1 // SGI's rope class implementation -*- C++ -*-
2 
3 // Copyright (C) 2001, 2002 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 2, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING.  If not, write to the Free
18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19 // USA.
20 
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction.  Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License.  This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
29 
30 /*
31  * Copyright (c) 1997
32  * Silicon Graphics Computer Systems, Inc.
33  *
34  * Permission to use, copy, modify, distribute and sell this software
35  * and its documentation for any purpose is hereby granted without fee,
36  * provided that the above copyright notice appear in all copies and
37  * that both that copyright notice and this permission notice appear
38  * in supporting documentation.  Silicon Graphics makes no
39  * representations about the suitability of this software for any
40  * purpose.  It is provided "as is" without express or implied warranty.
41  */
42 
43 /** @file ropeimpl.h
44  *  This is an internal header file, included by other library headers.
45  *  You should not attempt to use it directly.
46  */
47 
48 #include <cstdio>
49 #include <iostream>
50 #include <bits/functexcept.h>
51 
52 #include <ext/algorithm> // For copy_n and lexicographical_compare_3way
53 #include <ext/memory> // For uninitialized_copy_n
54 #include <ext/numeric> // For power
55 
56 namespace __gnu_cxx
57 {
58 using std::size_t;
59 using std::printf;
60 using std::basic_ostream;
61 using std::__throw_length_error;
62 using std::__alloc;
63 using std::_Destroy;
64 using std::uninitialized_fill_n;
65 
66 // Set buf_start, buf_end, and buf_ptr appropriately, filling tmp_buf
67 // if necessary.  Assumes _M_path_end[leaf_index] and leaf_pos are correct.
68 // Results in a valid buf_ptr if the iterator can be legitimately
69 // dereferenced.
70 template <class _CharT, class _Alloc>
71 void _Rope_iterator_base<_CharT,_Alloc>::_S_setbuf(
72   _Rope_iterator_base<_CharT,_Alloc>& __x)
73 {
74     const _RopeRep* __leaf = __x._M_path_end[__x._M_leaf_index];
75     size_t __leaf_pos = __x._M_leaf_pos;
76     size_t __pos = __x._M_current_pos;
77 
78     switch(__leaf->_M_tag) {
79 	case _RopeRep::_S_leaf:
80 	    __x._M_buf_start =
81 	      ((_Rope_RopeLeaf<_CharT,_Alloc>*)__leaf)->_M_data;
82 	    __x._M_buf_ptr = __x._M_buf_start + (__pos - __leaf_pos);
83 	    __x._M_buf_end = __x._M_buf_start + __leaf->_M_size;
84 	    break;
85 	case _RopeRep::_S_function:
86 	case _RopeRep::_S_substringfn:
87 	    {
88 		size_t __len = _S_iterator_buf_len;
89 		size_t __buf_start_pos = __leaf_pos;
90 		size_t __leaf_end = __leaf_pos + __leaf->_M_size;
91 		char_producer<_CharT>* __fn =
92 			((_Rope_RopeFunction<_CharT,_Alloc>*)__leaf)->_M_fn;
93 
94 		if (__buf_start_pos + __len <= __pos) {
95 		    __buf_start_pos = __pos - __len/4;
96 		    if (__buf_start_pos + __len > __leaf_end) {
97 			__buf_start_pos = __leaf_end - __len;
98 		    }
99 		}
100 		if (__buf_start_pos + __len > __leaf_end) {
101 		    __len = __leaf_end - __buf_start_pos;
102 		}
103 		(*__fn)(__buf_start_pos - __leaf_pos, __len, __x._M_tmp_buf);
104 		__x._M_buf_ptr = __x._M_tmp_buf + (__pos - __buf_start_pos);
105 		__x._M_buf_start = __x._M_tmp_buf;
106 		__x._M_buf_end = __x._M_tmp_buf + __len;
107 	    }
108 	    break;
109 	default:
110 	  break;
111     }
112 }
113 
114 // Set path and buffer inside a rope iterator.  We assume that
115 // pos and root are already set.
116 template <class _CharT, class _Alloc>
117 void _Rope_iterator_base<_CharT,_Alloc>::_S_setcache
118 (_Rope_iterator_base<_CharT,_Alloc>& __x)
119 {
120     const _RopeRep* __path[_RopeRep::_S_max_rope_depth+1];
121     const _RopeRep* __curr_rope;
122     int __curr_depth = -1;  /* index into path    */
123     size_t __curr_start_pos = 0;
124     size_t __pos = __x._M_current_pos;
125     unsigned char __dirns = 0; // Bit vector marking right turns in the path
126 
127     if (__pos >= __x._M_root->_M_size) {
128 	__x._M_buf_ptr = 0;
129 	return;
130     }
131     __curr_rope = __x._M_root;
132     if (0 != __curr_rope->_M_c_string) {
133 	/* Treat the root as a leaf. */
134 	__x._M_buf_start = __curr_rope->_M_c_string;
135 	__x._M_buf_end = __curr_rope->_M_c_string + __curr_rope->_M_size;
136 	__x._M_buf_ptr = __curr_rope->_M_c_string + __pos;
137 	__x._M_path_end[0] = __curr_rope;
138 	__x._M_leaf_index = 0;
139 	__x._M_leaf_pos = 0;
140 	return;
141     }
142     for(;;) {
143 	++__curr_depth;
144 	__path[__curr_depth] = __curr_rope;
145 	switch(__curr_rope->_M_tag) {
146 	  case _RopeRep::_S_leaf:
147 	  case _RopeRep::_S_function:
148 	  case _RopeRep::_S_substringfn:
149 	    __x._M_leaf_pos = __curr_start_pos;
150 	    goto done;
151 	  case _RopeRep::_S_concat:
152 	    {
153 		_Rope_RopeConcatenation<_CharT,_Alloc>* __c =
154 			(_Rope_RopeConcatenation<_CharT,_Alloc>*)__curr_rope;
155 		_RopeRep* __left = __c->_M_left;
156 		size_t __left_len = __left->_M_size;
157 
158 		__dirns <<= 1;
159 		if (__pos >= __curr_start_pos + __left_len) {
160 		    __dirns |= 1;
161 		    __curr_rope = __c->_M_right;
162 		    __curr_start_pos += __left_len;
163 		} else {
164 		    __curr_rope = __left;
165 		}
166 	    }
167 	    break;
168 	}
169     }
170   done:
171     // Copy last section of path into _M_path_end.
172       {
173 	int __i = -1;
174 	int __j = __curr_depth + 1 - _S_path_cache_len;
175 
176 	if (__j < 0) __j = 0;
177 	while (__j <= __curr_depth) {
178 	    __x._M_path_end[++__i] = __path[__j++];
179 	}
180 	__x._M_leaf_index = __i;
181       }
182       __x._M_path_directions = __dirns;
183       _S_setbuf(__x);
184 }
185 
186 // Specialized version of the above.  Assumes that
187 // the path cache is valid for the previous position.
