadInfo(OptionConverter::toBoolean(value, false));
 	}
 	else if (StringHelper::equalsIgnoreCase(option,
 			LOG4CXX_STR("PRETTYPRINT"), LOG4CXX_STR("prettyprint")))
 	{
 		setPrettyPrint(OptionConverter::toBoolean(value, false));
 	}
 }

 void JSONLayout::format(LogString& output,
 	const spi::LoggingEventPtr& event,
 	Pool& p) const
 {
 	auto& lsMsg = event->getRenderedMessage();
 	output.reserve(m_priv->expectedPatternLength + lsMsg.size());
 	output.append(LOG4CXX_STR("{"));
 	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		output.append(m_priv->ppIndentL1);
 	}

 	output.append(LOG4CXX_STR("\"timestamp\": \""));
 	m_priv->dateFormat.format(output, event->getTimeStamp(), p);
 	output.append(LOG4CXX_STR("\","));
 	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->threadInfo)
 	{
 		if (m_priv->prettyPrint)
 		{
 			output.append(m_priv->ppIndentL1);
 		}
 		appendQuotedEscapedString(output, LOG4CXX_STR("thread"));
 		output.append(LOG4CXX_STR(": "));
 		appendQuotedEscapedString(output, event->getThreadName());
 		output.append(LOG4CXX_STR(","));
 		output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
 	}

 	if (m_priv->prettyPrint)
 	{
 		output.append(m_priv->ppIndentL1);
 	}

 	output.append(LOG4CXX_STR("\"level\": "));
 	LogString level;
 	event->getLevel()->toString(level);
 	appendQuotedEscapedString(output, level);
 	output.append(LOG4CXX_STR(","));
 	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		output.append(m_priv->ppIndentL1);
 	}

 	output.append(LOG4CXX_STR("\"logger\": "));
 	appendQuotedEscapedString(output, event->getLoggerName());
 	output.append(LOG4CXX_STR(","));
 	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		output.append(m_priv->ppIndentL1);
 	}

 	output.append(LOG4CXX_STR("\"message\": "));
 	appendQuotedEscapedString(output, lsMsg);

 	appendSerializedMDC(output, event);
 	appendSerializedNDC(output, event);

 	if (m_priv->locationInfo)
 	{
 		output.append(LOG4CXX_STR(","));
 		output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
 		appendSerializedLocationInfo(output, event, p);
 	}

 	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
 	output.append(LOG4CXX_STR("}"));
 	output.append(LOG4CXX_EOL);
 }

 void JSONLayout::appendQuotedEscapedString(LogString& buf,
 	const LogString& input) const
 {
 	appendItem(input, buf);
 }

 void JSONLayout::appendItem(const LogString& input, LogString& buf)
 {
 	auto toHexDigit = [](int ch) -> int
 	{
 		return (10 <= ch ? (0x61 - 10) : 0x30) + ch;
 	};
 	/* add leading quote */
 	buf.push_back(0x22);

 	size_t start = 0;
 	size_t index = 0;

 	for (int ch : input)
 	{
 		if (0x22 == ch || 0x5c == ch)
 			;
 		else if (0x20 <= ch)
 		{
 			++index;
 			continue;
 		}
 		if (start < index)
 		{
 			buf.append(input, start, index - start);
 		}

 		switch (ch)
 		{
 			case 0x08:
 				/* \b backspace */
 				buf.push_back(0x5c);
 				buf.push_back('b');
 				break;

 			case 0x09:
 				/* \t tab */
 				buf.push_back(0x5c);
 				buf.push_back('t');
 				break;

 			case 0x0a:
 				/* \n newline */
 				buf.push_back(0x5c);
 				buf.push_back('n');
 				break;

 			case 0x0c:
 				/* \f form feed */
 				buf.push_back(0x5c);
 				buf.push_back('f');
 				break;

 			case 0x0d:
 				/* \r carriage return */
 				buf.push_back(0x5c);
 				buf.push_back('r');
 				break;

