viewer#819 Avoid reading the same XML file multiple times

6 files changed, 122 insertions, 57 deletions

diff --git a/indra/llxml/llcontrol.cpp b/indra/llxml/llcontrol.cpp
index e626bac7d0..71ba2b88bc 100644
--- a/indra/llxml/llcontrol.cpp
+++ b/indra/llxml/llcontrol.cpp
@@ -753,13 +753,13 @@ void LLControlGroup::setUntypedValue(std::string_view name, const LLSD& val)
 //---------------------------------------------------------------
 
 // Returns number of controls loaded, so 0 if failure
-U32 LLControlGroup::loadFromFileLegacy(const std::string& filename, bool require_declaration, eControlType declare_as)
+U32 LLControlGroup::loadFromFileLegacy(const std::string& filename, const std::string& xml, bool require_declaration, eControlType declare_as)
 {
 	std::string name;
 
 	LLXmlTree xml_controls;
 
-	if (!xml_controls.parseFile(filename))
+	if (!xml_controls.parseString(xml))
 	{
 		LL_WARNS("Settings") << "Unable to open control file " << filename << LL_ENDL;
 		return 0;
@@ -772,7 +772,7 @@ U32 LLControlGroup::loadFromFileLegacy(const std::string& filename, bool require
 		return 0;
 	}
 
-	U32		validitems = 0;
+	U32 validitems = 0;
 	S32 version;
 	
 	rootp->getAttributeS32("version", version);
@@ -990,24 +990,24 @@ U32 LLControlGroup::saveToFile(const std::string& filename, bool nondefault_only
 U32 LLControlGroup::loadFromFile(const std::string& filename, bool set_default_values, bool save_values)
 {
 	LLSD settings;
-	llifstream infile;
-	infile.open(filename.c_str());
-	if(!infile.is_open())
+
+	std::string xml = gDirUtilp->getFileContents(filename);
+	if (xml.empty())
 	{
 		LL_WARNS("Settings") << "Cannot find file " << filename << " to load." << LL_ENDL;
 		return 0;
 	}
 
-	if (LLSDParser::PARSE_FAILURE == LLSDSerialize::fromXML(settings, infile))
+	std::stringstream stream(xml);
+	if (LLSDParser::PARSE_FAILURE == LLSDSerialize::fromXML(settings, stream))
 	{
-		infile.close();
 		LL_WARNS("Settings") << "Unable to parse LLSD control file " << filename << ". Trying Legacy Method." << LL_ENDL;
-		return loadFromFileLegacy(filename, true, TYPE_STRING);
+		return loadFromFileLegacy(filename, xml, true, TYPE_STRING);
 	}
 
 	U32	validitems = 0;
 	bool hidefromsettingseditor = false;
-	
+
 	for(LLSD::map_const_iterator itr = settings.beginMap(); itr != settings.endMap(); ++itr)
 	{
 		LLControlVariable::ePersist persist = LLControlVariable::PERSIST_NONDFT;
@@ -1019,7 +1019,7 @@ U32 LLControlGroup::loadFromFile(const std::string& filename, bool set_default_v
 			persist = control_map["Persist"].asInteger()?
 					  LLControlVariable::PERSIST_NONDFT : LLControlVariable::PERSIST_NO;
 		}
-		
+
 		// Sometimes we want to use the settings system to provide cheap persistence, but we
 		// don't want the settings themselves to be easily manipulated in the UI because 
 		// doing so can cause support problems. So we have this option:
@@ -1031,7 +1031,7 @@ U32 LLControlGroup::loadFromFile(const std::string& filename, bool set_default_v
 		{
 			hidefromsettingseditor = false;
 		}
-		
+
 		// If the control exists just set the value from the input file.
 		LLControlVariable* existing_control = getControl(name);
 		if(existing_control)
diff --git a/indra/llxml/llcontrol.h b/indra/llxml/llcontrol.h
index a8bc584c48..e148b74292 100644
--- a/indra/llxml/llcontrol.h
+++ b/indra/llxml/llcontrol.h
@@ -300,7 +300,7 @@ public:
 	// Returns number of controls loaded, 0 if failed
 	// If require_declaration is false, will auto-declare controls it finds
 	// as the given type.
-	U32	loadFromFileLegacy(const std::string& filename, bool require_declaration = true, eControlType declare_as = TYPE_STRING);
+	U32	loadFromFileLegacy(const std::string& filename, const std::string& xml, bool require_declaration = true, eControlType declare_as = TYPE_STRING);
  	U32 saveToFile(const std::string& filename, bool nondefault_only);
  	U32	loadFromFile(const std::string& filename, bool default_values = false, bool save_values = true);
 	void	resetToDefaults();
diff --git a/indra/llxml/llxmlnode.cpp b/indra/llxml/llxmlnode.cpp
index 9c7ac66f01..627e99a1e6 100644
--- a/indra/llxml/llxmlnode.cpp
+++ b/indra/llxml/llxmlnode.cpp
@@ -650,34 +650,56 @@ bool LLXMLNode::updateNode(
 	return true;
 }
 