188 template <class _CharT, class _Alloc>
189 void _Rope_iterator_base<_CharT,_Alloc>::_S_setcache_for_incr
190 (_Rope_iterator_base<_CharT,_Alloc>& __x)
191 {
192     int __current_index = __x._M_leaf_index;
193     const _RopeRep* __current_node = __x._M_path_end[__current_index];
194     size_t __len = __current_node->_M_size;
195     size_t __node_start_pos = __x._M_leaf_pos;
196     unsigned char __dirns = __x._M_path_directions;
197     _Rope_RopeConcatenation<_CharT,_Alloc>* __c;
198 
199     if (__x._M_current_pos - __node_start_pos < __len) {
200 	/* More stuff in this leaf, we just didn't cache it. */
201 	_S_setbuf(__x);
202 	return;
203     }
204     //  node_start_pos is starting position of last_node.
205     while (--__current_index >= 0) {
206 	if (!(__dirns & 1) /* Path turned left */)
207 	  break;
208 	__current_node = __x._M_path_end[__current_index];
209 	__c = (_Rope_RopeConcatenation<_CharT,_Alloc>*)__current_node;
210 	// Otherwise we were in the right child.  Thus we should pop
211 	// the concatenation node.
212 	__node_start_pos -= __c->_M_left->_M_size;
213 	__dirns >>= 1;
214     }
215     if (__current_index < 0) {
216 	// We underflowed the cache. Punt.
217 	_S_setcache(__x);
218 	return;
219     }
220     __current_node = __x._M_path_end[__current_index];
221     __c = (_Rope_RopeConcatenation<_CharT,_Alloc>*)__current_node;
222     // current_node is a concatenation node.  We are positioned on the first
223     // character in its right child.
224     // node_start_pos is starting position of current_node.
225     __node_start_pos += __c->_M_left->_M_size;
226     __current_node = __c->_M_right;
227     __x._M_path_end[++__current_index] = __current_node;
228     __dirns |= 1;
229     while (_RopeRep::_S_concat == __current_node->_M_tag) {
230 	++__current_index;
231 	if (_S_path_cache_len == __current_index) {
232 	    int __i;
233 	    for (__i = 0; __i < _S_path_cache_len-1; __i++) {
234 		__x._M_path_end[__i] = __x._M_path_end[__i+1];
235 	    }
236 	    --__current_index;
237 	}
238 	__current_node =
239 	    ((_Rope_RopeConcatenation<_CharT,_Alloc>*)__current_node)->_M_left;
240 	__x._M_path_end[__current_index] = __current_node;
241 	__dirns <<= 1;
242 	// node_start_pos is unchanged.
243     }
244     __x._M_leaf_index = __current_index;
245     __x._M_leaf_pos = __node_start_pos;
246     __x._M_path_directions = __dirns;
247     _S_setbuf(__x);
248 }
249 
250 template <class _CharT, class _Alloc>
251 void _Rope_iterator_base<_CharT,_Alloc>::_M_incr(size_t __n) {
252     _M_current_pos += __n;
253     if (0 != _M_buf_ptr) {
254         size_t __chars_left = _M_buf_end - _M_buf_ptr;
255         if (__chars_left > __n) {
256             _M_buf_ptr += __n;
257         } else if (__chars_left == __n) {
258             _M_buf_ptr += __n;
259             _S_setcache_for_incr(*this);
260         } else {
261             _M_buf_ptr = 0;
262         }
263     }
264 }
265 
266 template <class _CharT, class _Alloc>
267 void _Rope_iterator_base<_CharT,_Alloc>::_M_decr(size_t __n) {
268     if (0 != _M_buf_ptr) {
269         size_t __chars_left = _M_buf_ptr - _M_buf_start;
270         if (__chars_left >= __n) {
271             _M_buf_ptr -= __n;
272         } else {
273             _M_buf_ptr = 0;
274         }
275     }
276     _M_current_pos -= __n;
277 }
278 
279 template <class _CharT, class _Alloc>
280 void _Rope_iterator<_CharT,_Alloc>::_M_check() {
281     if (_M_root_rope->_M_tree_ptr != _M_root) {
282         // _Rope was modified.  Get things fixed up.
283         _RopeRep::_S_unref(_M_root);
284         _M_root = _M_root_rope->_M_tree_ptr;
285         _RopeRep::_S_ref(_M_root);
286         _M_buf_ptr = 0;
287     }
288 }
289 
290 template <class _CharT, class _Alloc>
291 inline
292 _Rope_const_iterator<_CharT, _Alloc>::_Rope_const_iterator(
293   const _Rope_iterator<_CharT,_Alloc>& __x)
294 : _Rope_iterator_base<_CharT,_Alloc>(__x)
295 { }
296 
297 template <class _CharT, class _Alloc>
298 inline _Rope_iterator<_CharT,_Alloc>::_Rope_iterator(
299   rope<_CharT,_Alloc>& __r, size_t __pos)
300 : _Rope_iterator_base<_CharT,_Alloc>(__r._M_tree_ptr, __pos),
301   _M_root_rope(&__r)
302 {
303     _RopeRep::_S_ref(_M_root);
304 }
305 
306 template <class _CharT, class _Alloc>
307 inline size_t
308 rope<_CharT,_Alloc>::_S_char_ptr_len(const _CharT* __s)
309 {
310     const _CharT* __p = __s;
311 
312     while (!_S_is0(*__p)) { ++__p; }
313     return (__p - __s);
314 }
315 
316 
317 #ifndef __GC
318 
319 template <class _CharT, class _Alloc>
320 inline void _Rope_RopeRep<_CharT,_Alloc>::_M_free_c_string()
321 {
322     _CharT* __cstr = _M_c_string;
323     if (0 != __cstr) {
324 	size_t __size = _M_size + 1;
325 	_Destroy(__cstr, __cstr + __size);
326 	_Data_deallocate(__cstr, __size);
327     }
328 }
329 
330 
331 template <class _CharT, class _Alloc>
332   inline void _Rope_RopeRep<_CharT,_Alloc>::_S_free_string(_CharT* __s,
333 							   size_t __n,
334 						           allocator_type __a)
335 {
336     if (!_S_is_basic_char_type((_CharT*)0)) {
337 	_Destroy(__s, __s + __n);
338     }
339 //  This has to be a static member, so this gets a bit messy
340         __a.deallocate(
341 	    __s, _Rope_RopeLeaf<_CharT,_Alloc>::_S_rounded_up_size(__n));
342 }
343 
344 
345 //  There are several reasons for not doing this with virtual destructors
346 //  and a class specific delete operator:
347 //  - A class specific delete operator can't easily get access to
348 //    allocator instances if we need them.
349 //  - Any virtual function would need a 4 or byte vtable pointer;
350 //    this only requires a one byte tag per object.
