tools/aapt2/util/Util.cpp - platform/frameworks/base - Gitiles

 /*
  * 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/BigBuffer.h"
 #include "util/Maybe.h"
 #include "util/StringPiece.h"
 #include "util/Util.h"

 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utils/Unicode.h>
 #include <vector>

 namespace aapt {
 namespace util {

 static std::vector<std::string> splitAndTransform(const StringPiece& str, char sep,
         const std::function<char(char)>& f) {
     std::vector<std::string> parts;
     const StringPiece::const_iterator end = std::end(str);
     StringPiece::const_iterator start = std::begin(str);
     StringPiece::const_iterator current;
     do {
         current = std::find(start, end, sep);
         parts.emplace_back(str.substr(start, current).toString());
         if (f) {
             std::string& part = parts.back();
             std::transform(part.begin(), part.end(), part.begin(), f);
         }
         start = current + 1;
     } while (current != end);
     return parts;
 }

 std::vector<std::string> split(const StringPiece& str, char sep) {
     return splitAndTransform(str, sep, nullptr);
 }

 std::vector<std::string> splitAndLowercase(const StringPiece& str, char sep) {
     return splitAndTransform(str, sep, ::tolower);
 }

 bool stringStartsWith(const StringPiece& str, const StringPiece& prefix) {
     if (str.size() < prefix.size()) {
         return false;
     }
     return str.substr(0, prefix.size()) == prefix;
 }

 bool stringEndsWith(const StringPiece& str, const StringPiece& suffix) {
     if (str.size() < suffix.size()) {
         return false;
     }
     return str.substr(str.size() - suffix.size(), suffix.size()) == suffix;
 }

 StringPiece trimWhitespace(const StringPiece& str) {
     if (str.size() == 0 || str.data() == nullptr) {
         return str;
     }

     const char* start = str.data();
     const char* end = str.data() + str.length();

     while (start != end && isspace(*start)) {
         start++;
     }

     while (end != start && isspace(*(end - 1))) {
         end--;
     }

     return StringPiece(start, end - start);
 }

 StringPiece::const_iterator findNonAlphaNumericAndNotInSet(const StringPiece& str,
                                                            const StringPiece& allowedChars) {
     const auto endIter = str.end();
     for (auto iter = str.begin(); iter != endIter; ++iter) {
         char c = *iter;
         if ((c >= u'a' && c <= u'z') ||
                 (c >= u'A' && c <= u'Z') ||
                 (c >= u'0' && c <= u'9')) {
             continue;
         }

         bool match = false;
         for (char i : allowedChars) {
             if (c == i) {
                 match = true;
                 break;
             }
         }

         if (!match) {
             return iter;
         }
     }
     return endIter;
 }

 bool isJavaClassName(const StringPiece& str) {
     size_t pieces = 0;
     for (const StringPiece& piece : tokenize(str, '.')) {
         pieces++;
         if (piece.empty()) {
             return false;
         }

         // Can't have starting or trailing $ character.
         if (piece.data()[0] == '$' || piece.data()[piece.size() - 1] == '$') {
             return false;
         }

         if (findNonAlphaNumericAndNotInSet(piece, "$_") != piece.end()) {
             return false;
         }
     }
     return pieces >= 2;
 }

 bool isJavaPackageName(const StringPiece& str) {
     if (str.empty()) {
         return false;
     }

     size_t pieces = 0;
     for (const StringPiece& piece : tokenize(str, '.')) {
         pieces++;
         if (piece.empty()) {
             return false;
         }

         if (piece.data()[0] == '_' || piece.data()[piece.size() - 1] == '_') {
             return false;
         }

         if (findNonAlphaNumericAndNotInSet(piece, "_") != piece.end()) {
             return false;
         }
     }
     return pieces >= 1;
 }

 Maybe<std::string> getFullyQualifiedClassName(const StringPiece& package,
                                               const StringPiece& className) {
     if (className.empty()) {
         return {};
     }

     if (util::isJavaClassName(className)) {
         return className.toString();
     }

