tools/aapt2/xml/XmlPullParser.cpp - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2015 The Android Open Source Project
  *
  * Licensed 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 <iostream>
 #include <string>

 #include "util/Maybe.h"
 #include "util/Util.h"
 #include "xml/XmlPullParser.h"
 #include "xml/XmlUtil.h"

 using ::aapt::io::InputStream;
 using ::android::StringPiece;

 namespace aapt {
 namespace xml {

 constexpr char kXmlNamespaceSep = 1;

 XmlPullParser::XmlPullParser(InputStream* in) : in_(in), empty_(), depth_(0) {
   parser_ = XML_ParserCreateNS(nullptr, kXmlNamespaceSep);
   XML_SetUserData(parser_, this);
   XML_SetElementHandler(parser_, StartElementHandler, EndElementHandler);
   XML_SetNamespaceDeclHandler(parser_, StartNamespaceHandler,
                               EndNamespaceHandler);
   XML_SetCharacterDataHandler(parser_, CharacterDataHandler);
   XML_SetCommentHandler(parser_, CommentDataHandler);
   XML_SetCdataSectionHandler(parser_, StartCdataSectionHandler, EndCdataSectionHandler);
   event_queue_.push(EventData{Event::kStartDocument, 0, depth_++});
 }

 XmlPullParser::~XmlPullParser() {
   XML_ParserFree(parser_);
 }

 XmlPullParser::Event XmlPullParser::Next() {
   const Event currentEvent = event();
   if (currentEvent == Event::kBadDocument || currentEvent == Event::kEndDocument) {
     return currentEvent;
   }

   event_queue_.pop();
   while (event_queue_.empty()) {
     const char* buffer = nullptr;
     size_t buffer_size = 0;
     bool done = false;
     if (!in_->Next(reinterpret_cast<const void**>(&buffer), &buffer_size)) {
       if (in_->HadError()) {
         error_ = in_->GetError();
         event_queue_.push(EventData{Event::kBadDocument});
         break;
       }

       done = true;
     }

     if (XML_Parse(parser_, buffer, buffer_size, done) == XML_STATUS_ERROR) {
       error_ = XML_ErrorString(XML_GetErrorCode(parser_));
       event_queue_.push(EventData{Event::kBadDocument});
       break;
     }

     if (done) {
       event_queue_.push(EventData{Event::kEndDocument, 0, 0});
     }
   }

   Event next_event = event();

   // Record namespace prefixes and package names so that we can do our own
   // handling of references that use namespace aliases.
   if (next_event == Event::kStartNamespace ||
       next_event == Event::kEndNamespace) {
     Maybe<ExtractedPackage> result =
         ExtractPackageFromNamespace(namespace_uri());
     if (next_event == Event::kStartNamespace) {
       if (result) {
         package_aliases_.emplace_back(
             PackageDecl{namespace_prefix(), std::move(result.value())});
       }
     } else {
       if (result) {
         package_aliases_.pop_back();
       }
     }
   }

   return next_event;
 }

 XmlPullParser::Event XmlPullParser::event() const {
   return event_queue_.front().event;
 }

 const std::string& XmlPullParser::error() const { return error_; }

 const std::string& XmlPullParser::comment() const {
   return event_queue_.front().data1;
 }

 size_t XmlPullParser::line_number() const {
   return event_queue_.front().line_number;
 }

 size_t XmlPullParser::depth() const { return event_queue_.front().depth; }

 const std::string& XmlPullParser::text() const {
   if (event() != Event::kText) {
     return empty_;
   }
   return event_queue_.front().data1;
 }

 const std::string& XmlPullParser::namespace_prefix() const {
   const Event current_event = event();
   if (current_event != Event::kStartNamespace &&
       current_event != Event::kEndNamespace) {
     return empty_;
   }
   return event_queue_.front().data1;
 }

 const std::string& XmlPullParser::namespace_uri() const {
   const Event current_event = event();
   if (current_event != Event::kStartNamespace &&
       current_event != Event::kEndNamespace) {
     return empty_;
   }
   return event_queue_.front().data2;
 }

