AAPT2: Separate out the various steps
An early refactor. Some ideas became clearer as
development continued. Now the various phases are much
clearer and more easily reusable.
Also added a ton of tests!
Change-Id: Ic8f0a70c8222370352e63533b329c40457c0903e
diff --git a/tools/aapt2/XmlPullParser.cpp b/tools/aapt2/XmlPullParser.cpp
new file mode 100644
index 0000000..1b9499d
--- /dev/null
+++ b/tools/aapt2/XmlPullParser.cpp
@@ -0,0 +1,286 @@
+/*
+ * 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 "util/Maybe.h"
+#include "util/Util.h"
+#include "XmlPullParser.h"
+
+#include <iostream>
+#include <string>
+
+namespace aapt {
+
+constexpr char kXmlNamespaceSep = 1;
+
+XmlPullParser::XmlPullParser(std::istream& in) : mIn(in), mEmpty(), mDepth(0) {
+ mParser = XML_ParserCreateNS(nullptr, kXmlNamespaceSep);
+ XML_SetUserData(mParser, this);
+ XML_SetElementHandler(mParser, startElementHandler, endElementHandler);
+ XML_SetNamespaceDeclHandler(mParser, startNamespaceHandler, endNamespaceHandler);
+ XML_SetCharacterDataHandler(mParser, characterDataHandler);
+ XML_SetCommentHandler(mParser, commentDataHandler);
+ mEventQueue.push(EventData{ Event::kStartDocument, 0, mDepth++ });
+}
+
+XmlPullParser::~XmlPullParser() {
+ XML_ParserFree(mParser);
+}
+
+XmlPullParser::Event XmlPullParser::next() {
+ const Event currentEvent = getEvent();
+ if (currentEvent == Event::kBadDocument || currentEvent == Event::kEndDocument) {
+ return currentEvent;
+ }
+
+ mEventQueue.pop();
+ while (mEventQueue.empty()) {
+ mIn.read(mBuffer, sizeof(mBuffer) / sizeof(*mBuffer));
+
+ const bool done = mIn.eof();
+ if (mIn.bad() && !done) {
+ mLastError = strerror(errno);
+ mEventQueue.push(EventData{ Event::kBadDocument });
+ continue;
+ }
+
+ if (XML_Parse(mParser, mBuffer, mIn.gcount(), done) == XML_STATUS_ERROR) {
+ mLastError = XML_ErrorString(XML_GetErrorCode(mParser));
+ mEventQueue.push(EventData{ Event::kBadDocument });
+ continue;
+ }
+
+ if (done) {
+ mEventQueue.push(EventData{ Event::kEndDocument, 0, 0 });
+ }
+ }
+
+ Event event = getEvent();
+
+ // Record namespace prefixes and package names so that we can do our own
+ // handling of references that use namespace aliases.
+ if (event == Event::kStartNamespace || event == Event::kEndNamespace) {
+ Maybe<std::u16string> result = util::extractPackageFromNamespace(getNamespaceUri());
+ if (event == Event::kStartNamespace) {
+ if (result) {
+ mPackageAliases.emplace_back(getNamespacePrefix(), result.value());
+ }
+ } else {
+ if (result) {
+ assert(mPackageAliases.back().second == result.value());
+ mPackageAliases.pop_back();
+ }
+ }
+ }
+
+ return event;
+}
+
+XmlPullParser::Event XmlPullParser::getEvent() const {
+ return mEventQueue.front().event;
+}
+
+const std::string& XmlPullParser::getLastError() const {
+ return mLastError;
+}
+
+const std::u16string& XmlPullParser::getComment() const {
+ return mEventQueue.front().comment;
+}
+
+size_t XmlPullParser::getLineNumber() const {
+ return mEventQueue.front().lineNumber;
+}
+
+size_t XmlPullParser::getDepth() const {
+ return mEventQueue.front().depth;
+}
+
+const std::u16string& XmlPullParser::getText() const {
+ if (getEvent() != Event::kText) {
+ return mEmpty;
+ }
+ return mEventQueue.front().data1;
+}
+
+const std::u16string& XmlPullParser::getNamespacePrefix() const {
+ const Event currentEvent = getEvent();
+ if (currentEvent != Event::kStartNamespace && currentEvent != Event::kEndNamespace) {
+ return mEmpty;
+ }
+ return mEventQueue.front().data1;
+}
+
+const std::u16string& XmlPullParser::getNamespaceUri() const {
+ const Event currentEvent = getEvent();
+ if (currentEvent != Event::kStartNamespace && currentEvent != Event::kEndNamespace) {
+ return mEmpty;
+ }
+ return mEventQueue.front().data2;
+}
+
+Maybe<ResourceName> XmlPullParser::transformPackage(
+ const ResourceName& name, const StringPiece16& localPackage) const {
+ if (name.package.empty()) {
+ return ResourceName{ localPackage.toString(), name.type, name.entry };
+ }
+
+ const auto endIter = mPackageAliases.rend();
+ for (auto iter = mPackageAliases.rbegin(); iter != endIter; ++iter) {
+ if (name.package == iter->first) {
+ if (iter->second.empty()) {
