// 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)
    based on code by Marc Shapiro (shapiro@sor.inria.fr)

This file is part of GNU CC.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY.  No author or distributor
accepts responsibility to anyone for the consequences of using it
or for whether it serves any particular purpose or works at all,
unless he says so in writing.  Refer to the GNU CC General Public
License for full details.

Everyone is granted permission to copy, modify and redistribute
GNU CC, but only under the conditions described in the
GNU CC General Public License.   A copy of this license is
supposed to have been given to you along with GNU CC so you
can know your rights and responsibilities.  It should be in a
file named COPYING.  Among other things, the copyright notice
and this notice must be preserved on all copies.  
*/

#ifdef __GNUG__
#pragma implementation
#endif
#include "<T>.MPlex.h"

// <T>MChunk support


<T>MChunk::<T>MChunk(<T>*    d,      
               int      baseidx,
               int      lowidx, 
               int      fenceidx,
               int      topidx)
     : <T>IChunk(d, baseidx, lowidx, fenceidx, topidx)
{
  unused = fence - low;
  unsigned msize = (top - base)/_MAP_BITS + 1;
  map = (unsigned long *) (new long[msize]);
  bzero((void*)map, msize * sizeof(long));
}

void <T>MChunk:: shrink_high ()
{
  if (fence <= low) empty_error();
  --fence;
  if (!valid(fence)) 
    --unused;
  else
    free(fence);
  reset_high();
}

void <T>MChunk:: shrink_low ()
{
  if (fence <= low) empty_error();
  if (!valid(low)) 
    --unused;
  else
    free(low);
  ++low;
  reset_low();
}

void <T>MChunk::clear(int lo)
{
  int s = top - base;
  low = base = fence = lo;
  top = base + s;
  unused = 0;
  bzero((void*)map, ((top - base)/_MAP_BITS + 1) * sizeof(long));
}

void <T>MChunk::cleardown(int hi)
{
  int s = top - base;
  low = top = fence = hi;
  base = top - s;
  unused = 0;
  bzero((void*)map, ((top - base)/_MAP_BITS + 1) * sizeof(long));
}

int <T>MChunk::del(int idx)
{
  if (idx < low || idx >= fence) index_error();
  int v = valid(idx);
  if (v)
  {
    free(idx);
    ++unused;
  }
  return v;
}


int <T>MChunk::undel(int idx)
{
  if (idx < low || idx >= fence) index_error();
  int v = valid(idx);
  if (!v)
  {
    mark(idx);
    --unused;
  }
  return v;
}

int <T>MChunk::unused_index() const
{
  if (unused_indices() == 0) index_error();
  int slot;
  if (low == base)              // can traverse 32 slots at a time
  {
    int blk = 0;
    while (map[blk] == ~0L) ++blk;
    slot = blk * _MAP_BITS + base;
  }
  else
    slot = low;

  while(valid(slot)) ++slot;
  return slot;
}

int <T>MChunk::first_index() const
{
  if (empty()) return fence;
  int slot;
  if (low == base)
  {
    int blk = 0;
    while (map[blk] == 0) ++blk;
    slot = blk * _MAP_BITS + base;
  }
  else
    slot = low;

  while(!valid(slot)) ++slot;
  return slot;
}

int <T>MChunk::last_index() const
{
  if (empty()) return low - 1;
  int slot;
  if (top == fence)
  {
    int blk = (top - base) / _MAP_BITS;
    while (map[blk] == 0) --blk;
    slot = blk * _MAP_BITS + base + _MAP_BITS - 1;
  }
  else
    slot = fence - 1;

  while(!valid(slot)) --slot;
  return slot;
}


int <T>MChunk:: OK() const
{
  int v = data != 0;             // have some data
  v &= map != 0;                 // and a map
  v &= base <= low;              // ok, index-wise
  v &= low <= fence;
  v &= fence <= top;

  v &=  ((<T>MChunk*)(nxt->prev())) == this;      // and links are OK
  v &=  ((<T>MChunk*)(prv->next())) == this;

  int bitcount = 0;              // and unused count correct
  for (int i = low; i < fence; ++i) if (!valid(i)) ++bitcount;
  v &= unused == bitcount;
  
  if (!v) error("invariant failure");
  return(v);
}

<T>* <T>MChunk::succ(<T>* p) const
{
  int i = ((int) p - (int) data) / sizeof(<T>) + base + 1;
  if (p == 0 || i < low) return 0;
  while (i < fence && !valid(i)) ++i;
  if (i >= fence) return 0;
  return pointer_to(i);
}

