Issue-2434: Refactored string_to_name(str) in name.hpp

libraries/chain/include/eosio/chain/name.hpp

@@ -14,29 +14,28 @@ namespace eosio { namespace chain {
       return 0;
    }
 
-   static constexpr uint64_t string_to_name( const char* str ) {
-
-      uint32_t len = 0;
-      while( str[len] ) ++len;
-
-      uint64_t value = 0;
-
-      for( uint32_t i = 0; i <= 12; ++i ) {
-         uint64_t c = 0;
-         if( i < len && i <= 12 ) c = char_to_symbol( str[i] );
-
-         if( i < 12 ) {
-            c &= 0x1f;
-            c <<= 64-5*(i+1);
-         }
-         else {
-            c &= 0x0f;
-         }
-
-         value |= c;
+   // Each char of the string is encoded into 5-bit chunk and left-shifted
+   // to its 5-bit slot starting with the highest slot for the first char.
+   // The 13th char, if str is long enough, is encoded into 4-bit chunk
+   // and placed in the lowest 4 bits. 64 = 12 * 5 + 4
+   static constexpr uint64_t string_to_name( const char* str )
+   {
+      uint64_t name = 0;
+      int i;
+      for (i = 0; str[i] && i < 12; ++i) {
+         // Retrieve the encoding of str[i] (see 'charmap'
+         // operator string() method, in the .cpp file) and left-shift it
+         // to the 5-bit slot corresponding to the str[i] ordinal counted
+         // counted from the top, down.
+          name |= char_to_symbol(str[i]) << (64 - 5 * (i + 1));
       }
 
-      return value;
+      // The for-loop encoded up to 60 high bits into uint64 'name' variable,
+      // if (strlen(str) > 12) then encode str[12] into the low (remaining)
+      // 4 bits of 'name'
+      if (i == 12)
+          name |= char_to_symbol(str[12]) & 0x0F;
+      return name;
    }
 
 #define N(X) eosio::chain::string_to_name(#X)