--- a/Object.st	Fri Mar 21 16:07:33 1997 +0100
+++ b/Object.st	Fri Mar 21 17:42:57 1997 +0100
@@ -1394,6 +1394,70 @@
     ^ 0 "never reached, since redefined in UndefinedObject and SmallInteger"
 !
 
+identityHashForBinaryStore
+    "hash which is usable if the object does not change its class
+     and does not #become something else, while the hash is used.
+     This is only used by the binary storage mechanism, during the
+     object writing phase."
+
+%{  /* NOCONTEXT */
+
+    REGISTER unsigned hash, hash1, hash2, sz;
+    OBJ o;
+    static unsigned nextHash = 0;
+
+    if (__isNonNilObject(self)) {
+        /*
+         * my own identityHash
+         */
+        hash1 = __GET_HASH(self);
+        if (hash1 == 0) {
+            /* has no hash yet */
+
+            if (nextHash < __MAX_HASH__) {
+                hash1 = ++nextHash;
+            } else {
+                hash1 = nextHash = 1;
+            }
+
+            __SET_HASH(self, hash1);
+        }
+        /*
+         * my classes identityHash
+         */
+        o = __Class(self);
+        hash2 = __GET_HASH(o);
+        if (hash2 == 0) {
+            /* has no hash yet */
+
+            if (nextHash < __MAX_HASH__) {
+                hash2 = ++nextHash;
+            } else {
+                hash2 = nextHash = 1;
+            }
+
+            __SET_HASH(o, hash2);
+        }
+
+        /*
+         * 8 bits of my size
+         */
+        sz = __qSize(self);
+
+        /*
+         * now, we got 11 + 11 + 8 bits for hashing;
+         * make it as large as possible; since most hashers use the returned
+         * key and take it modulu some prime number, this will allow for
+         * better distribution (i.e. bigger empty spaces) in hashed collection.
+         */
+        hash = (hash1 << 11) | hash2;           /* 22 bits */
+        hash = (hash << 8) | (sz & 0xFF);       /* 30 bits */
+        RETURN ( __MKSMALLINT(hash) );
+    }
+%}.
+    ^ 0 "never reached, since UndefinedObject and SmallInteger are not hashed upon in binary storage"
+!
+
 isNil
     "return true, if the receiver is nil"
 
@@ -5656,6 +5720,6 @@
 !Object class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/Object.st,v 1.182 1997-03-21 15:07:33 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/Object.st,v 1.183 1997-03-21 16:42:57 cg Exp $'
 ! !
 Object initialize!