NetBSD/gnu/lib/libg++/include/gen/CHBag.ccP

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COBOL

// This may look like C code, but it is really -*- C++ -*-
/*
Copyright (C) 1988 Free Software Foundation
written by Doug Lea (dl@rocky.oswego.edu)
This file is part of the GNU C++ Library. This library is free
software; you can redistribute it and/or modify it under the terms of
the GNU Library General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version. This library is distributed in the hope
that it will be useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef __GNUG__
#pragma implementation
#endif
#include "<T>.CHBag.h"
// The nodes are linked together serially via a version
// of a trick used in some vtables: odd pointers are
// actually links to the next table entry.
// Not terrible, but not wonderful either
static inline int goodCHptr(<T>CHNode* t)
{
return ((((unsigned)t) & 1) == 0);
}
static inline <T>CHNode* index_to_CHptr(int i)
{
return (<T>CHNode*)((i << 1) + 1);
}
static inline int CHptr_to_index(<T>CHNode* t)
{
return ( ((unsigned) t) >> 1);
}
<T>CHBag::<T>CHBag(unsigned int sz)
{
tab = (<T>CHNode**)(new <T>CHNodePtr[size = sz]);
for (unsigned int i = 0; i < size; ++i) tab[i] = index_to_CHptr(i+1);
count = 0;
}
<T>CHBag::<T>CHBag(<T>CHBag& a)
{
tab = (<T>CHNode**)(new <T>CHNodePtr[size = a.size]);
for (unsigned int i = 0; i < size; ++i) tab[i] = index_to_CHptr(i+1);
count = 0;
for (Pix p = a.first(); p; a.next(p)) add(a(p));
}
Pix <T>CHBag::seek(<T&> key, Pix i)
{
<T>CHNode* p = (<T>CHNode*)i;
if (p == 0 || !<T>EQ(p->hd, key))
{
unsigned int h = <T>HASH(key) % size;
for (<T>CHNode* t = tab[h]; goodCHptr(t); t = t->tl)
if (<T>EQ(key, t->hd))
return Pix(t);
}
else
{
for (p = p->tl; goodCHptr(p); p = p->tl)
if (<T>EQ(p->hd, key))
return Pix(p);
}
return 0;
}
int <T>CHBag::nof(<T&> key)
{
int n = 0;
unsigned int h = <T>HASH(key) % size;
for (<T>CHNode* t = tab[h]; goodCHptr(t); t = t->tl)
if (<T>EQ(key, t->hd)) ++n;
return n;
}
Pix <T>CHBag::add(<T&> item)
{
unsigned int h = <T>HASH(item) % size;
<T>CHNode* t = new <T>CHNode(item);
t->tl = tab[h];
tab[h] = t;
++count;
return Pix(t);
}
void <T>CHBag::del(<T&> key)
{
unsigned int h = <T>HASH(key) % size;
<T>CHNode* t = tab[h];
<T>CHNode* trail = t;
while (goodCHptr(t))
{
if (<T>EQ(key, t->hd))
{
if (trail == t)
tab[h] = t->tl;
else
trail->tl = t->tl;
delete t;
--count;
return;
}
trail = t;
t = t->tl;
}
}
void <T>CHBag::remove(<T&> key)
{
unsigned int h = <T>HASH(key) % size;
<T>CHNode* t = tab[h];
<T>CHNode* trail = t;
while (goodCHptr(t))
{
if (<T>EQ(key, t->hd))
{
--count;
if (trail == t)
{
tab[h] = t->tl;
delete t;
t = trail = tab[h];
}
else
{
trail->tl = t->tl;
delete t;
t = trail->tl;
}
}
else
{
trail = t;
t = t->tl;
}
}
}
void <T>CHBag::clear()
{
for (unsigned int i = 0; i < size; ++i)
{
<T>CHNode* p = tab[i];
tab[i] = index_to_CHptr(i+1);
while (goodCHptr(p))
{
<T>CHNode* nxt = p->tl;
delete(p);
p = nxt;
}
}
count = 0;
}
Pix <T>CHBag::first()
{
for (unsigned int i = 0; i < size; ++i) if (goodCHptr(tab[i])) return Pix(tab[i]);
return 0;
}
void <T>CHBag::next(Pix& p)
{
if (p == 0) return;
<T>CHNode* t = ((<T>CHNode*)p)->tl;
if (goodCHptr(t))
p = Pix(t);
else
{
for (unsigned int i = CHptr_to_index(t); i < size; ++i)
{
if (goodCHptr(tab[i]))
{
p = Pix(tab[i]);
return;
}
}
p = 0;
}
}
int <T>CHBag::OK()
{
int v = tab != 0;
int n = 0;
for (unsigned int i = 0; i < size; ++i)
{
<T>CHNode* p;
for (p = tab[i]; goodCHptr(p); p = p->tl) ++n;
v &= CHptr_to_index(p) == i + 1;
}
v &= count == n;
if (!v) error("invariant failure");
return v;
}