<T>* <T>MChunk::pred(<T>* p) const
{
  int i = ((int) p - (int) data) / sizeof(<T>) + base - 1;
  if (p == 0 || i >= fence) return 0;
  while (i >= low && !valid(i)) --i;
  if (i < low) return 0;
  return pointer_to(i);
}

<T>* <T>MChunk::first_pointer() const
{
  if (empty()) return 0;
  int slot;
  if (low == base)
  {
    int blk = 0;
    while (map[blk] == 0) ++blk;
    slot = blk * _MAP_BITS + base;
  }
  else
    slot = low;

  while(!valid(slot)) ++slot;
  return pointer_to(slot);
}

<T>* <T>MChunk::last_pointer() const
{
  if (empty()) return 0;
  int slot;
  if (top == fence)
  {
    int blk = (top - base) / _MAP_BITS;
    while (map[blk] == 0) --blk;
    slot = blk * _MAP_BITS + base + _MAP_BITS - 1;
  }
  else
    slot = fence - 1;

  while(!valid(slot)) --slot;
  return pointer_to(slot);
}

<T>MPlex:: <T>MPlex()
{
  unused = 0;
  lo = fnc = 0;
  csize = DEFAULT_INITIAL_CAPACITY;
  <T>* data = new <T>[csize];
  hd = ch = new <T>MChunk(data,  lo, lo, fnc, lo+csize);
}

<T>MPlex:: <T>MPlex(int chunksize)
{
  if (chunksize == 0) error("invalid constructor specification");
  unused = 0;
  lo = fnc = 0;
  if (chunksize > 0)
  {
    csize = chunksize;
    <T>* data = new <T>[csize];
    hd = ch = new <T>MChunk(data,  lo, lo, fnc, csize);
  }
  else
  {
    csize = -chunksize;
    <T>* data = new <T>[csize];
    hd = ch = new <T>MChunk(data,  chunksize, lo, fnc, fnc);
  }
}


<T>MPlex:: <T>MPlex(int l, int chunksize)
{
  if (chunksize == 0) error("invalid constructor specification");
  unused = 0;
  lo = fnc = l;
  if (chunksize > 0)
  {
    csize = chunksize;
    <T>* data = new <T>[csize];
    hd = ch = new <T>MChunk(data,  lo, lo, fnc, csize+lo);
  }
  else
  {
    csize = -chunksize;
    <T>* data = new <T>[csize];
    hd = ch = new <T>MChunk(data,  chunksize+lo, lo, fnc, fnc);
  }
}


void <T>MPlex::make_initial_chunks(int up)
{
  int need = fnc - lo;
  hd = 0;
  if (up)
  {
    int l = lo;
    do
    {
      int sz;
      if (need >= csize)
        sz = csize;
      else
        sz = need;
      <T>* data = new <T> [csize];
      <T>MChunk* h = new <T>MChunk(data,  l, l, l+sz, l+csize);
      if (hd != 0)
        h->link_to_next(hd);
      else
        hd = h;
      l += sz;
      need -= sz;
    } while (need > 0);
  }
  else
  {
    int hi = fnc;
    do
    {
      int sz;
      if (need >= csize)
        sz = csize;
      else
        sz = need;
      <T>* data = new <T> [csize];
      <T>MChunk* h = new <T>MChunk(data,  hi-csize, hi-sz, hi, hi);
      if (hd != 0)
        h->link_to_next(hd);
      hd = h;
      hi -= sz;
      need -= sz;
    } while (need > 0);
  }
  ch = (<T>MChunk*) hd;
}

<T>MPlex:: <T>MPlex(int l, int hi, const <T&> initval, int chunksize)
{
  lo = l;
  fnc = hi + 1;
  if (chunksize == 0)
  {
    csize = fnc - l;
    make_initial_chunks(1);
  }
  else if (chunksize < 0)
  {
    csize = -chunksize;
    make_initial_chunks(0);
  }
  else
  {
    csize = chunksize;
    make_initial_chunks(1);
  }
  unused = fnc - lo;
  for (int i=lo; i<fnc; ++i)
    undel_index(i);
  fill(initval);
}