351 template <class _CharT, class _Alloc>
352 void _Rope_RopeRep<_CharT,_Alloc>::_M_free_tree()
353 {
354     switch(_M_tag) {
355 	case _S_leaf:
356 	    {
357 	        _Rope_RopeLeaf<_CharT,_Alloc>* __l
358 			= (_Rope_RopeLeaf<_CharT,_Alloc>*)this;
359 	        __l->_Rope_RopeLeaf<_CharT,_Alloc>::~_Rope_RopeLeaf();
360 	        _L_deallocate(__l, 1);
361 	        break;
362 	    }
363 	case _S_concat:
364 	    {
365 	        _Rope_RopeConcatenation<_CharT,_Alloc>* __c
366 		    = (_Rope_RopeConcatenation<_CharT,_Alloc>*)this;
367 	        __c->_Rope_RopeConcatenation<_CharT,_Alloc>::
368 		       ~_Rope_RopeConcatenation();
369 	        _C_deallocate(__c, 1);
370 	        break;
371 	    }
372 	case _S_function:
373 	    {
374 	        _Rope_RopeFunction<_CharT,_Alloc>* __f
375 		    = (_Rope_RopeFunction<_CharT,_Alloc>*)this;
376 	        __f->_Rope_RopeFunction<_CharT,_Alloc>::~_Rope_RopeFunction();
377 	        _F_deallocate(__f, 1);
378 	        break;
379 	    }
380 	case _S_substringfn:
381 	    {
382 	        _Rope_RopeSubstring<_CharT,_Alloc>* __ss =
383 			(_Rope_RopeSubstring<_CharT,_Alloc>*)this;
384 		__ss->_Rope_RopeSubstring<_CharT,_Alloc>::
385 		        ~_Rope_RopeSubstring();
386 		_S_deallocate(__ss, 1);
387 		break;
388 	    }
389     }
390 }
391 #else
392 
393 template <class _CharT, class _Alloc>
394   inline void _Rope_RopeRep<_CharT,_Alloc>::_S_free_string
395 		(const _CharT*, size_t, allocator_type)
396 {}
397 
398 #endif
399 
400 
401 // Concatenate a C string onto a leaf rope by copying the rope data.
402 // Used for short ropes.
403 template <class _CharT, class _Alloc>
404 typename rope<_CharT,_Alloc>::_RopeLeaf*
405 rope<_CharT,_Alloc>::_S_leaf_concat_char_iter
406 		(_RopeLeaf* __r, const _CharT* __iter, size_t __len)
407 {
408     size_t __old_len = __r->_M_size;
409     _CharT* __new_data = (_CharT*)
410 	_Data_allocate(_S_rounded_up_size(__old_len + __len));
411     _RopeLeaf* __result;
412 
413     uninitialized_copy_n(__r->_M_data, __old_len, __new_data);
414     uninitialized_copy_n(__iter, __len, __new_data + __old_len);
415     _S_cond_store_eos(__new_data[__old_len + __len]);
416     try {
417 	__result = _S_new_RopeLeaf(__new_data, __old_len + __len,
418 				   __r->get_allocator());
419     }
420     catch(...)
421       {
422 	_RopeRep::__STL_FREE_STRING(__new_data, __old_len + __len,
423 				    __r->get_allocator());
424 	__throw_exception_again;
425       }
426     return __result;
427 }
428 
429 #ifndef __GC
430 // As above, but it's OK to clobber original if refcount is 1
431 template <class _CharT, class _Alloc>
432 typename rope<_CharT,_Alloc>::_RopeLeaf*
433 rope<_CharT,_Alloc>::_S_destr_leaf_concat_char_iter
434 		(_RopeLeaf* __r, const _CharT* __iter, size_t __len)
435 {
436     if (__r->_M_ref_count > 1)
437       return _S_leaf_concat_char_iter(__r, __iter, __len);
438     size_t __old_len = __r->_M_size;
439     if (_S_allocated_capacity(__old_len) >= __old_len + __len) {
440 	// The space has been partially initialized for the standard
441 	// character types.  But that doesn't matter for those types.
442 	uninitialized_copy_n(__iter, __len, __r->_M_data + __old_len);
443 	if (_S_is_basic_char_type((_CharT*)0)) {
444 	    _S_cond_store_eos(__r->_M_data[__old_len + __len]);
445 	} else if (__r->_M_c_string != __r->_M_data && 0 != __r->_M_c_string) {
446 	    __r->_M_free_c_string();
447 	    __r->_M_c_string = 0;
448 	}
449 	__r->_M_size = __old_len + __len;
450 	__r->_M_ref_count = 2;
451 	return __r;
452     } else {
453 	_RopeLeaf* __result = _S_leaf_concat_char_iter(__r, __iter, __len);
454 	return __result;
455     }
456 }
457 #endif
458 
459 // Assumes left and right are not 0.
460 // Does not increment (nor decrement on exception) child reference counts.
461 // Result has ref count 1.
462 template <class _CharT, class _Alloc>
463 typename rope<_CharT,_Alloc>::_RopeRep*
464 rope<_CharT,_Alloc>::_S_tree_concat (_RopeRep* __left, _RopeRep* __right)
465 {
466   _RopeConcatenation* __result = _S_new_RopeConcatenation(__left, __right,
467 						      __left->get_allocator());
468   size_t __depth = __result->_M_depth;
469 
470   if (__depth > 20 && (__result->_M_size < 1000 ||
471 		       __depth > _RopeRep::_S_max_rope_depth))
472     {
473       _RopeRep* __balanced;
474 
475       try
476 	{
477 	  __balanced = _S_balance(__result);
478 	  __result->_M_unref_nonnil();
479         }
480       catch(...)
481 	{
482 	  _C_deallocate(__result,1);
483 	  __throw_exception_again;
484 	}
485       // In case of exception, we need to deallocate
486       // otherwise dangling result node.  But caller
487       // still owns its children.  Thus unref is
488       // inappropriate.
489       return __balanced;
490     }
491   else
492     return __result;
493 }
494 
495 template <class _CharT, class _Alloc>
496 typename
497 rope<_CharT,_Alloc>::_RopeRep* rope<_CharT,_Alloc>::_S_concat_char_iter
498 		(_RopeRep* __r, const _CharT*__s, size_t __slen)
499 {
500     _RopeRep* __result;
501     if (0 == __slen) {
502 	_S_ref(__r);
503 	return __r;
504     }
505     if (0 == __r)
506       return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,
507 					      __r->get_allocator());
508     if (_RopeRep::_S_leaf == __r->_M_tag &&
509           __r->_M_size + __slen <= _S_copy_max) {
510 	__result = _S_leaf_concat_char_iter((_RopeLeaf*)__r, __s, __slen);
511 	return __result;
512     }
513     if (_RopeRep::_S_concat == __r->_M_tag
514 	&& _RopeRep::_S_leaf == ((_RopeConcatenation*)__r)->_M_right->_M_tag) {
515 	_RopeLeaf* __right =
516 	  (_RopeLeaf* )(((_RopeConcatenation* )__r)->_M_right);
517 	if (__right->_M_size + __slen <= _S_copy_max) {
518 	  _RopeRep* __left = ((_RopeConcatenation*)__r)->_M_left;
519 	  _RopeRep* __nright =
520 	    _S_leaf_concat_char_iter((_RopeLeaf*)__right, __s, __slen);
521 	  __left->_M_ref_nonnil();
522 	  try {
523 	    __result = _S_tree_concat(__left, __nright);
524           }
525 	  catch(...)