 			case 0x22:
 				/* \" double quote */
 				buf.push_back(0x5c);
 				buf.push_back(0x22);
 				break;

 			case 0x5c:
 				/* \\ backslash */
 				buf.push_back(0x5c);
 				buf.push_back(0x5c);
 				break;

 			default:
 				buf.push_back(0x5c);
 				buf.push_back(0x75); // 'u'
 				buf.push_back(toHexDigit((ch & 0xF000) >> 12));
 				buf.push_back(toHexDigit((ch & 0xF00) >> 8));
 				buf.push_back(toHexDigit((ch & 0xF0) >> 4));
 				buf.push_back(toHexDigit(ch & 0xF));
 				break;
 		}
 		start = ++index;
 	}

 	if (start < input.size())
 	{
 		buf.append(input, start, input.size() - start);
 	}

 	/* add trailing quote */
 	buf.push_back(0x22);
 }

 void JSONLayout::appendSerializedMDC(LogString& buf,
 	const LoggingEventPtr& event) const
 {
 	LoggingEvent::KeySet keys = event->getMDCKeySet();

 	if (keys.empty())
 	{
 		return;
 	}

 	buf.append(LOG4CXX_STR(","));
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL1);
 	}

 	appendQuotedEscapedString(buf, LOG4CXX_STR("context_map"));
 	buf.append(LOG4CXX_STR(": {"));
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	for (LoggingEvent::KeySet::iterator it = keys.begin();
 		it != keys.end(); ++it)
 	{
 		if (m_priv->prettyPrint)
 		{
 			buf.append(m_priv->ppIndentL2);
 		}

 		appendQuotedEscapedString(buf, *it);
 		buf.append(LOG4CXX_STR(": "));
 		LogString value;
 		event->getMDC(*it, value);
 		appendQuotedEscapedString(buf, value);

 		/* if this isn't the last k:v pair, we need a comma */
 		if (it + 1 != keys.end())
 		{
 			buf.append(LOG4CXX_STR(","));
 			buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
 		}
 		else
 		{
 			buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
 		}
 	}

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL1);
 	}

 	buf.append(LOG4CXX_STR("}"));
 }

 void JSONLayout::appendSerializedNDC(LogString& buf,
 	const LoggingEventPtr& event) const
 {
 	LogString ndcVal;

 	if (!event->getNDC(ndcVal))
 	{
 		return;
 	}

 	buf.append(LOG4CXX_STR(","));
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL1);
 	}

 	appendQuotedEscapedString(buf, LOG4CXX_STR("context_stack"));
 	buf.append(LOG4CXX_STR(": ["));
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL2);
 	}

 	appendQuotedEscapedString(buf, ndcVal);
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL1);
 	}

 	buf.append(LOG4CXX_STR("]"));
 }

 void JSONLayout::appendSerializedLocationInfo(LogString& buf,
 	const LoggingEventPtr& event, Pool& p) const
 {
 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL1);
 	}

 	appendQuotedEscapedString(buf, LOG4CXX_STR("location_info"));
 	buf.append(LOG4CXX_STR(": {"));
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
 	const LocationInfo& locInfo = event->getLocationInformation();

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL2);
 	}

 	appendQuotedEscapedString(buf, LOG4CXX_STR("file"));
 	buf.append(LOG4CXX_STR(": "));
 	LOG4CXX_DECODE_CHAR(fileName, locInfo.getFileName());
 	appendQuotedEscapedString(buf, fileName);
 	buf.append(LOG4CXX_STR(","));
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL2);
 	}

 	appendQuotedEscapedString(buf, LOG4CXX_STR("line"));
 	buf.append(LOG4CXX_STR(": "));
 	LogString lineNumber;
 	StringHelper::toString(locInfo.getLineNumber(), p, lineNumber);
 	appendQuotedEscapedString(buf, lineNumber);
 	buf.append(LOG4CXX_STR(","));
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL2);
 	}