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

     std::string result(package.data(), package.size());
     if (className.data()[0] != '.') {
         result += '.';
     }

     result.append(className.data(), className.size());
     if (!isJavaClassName(result)) {
         return {};
     }
     return result;
 }

 static size_t consumeDigits(const char* start, const char* end) {
     const char* c = start;
     for (; c != end && *c >= '0' && *c <= '9'; c++) {}
     return static_cast<size_t>(c - start);
 }

 bool verifyJavaStringFormat(const StringPiece& str) {
     const char* c = str.begin();
     const char* const end = str.end();

     size_t argCount = 0;
     bool nonpositional = false;
     while (c != end) {
         if (*c == '%' && c + 1 < end) {
             c++;

             if (*c == '%') {
                 c++;
                 continue;
             }

             argCount++;

             size_t numDigits = consumeDigits(c, end);
             if (numDigits > 0) {
                 c += numDigits;
                 if (c != end && *c != '$') {
                     // The digits were a size, but not a positional argument.
                     nonpositional = true;
                 }
             } else if (*c == '<') {
                 // Reusing last argument, bad idea since positions can be moved around
                 // during translation.
                 nonpositional = true;

                 c++;

                 // Optionally we can have a $ after
                 if (c != end && *c == '$') {
                     c++;
                 }
             } else {
                 nonpositional = true;
             }

             // Ignore size, width, flags, etc.
             while (c != end && (*c == '-' ||
                     *c == '#' ||
                     *c == '+' ||
                     *c == ' ' ||
                     *c == ',' ||
                     *c == '(' ||
                     (*c >= '0' && *c <= '9'))) {
                 c++;
             }

             /*
              * This is a shortcut to detect strings that are going to Time.format()
              * instead of String.format()
              *
              * Comparison of String.format() and Time.format() args:
              *
              * String: ABC E GH  ST X abcdefgh  nost x
              *   Time:    DEFGHKMS W Za  d   hkm  s w yz
              *
              * Therefore we know it's definitely Time if we have:
              *     DFKMWZkmwyz
              */
             if (c != end) {
                 switch (*c) {
                 case 'D':
                 case 'F':
                 case 'K':
                 case 'M':
                 case 'W':
                 case 'Z':
                 case 'k':
                 case 'm':
                 case 'w':
                 case 'y':
                 case 'z':
                     return true;
                 }
             }
         }

         if (c != end) {
             c++;
         }
     }

     if (argCount > 1 && nonpositional) {
         // Multiple arguments were specified, but some or all were non positional. Translated
         // strings may rearrange the order of the arguments, which will break the string.
         return false;
     }
     return true;
 }

 static Maybe<std::string> parseUnicodeCodepoint(const char** start, const char* end) {
     char32_t code = 0;
     for (size_t i = 0; i < 4 && *start != end; i++, (*start)++) {
         char c = **start;
         char32_t a;
         if (c >= '0' && c <= '9') {
             a = c - '0';
         } else if (c >= 'a' && c <= 'f') {
             a = c - 'a' + 10;
         } else if (c >= 'A' && c <= 'F') {
             a = c - 'A' + 10;
         } else {
             return {};
         }
         code = (code << 4) | a;
     }

     ssize_t len = utf32_to_utf8_length(&code, 1);
     if (len < 0) {
         return {};
     }

     std::string resultUtf8;
     resultUtf8.resize(len);
     utf32_to_utf8(&code, 1, &*resultUtf8.begin(), len + 1);
     return resultUtf8;
 }

 StringBuilder& StringBuilder::append(const StringPiece& str) {
     if (!mError.empty()) {
         return *this;
     }

     const char* const end = str.end();
     const char* start = str.begin();
     const char* current = start;
     while (current != end) {
         if (mLastCharWasEscape) {
             switch (*current) {
                 case 't':
                     mStr += '\t';
                     break;
                 case 'n':
                     mStr += '\n';
                     break;
                 case '#':
                     mStr += '#';
                     break;
                 case '@':
                     mStr += '@';
                     break;
                 case '?':
                     mStr += '?';
                     break;
                 case '"':
                     mStr += '"';
                     break;
                 case '\'':
                     mStr += '\'';
                     break;
                 case '\\':
                     mStr += '\\';
                     break;
                 case 'u': {
                     current++;
                     Maybe<std::string> c = parseUnicodeCodepoint(&current, end);
                     if (!c) {
                         mError = "invalid unicode escape sequence";
                         return *this;
                     }
                     mStr += c.value();
                     current -= 1;
                     break;
                 }

