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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef AAPT_UTIL_H
     18 #define AAPT_UTIL_H
     19 
     20 #include "util/BigBuffer.h"
     21 #include "util/Maybe.h"
     22 #include "util/StringPiece.h"
     23 
     24 #include <androidfw/ResourceTypes.h>
     25 #include <functional>
     26 #include <memory>
     27 #include <ostream>
     28 #include <string>
     29 #include <vector>
     30 
     31 namespace aapt {
     32 namespace util {
     33 
     34 std::vector<std::string> split(const StringPiece& str, char sep);
     35 std::vector<std::string> splitAndLowercase(const StringPiece& str, char sep);
     36 
     37 /**
     38  * Returns true if the string starts with prefix.
     39  */
     40 template <typename T>
     41 bool stringStartsWith(const BasicStringPiece<T>& str, const BasicStringPiece<T>& prefix) {
     42     if (str.size() < prefix.size()) {
     43         return false;
     44     }
     45     return str.substr(0, prefix.size()) == prefix;
     46 }
     47 
     48 /**
     49  * Returns true if the string ends with suffix.
     50  */
     51 template <typename T>
     52 bool stringEndsWith(const BasicStringPiece<T>& str, const BasicStringPiece<T>& suffix) {
     53     if (str.size() < suffix.size()) {
     54         return false;
     55     }
     56     return str.substr(str.size() - suffix.size(), suffix.size()) == suffix;
     57 }
     58 
     59 /**
     60  * Creates a new StringPiece16 that points to a substring
     61  * of the original string without leading or trailing whitespace.
     62  */
     63 StringPiece16 trimWhitespace(const StringPiece16& str);
     64 
     65 StringPiece trimWhitespace(const StringPiece& str);
     66 
     67 /**
     68  * UTF-16 isspace(). It basically checks for lower range characters that are
     69  * whitespace.
     70  */
     71 inline bool isspace16(char16_t c) {
     72     return c < 0x0080 && isspace(c);
     73 }
     74 
     75 /**
     76  * Returns an iterator to the first character that is not alpha-numeric and that
     77  * is not in the allowedChars set.
     78  */
     79 StringPiece16::const_iterator findNonAlphaNumericAndNotInSet(const StringPiece16& str,
     80         const StringPiece16& allowedChars);
     81 
     82 /**
     83  * Tests that the string is a valid Java class name.
     84  */
     85 bool isJavaClassName(const StringPiece16& str);
     86 
     87 /**
     88  * Tests that the string is a valid Java package name.
     89  */
     90 bool isJavaPackageName(const StringPiece16& str);
     91 
     92 /**
     93  * Converts the class name to a fully qualified class name from the given `package`. Ex:
     94  *
     95  * asdf         --> package.asdf
     96  * .asdf        --> package.asdf
     97  * .a.b         --> package.a.b
     98  * asdf.adsf    --> asdf.adsf
     99  */
    100 Maybe<std::u16string> getFullyQualifiedClassName(const StringPiece16& package,
    101                                                  const StringPiece16& className);
    102 
    103 
    104 /**
    105  * Makes a std::unique_ptr<> with the template parameter inferred by the compiler.
    106  * This will be present in C++14 and can be removed then.
    107  */
    108 template <typename T, class... Args>
    109 std::unique_ptr<T> make_unique(Args&&... args) {
    110     return std::unique_ptr<T>(new T{std::forward<Args>(args)...});
    111 }
    112 
    113 /**
    114  * Writes a set of items to the std::ostream, joining the times with the provided
    115  * separator.