 	appendQuotedEscapedString(buf, LOG4CXX_STR("class"));
 	buf.append(LOG4CXX_STR(": "));
 	LOG4CXX_DECODE_CHAR(className, locInfo.getClassName());
 	appendQuotedEscapedString(buf, className);
 	buf.append(LOG4CXX_STR(","));
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL2);
 	}

 	appendQuotedEscapedString(buf, LOG4CXX_STR("method"));
 	buf.append(LOG4CXX_STR(": "));
 	LOG4CXX_DECODE_CHAR(methodName, locInfo.getMethodName());
 	appendQuotedEscapedString(buf, methodName);
 	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

 	if (m_priv->prettyPrint)
 	{
 		buf.append(m_priv->ppIndentL1);
 	}

 	buf.append(LOG4CXX_STR("}"));
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <log4cxx/logstring.h>
	#include <log4cxx/jsonlayout.h>
	#include <log4cxx/spi/loggingevent.h>
	#include <log4cxx/level.h>
	#include <log4cxx/helpers/optionconverter.h>
	#include <log4cxx/helpers/cacheddateformat.h>
	#include <log4cxx/helpers/simpledateformat.h>
	#include <log4cxx/helpers/stringhelper.h>
	#include <log4cxx/helpers/transcoder.h>

	#include <string.h>

	using namespace LOG4CXX_NS;
	using namespace LOG4CXX_NS::helpers;
	using namespace LOG4CXX_NS::spi;

	IMPLEMENT_LOG4CXX_OBJECT(JSONLayout)

	struct JSONLayout::JSONLayoutPrivate
	{
	JSONLayoutPrivate() :
	locationInfo(false),
	prettyPrint(false),
	ppIndentL1(LOG4CXX_STR(" ")),
	ppIndentL2(LOG4CXX_STR(" ")),
	expectedPatternLength(100),
	threadInfo(false) {}

	// Print no location info by default
	bool locationInfo; //= false
	bool prettyPrint; //= false

	pattern::CachedDateFormat dateFormat
	{ std::make_shared<helpers::SimpleDateFormat>(LOG4CXX_STR("yyyy-MM-dd HH:mm:ss,SSS"))
	, pattern::CachedDateFormat::getMaximumCacheValidity(LOG4CXX_STR("yyyy-MM-dd HH:mm:ss,SSS"))
	};

	LogString ppIndentL1;
	LogString ppIndentL2;

	// Expected length of a formatted event excluding the message text
	size_t expectedPatternLength;

	// Thread info is not included by default
	bool threadInfo; //= false
	};

	JSONLayout::JSONLayout() :
	m_priv(std::make_unique<JSONLayoutPrivate>())
	{
	}

	JSONLayout::~JSONLayout(){}

	void JSONLayout::setLocationInfo(bool locationInfoFlag)
	{
	m_priv->locationInfo = locationInfoFlag;
	}

	bool JSONLayout::getLocationInfo() const
	{
	return m_priv->locationInfo;
	}

	void JSONLayout::setPrettyPrint(bool prettyPrintFlag)
	{
	m_priv->prettyPrint = prettyPrintFlag;
	}

	bool JSONLayout::getPrettyPrint() const
	{
	return m_priv->prettyPrint;
	}

	void JSONLayout::setThreadInfo(bool newValue)
	{
	m_priv->threadInfo = newValue;
	}

	bool JSONLayout::getThreadInfo() const
	{
	return m_priv->threadInfo;
	}

	LogString JSONLayout::getContentType() const
	{
	return LOG4CXX_STR("application/json");
	}

	void JSONLayout::activateOptions(helpers::Pool& /* p */)
	{
	m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
	}

	void JSONLayout::setOption(const LogString& option, const LogString& value)
	{
	if (StringHelper::equalsIgnoreCase(option,
	LOG4CXX_STR("LOCATIONINFO"), LOG4CXX_STR("locationinfo")))
	{
	setLocationInfo(OptionConverter::toBoolean(value, false));
	}
	else if (StringHelper::equalsIgnoreCase(option,
	LOG4CXX_STR("THREADINFO"), LOG4CXX_STR("threadinfo")))
	{
	setThreadInfo(OptionConverter::toBoolean(value, false));
	}
	else if (StringHelper::equalsIgnoreCase(option,
	LOG4CXX_STR("PRETTYPRINT"), LOG4CXX_STR("prettyprint")))
	{
	setPrettyPrint(OptionConverter::toBoolean(value, false));
	}
	}