 Maybe<ExtractedPackage> XmlPullParser::TransformPackageAlias(const StringPiece& alias) const {
   if (alias.empty()) {
     return ExtractedPackage{{}, false /*private*/};
   }

   const auto end_iter = package_aliases_.rend();
   for (auto iter = package_aliases_.rbegin(); iter != end_iter; ++iter) {
     if (alias == iter->prefix) {
       if (iter->package.package.empty()) {
         return ExtractedPackage{{}, iter->package.private_namespace};
       }
       return iter->package;
     }
   }
   return {};
 }

 const std::string& XmlPullParser::element_namespace() const {
   const Event current_event = event();
   if (current_event != Event::kStartElement &&
       current_event != Event::kEndElement) {
     return empty_;
   }
   return event_queue_.front().data1;
 }

 const std::string& XmlPullParser::element_name() const {
   const Event current_event = event();
   if (current_event != Event::kStartElement &&
       current_event != Event::kEndElement) {
     return empty_;
   }
   return event_queue_.front().data2;
 }

 XmlPullParser::const_iterator XmlPullParser::begin_attributes() const {
   return event_queue_.front().attributes.begin();
 }

 XmlPullParser::const_iterator XmlPullParser::end_attributes() const {
   return event_queue_.front().attributes.end();
 }

 size_t XmlPullParser::attribute_count() const {
   if (event() != Event::kStartElement) {
     return 0;
   }
   return event_queue_.front().attributes.size();
 }

 /**
  * Extracts the namespace and name of an expanded element or attribute name.
  */
 static void SplitName(const char* name, std::string* out_ns, std::string* out_name) {
   const char* p = name;
   while (*p != 0 && *p != kXmlNamespaceSep) {
     p++;
   }

   if (*p == 0) {
     out_ns->clear();
     out_name->assign(name);
   } else {
     out_ns->assign(name, (p - name));
     out_name->assign(p + 1);
   }
 }

 void XMLCALL XmlPullParser::StartNamespaceHandler(void* user_data,
                                                   const char* prefix,
                                                   const char* uri) {
   XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);
   std::string namespace_uri = uri != nullptr ? uri : std::string();
   parser->namespace_uris_.push(namespace_uri);
   parser->event_queue_.push(
       EventData{Event::kStartNamespace,
                 XML_GetCurrentLineNumber(parser->parser_), parser->depth_++,
                 prefix != nullptr ? prefix : std::string(), namespace_uri});
 }

 void XMLCALL XmlPullParser::StartElementHandler(void* user_data,
                                                 const char* name,
                                                 const char** attrs) {
   XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

   EventData data = {Event::kStartElement,
                     XML_GetCurrentLineNumber(parser->parser_),
                     parser->depth_++};
   SplitName(name, &data.data1, &data.data2);

   while (*attrs) {
     Attribute attribute;
     SplitName(*attrs++, &attribute.namespace_uri, &attribute.name);
     attribute.value = *attrs++;

     // Insert in sorted order.
     auto iter = std::lower_bound(data.attributes.begin(), data.attributes.end(),
                                  attribute);
     data.attributes.insert(iter, std::move(attribute));
   }

   // Move the structure into the queue (no copy).
   parser->event_queue_.push(std::move(data));
 }

 void XMLCALL XmlPullParser::CharacterDataHandler(void* user_data, const char* s,
                                                  int len) {
   XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

   parser->event_queue_.push(EventData{Event::kText, XML_GetCurrentLineNumber(parser->parser_),
                                       parser->depth_, std::string(s, len)});
 }

 void XMLCALL XmlPullParser::EndElementHandler(void* user_data,
                                               const char* name) {
   XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

   EventData data = {Event::kEndElement,
                     XML_GetCurrentLineNumber(parser->parser_),
                     --(parser->depth_)};
   SplitName(name, &data.data1, &data.data2);