<T>MPlex::<T>MPlex(const <T>MPlex& a)
{
  lo = a.lo;
  fnc = a.fnc;
  csize = a.csize;
  unused = fnc - lo;
  hd = 0;
  const <T>IChunk* p = a.hd;
  do
  {
    <T>* data = new <T> [p->size()];
    <T>MChunk* h = new <T>MChunk(data,  p->base_index(),
                          p->low_index(), p->fence_index(), p->top_index());
    if (hd != 0)
      h->link_to_next(hd);
    else
      hd = h;
    p = p->next();
  } while (p != a.hd);
  ch = (<T>MChunk*) hd;
  for (int i = a.low(); i < a.fence(); a.next(i)) 
  {
    undel_index(i);
    (*this)[i] = a[i];
  }
}

void <T>MPlex::operator= (const <T>MPlex& a)
{
  if (&a != this)
  {
    invalidate();
    lo = a.lo;
    fnc = a.fnc;
    csize = a.csize;
    unused = fnc - lo;
    hd = 0;
    const <T>IChunk* p = a.hd;
    do
    {
      <T>* data = new <T> [p->size()];
      <T>MChunk* h = new <T>MChunk(data,  p->base_index(),
                                   p->low_index(), p->fence_index(), 
                                   p->top_index());
      if (hd != 0)
        h->link_to_next(hd);
      else
        hd = h;
      p = p->next();
    } while (p != a.hd);
    ch = (<T>MChunk*) hd;
    for (int i = a.low(); i < a.fence(); a.next(i)) 
    {
      undel_index(i);
      (*this)[i] = a[i];
    }
  }
}

int <T>MPlex::valid(int idx) const
{
  const <T>MChunk* tail = (<T>MChunk*)tl();
  const <T>MChunk* t = ch;
  while (idx >= t->fence_index())
  {
    if (t == tail)  return 0; 
    t = ((<T>MChunk*)(t->next()));
  }
  while (idx < t->low_index())
  {
    if (t == (<T>MChunk*)(hd)) return 0; 
    t = ((<T>MChunk*)(t->prev()));
  }
  set_cache(t);
  return t-><T>MChunk::valid_index(idx);
}

void <T>MPlex::cache(int idx) const
{
  const <T>MChunk* tail = (<T>MChunk*)tl();
  const <T>MChunk* t = ch;
  while (idx >= t->fence_index())
  {
    if (t == tail) index_error();
    t = ((<T>MChunk*)(t->next()));
  }
  while (idx < t->low_index())
  {
    if (t == (<T>MChunk*)hd) index_error();
    t = ((<T>MChunk*)(t->prev()));
  }
  if (!t-><T>MChunk::valid_index(idx)) index_error();
  set_cache(t);
}

void <T>MPlex::cache(const <T>* p) const
{
  const <T>MChunk* old = ch;
  const <T>MChunk* t = ch;
  while (!t->actual_pointer(p))
  {
    t = ((<T>MChunk*)(t->next()));
    if (t == old) index_error();
  }
  if (!t-><T>MChunk::valid_pointer(p)) index_error();
  set_cache(t);
}

int <T>MPlex::owns(Pix px) const
{
  <T>* p = (<T>*)px;
  const <T>MChunk* old = ch;
  const <T>MChunk* t = ch;
  while (!t->actual_pointer(p))
  {
    t = ((<T>MChunk*)(t->next()));
    if (t == old)  return 0; 
  }
  set_cache(t);
  return t-><T>MChunk::valid_pointer(p);
}

int <T>MPlex::add_high(const <T&> elem)
{
  <T>MChunk* t = ((<T>MChunk*) tl());

  if (!t->can_grow_high())
  {
    <T>* data = new <T> [csize];
    t = (new <T>MChunk(data, fnc,fnc,fnc,fnc+csize));
    t->link_to_prev(tl());
  }

  *((t-><T>MChunk::grow_high())) = elem;
  set_cache(t);
  return fnc++;
}

int <T>MPlex::add_low (const <T&> elem)
{
  <T>MChunk* t = ((<T>MChunk*) hd);
  if (!t->can_grow_low())
  {
    <T>* data = new <T> [csize];
    hd = new <T>MChunk(data,  lo-csize, lo, lo, lo);
    hd->link_to_next(t);
    t = ((<T>MChunk*) hd);
  }