                 default:
                     // Ignore.
                     break;
             }
             mLastCharWasEscape = false;
             start = current + 1;
         } else if (*current == '"') {
             if (!mQuote && mTrailingSpace) {
                 // We found an opening quote, and we have
                 // trailing space, so we should append that
                 // space now.
                 if (mTrailingSpace) {
                     // We had trailing whitespace, so
                     // replace with a single space.
                     if (!mStr.empty()) {
                         mStr += ' ';
                     }
                     mTrailingSpace = false;
                 }
             }
             mQuote = !mQuote;
             mStr.append(start, current - start);
             start = current + 1;
         } else if (*current == '\'' && !mQuote) {
             // This should be escaped.
             mError = "unescaped apostrophe";
             return *this;
         } else if (*current == '\\') {
             // This is an escape sequence, convert to the real value.
             if (!mQuote && mTrailingSpace) {
                 // We had trailing whitespace, so
                 // replace with a single space.
                 if (!mStr.empty()) {
                     mStr += ' ';
                 }
                 mTrailingSpace = false;
             }
             mStr.append(start, current - start);
             start = current + 1;
             mLastCharWasEscape = true;
         } else if (!mQuote) {
             // This is not quoted text, so look for whitespace.
             if (isspace(*current)) {
                 // We found whitespace, see if we have seen some
                 // before.
                 if (!mTrailingSpace) {
                     // We didn't see a previous adjacent space,
                     // so mark that we did.
                     mTrailingSpace = true;
                     mStr.append(start, current - start);
                 }

                 // Keep skipping whitespace.
                 start = current + 1;
             } else if (mTrailingSpace) {
                 // We saw trailing space before, so replace all
                 // that trailing space with one space.
                 if (!mStr.empty()) {
                     mStr += ' ';
                 }
                 mTrailingSpace = false;
             }
         }
         current++;
     }
     mStr.append(start, end - start);
     return *this;
 }

 std::u16string utf8ToUtf16(const StringPiece& utf8) {
     ssize_t utf16Length = utf8_to_utf16_length(reinterpret_cast<const uint8_t*>(utf8.data()),
             utf8.length());
     if (utf16Length <= 0) {
         return {};
     }

     std::u16string utf16;
     utf16.resize(utf16Length);
     utf8_to_utf16(reinterpret_cast<const uint8_t*>(utf8.data()), utf8.length(), &*utf16.begin());
     return utf16;
 }

 std::string utf16ToUtf8(const StringPiece16& utf16) {
     ssize_t utf8Length = utf16_to_utf8_length(utf16.data(), utf16.length());
     if (utf8Length <= 0) {
         return {};
     }

     std::string utf8;
     utf8.resize(utf8Length);
     utf16_to_utf8(utf16.data(), utf16.length(), &*utf8.begin(), utf8Length + 1);
     return utf8;
 }

 bool writeAll(std::ostream& out, const BigBuffer& buffer) {
     for (const auto& b : buffer) {
         if (!out.write(reinterpret_cast<const char*>(b.buffer.get()), b.size)) {
             return false;
         }
     }
     return true;
 }

 std::unique_ptr<uint8_t[]> copy(const BigBuffer& buffer) {
     std::unique_ptr<uint8_t[]> data = std::unique_ptr<uint8_t[]>(new uint8_t[buffer.size()]);
     uint8_t* p = data.get();
     for (const auto& block : buffer) {
         memcpy(p, block.buffer.get(), block.size);
         p += block.size;
     }
     return data;
 }

 typename Tokenizer::iterator& Tokenizer::iterator::operator++() {
     const char* start = mToken.end();
     const char* end = mStr.end();
     if (start == end) {
         mEnd = true;
         mToken.assign(mToken.end(), 0);
         return *this;
     }

     start += 1;
     const char* current = start;
     while (current != end) {
         if (*current == mSeparator) {
             mToken.assign(start, current - start);
             return *this;
         }
         ++current;
     }
     mToken.assign(start, end - start);
     return *this;
 }

 bool Tokenizer::iterator::operator==(const iterator& rhs) const {
     // We check equality here a bit differently.
     // We need to know that the addresses are the same.
     return mToken.begin() == rhs.mToken.begin() && mToken.end() == rhs.mToken.end() &&
             mEnd == rhs.mEnd;
 }

 bool Tokenizer::iterator::operator!=(const iterator& rhs) const {
     return !(*this == rhs);
 }