   // Move the data into the queue (no copy).
   parser->event_queue_.push(std::move(data));
 }

 void XMLCALL XmlPullParser::EndNamespaceHandler(void* user_data,
                                                 const char* prefix) {
   XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

   parser->event_queue_.push(
       EventData{Event::kEndNamespace, XML_GetCurrentLineNumber(parser->parser_),
                 --(parser->depth_), prefix != nullptr ? prefix : std::string(),
                 parser->namespace_uris_.top()});
   parser->namespace_uris_.pop();
 }

 void XMLCALL XmlPullParser::CommentDataHandler(void* user_data,
                                                const char* comment) {
   XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

   parser->event_queue_.push(EventData{Event::kComment,
                                       XML_GetCurrentLineNumber(parser->parser_),
                                       parser->depth_, comment});
 }

 void XMLCALL XmlPullParser::StartCdataSectionHandler(void* user_data) {
   XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

   parser->event_queue_.push(EventData{Event::kCdataStart,
                                       XML_GetCurrentLineNumber(parser->parser_),
                                       parser->depth_ });
 }

 void XMLCALL XmlPullParser::EndCdataSectionHandler(void* user_data) {
   XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

   parser->event_queue_.push(EventData{Event::kCdataEnd,
                                       XML_GetCurrentLineNumber(parser->parser_),
                                       parser->depth_ });
 }

 Maybe<StringPiece> FindAttribute(const XmlPullParser* parser,
                                  const StringPiece& name) {
   auto iter = parser->FindAttribute("", name);
   if (iter != parser->end_attributes()) {
     return StringPiece(util::TrimWhitespace(iter->value));
   }
   return {};
 }

 Maybe<StringPiece> FindNonEmptyAttribute(const XmlPullParser* parser,
                                          const StringPiece& name) {
   auto iter = parser->FindAttribute("", name);
   if (iter != parser->end_attributes()) {
     StringPiece trimmed = util::TrimWhitespace(iter->value);
     if (!trimmed.empty()) {
       return trimmed;
     }
   }
   return {};
 }

 }  // namespace xml
 }  // namespace aapt
	/*
	* Copyright (C) 2015 The Android Open Source Project
	*
	* Licensed 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 <iostream>
	#include <string>

	#include "util/Maybe.h"
	#include "util/Util.h"
	#include "xml/XmlPullParser.h"
	#include "xml/XmlUtil.h"

	using ::aapt::io::InputStream;
	using ::android::StringPiece;

	namespace aapt {
	namespace xml {

	constexpr char kXmlNamespaceSep = 1;

	XmlPullParser::XmlPullParser(InputStream* in) : in_(in), empty_(), depth_(0) {
	parser_ = XML_ParserCreateNS(nullptr, kXmlNamespaceSep);
	XML_SetUserData(parser_, this);
	XML_SetElementHandler(parser_, StartElementHandler, EndElementHandler);
	XML_SetNamespaceDeclHandler(parser_, StartNamespaceHandler,
	EndNamespaceHandler);
	XML_SetCharacterDataHandler(parser_, CharacterDataHandler);
	XML_SetCommentHandler(parser_, CommentDataHandler);
	XML_SetCdataSectionHandler(parser_, StartCdataSectionHandler, EndCdataSectionHandler);
	event_queue_.push(EventData{Event::kStartDocument, 0, depth_++});
	}

	XmlPullParser::~XmlPullParser() {
	XML_ParserFree(parser_);
	}

	XmlPullParser::Event XmlPullParser::Next() {
	const Event currentEvent = event();
	if (currentEvent == Event::kBadDocument \|\| currentEvent == Event::kEndDocument) {
	return currentEvent;
	}

	event_queue_.pop();
	while (event_queue_.empty()) {
	const char* buffer = nullptr;
	size_t buffer_size = 0;
	bool done = false;
	if (!in_->Next(reinterpret_cast<const void**>(&buffer), &buffer_size)) {
	if (in_->HadError()) {
	error_ = in_->GetError();
	event_queue_.push(EventData{Event::kBadDocument});
	break;
	}

	done = true;
	}

	if (XML_Parse(parser_, buffer, buffer_size, done) == XML_STATUS_ERROR) {
	error_ = XML_ErrorString(XML_GetErrorCode(parser_));
	event_queue_.push(EventData{Event::kBadDocument});
	break;
	}

	if (done) {
	event_queue_.push(EventData{Event::kEndDocument, 0, 0});
	}
	}

	Event next_event = event();

