I found that the last Rehash() of the hashtable othen is really last: the
table becomes broken.
As the shortest example Test_THashTable from tcollex.cxx with 4 edited
lines (marked VT:) :
.................................................................................
void Test_THashTable()
{
Printf(
"////////////////////////////////////////////////////////////////\n"
"// Test of THashTable //\n"
"////////////////////////////////////////////////////////////////"
);
int i;
// Create a hash table with an initial size of 20 (actually the nextprime
// above 20). No automatic rehashing.
THashTable ht(20);
Printf("Filling THashTable");
Printf("Number of slots before filling: %d", ht.Capacity());
for (i = 0; i < 100; i++) // VT: change loop to 100
ht.Add(new TObjNum(i)); // VT: TObjNum instead TObject
ht.Print(); // VT: printed ok
Printf("Average collisions: %f", ht.AverageCollisions());
// rehash the hash table to reduce the collission rate
ht.Rehash(ht.GetSize());
ht.Print(); // VT: print 1 empty line
Printf("Number of slots after rehash: %d", ht.Capacity());
Printf("Average collisions after rehash: %f", ht.AverageCollisions());
................................................................................
In fact after the last rehash nothing works also in my programs.
Moreother if I declare table with the automatic rehash
THashTable ht(100,10); for example - the effect depends dramatically on
the parameters
The next code I add to tcollex.cxx as one more example:
void Test_T()
{
TObjNum *x=0, *y=0;
THashTable *h = new THashTable(100,10);
for(int i=0; i<2000; i++) {
x = new TObjNum(i);
h->Add(x);
}
y = new TObjNum(10);
((TObjNum*)h->FindObject(y))->Print(""); // 1
printf("%f \n", h->AverageCollisions());
h->Rehash(h->GetSize());
printf("%f \n", h->AverageCollisions());
h->Print(); // 2
((TObjNum*)h->FindObject(y))->Print(""); // 3
}
This code brakes at line // 1 . If one change the table declaration to
THashTable(100,20); or reduce the cycle to 200 - it works up to line //2.
Line //3 brakes anyway.
Is it a bug or I do something wrong?
I tested it only on one system RH5.2+egcs-1.0.3
Best regards
Valeri