	void JSONLayout::format(LogString& output,
	const spi::LoggingEventPtr& event,
	Pool& p) const
	{
	auto& lsMsg = event->getRenderedMessage();
	output.reserve(m_priv->expectedPatternLength + lsMsg.size());
	output.append(LOG4CXX_STR("{"));
	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	output.append(m_priv->ppIndentL1);
	}

	output.append(LOG4CXX_STR("\"timestamp\": \""));
	m_priv->dateFormat.format(output, event->getTimeStamp(), p);
	output.append(LOG4CXX_STR("\","));
	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->threadInfo)
	{
	if (m_priv->prettyPrint)
	{
	output.append(m_priv->ppIndentL1);
	}
	appendQuotedEscapedString(output, LOG4CXX_STR("thread"));
	output.append(LOG4CXX_STR(": "));
	appendQuotedEscapedString(output, event->getThreadName());
	output.append(LOG4CXX_STR(","));
	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
	}

	if (m_priv->prettyPrint)
	{
	output.append(m_priv->ppIndentL1);
	}

	output.append(LOG4CXX_STR("\"level\": "));
	LogString level;
	event->getLevel()->toString(level);
	appendQuotedEscapedString(output, level);
	output.append(LOG4CXX_STR(","));
	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	output.append(m_priv->ppIndentL1);
	}

	output.append(LOG4CXX_STR("\"logger\": "));
	appendQuotedEscapedString(output, event->getLoggerName());
	output.append(LOG4CXX_STR(","));
	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	output.append(m_priv->ppIndentL1);
	}

	output.append(LOG4CXX_STR("\"message\": "));
	appendQuotedEscapedString(output, lsMsg);

	appendSerializedMDC(output, event);
	appendSerializedNDC(output, event);

	if (m_priv->locationInfo)
	{
	output.append(LOG4CXX_STR(","));
	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
	appendSerializedLocationInfo(output, event, p);
	}

	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
	output.append(LOG4CXX_STR("}"));
	output.append(LOG4CXX_EOL);
	}

	void JSONLayout::appendQuotedEscapedString(LogString& buf,
	const LogString& input) const
	{
	appendItem(input, buf);
	}

	void JSONLayout::appendItem(const LogString& input, LogString& buf)
	{
	auto toHexDigit = [](int ch) -> int
	{
	return (10 <= ch ? (0x61 - 10) : 0x30) + ch;
	};
	/* add leading quote */
	buf.push_back(0x22);

	size_t start = 0;
	size_t index = 0;

	for (int ch : input)
	{
	if (0x22 == ch \|\| 0x5c == ch)
	;
	else if (0x20 <= ch)
	{
	++index;
	continue;
	}
	if (start < index)
	{
	buf.append(input, start, index - start);
	}

	switch (ch)
	{
	case 0x08:
	/* \b backspace */
	buf.push_back(0x5c);
	buf.push_back('b');
	break;

	case 0x09:
	/* \t tab */
	buf.push_back(0x5c);
	buf.push_back('t');
	break;

	case 0x0a:
	/* \n newline */
	buf.push_back(0x5c);
	buf.push_back('n');
	break;

	case 0x0c:
	/* \f form feed */
	buf.push_back(0x5c);
	buf.push_back('f');
	break;

	case 0x0d:
	/* \r carriage return */
	buf.push_back(0x5c);
	buf.push_back('r');
	break;

	case 0x22:
	/* \" double quote */
	buf.push_back(0x5c);
	buf.push_back(0x22);
	break;

	case 0x5c:
	/* \\ backslash */
	buf.push_back(0x5c);
	buf.push_back(0x5c);
	break;