    116  */
    117 template <typename Iterator>
    118 ::std::function<::std::ostream&(::std::ostream&)> joiner(Iterator begin, Iterator end,
    119         const char* sep) {
    120     return [begin, end, sep](::std::ostream& out) -> ::std::ostream& {
    121         for (auto iter = begin; iter != end; ++iter) {
    122             if (iter != begin) {
    123                 out << sep;
    124             }
    125             out << *iter;
    126         }
    127         return out;
    128     };
    129 }
    130 
    131 inline ::std::function<::std::ostream&(::std::ostream&)> formatSize(size_t size) {
    132     return [size](::std::ostream& out) -> ::std::ostream& {
    133         constexpr size_t K = 1024u;
    134         constexpr size_t M = K * K;
    135         constexpr size_t G = M * K;
    136         if (size < K) {
    137             out << size << "B";
    138         } else if (size < M) {
    139             out << (double(size) / K) << " KiB";
    140         } else if (size < G) {
    141             out << (double(size) / M) << " MiB";
    142         } else {
    143             out << (double(size) / G) << " GiB";
    144         }
    145         return out;
    146     };
    147 }
    148 
    149 /**
    150  * Helper method to extract a string from a StringPool.
    151  */
    152 inline StringPiece16 getString(const android::ResStringPool& pool, size_t idx) {
    153     size_t len;
    154     const char16_t* str = pool.stringAt(idx, &len);
    155     if (str != nullptr) {
    156         return StringPiece16(str, len);
    157     }
    158     return StringPiece16();
    159 }
    160 
    161 inline StringPiece getString8(const android::ResStringPool& pool, size_t idx) {
    162     size_t len;
    163     const char* str = pool.string8At(idx, &len);
    164     if (str != nullptr) {
    165         return StringPiece(str, len);
    166     }
    167     return StringPiece();
    168 }
    169 
    170 /**
    171  * Checks that the Java string format contains no non-positional arguments (arguments without
    172  * explicitly specifying an index) when there are more than one argument. This is an error
    173  * because translations may rearrange the order of the arguments in the string, which will
    174  * break the string interpolation.
    175  */
    176 bool verifyJavaStringFormat(const StringPiece16& str);
    177 
    178 class StringBuilder {
    179 public:
    180     StringBuilder& append(const StringPiece16& str);
    181     const std::u16string& str() const;
    182     const std::string& error() const;
    183     operator bool() const;
    184 
    185 private:
    186     std::u16string mStr;
    187     bool mQuote = false;
    188     bool mTrailingSpace = false;
    189     bool mLastCharWasEscape = false;
    190     std::string mError;
    191 };
    192 
    193 inline const std::u16string& StringBuilder::str() const {
    194     return mStr;
    195 }
    196 
    197 inline const std::string& StringBuilder::error() const {
    198     return mError;
    199 }
    200 
    201 inline StringBuilder::operator bool() const {
    202     return mError.empty();
    203 }
    204 
    205 /**
    206  * Converts a UTF8 string to a UTF16 string.
    207  */
    208 std::u16string utf8ToUtf16(const StringPiece& utf8);
    209 std::string utf16ToUtf8(const StringPiece16& utf8);
    210 
    211 /**
    212  * Writes the entire BigBuffer to the output stream.
    213  */
    214 bool writeAll(std::ostream& out, const BigBuffer& buffer);
    215 
    216 /*
    217  * Copies the entire BigBuffer into a single buffer.
    218  */
    219 std::unique_ptr<uint8_t[]> copy(const BigBuffer& buffer);
    220 
    221 /**
    222  * A Tokenizer implemented as an iterable collection. It does not allocate
    223  * any memory on the heap nor use standard containers.
