hotspot/src/share/vm/classfile/javaClasses.hpp
changeset 8885 eed0ba1d011b
parent 8725 8c1e3dd5fe1b
child 9321 c29711c6ae35
--- a/hotspot/src/share/vm/classfile/javaClasses.hpp	Thu Mar 31 02:31:57 2011 -0700
+++ b/hotspot/src/share/vm/classfile/javaClasses.hpp	Thu Mar 31 14:00:41 2011 -0700
@@ -109,6 +109,30 @@
   static char*  as_platform_dependent_str(Handle java_string, TRAPS);
   static jchar* as_unicode_string(oop java_string, int& length);
 
+  // Compute the hash value for a java.lang.String object which would
+  // contain the characters passed in. This hash value is used for at
+  // least two purposes.
+  //
+  // (a) As the hash value used by the StringTable for bucket selection
+  //     and comparison (stored in the HashtableEntry structures).  This
+  //     is used in the String.intern() method.
+  //
+  // (b) As the hash value used by the String object itself, in
+  //     String.hashCode().  This value is normally calculate in Java code
+  //     in the String.hashCode method(), but is precomputed for String
+  //     objects in the shared archive file.
+  //
+  //     For this reason, THIS ALGORITHM MUST MATCH String.hashCode().
+  static unsigned int hash_string(jchar* s, int len) {
+    unsigned int h = 0;
+    while (len-- > 0) {
+      h = 31*h + (unsigned int) *s;
+      s++;
+    }
+    return h;
+  }
+  static unsigned int hash_string(oop java_string);
+
   static bool equals(oop java_string, jchar* chars, int len);
 
   // Conversion between '.' and '/' formats