-// static
-bool LLXMLNode::parseFile(const std::string& filename, LLXMLNodePtr& node, LLXMLNode* defaults_tree)
+static std::map<std::string, LLXMLNodePtr> sXMLCache;
+static LLSharedMutex sXMLCacheMutex;
+
+static void saveToCache(const std::string& filename, LLXMLNodePtr& node)
 {
-	// Read file
-	LL_DEBUGS("XMLNode") << "parsing XML file: " << filename << LL_ENDL;
-	LLFILE* fp = LLFile::fopen(filename, "rb");		/* Flawfinder: ignore */
-	if (fp == NULL)
-	{
-		node = NULL ;
-		return false;
-	}
-	fseek(fp, 0, SEEK_END);
-	U32 length = ftell(fp);
-	fseek(fp, 0, SEEK_SET);
+    LLExclusiveMutexLock lock(&sXMLCacheMutex);
+    sXMLCache.emplace(filename, node.notNull() ? node->deepCopy() : nullptr);
+}
 
-	U8* buffer = new U8[length+1];
-	size_t nread = fread(buffer, 1, length, fp);
-	buffer[nread] = 0;
-	fclose(fp);
+static bool loadFromCache(const std::string& filename, LLXMLNodePtr& node)
+{
+    LLSharedMutexLock lock(&sXMLCacheMutex);
+    auto it = sXMLCache.find(filename);
+    if (it == sXMLCache.end())
+        return false;
+    node = it->second.notNull() ? it->second->deepCopy() : nullptr;
+    return node.notNull();
+}
 
-	bool rv = parseBuffer(buffer, nread, node, defaults_tree);
-	delete [] buffer;
-	return rv;
+// static
+bool LLXMLNode::parseFile(const std::string& filename, LLXMLNodePtr& node, LLXMLNode* defaults_tree, bool cacheable)
+{
+    // Try to read from cache
+    if (cacheable)
+    {
+        if (loadFromCache(filename, node))
+            return true;
+    }
+
+    std::string xml = gDirUtilp->getFileContents(filename);
+    if (xml.empty())
+    {
+        LL_WARNS("XMLNode") << "no XML file: " << filename << LL_ENDL;
+    }
+    else if (parseBuffer(xml.data(), xml.size(), node, defaults_tree))
+    {
+        if (cacheable)
+        {
+            saveToCache(filename, node);
+        }
+        return true;
+    }
+
+    node = nullptr;
+    return false;
 }
 
 // static
 bool LLXMLNode::parseBuffer(
-	U8* buffer,
+	const char* buffer,
 	U32 length,
 	LLXMLNodePtr& node, 
 	LLXMLNode* defaults)
@@ -696,7 +718,7 @@ bool LLXMLNode::parseBuffer(
 	XML_SetUserData(my_parser, (void *)file_node_ptr);
 
 	// Do the parsing
-	if (XML_Parse(my_parser, (const char *)buffer, length, true) != XML_STATUS_OK)
+	if (XML_Parse(my_parser, buffer, length, true) != XML_STATUS_OK)
 	{
 		LL_WARNS() << "Error parsing xml error code: "
 				<< XML_ErrorString(XML_GetErrorCode(my_parser))
@@ -824,18 +846,20 @@ bool LLXMLNode::isFullyDefault()
 }
 
 // static
-bool LLXMLNode::getLayeredXMLNode(LLXMLNodePtr& root,
-								  const std::vector<std::string>& paths)
+bool LLXMLNode::getLayeredXMLNode(LLXMLNodePtr& root, const std::vector<std::string>& paths, bool cacheable)
 {
-	if (paths.empty()) return false;
+	if (paths.empty())
+	{
+		return false;
+	}
 
 	std::string filename = paths.front();
 	if (filename.empty())
 	{
 		return false;
 	}
-	
-	if (!LLXMLNode::parseFile(filename, root, NULL))
+
+	if (!LLXMLNode::parseFile(filename, root, nullptr, cacheable))
 	{
 		LL_WARNS() << "Problem reading UI description file: " << filename << LL_ENDL;
 		return false;
diff --git a/indra/llxml/llxmlnode.h b/indra/llxml/llxmlnode.h
index d5b8b36d86..32aee057ed 100644
--- a/indra/llxml/llxmlnode.h
+++ b/indra/llxml/llxmlnode.h
@@ -126,34 +126,34 @@ public:
 	bool isNull();
 
 	bool deleteChild(LLXMLNode* child);
-    void addChild(LLXMLNodePtr& new_child); 
+    void addChild(LLXMLNodePtr& new_child);
     void setParent(LLXMLNodePtr& new_parent); // reparent if necessary
 
