Home | History | Annotate | Download | only in minikin 
      1 /*
      2  * Copyright (C) 2017 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 MINIKIN_STRING_PIECE_H
     18 #define MINIKIN_STRING_PIECE_H
     19 
     20 #include <cstdint>
     21 #include <string>
     22 #include <vector>
     23 
     24 namespace minikin {
     25 
     26 class StringPiece {
     27 public:
     28     StringPiece() : mData(nullptr), mLength(0) {}
     29     StringPiece(const char* data) : mData(data), mLength(data == nullptr ? 0 : strlen(data)) {}
     30     StringPiece(const char* data, size_t length) : mData(data), mLength(length) {}
     31     StringPiece(const std::string& str) : mData(str.data()), mLength(str.size()) {}
     32 
     33     inline const char* data() const { return mData; }
     34     inline size_t length() const { return mLength; }
     35     inline size_t size() const { return mLength; }
     36     inline bool empty() const { return mLength == 0; }
     37 
     38     inline char operator[](size_t i) const { return mData[i]; }
     39 
     40     inline StringPiece substr(size_t from, size_t length) const {
     41         return StringPiece(mData + from, length);
     42     }
     43 
     44     inline size_t find(size_t from, char c) const {
     45         if (from >= mLength) {
     46             return mLength;
     47         }
     48         const char* p = static_cast<const char*>(memchr(mData + from, c, mLength - from));
     49         return p == nullptr ? mLength : p - mData;
     50     }
     51 
     52     std::string toString() const { return std::string(mData, mData + mLength); }
     53 
     54 private:
     55     const char* mData;
     56     size_t mLength;
     57 };
     58 
     59 inline bool operator==(const StringPiece& l, const StringPiece& r) {
     60     const size_t len = l.size();
     61     if (len != r.size()) {
     62         return false;
     63     }
     64     const char* lData = l.data();
     65     const char* rData = r.data();
     66     if (lData == rData) {
     67         return true;
     68     }
     69     return memcmp(lData, rData, len) == 0;
     70 }
     71 
     72 inline bool operator==(const StringPiece& l, const char* s) {
     73     const size_t len = l.size();
     74     if (len != strlen(s)) {
     75         return false;
     76     }
     77     return memcmp(l.data(), s, len) == 0;
     78 }
     79 
     80 inline bool operator!=(const StringPiece& l, const StringPiece& r) {
     81     return !(l == r);
     82 }
     83 
     84 inline bool operator!=(const StringPiece& l, const char* s) {
     85     return !(l == s);
     86 }
     87 
     88 class SplitIterator {
     89 public:
     90     SplitIterator(const StringPiece& string, char delimiter)
     91             : mStarted(false), mCurrent(0), mString(string), mDelimiter(delimiter) {}
     92 
     93     inline StringPiece next() {
     94         if (!hasNext()) {
     95             return StringPiece();
     96         }
     97         const size_t searchFrom = mStarted ? mCurrent + 1 : 0;
     98         mStarted = true;
     99         mCurrent = mString.find(searchFrom, mDelimiter);
    100         return mString.substr(searchFrom, mCurrent - searchFrom);
    101     }
    102     inline bool hasNext() const { return mCurrent < mString.size(); }
    103 
    104 private:
    105     bool mStarted;
    106     size_t mCurrent;
    107     StringPiece mString;
    108     char mDelimiter;
    109 };
    110 
    111 }  // namespace minikin
    112 
    113 #endif  // MINIKIN_STRING_PIECE_H
    114