[GitHub] [incubator-pegasus] empiredan opened a new issue, #1239: Refactor: improve split_args for strings

[GitBox <gi...@apache.org>]

empiredan opened a new issue, #1239:
URL: https://github.com/apache/incubator-pegasus/issues/1239

   While analyzing the code of `split_args` and `trim_string`, some problems could be found.
   
   - Both `std::string v(args)` and `v.substr(...)` will copy string, which will lead to overhead for performance.
   - In `trim_string`, all trailing spaces will be updated with `\0`, which is unnecessary.
   
   Based on the above problems, I think we can improve `split_args`.
   
   The code of current `split_args` and `trim_string` are listed as below:
   
   ```c++
   void split_args(const char *args,
                   /*out*/ std::vector<std::string> &sargs,
                   char splitter,
                   bool keep_place_holder)
   {
       sargs.clear();
       std::string v(args);
       uint64_t last_pos = 0;
       while (true) {
           auto pos = v.find(splitter, last_pos);
           if (pos != std::string::npos) {
               std::string s = trim_string((char *)v.substr(last_pos, pos - last_pos).c_str());
               if (!s.empty()) {
                   sargs.push_back(s);
               } else if (keep_place_holder) {
                   sargs.emplace_back("");
               }
               last_pos = pos + 1;
           } else {
               std::string s = trim_string((char *)v.substr(last_pos).c_str());
               if (!s.empty()) {
                   sargs.push_back(s);
               } else if (keep_place_holder) {
                   sargs.emplace_back("");
               }
               break;
           }
       }
   }
   ```
   
   ```c++
   char *trim_string(char *s)
   {
       while (*s != '\0' && (*s == ' ' || *s == '\t')) {
           s++;
       }
       char *r = s;
       s += strlen(s);
       while (s >= r && (*s == '\0' || *s == ' ' || *s == '\t' || *s == '\r' || *s == '\n')) {
           *s = '\0';
           s--;
       }
       return r;
   }
   ```


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[GitHub] [incubator-pegasus] empiredan closed issue #1239: Refactor: improve split_args for strings

[GitBox <gi...@apache.org>]

empiredan closed issue #1239: Refactor: improve split_args for strings
URL: https://github.com/apache/incubator-pegasus/issues/1239


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