    224  */
    225 template <typename Char>
    226 class Tokenizer {
    227 public:
    228     class iterator {
    229     public:
    230         iterator(const iterator&) = default;
    231         iterator& operator=(const iterator&) = default;
    232 
    233         iterator& operator++();
    234         BasicStringPiece<Char> operator*();
    235         bool operator==(const iterator& rhs) const;
    236         bool operator!=(const iterator& rhs) const;
    237 
    238     private:
    239         friend class Tokenizer<Char>;
    240 
    241         iterator(BasicStringPiece<Char> s, Char sep, BasicStringPiece<Char> tok, bool end);
    242 
    243         BasicStringPiece<Char> mStr;
    244         Char mSeparator;
    245         BasicStringPiece<Char> mToken;
    246         bool mEnd;
    247     };
    248 
    249     Tokenizer(BasicStringPiece<Char> str, Char sep);
    250     iterator begin();
    251     iterator end();
    252 
    253 private:
    254     const iterator mBegin;
    255     const iterator mEnd;
    256 };
    257 
    258 template <typename Char>
    259 inline Tokenizer<Char> tokenize(BasicStringPiece<Char> str, Char sep) {
    260     return Tokenizer<Char>(str, sep);
    261 }
    262 
    263 template <typename Char>
    264 typename Tokenizer<Char>::iterator& Tokenizer<Char>::iterator::operator++() {
    265     const Char* start = mToken.end();
    266     const Char* end = mStr.end();
    267     if (start == end) {
    268         mEnd = true;
    269         mToken.assign(mToken.end(), 0);
    270         return *this;
    271     }
    272 
    273     start += 1;
    274     const Char* current = start;
    275     while (current != end) {
    276         if (*current == mSeparator) {
    277             mToken.assign(start, current - start);
    278             return *this;
    279         }
    280         ++current;
    281     }
    282     mToken.assign(start, end - start);
    283     return *this;
    284 }
    285 
    286 template <typename Char>
    287 inline BasicStringPiece<Char> Tokenizer<Char>::iterator::operator*() {
    288     return mToken;
    289 }
    290 
    291 template <typename Char>
    292 inline bool Tokenizer<Char>::iterator::operator==(const iterator& rhs) const {
    293     // We check equality here a bit differently.
    294     // We need to know that the addresses are the same.
    295     return mToken.begin() == rhs.mToken.begin() && mToken.end() == rhs.mToken.end() &&
    296             mEnd == rhs.mEnd;
    297 }
    298 
    299 template <typename Char>
    300 inline bool Tokenizer<Char>::iterator::operator!=(const iterator& rhs) const {
    301     return !(*this == rhs);
    302 }
    303 
    304 template <typename Char>
    305 inline Tokenizer<Char>::iterator::iterator(BasicStringPiece<Char> s, Char sep,
    306                                            BasicStringPiece<Char> tok, bool end) :
    307         mStr(s), mSeparator(sep), mToken(tok), mEnd(end) {
    308 }
    309 
    310 template <typename Char>
    311 inline typename Tokenizer<Char>::iterator Tokenizer<Char>::begin() {
    312     return mBegin;
    313 }
    314 
    315 template <typename Char>
    316 inline typename Tokenizer<Char>::iterator Tokenizer<Char>::end() {
    317     return mEnd;
    318 }
    319 
    320 template <typename Char>
    321 inline Tokenizer<Char>::Tokenizer(BasicStringPiece<Char> str, Char sep) :
    322         mBegin(++iterator(str, sep, BasicStringPiece<Char>(str.begin() - 1, 0), false)),
    323         mEnd(str, sep, BasicStringPiece<Char>(str.end(), 0), true) {
    324 }
    325 
    326 inline uint16_t hostToDevice16(uint16_t value) {
    327     return htods(value);
    328 }
    329 
    330 inline uint32_t hostToDevice32(uint32_t value) {
    331     return htodl(value);
    332 }
    333 
    334 inline uint16_t deviceToHost16(uint16_t value) {
    335     return dtohs(value);
    336 }
    337 
    338 inline uint32_t deviceToHost32(uint32_t value) {
    339     return dtohl(value);
    340 }
    341 
    342 /**
    343  * Given a path like: res/xml-sw600dp/foo.xml
    344  *
    345  * Extracts "res/xml-sw600dp/" into outPrefix.
    346  * Extracts "foo" into outEntry.
    347  * Extracts ".xml" into outSuffix.
    348  *
    349  * Returns true if successful.
    350  */
    351 bool extractResFilePathParts(const StringPiece16& path, StringPiece16* outPrefix,
    352                              StringPiece16* outEntry, StringPiece16* outSuffix);
    353 
    354 } // namespace util
    355 
    356 /**
    357  * Stream operator for functions. Calls the function with the stream as an argument.
    358  * In the aapt namespace for lookup.
    359  */
    360 inline ::std::ostream& operator<<(::std::ostream& out,
    361                                   ::std::function<::std::ostream&(::std::ostream&)> f) {
    362     return f(out);
    363 }
    364 
    365 } // namespace aapt
    366 
    367 #endif // AAPT_UTIL_H
    368