	default:
	buf.push_back(0x5c);
	buf.push_back(0x75); // 'u'
	buf.push_back(toHexDigit((ch & 0xF000) >> 12));
	buf.push_back(toHexDigit((ch & 0xF00) >> 8));
	buf.push_back(toHexDigit((ch & 0xF0) >> 4));
	buf.push_back(toHexDigit(ch & 0xF));
	break;
	}
	start = ++index;
	}

	if (start < input.size())
	{
	buf.append(input, start, input.size() - start);
	}

	/* add trailing quote */
	buf.push_back(0x22);
	}

	void JSONLayout::appendSerializedMDC(LogString& buf,
	const LoggingEventPtr& event) const
	{
	LoggingEvent::KeySet keys = event->getMDCKeySet();

	if (keys.empty())
	{
	return;
	}

	buf.append(LOG4CXX_STR(","));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL1);
	}

	appendQuotedEscapedString(buf, LOG4CXX_STR("context_map"));
	buf.append(LOG4CXX_STR(": {"));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	for (LoggingEvent::KeySet::iterator it = keys.begin();
	it != keys.end(); ++it)
	{
	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL2);
	}

	appendQuotedEscapedString(buf, *it);
	buf.append(LOG4CXX_STR(": "));
	LogString value;
	event->getMDC(*it, value);
	appendQuotedEscapedString(buf, value);

	/* if this isn't the last k:v pair, we need a comma */
	if (it + 1 != keys.end())
	{
	buf.append(LOG4CXX_STR(","));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
	}
	else
	{
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
	}
	}

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL1);
	}

	buf.append(LOG4CXX_STR("}"));
	}

	void JSONLayout::appendSerializedNDC(LogString& buf,
	const LoggingEventPtr& event) const
	{
	LogString ndcVal;

	if (!event->getNDC(ndcVal))
	{
	return;
	}

	buf.append(LOG4CXX_STR(","));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL1);
	}

	appendQuotedEscapedString(buf, LOG4CXX_STR("context_stack"));
	buf.append(LOG4CXX_STR(": ["));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL2);
	}

	appendQuotedEscapedString(buf, ndcVal);
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL1);
	}

	buf.append(LOG4CXX_STR("]"));
	}

	void JSONLayout::appendSerializedLocationInfo(LogString& buf,
	const LoggingEventPtr& event, Pool& p) const
	{
	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL1);
	}

	appendQuotedEscapedString(buf, LOG4CXX_STR("location_info"));
	buf.append(LOG4CXX_STR(": {"));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
	const LocationInfo& locInfo = event->getLocationInformation();

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL2);
	}

	appendQuotedEscapedString(buf, LOG4CXX_STR("file"));
	buf.append(LOG4CXX_STR(": "));
	LOG4CXX_DECODE_CHAR(fileName, locInfo.getFileName());
	appendQuotedEscapedString(buf, fileName);
	buf.append(LOG4CXX_STR(","));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL2);
	}

	appendQuotedEscapedString(buf, LOG4CXX_STR("line"));
	buf.append(LOG4CXX_STR(": "));
	LogString lineNumber;
	StringHelper::toString(locInfo.getLineNumber(), p, lineNumber);
	appendQuotedEscapedString(buf, lineNumber);
	buf.append(LOG4CXX_STR(","));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL2);
	}

	appendQuotedEscapedString(buf, LOG4CXX_STR("class"));
	buf.append(LOG4CXX_STR(": "));
	LOG4CXX_DECODE_CHAR(className, locInfo.getClassName());
	appendQuotedEscapedString(buf, className);
	buf.append(LOG4CXX_STR(","));
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL2);
	}

	appendQuotedEscapedString(buf, LOG4CXX_STR("method"));
	buf.append(LOG4CXX_STR(": "));
	LOG4CXX_DECODE_CHAR(methodName, locInfo.getMethodName());
	appendQuotedEscapedString(buf, methodName);
	buf.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));

	if (m_priv->prettyPrint)
	{
	buf.append(m_priv->ppIndentL1);
	}

	buf.append(LOG4CXX_STR("}"));
	}