 Tokenizer::iterator::iterator(StringPiece s, char sep, StringPiece tok, bool end) :
         mStr(s), mSeparator(sep), mToken(tok), mEnd(end) {
 }

 Tokenizer::Tokenizer(StringPiece str, char sep) :
         mBegin(++iterator(str, sep, StringPiece(str.begin() - 1, 0), false)),
         mEnd(str, sep, StringPiece(str.end(), 0), true) {
 }

 bool extractResFilePathParts(const StringPiece& path, StringPiece* outPrefix,
                              StringPiece* outEntry, StringPiece* outSuffix) {
     const StringPiece resPrefix("res/");
     if (!stringStartsWith(path, resPrefix)) {
         return false;
     }

     StringPiece::const_iterator lastOccurence = path.end();
     for (auto iter = path.begin() + resPrefix.size(); iter != path.end(); ++iter) {
         if (*iter == '/') {
             lastOccurence = iter;
         }
     }

     if (lastOccurence == path.end()) {
         return false;
     }

     auto iter = std::find(lastOccurence, path.end(), '.');
     *outSuffix = StringPiece(iter, path.end() - iter);
     *outEntry = StringPiece(lastOccurence + 1, iter - lastOccurence - 1);
     *outPrefix = StringPiece(path.begin(), lastOccurence - path.begin() + 1);
     return true;
 }

 StringPiece16 getString16(const android::ResStringPool& pool, size_t idx) {
     size_t len;
     const char16_t* str = pool.stringAt(idx, &len);
     if (str != nullptr) {
         return StringPiece16(str, len);
     }
     return StringPiece16();
 }

 std::string getString(const android::ResStringPool& pool, size_t idx) {
     size_t len;
     const char* str = pool.string8At(idx, &len);
     if (str != nullptr) {
         return std::string(str, len);
     }
     return utf16ToUtf8(getString16(pool, idx));
 }

 } // namespace util
 } // 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 "util/BigBuffer.h"
	#include "util/Maybe.h"
	#include "util/StringPiece.h"
	#include "util/Util.h"

	#include <algorithm>
	#include <ostream>
	#include <string>
	#include <utils/Unicode.h>
	#include <vector>

	namespace aapt {
	namespace util {

	static std::vector<std::string> splitAndTransform(const StringPiece& str, char sep,
	const std::function<char(char)>& f) {
	std::vector<std::string> parts;
	const StringPiece::const_iterator end = std::end(str);
	StringPiece::const_iterator start = std::begin(str);
	StringPiece::const_iterator current;
	do {
	current = std::find(start, end, sep);
	parts.emplace_back(str.substr(start, current).toString());
	if (f) {
	std::string& part = parts.back();
	std::transform(part.begin(), part.end(), part.begin(), f);
	}
	start = current + 1;
	} while (current != end);
	return parts;
	}

	std::vector<std::string> split(const StringPiece& str, char sep) {
	return splitAndTransform(str, sep, nullptr);
	}

	std::vector<std::string> splitAndLowercase(const StringPiece& str, char sep) {
	return splitAndTransform(str, sep, ::tolower);
	}

	bool stringStartsWith(const StringPiece& str, const StringPiece& prefix) {
	if (str.size() < prefix.size()) {
	return false;
	}
	return str.substr(0, prefix.size()) == prefix;
	}

	bool stringEndsWith(const StringPiece& str, const StringPiece& suffix) {
	if (str.size() < suffix.size()) {
	return false;
	}
	return str.substr(str.size() - suffix.size(), suffix.size()) == suffix;
	}