526 	    {
527 	      _S_unref(__left);
528 	      _S_unref(__nright);
529 	      __throw_exception_again;
530 	    }
531 	  return __result;
532 	}
533     }
534     _RopeRep* __nright =
535       __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->get_allocator());
536     try {
537       __r->_M_ref_nonnil();
538       __result = _S_tree_concat(__r, __nright);
539     }
540     catch(...)
541       {
542 	_S_unref(__r);
543 	_S_unref(__nright);
544 	__throw_exception_again;
545       }
546     return __result;
547 }
548 
549 #ifndef __GC
550 template <class _CharT, class _Alloc>
551 typename rope<_CharT,_Alloc>::_RopeRep*
552 rope<_CharT,_Alloc>::_S_destr_concat_char_iter(
553   _RopeRep* __r, const _CharT* __s, size_t __slen)
554 {
555     _RopeRep* __result;
556     if (0 == __r)
557       return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,
558 					      __r->get_allocator());
559     size_t __count = __r->_M_ref_count;
560     size_t __orig_size = __r->_M_size;
561     if (__count > 1) return _S_concat_char_iter(__r, __s, __slen);
562     if (0 == __slen) {
563 	__r->_M_ref_count = 2;      // One more than before
564 	return __r;
565     }
566     if (__orig_size + __slen <= _S_copy_max &&
567           _RopeRep::_S_leaf == __r->_M_tag) {
568 	__result = _S_destr_leaf_concat_char_iter((_RopeLeaf*)__r, __s, __slen);
569 	return __result;
570     }
571     if (_RopeRep::_S_concat == __r->_M_tag) {
572 	_RopeLeaf* __right = (_RopeLeaf*)(((_RopeConcatenation*)__r)->_M_right);
573 	if (_RopeRep::_S_leaf == __right->_M_tag
574 	    && __right->_M_size + __slen <= _S_copy_max) {
575 	  _RopeRep* __new_right =
576 	    _S_destr_leaf_concat_char_iter(__right, __s, __slen);
577 	  if (__right == __new_right)
578 	    __new_right->_M_ref_count = 1;
579 	  else
580 	    __right->_M_unref_nonnil();
581 	  __r->_M_ref_count = 2;    // One more than before.
582 	  ((_RopeConcatenation*)__r)->_M_right = __new_right;
583 	  __r->_M_size = __orig_size + __slen;
584 	  if (0 != __r->_M_c_string) {
585 	      __r->_M_free_c_string();
586 	      __r->_M_c_string = 0;
587 	  }
588 	  return __r;
589 	}
590     }
591     _RopeRep* __right =
592       __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->get_allocator());
593     __r->_M_ref_nonnil();
594     try {
595       __result = _S_tree_concat(__r, __right);
596     }
597     catch(...)
598       {
599 	_S_unref(__r);
600 	_S_unref(__right);
601 	__throw_exception_again;
602       }
603     return __result;
604 }
605 #endif /* !__GC */
606 
607 template <class _CharT, class _Alloc>
608 typename rope<_CharT,_Alloc>::_RopeRep*
609 rope<_CharT,_Alloc>::_S_concat(_RopeRep* __left, _RopeRep* __right)
610 {
611     if (0 == __left) {
612 	_S_ref(__right);
613 	return __right;
614     }
615     if (0 == __right) {
616 	__left->_M_ref_nonnil();
617 	return __left;
618     }
619     if (_RopeRep::_S_leaf == __right->_M_tag) {
620 	if (_RopeRep::_S_leaf == __left->_M_tag) {
621 	  if (__right->_M_size + __left->_M_size <= _S_copy_max) {
622 	    return _S_leaf_concat_char_iter((_RopeLeaf*)__left,
623 					 ((_RopeLeaf*)__right)->_M_data,
624 					 __right->_M_size);
625 	  }
626 	} else if (_RopeRep::_S_concat == __left->_M_tag
627 		   && _RopeRep::_S_leaf ==
628 		      ((_RopeConcatenation*)__left)->_M_right->_M_tag) {
629 	  _RopeLeaf* __leftright =
630 		    (_RopeLeaf*)(((_RopeConcatenation*)__left)->_M_right);
631 	  if (__leftright->_M_size + __right->_M_size <= _S_copy_max) {
632 	    _RopeRep* __leftleft = ((_RopeConcatenation*)__left)->_M_left;
633 	    _RopeRep* __rest = _S_leaf_concat_char_iter(__leftright,
634 					   ((_RopeLeaf*)__right)->_M_data,
635 					   __right->_M_size);
636 	    __leftleft->_M_ref_nonnil();
637 	    try {
638 	      return(_S_tree_concat(__leftleft, __rest));
639             }
640 	    catch(...)
641 	      {
642 		_S_unref(__leftleft);
643 		_S_unref(__rest);
644 		__throw_exception_again;
645 	      }
646 	  }
647 	}
648     }
649     __left->_M_ref_nonnil();
650     __right->_M_ref_nonnil();
651     try {
652       return(_S_tree_concat(__left, __right));
653     }
654     catch(...)
655       {
656 	_S_unref(__left);
657 	_S_unref(__right);
658 	__throw_exception_again;
659       }
660 }
661 
662 template <class _CharT, class _Alloc>
663 typename rope<_CharT,_Alloc>::_RopeRep*
664 rope<_CharT,_Alloc>::_S_substring(_RopeRep* __base,
665                                size_t __start, size_t __endp1)
666 {
667     if (0 == __base) return 0;
668     size_t __len = __base->_M_size;
669     size_t __adj_endp1;
670     const size_t __lazy_threshold = 128;
671 
672     if (__endp1 >= __len) {
673 	if (0 == __start) {
674 	    __base->_M_ref_nonnil();
675 	    return __base;
676 	} else {
677 	    __adj_endp1 = __len;
678 	}
679     } else {
680 	__adj_endp1 = __endp1;
681     }
682     switch(__base->_M_tag) {
683 	case _RopeRep::_S_concat:
684 	    {
685 		_RopeConcatenation* __c = (_RopeConcatenation*)__base;
686 		_RopeRep* __left = __c->_M_left;
687 		_RopeRep* __right = __c->_M_right;
688 		size_t __left_len = __left->_M_size;
689 		_RopeRep* __result;
690 
691 		if (__adj_endp1 <= __left_len) {
692 		    return _S_substring(__left, __start, __endp1);
693 		} else if (__start >= __left_len) {
694 		    return _S_substring(__right, __start - __left_len,
695 				  __adj_endp1 - __left_len);
696 		}
697 		_Self_destruct_ptr __left_result(
698 		  _S_substring(__left, __start, __left_len));
699 		_Self_destruct_ptr __right_result(
700 		  _S_substring(__right, 0, __endp1 - __left_len));
701 		__result = _S_concat(__left_result, __right_result);
702 		return __result;
703 	    }
704 	case _RopeRep::_S_leaf:
705 	    {
706 		_RopeLeaf* __l = (_RopeLeaf*)__base;
707 		_RopeLeaf* __result;
708 		size_t __result_len;
709 		if (__start >= __adj_endp1) return 0;
710 		__result_len = __adj_endp1 - __start;
711 		if (__result_len > __lazy_threshold) goto lazy;
712 #               ifdef __GC
713 		    const _CharT* __section = __l->_M_data + __start;
714 		    __result = _S_new_RopeLeaf(__section, __result_len,
715 					  __base->get_allocator());
716 		    __result->_M_c_string = 0;  // Not eos terminated.
