Reduce logging overhead by reserving storage in the output string (#246)

apache · Aug 4, 2023 · 610018a · 610018a
1 parent cc7235a
commit 610018a
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Showing 7 changed files with 77 additions and 12 deletions.
diff --git a/src/main/cpp/fmtlayout.cpp b/src/main/cpp/fmtlayout.cpp
@@ -31,13 +31,19 @@ using namespace log4cxx;
 using namespace log4cxx::spi;
 
 struct FMTLayout::FMTLayoutPrivate{
-	FMTLayoutPrivate(){}
+	FMTLayoutPrivate()
+		: expectedPatternLength(100)
+		{}
 
-	FMTLayoutPrivate(const LogString& pattern) :
-		conversionPattern(pattern)
+	FMTLayoutPrivate(const LogString& pattern)
+		: conversionPattern(pattern)
+		, expectedPatternLength(100)
 	{}
 
 	LogString conversionPattern;
+
+	// Expected length of a formatted event excluding the message text
+	size_t expectedPatternLength;
 };
 
 IMPLEMENT_LOG4CXX_OBJECT(FMTLayout)
@@ -76,13 +82,14 @@ void FMTLayout::setOption(const LogString& option, const LogString& value)
 
 void FMTLayout::activateOptions(helpers::Pool&)
 {
-
+	m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 }
 
 void FMTLayout::format(LogString& output,
 	const spi::LoggingEventPtr& event,
 	log4cxx::helpers::Pool&) const
 {
+	output.reserve(m_priv->expectedPatternLength + event->getMessage().size());
 	auto locationFull = fmt::format("{}({})",
 										 event->getLocationInformation().getFileName(),
 										 event->getLocationInformation().getLineNumber());

diff --git a/src/main/cpp/htmllayout.cpp b/src/main/cpp/htmllayout.cpp
@@ -35,15 +35,22 @@ using namespace log4cxx::spi;
 
 struct HTMLLayout::HTMLLayoutPrivate
 {
-	HTMLLayoutPrivate() : locationInfo(false), title(LOG4CXX_STR("Log4cxx Log Messages")),
-		dateFormat() {}
+	HTMLLayoutPrivate()
+		: locationInfo(false)
+		, title(LOG4CXX_STR("Log4cxx Log Messages"))
+		, dateFormat()
+		, expectedPatternLength(100)
+		{}
 
 	// Print no location info by default
 	bool locationInfo; //= false
 
 	LogString title;
 
 	helpers::ISO8601DateFormat dateFormat;
+
+	// Expected length of a formatted event excluding the message text
+	size_t expectedPatternLength;
 };
 
 IMPLEMENT_LOG4CXX_OBJECT(HTMLLayout)
@@ -53,6 +60,7 @@ HTMLLayout::HTMLLayout()
 	: m_priv(std::make_unique<HTMLLayoutPrivate>())
 {
 	m_priv->dateFormat.setTimeZone(TimeZone::getGMT());
+	m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 }
 
 HTMLLayout::~HTMLLayout() {}
@@ -71,13 +79,15 @@ void HTMLLayout::setOption(const LogString& option,
 			LOG4CXX_STR("LOCATIONINFO"), LOG4CXX_STR("locationinfo")))
 	{
 		setLocationInfo(OptionConverter::toBoolean(value, false));
+		m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 	}
 }
 
 void HTMLLayout::format(LogString& output,
 	const spi::LoggingEventPtr& event,
 	Pool& p) const
 {
+	output.reserve(m_priv->expectedPatternLength + event->getMessage().size());
 	output.append(LOG4CXX_EOL);
 	output.append(LOG4CXX_STR("<tr>"));
 	output.append(LOG4CXX_EOL);

diff --git a/src/main/cpp/jsonlayout.cpp b/src/main/cpp/jsonlayout.cpp
@@ -39,7 +39,8 @@ struct JSONLayout::JSONLayoutPrivate
 		prettyPrint(false),
 		dateFormat(),
 		ppIndentL1(LOG4CXX_STR("  ")),
-		ppIndentL2(LOG4CXX_STR("    ")) {}
+		ppIndentL2(LOG4CXX_STR("    ")),
+		expectedPatternLength(100) {}
 
 	// Print no location info by default
 	bool locationInfo; //= false
@@ -49,6 +50,9 @@ struct JSONLayout::JSONLayoutPrivate
 
 	LogString ppIndentL1;
 	LogString ppIndentL2;
+
+	// Expected length of a formatted event excluding the message text
+	size_t expectedPatternLength;
 };
 