-    // Serialization
+    // Deserialization
 	static bool parseFile(
 		const std::string& filename,
-		LLXMLNodePtr& node, 
-		LLXMLNode* defaults_tree);
+		LLXMLNodePtr& node,
+		LLXMLNode* defaults_tree,
+		bool cacheable = false);
 	static bool parseBuffer(
-		U8* buffer,
+		const char* buffer,
 		U32 length,
-		LLXMLNodePtr& node, 
+		LLXMLNodePtr& node,
 		LLXMLNode* defaults);
 	static bool parseStream(
 		std::istream& str,
-		LLXMLNodePtr& node, 
+		LLXMLNodePtr& node,
 		LLXMLNode* defaults);
 	static bool updateNode(
 		LLXMLNodePtr& node,
 		LLXMLNodePtr& update_node);
-	
-	static bool getLayeredXMLNode(LLXMLNodePtr& root, const std::vector<std::string>& paths);
-	
-	
+
+	static bool getLayeredXMLNode(LLXMLNodePtr& root, const std::vector<std::string>& paths, bool cacheable = false);
+
 	// Write standard XML file header:
 	// <?xml version="1.0" encoding="utf-8" standalone="yes" ?>
 	static void writeHeaderToFile(LLFILE *out_file);
-	
+
 	// Write XML to file with one attribute per line.
 	// XML escapes values as they are written.
     void writeToFile(LLFILE *out_file, const std::string& indent = std::string(), bool use_type_decorations=true);
@@ -237,7 +237,7 @@ public:
 	// Setters
 
 	bool setAttributeString(const char* attr, const std::string& value);
-	
+
 	void setBoolValue(const bool value)	{ setBoolValue(1, &value); }
 	void setByteValue(const U8 value, Encoding encoding = ENCODING_DEFAULT) { setByteValue(1, &value, encoding); }
 	void setIntValue(const S32 value, Encoding encoding = ENCODING_DEFAULT) { setIntValue(1, &value, encoding); }
diff --git a/indra/llxml/llxmltree.cpp b/indra/llxml/llxmltree.cpp
index be3bcf2a66..38321847c3 100644
--- a/indra/llxml/llxmltree.cpp
+++ b/indra/llxml/llxmltree.cpp
@@ -35,6 +35,7 @@
 #include "v4math.h"
 #include "llquaternion.h"
 #include "lluuid.h"
+#include "lldir.h"
 
 //////////////////////////////////////////////////////////////
 // LLXmlTree
@@ -60,20 +61,37 @@ void LLXmlTree::cleanup()
 	mNodeNames.cleanup();
 }
 
+bool LLXmlTree::parseFile(const std::string & filename, bool keep_contents)
+{
+	delete mRoot;
+	mRoot = NULL;
+
+	std::string xml = gDirUtilp->getFileContents(filename);
+	if (xml.empty())
+	{
+		LL_WARNS() << "LLXmlTree parse failed. No XML file: " << filename << LL_ENDL;
+		return false;
+	}
+
+	bool success = parseString(xml, keep_contents);
 
-bool LLXmlTree::parseFile(const std::string &path, bool keep_contents)
+	return success;
+}
+
+bool LLXmlTree::parseString(const std::string &xml, bool keep_contents)
 {
 	delete mRoot;
 	mRoot = NULL;
 
 	LLXmlTreeParser parser(this);
-	bool success = parser.parseFile( path, &mRoot, keep_contents );
-	if( !success )
+	bool success = parser.parseString(xml, &mRoot, keep_contents);
+	if (!success)
 	{
 		S32 line_number = parser.getCurrentLineNumber();
 		const char* error =  parser.getErrorString();
 		LL_WARNS() << "LLXmlTree parse failed.  Line " << line_number << ": " << error << LL_ENDL;
 	}
+
 	return success;
 }
 
@@ -536,6 +554,27 @@ bool LLXmlTreeParser::parseFile(const std::string &path, LLXmlTreeNode** root, b
 	return success;
 }
 
+bool LLXmlTreeParser::parseString(const std::string& xml, LLXmlTreeNode** root, bool keep_contents)
+{
+	llassert( !mRoot );
+	llassert( !mCurrent );
+
+	mKeepContents = keep_contents;
+
+	bool success = LLXmlParser::parse(xml.data(), (int)xml.size(), true);
+
+	*root = mRoot;
+	mRoot = NULL;
+
+	if (success)
+	{
+		llassert(!mCurrent);
+	}
+
+	mCurrent = NULL;
+	
+	return success;
+}
 
 const std::string& LLXmlTreeParser::tabs()
 {
diff --git a/indra/llxml/llxmltree.h b/indra/llxml/llxmltree.h
index 5d15c4c7f5..d47f26f731 100644
--- a/indra/llxml/llxmltree.h
+++ b/indra/llxml/llxmltree.h
@@ -56,6 +56,7 @@ public:
 	void cleanup();
 
 	virtual bool	parseFile(const std::string &path, bool keep_contents = true);
+	virtual bool	parseString(const std::string &xml, bool keep_contents = true);
 
 	LLXmlTreeNode*	getRoot() { return mRoot; }
 
@@ -199,7 +200,8 @@ public:
 	LLXmlTreeParser(LLXmlTree* tree);
 	virtual ~LLXmlTreeParser();
 
-	bool parseFile(const std::string &path, LLXmlTreeNode** root, bool keep_contents );
+	bool parseFile(const std::string &path, LLXmlTreeNode** root, bool keep_contents);
+	bool parseString(const std::string &xml, LLXmlTreeNode** root, bool keep_contents);
 
 protected:
 	const std::string& tabs();