717 #               else
718 		    // We should sometimes create substring node instead.
719 		    __result = __STL_ROPE_FROM_UNOWNED_CHAR_PTR(
720 					__l->_M_data + __start, __result_len,
721 					__base->get_allocator());
722 #               endif
723 		return __result;
724 	    }
725 	case _RopeRep::_S_substringfn:
726 	    // Avoid introducing multiple layers of substring nodes.
727 	    {
728 		_RopeSubstring* __old = (_RopeSubstring*)__base;
729 		size_t __result_len;
730 		if (__start >= __adj_endp1) return 0;
731 		__result_len = __adj_endp1 - __start;
732 		if (__result_len > __lazy_threshold) {
733 		    _RopeSubstring* __result =
734 			_S_new_RopeSubstring(__old->_M_base,
735 					  __start + __old->_M_start,
736 					  __adj_endp1 - __start,
737 					  __base->get_allocator());
738 		    return __result;
739 
740 		} // *** else fall through: ***
741 	    }
742 	case _RopeRep::_S_function:
743 	    {
744 		_RopeFunction* __f = (_RopeFunction*)__base;
745 		_CharT* __section;
746 		size_t __result_len;
747 		if (__start >= __adj_endp1) return 0;
748 		__result_len = __adj_endp1 - __start;
749 
750 		if (__result_len > __lazy_threshold) goto lazy;
751 		__section = (_CharT*)
752 			_Data_allocate(_S_rounded_up_size(__result_len));
753 		try {
754 		  (*(__f->_M_fn))(__start, __result_len, __section);
755                 }
756 		catch(...)
757 		  {
758 		    _RopeRep::__STL_FREE_STRING(
759 	               __section, __result_len, __base->get_allocator());
760 		    __throw_exception_again;
761 		  }
762 		_S_cond_store_eos(__section[__result_len]);
763 		return _S_new_RopeLeaf(__section, __result_len,
764 				       __base->get_allocator());
765 	    }
766     }
767   lazy:
768     {
769 	// Create substring node.
770 	return _S_new_RopeSubstring(__base, __start, __adj_endp1 - __start,
771 			       __base->get_allocator());
772     }
773 }
774 
775 template<class _CharT>
776 class _Rope_flatten_char_consumer : public _Rope_char_consumer<_CharT> {
777     private:
778 	_CharT* _M_buf_ptr;
779     public:
780 
781 	_Rope_flatten_char_consumer(_CharT* __buffer) {
782 	    _M_buf_ptr = __buffer;
783 	};
784 	~_Rope_flatten_char_consumer() {}
785 	bool operator() (const _CharT* __leaf, size_t __n) {
786 	    uninitialized_copy_n(__leaf, __n, _M_buf_ptr);
787 	    _M_buf_ptr += __n;
788 	    return true;
789 	}
790 };
791 
792 template<class _CharT>
793 class _Rope_find_char_char_consumer : public _Rope_char_consumer<_CharT> {
794     private:
795 	_CharT _M_pattern;
796     public:
797 	size_t _M_count;  // Number of nonmatching characters
798 	_Rope_find_char_char_consumer(_CharT __p)
799 	  : _M_pattern(__p), _M_count(0) {}
800 	~_Rope_find_char_char_consumer() {}
801 	bool operator() (const _CharT* __leaf, size_t __n) {
802 	    size_t __i;
803 	    for (__i = 0; __i < __n; __i++) {
804 		if (__leaf[__i] == _M_pattern) {
805 		    _M_count += __i; return false;
806 		}
807 	    }
808 	    _M_count += __n; return true;
809 	}
810 };
811 
812   template<class _CharT, class _Traits>
813   // Here _CharT is both the stream and rope character type.
814 class _Rope_insert_char_consumer : public _Rope_char_consumer<_CharT> {
815     private:
816 	  typedef basic_ostream<_CharT,_Traits> _Insert_ostream;
817 	_Insert_ostream& _M_o;
818     public:
819 	_Rope_insert_char_consumer(_Insert_ostream& __writer)
820 	  : _M_o(__writer) {};
821 	~_Rope_insert_char_consumer() { };
822 		// Caller is presumed to own the ostream
823 	bool operator() (const _CharT* __leaf, size_t __n);
824 		// Returns true to continue traversal.
825 };
826 
827 template<class _CharT, class _Traits>
828 bool _Rope_insert_char_consumer<_CharT, _Traits>::operator()
829                                       (const _CharT* __leaf, size_t __n)
830 {
831   size_t __i;
832   //  We assume that formatting is set up correctly for each element.
833   for (__i = 0; __i < __n; __i++) _M_o.put(__leaf[__i]);
834   return true;
835 }
836 
837 template <class _CharT, class _Alloc>
838 bool rope<_CharT, _Alloc>::_S_apply_to_pieces(
839 				_Rope_char_consumer<_CharT>& __c,
840 				const _RopeRep* __r,
841 				size_t __begin, size_t __end)
842 {
843     if (0 == __r) return true;
844     switch(__r->_M_tag) {
845 	case _RopeRep::_S_concat:
846 	    {
847 		_RopeConcatenation* __conc = (_RopeConcatenation*)__r;
848 		_RopeRep* __left =  __conc->_M_left;
849 		size_t __left_len = __left->_M_size;
850 		if (__begin < __left_len) {
851 		    size_t __left_end = std::min(__left_len, __end);
852 		    if (!_S_apply_to_pieces(__c, __left, __begin, __left_end))
853 			return false;
854 		}
855 		if (__end > __left_len) {
856 		    _RopeRep* __right =  __conc->_M_right;
857 		    size_t __right_start = std::max(__left_len, __begin);
858 		    if (!_S_apply_to_pieces(__c, __right,
859 					 __right_start - __left_len,
860 					 __end - __left_len)) {
861 			return false;
862 		    }
863 		}
864 	    }
865 	    return true;
866 	case _RopeRep::_S_leaf:
867 	    {
868 		_RopeLeaf* __l = (_RopeLeaf*)__r;
869 		return __c(__l->_M_data + __begin, __end - __begin);
870 	    }
871 	case _RopeRep::_S_function:
872 	case _RopeRep::_S_substringfn:
873 	    {
874 		_RopeFunction* __f = (_RopeFunction*)__r;
875 		size_t __len = __end - __begin;
876 		bool __result;
877 		_CharT* __buffer =
878 		  (_CharT*)__alloc::allocate(__len * sizeof(_CharT));
879 		try {
880 		  (*(__f->_M_fn))(__begin, __len, __buffer);
881 		  __result = __c(__buffer, __len);
882                   __alloc::deallocate(__buffer, __len * sizeof(_CharT));
883                 }
884 		catch(...)