  *((t-><T>MChunk::grow_low())) = elem;
  set_cache(t);
  return --lo;
}

void <T>MPlex::adjust_bounds()
{
  <T>MChunk* t = ((<T>MChunk*) tl());

  // clean up tail

  t->reset_high();
  while (t-><T>MChunk::empty() && !one_chunk())
  {
    <T>MChunk* pred = (<T>MChunk*)(t->prev());
    del_chunk(t);
    pred->reset_high();
    t = (pred);
  }
  if (one_chunk())
    t->reset_high();

  int oldfnc = fnc;
  fnc = t->fence_index();
  unused -= oldfnc - fnc;

  // and head..
  t = ((<T>MChunk*) hd);
  t->reset_low();
  while (t-><T>MChunk::empty() && !one_chunk())
  {
    hd = (<T>MChunk*)(t->next());
    del_chunk(t);
    t = ((<T>MChunk*) hd);
    t->reset_low();
  }

  int oldlo = lo;
  lo = t->low_index();
  unused -= lo - oldlo;


  set_cache(t);
}

int <T>MPlex::del_high ()
{
  if (empty()) empty_error();
  <T>MChunk* t = ((<T>MChunk*) tl());
  while (t-><T>MChunk::empty() && !one_chunk()) // possible stragglers
  {
    <T>MChunk* pred = (<T>MChunk*)(t->prev());
    del_chunk(t);
    pred->reset_high();
    t = (pred);
  }
  t-><T>MChunk::shrink_high();
  while (t-><T>MChunk::empty() && !one_chunk())
  {
    <T>MChunk* pred = (<T>MChunk*)(t->prev());
    del_chunk(t);
    pred->reset_high();
    t = (pred);
  }
  int oldfnc = fnc;
  fnc = t->fence_index();
  unused -= oldfnc - fnc - 1;
  set_cache(t);
  return fnc - 1;
}

int <T>MPlex::del_low ()
{
  if (empty()) empty_error();
  <T>MChunk* t = ((<T>MChunk*) hd);
  while (t-><T>MChunk::empty() && !one_chunk())
  {
    hd = (<T>MChunk*)(t->next());
    del_chunk(t);
    t = ((<T>MChunk*) hd);
    t->reset_low();
  }
  t-><T>MChunk::shrink_low();
  while (t-><T>MChunk::empty() && !one_chunk())
  {
    hd = (<T>MChunk*)(t->next());
    del_chunk(t);
    t = ((<T>MChunk*) hd);
    t->reset_low();
  }
  int oldlo = lo;
  lo = t->low_index();
  unused -= lo - oldlo - 1;
  set_cache(t);
  return lo;
}

int <T>MPlex::add(const <T&> elem)
{
  if (unused == 0) 
    return add_high(elem);

  for(<T>MChunk* t = ch; 
      t->unused_indices() == 0; 
      t = (<T>MChunk*)(t->prev()))
    ;

  int i =  t->unused_index();
  set_cache(t);
  undel_index(i);
  (*this)[i] = elem;
  return i;
}

int <T>MPlex::unused_index() const
{
  if (unused == 0) index_error();

  for(<T>MChunk* t = ch; 
      t->unused_indices() == 0; 
      t = (<T>MChunk*)(t->prev()))
    ;

  set_cache(t);
  return t->unused_index();
}

Pix <T>MPlex::unused_Pix() const
{
  if (unused == 0) return 0;

  for(<T>MChunk* t = ch; 
      t->unused_indices() == 0; 
      t = (<T>MChunk*)(t->prev()))
    ;

  set_cache(t);
  return t->pointer_to(t->unused_index()); 
}

int <T>MPlex::del_index(int idx)
{
  if (idx < lo || idx >= fnc) index_error();
  if (<T>MPlex::valid(idx))
  {
    ++unused;
    ch-><T>MChunk::del(idx);
    return 1;
  }
  else
    return 0;
}

int <T>MPlex::dopred(int idx) const
{

  if (idx >= fnc) idx = fnc;
  if (idx <= lo) return lo - 1;

  const <T>MChunk* t = ch;
  
  while (idx > t->fence_index())
  {
    t = ((<T>MChunk*)(t->next()));
  }
  while (idx <= t->low_index())
  {
    t = ((<T>MChunk*)(t->prev()));
  }
  int i = t-><T>MChunk::pred(idx);
  while (i < t->low_index() && i >= lo)
  {
    t = ((<T>MChunk*)(t->prev()));
    i = t-><T>MChunk::last_index();
  }
  set_cache(t);
  return i;
}