	StringPiece trimWhitespace(const StringPiece& str) {
	if (str.size() == 0 \|\| str.data() == nullptr) {
	return str;
	}

	const char* start = str.data();
	const char* end = str.data() + str.length();

	while (start != end && isspace(*start)) {
	start++;
	}

	while (end != start && isspace(*(end - 1))) {
	end--;
	}

	return StringPiece(start, end - start);
	}

	StringPiece::const_iterator findNonAlphaNumericAndNotInSet(const StringPiece& str,
	const StringPiece& allowedChars) {
	const auto endIter = str.end();
	for (auto iter = str.begin(); iter != endIter; ++iter) {
	char c = *iter;
	if ((c >= u'a' && c <= u'z') \|\|
	(c >= u'A' && c <= u'Z') \|\|
	(c >= u'0' && c <= u'9')) {
	continue;
	}

	bool match = false;
	for (char i : allowedChars) {
	if (c == i) {
	match = true;
	break;
	}
	}

	if (!match) {
	return iter;
	}
	}
	return endIter;
	}

	bool isJavaClassName(const StringPiece& str) {
	size_t pieces = 0;
	for (const StringPiece& piece : tokenize(str, '.')) {
	pieces++;
	if (piece.empty()) {
	return false;
	}

	// Can't have starting or trailing $ character.
	if (piece.data()[0] == '$' \|\| piece.data()[piece.size() - 1] == '$') {
	return false;
	}

	if (findNonAlphaNumericAndNotInSet(piece, "$_") != piece.end()) {
	return false;
	}
	}
	return pieces >= 2;
	}

	bool isJavaPackageName(const StringPiece& str) {
	if (str.empty()) {
	return false;
	}

	size_t pieces = 0;
	for (const StringPiece& piece : tokenize(str, '.')) {
	pieces++;
	if (piece.empty()) {
	return false;
	}

	if (piece.data()[0] == '_' \|\| piece.data()[piece.size() - 1] == '_') {
	return false;
	}

	if (findNonAlphaNumericAndNotInSet(piece, "_") != piece.end()) {
	return false;
	}
	}
	return pieces >= 1;
	}

	Maybe<std::string> getFullyQualifiedClassName(const StringPiece& package,
	const StringPiece& className) {
	if (className.empty()) {
	return {};
	}

	if (util::isJavaClassName(className)) {
	return className.toString();
	}

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

	std::string result(package.data(), package.size());
	if (className.data()[0] != '.') {
	result += '.';
	}

	result.append(className.data(), className.size());
	if (!isJavaClassName(result)) {
	return {};
	}
	return result;
	}

	static size_t consumeDigits(const char* start, const char* end) {
	const char* c = start;
	for (; c != end && c >= '0' && c <= '9'; c++) {}
	return static_cast<size_t>(c - start);
	}

	bool verifyJavaStringFormat(const StringPiece& str) {
	const char* c = str.begin();
	const char* const end = str.end();

	size_t argCount = 0;
	bool nonpositional = false;
	while (c != end) {
	if (*c == '%' && c + 1 < end) {
	c++;

	if (*c == '%') {
	c++;
	continue;
	}

	argCount++;

	size_t numDigits = consumeDigits(c, end);
	if (numDigits > 0) {
	c += numDigits;
	if (c != end && *c != '$') {
	// The digits were a size, but not a positional argument.
	nonpositional = true;
	}
	} else if (*c == '<') {
	// Reusing last argument, bad idea since positions can be moved around
	// during translation.
	nonpositional = true;

	c++;

	// Optionally we can have a $ after
	if (c != end && *c == '$') {
	c++;
	}
	} else {
	nonpositional = true;
	}

	// Ignore size, width, flags, etc.
	while (c != end && (*c == '-' \|\|
	*c == '#' \|\|
	*c == '+' \|\|
	*c == ' ' \|\|
	*c == ',' \|\|
	*c == '(' \|\|
	(c >= '0' && c <= '9'))) {
	c++;
	}