885 		  {
886 		    __alloc::deallocate(__buffer, __len * sizeof(_CharT));
887 		    __throw_exception_again;
888 		  }
889 		return __result;
890 	    }
891 	default:
892 	  return false;
893     }
894 }
895 
896   template<class _CharT, class _Traits>
897   inline void _Rope_fill(basic_ostream<_CharT, _Traits>& __o, size_t __n)
898 {
899     char __f = __o.fill();
900     size_t __i;
901 
902     for (__i = 0; __i < __n; __i++) __o.put(__f);
903 }
904 
905 
906 template <class _CharT> inline bool _Rope_is_simple(_CharT*) { return false; }
907 inline bool _Rope_is_simple(char*) { return true; }
908 inline bool _Rope_is_simple(wchar_t*) { return true; }
909 
910 template<class _CharT, class _Traits, class _Alloc>
911 basic_ostream<_CharT, _Traits>& operator<< (basic_ostream<_CharT, _Traits>& __o,
912                                             const rope<_CharT, _Alloc>& __r)
913 {
914     size_t __w = __o.width();
915     bool __left = bool(__o.flags() & std::ios::left);
916     size_t __pad_len;
917     size_t __rope_len = __r.size();
918       _Rope_insert_char_consumer<_CharT, _Traits> __c(__o);
919     bool __is_simple = _Rope_is_simple((_CharT*)0);
920 
921     if (__rope_len < __w) {
922 	__pad_len = __w - __rope_len;
923     } else {
924 	__pad_len = 0;
925     }
926     if (!__is_simple) __o.width(__w/__rope_len);
927     try {
928       if (__is_simple && !__left && __pad_len > 0) {
929 	_Rope_fill(__o, __pad_len);
930       }
931       __r.apply_to_pieces(0, __r.size(), __c);
932       if (__is_simple && __left && __pad_len > 0) {
933 	_Rope_fill(__o, __pad_len);
934       }
935       if (!__is_simple)
936         __o.width(__w);
937     }
938     catch(...)
939       {
940 	if (!__is_simple)
941 	  __o.width(__w);
942 	__throw_exception_again;
943       }
944     return __o;
945 }
946 
947 template <class _CharT, class _Alloc>
948 _CharT*
949 rope<_CharT,_Alloc>::_S_flatten(_RopeRep* __r,
950 				 size_t __start, size_t __len,
951 				 _CharT* __buffer)
952 {
953     _Rope_flatten_char_consumer<_CharT> __c(__buffer);
954     _S_apply_to_pieces(__c, __r, __start, __start + __len);
955     return(__buffer + __len);
956 }
957 
958 template <class _CharT, class _Alloc>
959 size_t
960 rope<_CharT,_Alloc>::find(_CharT __pattern, size_t __start) const
961 {
962     _Rope_find_char_char_consumer<_CharT> __c(__pattern);
963     _S_apply_to_pieces(__c, _M_tree_ptr, __start, size());
964     size_type __result_pos = __start + __c._M_count;
965 #   ifndef __STL_OLD_ROPE_SEMANTICS
966 	if (__result_pos == size()) __result_pos = npos;
967 #   endif
968     return __result_pos;
969 }
970 
971 template <class _CharT, class _Alloc>
972 _CharT*
973 rope<_CharT,_Alloc>::_S_flatten(_RopeRep* __r, _CharT* __buffer)
974 {
975     if (0 == __r) return __buffer;
976     switch(__r->_M_tag) {
977 	case _RopeRep::_S_concat:
978 	    {
979 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
980 		_RopeRep* __left = __c->_M_left;
981 		_RopeRep* __right = __c->_M_right;
982 		_CharT* __rest = _S_flatten(__left, __buffer);
983 		return _S_flatten(__right, __rest);
984 	    }
985 	case _RopeRep::_S_leaf:
986 	    {
987 		_RopeLeaf* __l = (_RopeLeaf*)__r;
988 		return copy_n(__l->_M_data, __l->_M_size, __buffer).second;
989 	    }
990 	case _RopeRep::_S_function:
991 	case _RopeRep::_S_substringfn:
992 	    // We don't yet do anything with substring nodes.
993 	    // This needs to be fixed before ropefiles will work well.
994 	    {
995 		_RopeFunction* __f = (_RopeFunction*)__r;
996 		(*(__f->_M_fn))(0, __f->_M_size, __buffer);
997 		return __buffer + __f->_M_size;
998 	    }
999 	default:
1000 	    return 0;
1001     }
1002 }
1003 
1004 
1005 // This needs work for _CharT != char
1006 template <class _CharT, class _Alloc>
1007 void
1008 rope<_CharT,_Alloc>::_S_dump(_RopeRep* __r, int __indent)
1009 {
1010     for (int __i = 0; __i < __indent; __i++) putchar(' ');
1011     if (0 == __r) {
1012 	printf("NULL\n"); return;
1013     }
1014     if (_RopeRep::_S_concat == __r->_M_tag) {
1015 	_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1016 	_RopeRep* __left = __c->_M_left;
1017 	_RopeRep* __right = __c->_M_right;
1018 
1019 #       ifdef __GC
1020 	  printf("Concatenation %p (depth = %d, len = %ld, %s balanced)\n",
1021 	    __r, __r->_M_depth, __r->_M_size, __r->_M_is_balanced? "" : "not");
1022 #       else
1023 	  printf("Concatenation %p (rc = %ld, depth = %d, "
1024 	           "len = %ld, %s balanced)\n",
1025 		 __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size,
1026 		 __r->_M_is_balanced? "" : "not");
1027 #       endif
1028 	_S_dump(__left, __indent + 2);
1029 	_S_dump(__right, __indent + 2);
1030 	return;
1031     } else {
1032 	char* __kind;
1033 
1034 	switch (__r->_M_tag) {
1035 	    case _RopeRep::_S_leaf:
1036 		__kind = "Leaf";
1037 		break;
1038 	    case _RopeRep::_S_function:
1039 		__kind = "Function";
1040 		break;
1041 	    case _RopeRep::_S_substringfn:
1042 		__kind = "Function representing substring";
1043 		break;
1044 	    default:
1045 		__kind = "(corrupted kind field!)";
1046 	}
1047 #       ifdef __GC
1048 	  printf("%s %p (depth = %d, len = %ld) ",
1049 		 __kind, __r, __r->_M_depth, __r->_M_size);
1050 #       else
1051 	  printf("%s %p (rc = %ld, depth = %d, len = %ld) ",
1052 		 __kind, __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size);
1053 #       endif
1054 	if (_S_is_one_byte_char_type((_CharT*)0)) {
1055 	    const int __max_len = 40;
1056 	    _Self_destruct_ptr __prefix(_S_substring(__r, 0, __max_len));
1057 	    _CharT __buffer[__max_len + 1];
1058 	    bool __too_big = __r->_M_size > __prefix->_M_size;
1059 
1060 	    _S_flatten(__prefix, __buffer);
1061 	    __buffer[__prefix->_M_size] = _S_eos((_CharT*)0);
1062 	    printf("%s%s\n",
1063 	           (char*)__buffer, __too_big? "...\n" : "\n");
1064 	} else {
1065 	    printf("\n");
1066 	}
1067     }
1068 }
1069 
1070 template <class _CharT, class _Alloc>
1071 const unsigned long
1072 rope<_CharT,_Alloc>::_S_min_len[
1073   _Rope_RopeRep<_CharT,_Alloc>::_S_max_rope_depth + 1] = {
1074 /* 0 */1, /* 1 */2, /* 2 */3, /* 3 */5, /* 4 */8, /* 5 */13, /* 6 */21,
1075 /* 7 */34, /* 8 */55, /* 9 */89, /* 10 */144, /* 11 */233, /* 12 */377,
1076 /* 13 */610, /* 14 */987, /* 15 */1597, /* 16 */2584, /* 17 */4181,
1077 /* 18 */6765, /* 19 */10946, /* 20 */17711, /* 21 */28657, /* 22 */46368,
1078 /* 23 */75025, /* 24 */121393, /* 25 */196418, /* 26 */317811,
1079 /* 27 */514229, /* 28 */832040, /* 29 */1346269, /* 30 */2178309,
1080 /* 31 */3524578, /* 32 */5702887, /* 33 */9227465, /* 34 */14930352,
1081 /* 35 */24157817, /* 36 */39088169, /* 37 */63245986, /* 38 */102334155,
1082 /* 39 */165580141, /* 40 */267914296, /* 41 */433494437,
1083 /* 42 */701408733, /* 43 */1134903170, /* 44 */1836311903,
1084 /* 45 */2971215073u };
1085 // These are Fibonacci numbers < 2**32.