	// Record namespace prefixes and package names so that we can do our own
	// handling of references that use namespace aliases.
	if (next_event == Event::kStartNamespace \|\|
	next_event == Event::kEndNamespace) {
	Maybe<ExtractedPackage> result =
	ExtractPackageFromNamespace(namespace_uri());
	if (next_event == Event::kStartNamespace) {
	if (result) {
	package_aliases_.emplace_back(
	PackageDecl{namespace_prefix(), std::move(result.value())});
	}
	} else {
	if (result) {
	package_aliases_.pop_back();
	}
	}
	}

	return next_event;
	}

	XmlPullParser::Event XmlPullParser::event() const {
	return event_queue_.front().event;
	}

	const std::string& XmlPullParser::error() const { return error_; }

	const std::string& XmlPullParser::comment() const {
	return event_queue_.front().data1;
	}

	size_t XmlPullParser::line_number() const {
	return event_queue_.front().line_number;
	}

	size_t XmlPullParser::depth() const { return event_queue_.front().depth; }

	const std::string& XmlPullParser::text() const {
	if (event() != Event::kText) {
	return empty_;
	}
	return event_queue_.front().data1;
	}

	const std::string& XmlPullParser::namespace_prefix() const {
	const Event current_event = event();
	if (current_event != Event::kStartNamespace &&
	current_event != Event::kEndNamespace) {
	return empty_;
	}
	return event_queue_.front().data1;
	}

	const std::string& XmlPullParser::namespace_uri() const {
	const Event current_event = event();
	if (current_event != Event::kStartNamespace &&
	current_event != Event::kEndNamespace) {
	return empty_;
	}
	return event_queue_.front().data2;
	}

	Maybe<ExtractedPackage> XmlPullParser::TransformPackageAlias(const StringPiece& alias) const {
	if (alias.empty()) {
	return ExtractedPackage{{}, false /private/};
	}

	const auto end_iter = package_aliases_.rend();
	for (auto iter = package_aliases_.rbegin(); iter != end_iter; ++iter) {
	if (alias == iter->prefix) {
	if (iter->package.package.empty()) {
	return ExtractedPackage{{}, iter->package.private_namespace};
	}
	return iter->package;
	}
	}
	return {};
	}

	const std::string& XmlPullParser::element_namespace() const {
	const Event current_event = event();
	if (current_event != Event::kStartElement &&
	current_event != Event::kEndElement) {
	return empty_;
	}
	return event_queue_.front().data1;
	}

	const std::string& XmlPullParser::element_name() const {
	const Event current_event = event();
	if (current_event != Event::kStartElement &&
	current_event != Event::kEndElement) {
	return empty_;
	}
	return event_queue_.front().data2;
	}

	XmlPullParser::const_iterator XmlPullParser::begin_attributes() const {
	return event_queue_.front().attributes.begin();
	}

	XmlPullParser::const_iterator XmlPullParser::end_attributes() const {
	return event_queue_.front().attributes.end();
	}

	size_t XmlPullParser::attribute_count() const {
	if (event() != Event::kStartElement) {
	return 0;
	}
	return event_queue_.front().attributes.size();
	}