	/*
	* This is a shortcut to detect strings that are going to Time.format()
	* instead of String.format()
	*
	* Comparison of String.format() and Time.format() args:
	*
	* String: ABC E GH ST X abcdefgh nost x
	* Time: DEFGHKMS W Za d hkm s w yz
	*
	* Therefore we know it's definitely Time if we have:
	* DFKMWZkmwyz
	*/
	if (c != end) {
	switch (*c) {
	case 'D':
	case 'F':
	case 'K':
	case 'M':
	case 'W':
	case 'Z':
	case 'k':
	case 'm':
	case 'w':
	case 'y':
	case 'z':
	return true;
	}
	}
	}

	if (c != end) {
	c++;
	}
	}

	if (argCount > 1 && nonpositional) {
	// Multiple arguments were specified, but some or all were non positional. Translated
	// strings may rearrange the order of the arguments, which will break the string.
	return false;
	}
	return true;
	}

	static Maybe<std::string> parseUnicodeCodepoint(const char** start, const char* end) {
	char32_t code = 0;
	for (size_t i = 0; i < 4 && start != end; i++, (start)++) {
	char c = **start;
	char32_t a;
	if (c >= '0' && c <= '9') {
	a = c - '0';
	} else if (c >= 'a' && c <= 'f') {
	a = c - 'a' + 10;
	} else if (c >= 'A' && c <= 'F') {
	a = c - 'A' + 10;
	} else {
	return {};
	}
	code = (code << 4) \| a;
	}

	ssize_t len = utf32_to_utf8_length(&code, 1);
	if (len < 0) {
	return {};
	}

	std::string resultUtf8;
	resultUtf8.resize(len);
	utf32_to_utf8(&code, 1, &*resultUtf8.begin(), len + 1);
	return resultUtf8;
	}

	StringBuilder& StringBuilder::append(const StringPiece& str) {
	if (!mError.empty()) {
	return *this;
	}

	const char* const end = str.end();
	const char* start = str.begin();
	const char* current = start;
	while (current != end) {
	if (mLastCharWasEscape) {
	switch (*current) {
	case 't':
	mStr += '\t';
	break;
	case 'n':
	mStr += '\n';
	break;
	case '#':
	mStr += '#';
	break;
	case '@':
	mStr += '@';
	break;
	case '?':
	mStr += '?';
	break;
	case '"':
	mStr += '"';
	break;
	case '\'':
	mStr += '\'';
	break;
	case '\\':
	mStr += '\\';
	break;
	case 'u': {
	current++;
	Maybe<std::string> c = parseUnicodeCodepoint(&current, end);
	if (!c) {
	mError = "invalid unicode escape sequence";
	return *this;
	}
	mStr += c.value();
	current -= 1;
	break;
	}

	default:
	// Ignore.
	break;
	}
	mLastCharWasEscape = false;
	start = current + 1;
	} else if (*current == '"') {
	if (!mQuote && mTrailingSpace) {
	// We found an opening quote, and we have
	// trailing space, so we should append that
	// space now.
	if (mTrailingSpace) {
	// We had trailing whitespace, so
	// replace with a single space.
	if (!mStr.empty()) {
	mStr += ' ';
	}
	mTrailingSpace = false;
	}
	}
	mQuote = !mQuote;
	mStr.append(start, current - start);
	start = current + 1;
	} else if (*current == '\'' && !mQuote) {
	// This should be escaped.
	mError = "unescaped apostrophe";
	return *this;
	} else if (*current == '\\') {
	// This is an escape sequence, convert to the real value.
	if (!mQuote && mTrailingSpace) {
	// We had trailing whitespace, so
	// replace with a single space.
	if (!mStr.empty()) {
	mStr += ' ';
	}
	mTrailingSpace = false;
	}
	mStr.append(start, current - start);
	start = current + 1;
	mLastCharWasEscape = true;
	} else if (!mQuote) {
	// This is not quoted text, so look for whitespace.
	if (isspace(*current)) {
	// We found whitespace, see if we have seen some
	// before.
	if (!mTrailingSpace) {
	// We didn't see a previous adjacent space,
	// so mark that we did.
	mTrailingSpace = true;
	mStr.append(start, current - start);
	}