1086 
1087 template <class _CharT, class _Alloc>
1088 typename rope<_CharT,_Alloc>::_RopeRep*
1089 rope<_CharT,_Alloc>::_S_balance(_RopeRep* __r)
1090 {
1091     _RopeRep* __forest[_RopeRep::_S_max_rope_depth + 1];
1092     _RopeRep* __result = 0;
1093     int __i;
1094     // Invariant:
1095     // The concatenation of forest in descending order is equal to __r.
1096     // __forest[__i]._M_size >= _S_min_len[__i]
1097     // __forest[__i]._M_depth = __i
1098     // References from forest are included in refcount.
1099 
1100     for (__i = 0; __i <= _RopeRep::_S_max_rope_depth; ++__i)
1101       __forest[__i] = 0;
1102     try {
1103       _S_add_to_forest(__r, __forest);
1104       for (__i = 0; __i <= _RopeRep::_S_max_rope_depth; ++__i)
1105         if (0 != __forest[__i]) {
1106 #	ifndef __GC
1107 	  _Self_destruct_ptr __old(__result);
1108 #	endif
1109 	  __result = _S_concat(__forest[__i], __result);
1110 	__forest[__i]->_M_unref_nonnil();
1111 #	if !defined(__GC) && defined(__EXCEPTIONS)
1112 	  __forest[__i] = 0;
1113 #	endif
1114       }
1115     }
1116     catch(...)
1117       {
1118 	for(__i = 0; __i <= _RopeRep::_S_max_rope_depth; __i++)
1119 	  _S_unref(__forest[__i]);
1120 	__throw_exception_again;
1121       }
1122 
1123     if (__result->_M_depth > _RopeRep::_S_max_rope_depth)
1124       __throw_length_error("rope too long");
1125     return(__result);
1126 }
1127 
1128 
1129 template <class _CharT, class _Alloc>
1130 void
1131 rope<_CharT,_Alloc>::_S_add_to_forest(_RopeRep* __r, _RopeRep** __forest)
1132 {
1133     if (__r->_M_is_balanced) {
1134 	_S_add_leaf_to_forest(__r, __forest);
1135 	return;
1136     }
1137 
1138     {
1139 	_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1140 
1141 	_S_add_to_forest(__c->_M_left, __forest);
1142 	_S_add_to_forest(__c->_M_right, __forest);
1143     }
1144 }
1145 
1146 
1147 template <class _CharT, class _Alloc>
1148 void
1149 rope<_CharT,_Alloc>::_S_add_leaf_to_forest(_RopeRep* __r, _RopeRep** __forest)
1150 {
1151     _RopeRep* __insertee;   		// included in refcount
1152     _RopeRep* __too_tiny = 0;    	// included in refcount
1153     int __i;  				// forest[0..__i-1] is empty
1154     size_t __s = __r->_M_size;
1155 
1156     for (__i = 0; __s >= _S_min_len[__i+1]/* not this bucket */; ++__i) {
1157 	if (0 != __forest[__i]) {
1158 #	    ifndef __GC
1159 	      _Self_destruct_ptr __old(__too_tiny);
1160 #	    endif
1161 	    __too_tiny = _S_concat_and_set_balanced(__forest[__i], __too_tiny);
1162 	    __forest[__i]->_M_unref_nonnil();
1163 	    __forest[__i] = 0;
1164 	}
1165     }
1166     {
1167 #	ifndef __GC
1168 	  _Self_destruct_ptr __old(__too_tiny);
1169 #	endif
1170 	__insertee = _S_concat_and_set_balanced(__too_tiny, __r);
1171     }
1172     // Too_tiny dead, and no longer included in refcount.
1173     // Insertee is live and included.
1174     for (;; ++__i) {
1175 	if (0 != __forest[__i]) {
1176 #	    ifndef __GC
1177 	      _Self_destruct_ptr __old(__insertee);
1178 #	    endif
1179 	    __insertee = _S_concat_and_set_balanced(__forest[__i], __insertee);
1180 	    __forest[__i]->_M_unref_nonnil();
1181 	    __forest[__i] = 0;
1182 	}
1183 	if (__i == _RopeRep::_S_max_rope_depth ||
1184 	      __insertee->_M_size < _S_min_len[__i+1]) {
1185 	    __forest[__i] = __insertee;
1186 	    // refcount is OK since __insertee is now dead.
1187 	    return;
1188 	}
1189     }
1190 }
1191 
1192 template <class _CharT, class _Alloc>
1193 _CharT
1194 rope<_CharT,_Alloc>::_S_fetch(_RopeRep* __r, size_type __i)
1195 {
1196     __GC_CONST _CharT* __cstr = __r->_M_c_string;
1197 
1198     if (0 != __cstr) return __cstr[__i];
1199     for(;;) {
1200       switch(__r->_M_tag) {
1201 	case _RopeRep::_S_concat:
1202 	    {
1203 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1204 		_RopeRep* __left = __c->_M_left;
1205 		size_t __left_len = __left->_M_size;
1206 
1207 		if (__i >= __left_len) {
1208 		    __i -= __left_len;
1209 		    __r = __c->_M_right;
1210 		} else {
1211 		    __r = __left;
1212 		}
1213 	    }
1214 	    break;
1215 	case _RopeRep::_S_leaf:
1216 	    {
1217 		_RopeLeaf* __l = (_RopeLeaf*)__r;
1218 		return __l->_M_data[__i];
1219 	    }
1220 	case _RopeRep::_S_function:
1221 	case _RopeRep::_S_substringfn:
1222 	    {
1223 		_RopeFunction* __f = (_RopeFunction*)__r;
1224 		_CharT __result;
1225 
1226 		(*(__f->_M_fn))(__i, 1, &__result);
1227 		return __result;
1228 	    }
1229       }
1230     }
1231 }
1232 
1233 # ifndef __GC
1234 // Return a uniquely referenced character slot for the given
1235 // position, or 0 if that's not possible.