	/**
	* Extracts the namespace and name of an expanded element or attribute name.
	*/
	static void SplitName(const char* name, std::string* out_ns, std::string* out_name) {
	const char* p = name;
	while (p != 0 && p != kXmlNamespaceSep) {
	p++;
	}

	if (*p == 0) {
	out_ns->clear();
	out_name->assign(name);
	} else {
	out_ns->assign(name, (p - name));
	out_name->assign(p + 1);
	}
	}

	void XMLCALL XmlPullParser::StartNamespaceHandler(void* user_data,
	const char* prefix,
	const char* uri) {
	XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);
	std::string namespace_uri = uri != nullptr ? uri : std::string();
	parser->namespace_uris_.push(namespace_uri);
	parser->event_queue_.push(
	EventData{Event::kStartNamespace,
	XML_GetCurrentLineNumber(parser->parser_), parser->depth_++,
	prefix != nullptr ? prefix : std::string(), namespace_uri});
	}

	void XMLCALL XmlPullParser::StartElementHandler(void* user_data,
	const char* name,
	const char** attrs) {
	XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

	EventData data = {Event::kStartElement,
	XML_GetCurrentLineNumber(parser->parser_),
	parser->depth_++};
	SplitName(name, &data.data1, &data.data2);

	while (*attrs) {
	Attribute attribute;
	SplitName(*attrs++, &attribute.namespace_uri, &attribute.name);
	attribute.value = *attrs++;

	// Insert in sorted order.
	auto iter = std::lower_bound(data.attributes.begin(), data.attributes.end(),
	attribute);
	data.attributes.insert(iter, std::move(attribute));
	}

	// Move the structure into the queue (no copy).
	parser->event_queue_.push(std::move(data));
	}

	void XMLCALL XmlPullParser::CharacterDataHandler(void* user_data, const char* s,
	int len) {
	XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

	parser->event_queue_.push(EventData{Event::kText, XML_GetCurrentLineNumber(parser->parser_),
	parser->depth_, std::string(s, len)});
	}

	void XMLCALL XmlPullParser::EndElementHandler(void* user_data,
	const char* name) {
	XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

	EventData data = {Event::kEndElement,
	XML_GetCurrentLineNumber(parser->parser_),
	--(parser->depth_)};
	SplitName(name, &data.data1, &data.data2);

	// Move the data into the queue (no copy).
	parser->event_queue_.push(std::move(data));
	}

	void XMLCALL XmlPullParser::EndNamespaceHandler(void* user_data,
	const char* prefix) {
	XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

	parser->event_queue_.push(
	EventData{Event::kEndNamespace, XML_GetCurrentLineNumber(parser->parser_),
	--(parser->depth_), prefix != nullptr ? prefix : std::string(),
	parser->namespace_uris_.top()});
	parser->namespace_uris_.pop();
	}

	void XMLCALL XmlPullParser::CommentDataHandler(void* user_data,
	const char* comment) {
	XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

	parser->event_queue_.push(EventData{Event::kComment,
	XML_GetCurrentLineNumber(parser->parser_),
	parser->depth_, comment});
	}

	void XMLCALL XmlPullParser::StartCdataSectionHandler(void* user_data) {
	XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

	parser->event_queue_.push(EventData{Event::kCdataStart,
	XML_GetCurrentLineNumber(parser->parser_),
	parser->depth_ });
	}

	void XMLCALL XmlPullParser::EndCdataSectionHandler(void* user_data) {
	XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(user_data);

	parser->event_queue_.push(EventData{Event::kCdataEnd,
	XML_GetCurrentLineNumber(parser->parser_),
	parser->depth_ });
	}

	Maybe<StringPiece> FindAttribute(const XmlPullParser* parser,
	const StringPiece& name) {
	auto iter = parser->FindAttribute("", name);
	if (iter != parser->end_attributes()) {
	return StringPiece(util::TrimWhitespace(iter->value));
	}
	return {};
	}

	Maybe<StringPiece> FindNonEmptyAttribute(const XmlPullParser* parser,
	const StringPiece& name) {
	auto iter = parser->FindAttribute("", name);
	if (iter != parser->end_attributes()) {
	StringPiece trimmed = util::TrimWhitespace(iter->value);
	if (!trimmed.empty()) {
	return trimmed;
	}
	}
	return {};
	}

	} // namespace xml
	} // namespace aapt