+ return ResourceName{ localPackage.toString(), name.type, name.entry };
+ } else {
+ return ResourceName{ iter->second, name.type, name.entry };
+ }
+ }
+ }
+ return {};
+}
+
+const std::u16string& XmlPullParser::getElementNamespace() const {
+ const Event currentEvent = getEvent();
+ if (currentEvent != Event::kStartElement && currentEvent != Event::kEndElement) {
+ return mEmpty;
+ }
+ return mEventQueue.front().data1;
+}
+
+const std::u16string& XmlPullParser::getElementName() const {
+ const Event currentEvent = getEvent();
+ if (currentEvent != Event::kStartElement && currentEvent != Event::kEndElement) {
+ return mEmpty;
+ }
+ return mEventQueue.front().data2;
+}
+
+XmlPullParser::const_iterator XmlPullParser::beginAttributes() const {
+ return mEventQueue.front().attributes.begin();
+}
+
+XmlPullParser::const_iterator XmlPullParser::endAttributes() const {
+ return mEventQueue.front().attributes.end();
+}
+
+size_t XmlPullParser::getAttributeCount() const {
+ if (getEvent() != Event::kStartElement) {
+ return 0;
+ }
+ return mEventQueue.front().attributes.size();
+}
+
+/**
+ * Extracts the namespace and name of an expanded element or attribute name.
+ */
+static void splitName(const char* name, std::u16string& outNs, std::u16string& outName) {
+ const char* p = name;
+ while (*p != 0 && *p != kXmlNamespaceSep) {
+ p++;
+ }
+
+ if (*p == 0) {
+ outNs = std::u16string();
+ outName = util::utf8ToUtf16(name);
+ } else {
+ outNs = util::utf8ToUtf16(StringPiece(name, (p - name)));
+ outName = util::utf8ToUtf16(p + 1);
+ }
+}
+
+void XMLCALL XmlPullParser::startNamespaceHandler(void* userData, const char* prefix,
+ const char* uri) {
+ XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(userData);
+ std::u16string namespaceUri = uri != nullptr ? util::utf8ToUtf16(uri) : std::u16string();
+ parser->mNamespaceUris.push(namespaceUri);
+ parser->mEventQueue.push(EventData{
+ Event::kStartNamespace,
+ XML_GetCurrentLineNumber(parser->mParser),
+ parser->mDepth++,
+ prefix != nullptr ? util::utf8ToUtf16(prefix) : std::u16string(),
+ namespaceUri
+ });
+}
+
+void XMLCALL XmlPullParser::startElementHandler(void* userData, const char* name,
+ const char** attrs) {
+ XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(userData);
+
+ EventData data = {
+ Event::kStartElement, XML_GetCurrentLineNumber(parser->mParser), parser->mDepth++
+ };
+ splitName(name, data.data1, data.data2);
+
+ while (*attrs) {
+ Attribute attribute;
+ splitName(*attrs++, attribute.namespaceUri, attribute.name);
+ attribute.value = util::utf8ToUtf16(*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->mEventQueue.push(std::move(data));
+}
+
+void XMLCALL XmlPullParser::characterDataHandler(void* userData, const char* s, int len) {
+ XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(userData);
+
+ parser->mEventQueue.push(EventData{
+ Event::kText,
+ XML_GetCurrentLineNumber(parser->mParser),
+ parser->mDepth,
+ util::utf8ToUtf16(StringPiece(s, len))
+ });
+}
+
+void XMLCALL XmlPullParser::endElementHandler(void* userData, const char* name) {
+ XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(userData);
+
+ EventData data = {
+ Event::kEndElement, XML_GetCurrentLineNumber(parser->mParser), --(parser->mDepth)
+ };
+ splitName(name, data.data1, data.data2);
+
+ // Move the data into the queue (no copy).
+ parser->mEventQueue.push(std::move(data));
+}
+
+void XMLCALL XmlPullParser::endNamespaceHandler(void* userData, const char* prefix) {
+ XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(userData);
+
+ parser->mEventQueue.push(EventData{
+ Event::kEndNamespace,
+ XML_GetCurrentLineNumber(parser->mParser),
+ --(parser->mDepth),
+ prefix != nullptr ? util::utf8ToUtf16(prefix) : std::u16string(),
+ parser->mNamespaceUris.top()
+ });
+ parser->mNamespaceUris.pop();
+}
+
+void XMLCALL XmlPullParser::commentDataHandler(void* userData, const char* comment) {
+ XmlPullParser* parser = reinterpret_cast<XmlPullParser*>(userData);
+
+ parser->mEventQueue.push(EventData{
+ Event::kComment,
+ XML_GetCurrentLineNumber(parser->mParser),
+ parser->mDepth,
+ util::utf8ToUtf16(comment)
+ });
+}
+
+} // namespace aapt