 JSONLayout::JSONLayout() :
@@ -85,7 +89,7 @@ LogString JSONLayout::getContentType() const
 
 void JSONLayout::activateOptions(helpers::Pool& /* p */)
 {
-
+	m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 }
 
 void JSONLayout::setOption(const LogString& option, const LogString& value)
@@ -106,6 +110,7 @@ void JSONLayout::format(LogString& output,
 	const spi::LoggingEventPtr& event,
 	Pool& p) const
 {
+	output.reserve(m_priv->expectedPatternLength + event->getMessage().size());
 	output.append(LOG4CXX_STR("{"));
 	output.append(m_priv->prettyPrint ? LOG4CXX_EOL : LOG4CXX_STR(" "));
 

diff --git a/src/main/cpp/layout.cpp b/src/main/cpp/layout.cpp
@@ -33,3 +33,20 @@ LogString Layout::getContentType() const
 void Layout::appendHeader(LogString&, log4cxx::helpers::Pool&) {}
 
 void Layout::appendFooter(LogString&, log4cxx::helpers::Pool&) {}
+
+/**
+ * The expected length of a formatted event excluding the message text
+ */
+size_t Layout::getFormattedEventCharacterCount() const
+{
+	auto exampleEvent = std::make_shared<spi::LoggingEvent>
+		( LOG4CXX_STR("example.logger")
+		, Level::getDebug()
+		, LOG4CXX_LOCATION
+		, LogString()
+		);
+	LogString text;
+	Pool pool;
+	format(text, exampleEvent, pool);
+	return text.size();
+}
diff --git a/src/main/cpp/patternlayout.cpp b/src/main/cpp/patternlayout.cpp
@@ -57,9 +57,13 @@ using namespace log4cxx::pattern;
 
 struct PatternLayout::PatternLayoutPrivate
 {
-	PatternLayoutPrivate() {}
-	PatternLayoutPrivate(const LogString& pattern) :
-		conversionPattern(pattern) {}
+	PatternLayoutPrivate()
+		: expectedPatternLength(100)
+		{}
+	PatternLayoutPrivate(const LogString& pattern)
+		: conversionPattern(pattern)
+		, expectedPatternLength(100)
+		{}
 
 	/**
 	 * Conversion pattern.
@@ -82,6 +86,9 @@ struct PatternLayout::PatternLayoutPrivate
 	LogString m_infoColor = LOG4CXX_STR("\\x1B[32m"); //green
 	LogString m_debugColor = LOG4CXX_STR("\\x1B[36m"); //cyan;
 	LogString m_traceColor = LOG4CXX_STR("\\x1B[34m"); //blue;
+
+	// Expected length of a formatted event excluding the message text
+	size_t expectedPatternLength;
 };
 
 IMPLEMENT_LOG4CXX_OBJECT(PatternLayout)
@@ -115,6 +122,7 @@ void PatternLayout::format(LogString& output,
 	const spi::LoggingEventPtr& event,
 	Pool& pool) const
 {
+	output.reserve(m_priv->expectedPatternLength + event->getMessage().size());
 	std::vector<FormattingInfoPtr>::const_iterator formatterIter =
 		m_priv->patternFields.begin();
 
@@ -199,6 +207,7 @@ void PatternLayout::activateOptions(Pool&)
 			m_priv->patternConverters.push_back(eventConverter);
 		}
 	}
+	m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 }
 
 #define RULES_PUT(spec, cls) \

diff --git a/src/main/cpp/xmllayout.cpp b/src/main/cpp/xmllayout.cpp
@@ -34,18 +34,26 @@ using namespace log4cxx::xml;
 
 struct XMLLayout::XMLLayoutPrivate
 {
-	XMLLayoutPrivate() : locationInfo(false), properties(false) {}
+	XMLLayoutPrivate()
+		: locationInfo(false)
+		, properties(false)
+		, expectedPatternLength(100)
+		{}
 
 	// Print no location info by default
 	bool locationInfo; //= false
 	bool properties; // = false
+
+	// Expected length of a formatted event excluding the message text
+	size_t expectedPatternLength;
 };
 
 IMPLEMENT_LOG4CXX_OBJECT(XMLLayout)
 
 XMLLayout::XMLLayout()
 	: m_priv(std::make_unique<XMLLayoutPrivate>())
 {
+	m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 }
 
 XMLLayout::~XMLLayout() {}
@@ -56,18 +64,21 @@ void XMLLayout::setOption(const LogString& option,
 	if (StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("LOCATIONINFO"), LOG4CXX_STR("locationinfo")))
 	{
 		setLocationInfo(OptionConverter::toBoolean(value, false));
+		m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 	}
 
 	if (StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("PROPERTIES"), LOG4CXX_STR("properties")))
 	{
 		setProperties(OptionConverter::toBoolean(value, false));
+		m_priv->expectedPatternLength = getFormattedEventCharacterCount() * 2;
 	}
 }
 
 void XMLLayout::format(LogString& output,
 	const spi::LoggingEventPtr& event,
 	Pool& p) const
 {
+	output.reserve(m_priv->expectedPatternLength + event->getMessage().size());
 	output.append(LOG4CXX_STR("<log4j:event logger=\""));
 	Transform::appendEscapingTags(output, event->getLoggerName());
 	output.append(LOG4CXX_STR("\" timestamp=\""));

diff --git a/src/main/include/log4cxx/layout.h b/src/main/include/log4cxx/layout.h
@@ -75,6 +75,12 @@ class LOG4CXX_EXPORT Layout :
 		The other layouts return <code>false</code>.
 		*/
 		virtual bool ignoresThrowable() const = 0;
+
+	protected:
+		/**
+		 * The expected length of a formatted event excluding the message text
+		 */
+		size_t getFormattedEventCharacterCount() const;
 };
 LOG4CXX_PTR_DEF(Layout);
 }