int <T>MPlex::dosucc(int idx) const
{
  if (idx < lo) idx = lo;
  if (idx >= fnc - 1) return fnc;

  const <T>MChunk* t = ch;
  while (idx >= t->fence_index())
  {
    t = ((<T>MChunk*)(t->next()));
  }
  while (idx < t->low_index())
  {
    t = ((<T>MChunk*)(t->prev()));
  }
  int i = t-><T>MChunk::succ(idx);
  while (i >= t->fence_index() && i < fnc)
  {
    t = (<T>MChunk*)(t->next());
    i = t-><T>MChunk::first_index();
  }
  set_cache(t);
  return i;
}

void <T>MPlex::prev(Pix& i) const
{
  if (i == 0) return;

  <T>* p = (<T>*) i;
  const <T>MChunk* old = ch;
  const <T>MChunk* t = ch;

  while (!t->actual_pointer(p))
  {
    t = ((<T>MChunk*)(t->prev()));
    if (t == old) 
    { 
      i = 0; 
      return; 
    }
  }
  <T>* q = t-><T>MChunk::pred(p);
  while (q == 0 && t != (<T>MChunk*)hd)
  {
    t = ((<T>MChunk*)(t->prev()));
    q = t-><T>MChunk::last_pointer();
  }

  i = Pix(q); 
  set_cache(t);
  return; 
}

void <T>MPlex::next(Pix& i) const
{
  if (i == 0) return;

  <T>* p = (<T>*) i;
  const <T>MChunk* tail = (<T>MChunk*)(tl());
  const <T>MChunk* old = ch;
  const <T>MChunk* t = ch;

  while (!t->actual_pointer(p))
  {
    t = ((<T>MChunk*)(t->next()));
    if (t == old) 
    { 
      i = 0; 
      return; 
    }
  }
  <T>* q = t-><T>MChunk::succ(p);
  while  (q == 0 && t != tail)
  {
    t = ((<T>MChunk*)(t->next()));
    q = t-><T>MChunk::first_pointer();
  }

  i = Pix(q); 
  set_cache(t);
  return; 
}

    
void <T>MPlex::undel_index(int idx)
{
  if (idx < lo || idx >= fnc) index_error();

  <T>MChunk* t = ch;
  while (idx >= t->fence_index())
  {
    t = ((<T>MChunk*)(t->next()));
  }
  while (idx < t->low_index())
  {
    t = ((<T>MChunk*)(t->prev()));
  }
  int was_present = t-><T>MChunk::undel(idx);
  if (!was_present) 
  {
    --unused;
  }
  set_cache(t);
  return;
}

void <T>MPlex::clear()
{
  if (fnc != lo)
  {
    <T>MChunk* t = ((<T>MChunk*)tl());
    while (t != hd)
    {
      <T>MChunk* prv = (<T>MChunk*)(t->prev());
      del_chunk(t);
      t = prv;
    }
    t-><T>MChunk::clear(lo);
    set_cache(t);
    fnc = lo;
    unused = 0;
  }
}

int <T>MPlex::OK () const
{
  int v = hd != 0;                    // at least one chunk

  int found_ch = 0;                   // to make sure ch is in list;

  int count = 0;                      // to count unused slots

  const <T>MChunk* t = (<T>MChunk*)(hd);

  int gap = t->low_index() - lo;
  v &= gap == 0;                      // hd lo not less than lo.
  count += gap;

  for (;;)
  {
    if (t == ch) ++found_ch;
    v &= t-><T>MChunk::OK();             // each chunk is OK
    count += t->unused_indices();
    if (t == (<T>MChunk*)(tl()))
      break;
    else                              // and has indices less than succ
    {
      gap = t->next()->base_index() - t->top_index();
      v &= gap == 0;
      count += gap;

      if (t != (<T>MChunk*)hd)                  // internal chunks can't grow
        v &= !t->can_grow_low() && !t->can_grow_high();

      t = (const <T>MChunk*)(t->next());
    }
  }
  gap = fnc - t->fence_index();
  v &= gap == 0;
  count += gap;

  v &= count == unused;              // chunk counts agree with plex

  v &= found_ch == 1;
  if (!v) error("invariant failure");
  return v;
}