Derive string size constants...

src/objects.h

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4052 matching lines @@
   void StringPrint();
   void StringVerify();
 #endif
   inline bool IsFlat();
 
   // Layout description.
   static const int kLengthOffset = HeapObject::kHeaderSize;
   static const int kSize = kLengthOffset + kIntSize;
   // Notice: kSize is not pointer-size aligned if pointers are 64-bit.
 
-  // Limits on sizes of different types of strings.
-  static const int kMaxShortStringSize = 63;
-  static const int kMaxMediumStringSize = 16383;
-
+  // Maximum number of characters to consider when trying to convert a string
+  // value into an array index.
   static const int kMaxArrayIndexSize = 10;
 
   // Max ascii char code.
   static const int kMaxAsciiCharCode = unibrow::Utf8::kMaxOneByteChar;
   static const unsigned kMaxAsciiCharCodeU = unibrow::Utf8::kMaxOneByteChar;
   static const int kMaxUC16CharCode = 0xffff;
 
   // Minimum length for a cons or sliced string.
   static const int kMinNonFlatLength = 13;
 
   // Mask constant for checking if a string has a computed hash code
   // and if it is an array index.  The least significant bit indicates
   // whether a hash code has been computed.  If the hash code has been
   // computed the 2nd bit tells whether the string can be used as an
   // array index.
   static const int kHashComputedMask = 1;
   static const int kIsArrayIndexMask = 1 << 1;
   static const int kNofLengthBitFields = 2;
 
   // Array index strings this short can keep their index in the hash
   // field.
   static const int kMaxCachedArrayIndexLength = 7;
 
-  // Shift constants for retriving length and hash code from
+  // Shift constants for retrieving length and hash code from
   // length/hash field.
   static const int kHashShift = kNofLengthBitFields;
   static const int kShortLengthShift = kHashShift + kShortStringTag;
   static const int kMediumLengthShift = kHashShift + kMediumStringTag;
   static const int kLongLengthShift = kHashShift + kLongStringTag;
-  // Maximal string length that can be stored in the hash/length field.
+
+  // Maximal string length that can be stored in the hash/length field for
+  // different types of strings.
+  static const int kMaxShortSize = (1 << (32 - kShortLengthShift)) - 1;
+  static const int kMaxMediumSize = (1 << (32 - kMediumLengthShift)) - 1;
   static const int kMaxLength = (1 << (32 - kLongLengthShift)) - 1;
 
   // Limit for truncation in short printing.
   static const int kMaxShortPrintLength = 1024;
 
   // Support for regular expressions.
   const uc16* GetTwoByteData();
   const uc16* GetTwoByteData(unsigned start);
 
   // Support for StringInputBuffer
@@ skipping 1027 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_