	// Keep skipping whitespace.
	start = current + 1;
	} else if (mTrailingSpace) {
	// We saw trailing space before, so replace all
	// that trailing space with one space.
	if (!mStr.empty()) {
	mStr += ' ';
	}
	mTrailingSpace = false;
	}
	}
	current++;
	}
	mStr.append(start, end - start);
	return *this;
	}

	std::u16string utf8ToUtf16(const StringPiece& utf8) {
	ssize_t utf16Length = utf8_to_utf16_length(reinterpret_cast<const uint8_t*>(utf8.data()),
	utf8.length());
	if (utf16Length <= 0) {
	return {};
	}

	std::u16string utf16;
	utf16.resize(utf16Length);
	utf8_to_utf16(reinterpret_cast<const uint8_t>(utf8.data()), utf8.length(), &utf16.begin());
	return utf16;
	}

	std::string utf16ToUtf8(const StringPiece16& utf16) {
	ssize_t utf8Length = utf16_to_utf8_length(utf16.data(), utf16.length());
	if (utf8Length <= 0) {
	return {};
	}

	std::string utf8;
	utf8.resize(utf8Length);
	utf16_to_utf8(utf16.data(), utf16.length(), &*utf8.begin(), utf8Length + 1);
	return utf8;
	}

	bool writeAll(std::ostream& out, const BigBuffer& buffer) {
	for (const auto& b : buffer) {
	if (!out.write(reinterpret_cast<const char*>(b.buffer.get()), b.size)) {
	return false;
	}
	}
	return true;
	}

	std::unique_ptr<uint8_t[]> copy(const BigBuffer& buffer) {
	std::unique_ptr<uint8_t[]> data = std::unique_ptr<uint8_t[]>(new uint8_t[buffer.size()]);
	uint8_t* p = data.get();
	for (const auto& block : buffer) {
	memcpy(p, block.buffer.get(), block.size);
	p += block.size;
	}
	return data;
	}

	typename Tokenizer::iterator& Tokenizer::iterator::operator++() {
	const char* start = mToken.end();
	const char* end = mStr.end();
	if (start == end) {
	mEnd = true;
	mToken.assign(mToken.end(), 0);
	return *this;
	}

	start += 1;
	const char* current = start;
	while (current != end) {
	if (*current == mSeparator) {
	mToken.assign(start, current - start);
	return *this;
	}
	++current;
	}
	mToken.assign(start, end - start);
	return *this;
	}

	bool Tokenizer::iterator::operator==(const iterator& rhs) const {
	// We check equality here a bit differently.
	// We need to know that the addresses are the same.
	return mToken.begin() == rhs.mToken.begin() && mToken.end() == rhs.mToken.end() &&
	mEnd == rhs.mEnd;
	}

	bool Tokenizer::iterator::operator!=(const iterator& rhs) const {
	return !(*this == rhs);
	}

	Tokenizer::iterator::iterator(StringPiece s, char sep, StringPiece tok, bool end) :
	mStr(s), mSeparator(sep), mToken(tok), mEnd(end) {
	}

	Tokenizer::Tokenizer(StringPiece str, char sep) :
	mBegin(++iterator(str, sep, StringPiece(str.begin() - 1, 0), false)),
	mEnd(str, sep, StringPiece(str.end(), 0), true) {
	}

	bool extractResFilePathParts(const StringPiece& path, StringPiece* outPrefix,
	StringPiece* outEntry, StringPiece* outSuffix) {
	const StringPiece resPrefix("res/");
	if (!stringStartsWith(path, resPrefix)) {
	return false;
	}

	StringPiece::const_iterator lastOccurence = path.end();
	for (auto iter = path.begin() + resPrefix.size(); iter != path.end(); ++iter) {
	if (*iter == '/') {
	lastOccurence = iter;
	}
	}

	if (lastOccurence == path.end()) {
	return false;
	}

	auto iter = std::find(lastOccurence, path.end(), '.');
	*outSuffix = StringPiece(iter, path.end() - iter);
	*outEntry = StringPiece(lastOccurence + 1, iter - lastOccurence - 1);
	*outPrefix = StringPiece(path.begin(), lastOccurence - path.begin() + 1);
	return true;
	}

	StringPiece16 getString16(const android::ResStringPool& pool, size_t idx) {
	size_t len;
	const char16_t* str = pool.stringAt(idx, &len);
	if (str != nullptr) {
	return StringPiece16(str, len);
	}
	return StringPiece16();
	}

	std::string getString(const android::ResStringPool& pool, size_t idx) {
	size_t len;
	const char* str = pool.string8At(idx, &len);
	if (str != nullptr) {
	return std::string(str, len);
	}
	return utf16ToUtf8(getString16(pool, idx));
	}

	} // namespace util
	} // namespace aapt