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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 SIMPLE_PERF_BUILD_ID_H_
     18 #define SIMPLE_PERF_BUILD_ID_H_
     19 
     20 #include <string.h>
     21 #include <algorithm>
     22 #include <android-base/stringprintf.h>
     23 
     24 constexpr size_t BUILD_ID_SIZE = 20;
     25 
     26 class BuildId {
     27  public:
     28   static size_t Size() {
     29     return BUILD_ID_SIZE;
     30   }
     31 
     32   BuildId() {
     33     memset(data_, '\0', BUILD_ID_SIZE);
     34   }
     35 
     36   // Copy build id from a byte array, like {0x76, 0x00, 0x32,...}.
     37   BuildId(const void* data, size_t len) : BuildId() {
     38     memcpy(data_, data, std::min(len, BUILD_ID_SIZE));
     39   }
     40 
     41   // Read build id from a hex string, like "7600329e31058e12b145d153ef27cd40e1a5f7b9".
     42   explicit BuildId(const std::string& s) : BuildId() {
     43     for (size_t i = 0; i < s.size() && i < BUILD_ID_SIZE * 2; i += 2) {
     44       unsigned char ch = 0;
     45       for (size_t j = i; j < i + 2; ++j) {
     46         ch <<= 4;
     47         if (s[j] >= '0' && s[j] <= '9') {
     48           ch |= s[j] - '0';
     49         } else if (s[j] >= 'a' && s[j] <= 'f') {
     50           ch |= s[j] - 'a' + 10;
     51         } else if (s[j] >= 'A' && s[j] <= 'F') {
     52           ch |= s[j] - 'A' + 10;
     53         }
     54       }
     55       data_[i / 2] = ch;
     56     }
     57   }
     58 
     59   const unsigned char* Data() const {
     60     return data_;
     61   }
     62 
     63   std::string ToString() const {
     64     std::string s = "0x";
     65     for (size_t i = 0; i < BUILD_ID_SIZE; ++i) {
     66       s += android::base::StringPrintf("%02x", data_[i]);
     67     }
     68     return s;
     69   }
     70 
     71   bool operator==(const BuildId& build_id) const {
     72     return memcmp(data_, build_id.data_, BUILD_ID_SIZE) == 0;
     73   }
     74 
     75   bool operator!=(const BuildId& build_id) const {
     76     return !(*this == build_id);
     77   }
     78 
     79   bool IsEmpty() const {
     80     static BuildId empty_build_id;
     81     return *this == empty_build_id;
     82   }
     83 
     84  private:
     85   unsigned char data_[BUILD_ID_SIZE];
     86 };
     87 
     88 #endif  // SIMPLE_PERF_BUILD_ID_H_
     89