1236 template <class _CharT, class _Alloc>
1237 _CharT*
1238 rope<_CharT,_Alloc>::_S_fetch_ptr(_RopeRep* __r, size_type __i)
1239 {
1240     _RopeRep* __clrstack[_RopeRep::_S_max_rope_depth];
1241     size_t __csptr = 0;
1242 
1243     for(;;) {
1244       if (__r->_M_ref_count > 1) return 0;
1245       switch(__r->_M_tag) {
1246 	case _RopeRep::_S_concat:
1247 	    {
1248 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1249 		_RopeRep* __left = __c->_M_left;
1250 		size_t __left_len = __left->_M_size;
1251 
1252 		if (__c->_M_c_string != 0) __clrstack[__csptr++] = __c;
1253 		if (__i >= __left_len) {
1254 		    __i -= __left_len;
1255 		    __r = __c->_M_right;
1256 		} else {
1257 		    __r = __left;
1258 		}
1259 	    }
1260 	    break;
1261 	case _RopeRep::_S_leaf:
1262 	    {
1263 		_RopeLeaf* __l = (_RopeLeaf*)__r;
1264 		if (__l->_M_c_string != __l->_M_data && __l->_M_c_string != 0)
1265 		    __clrstack[__csptr++] = __l;
1266 		while (__csptr > 0) {
1267 		    -- __csptr;
1268 		    _RopeRep* __d = __clrstack[__csptr];
1269 		    __d->_M_free_c_string();
1270 		    __d->_M_c_string = 0;
1271 		}
1272 		return __l->_M_data + __i;
1273 	    }
1274 	case _RopeRep::_S_function:
1275 	case _RopeRep::_S_substringfn:
1276 	    return 0;
1277       }
1278     }
1279 }
1280 # endif /* __GC */
1281 
1282 // The following could be implemented trivially using
1283 // lexicographical_compare_3way.
1284 // We do a little more work to avoid dealing with rope iterators for
1285 // flat strings.
1286 template <class _CharT, class _Alloc>
1287 int
1288 rope<_CharT,_Alloc>::_S_compare (const _RopeRep* __left,
1289                                  const _RopeRep* __right)
1290 {
1291     size_t __left_len;
1292     size_t __right_len;
1293 
1294     if (0 == __right) return 0 != __left;
1295     if (0 == __left) return -1;
1296     __left_len = __left->_M_size;
1297     __right_len = __right->_M_size;
1298     if (_RopeRep::_S_leaf == __left->_M_tag) {
1299 	_RopeLeaf* __l = (_RopeLeaf*) __left;
1300 	if (_RopeRep::_S_leaf == __right->_M_tag) {
1301 	    _RopeLeaf* __r = (_RopeLeaf*) __right;
1302 	    return lexicographical_compare_3way(
1303 			__l->_M_data, __l->_M_data + __left_len,
1304 			__r->_M_data, __r->_M_data + __right_len);
1305 	} else {
1306 	    const_iterator __rstart(__right, 0);
1307 	    const_iterator __rend(__right, __right_len);
1308 	    return lexicographical_compare_3way(
1309 			__l->_M_data, __l->_M_data + __left_len,
1310 			__rstart, __rend);
1311 	}
1312     } else {
1313 	const_iterator __lstart(__left, 0);
1314 	const_iterator __lend(__left, __left_len);
1315 	if (_RopeRep::_S_leaf == __right->_M_tag) {
1316 	    _RopeLeaf* __r = (_RopeLeaf*) __right;
1317 	    return lexicographical_compare_3way(
1318 				   __lstart, __lend,
1319 				   __r->_M_data, __r->_M_data + __right_len);
1320 	} else {
1321 	    const_iterator __rstart(__right, 0);
1322 	    const_iterator __rend(__right, __right_len);
1323 	    return lexicographical_compare_3way(
1324 				   __lstart, __lend,
1325 				   __rstart, __rend);
1326 	}
1327     }
1328 }
1329 
1330 // Assignment to reference proxies.
1331 template <class _CharT, class _Alloc>
1332 _Rope_char_ref_proxy<_CharT, _Alloc>&
1333 _Rope_char_ref_proxy<_CharT, _Alloc>::operator= (_CharT __c) {
1334     _RopeRep* __old = _M_root->_M_tree_ptr;
1335 #   ifndef __GC
1336 	// First check for the case in which everything is uniquely
1337 	// referenced.  In that case we can do this destructively.
1338 	_CharT* __ptr = _My_rope::_S_fetch_ptr(__old, _M_pos);
1339 	if (0 != __ptr) {
1340 	    *__ptr = __c;
1341 	    return *this;
1342 	}
1343 #   endif
1344     _Self_destruct_ptr __left(
1345       _My_rope::_S_substring(__old, 0, _M_pos));
1346     _Self_destruct_ptr __right(
1347       _My_rope::_S_substring(__old, _M_pos+1, __old->_M_size));
1348     _Self_destruct_ptr __result_left(
1349       _My_rope::_S_destr_concat_char_iter(__left, &__c, 1));
1350 
1351     _RopeRep* __result =
1352 		_My_rope::_S_concat(__result_left, __right);
1353 #   ifndef __GC
1354       _RopeRep::_S_unref(__old);
1355 #   endif
1356     _M_root->_M_tree_ptr = __result;
1357     return *this;
1358 }
1359 
1360 template <class _CharT, class _Alloc>
1361 inline _Rope_char_ref_proxy<_CharT, _Alloc>::operator _CharT () const
1362 {
1363     if (_M_current_valid) {
1364 	return _M_current;
1365     } else {
1366         return _My_rope::_S_fetch(_M_root->_M_tree_ptr, _M_pos);
1367     }
1368 }
1369 template <class _CharT, class _Alloc>
1370 _Rope_char_ptr_proxy<_CharT, _Alloc>
1371 _Rope_char_ref_proxy<_CharT, _Alloc>::operator& () const {
1372     return _Rope_char_ptr_proxy<_CharT, _Alloc>(*this);
1373 }
1374 
1375 template <class _CharT, class _Alloc>
1376 rope<_CharT, _Alloc>::rope(size_t __n, _CharT __c,
1377 			   const allocator_type& __a)
1378 : _Base(__a)
1379 {
1380     rope<_CharT,_Alloc> __result;
1381     const size_t __exponentiate_threshold = 32;
1382     size_t __exponent;
1383     size_t __rest;
1384     _CharT* __rest_buffer;
1385     _RopeRep* __remainder;
1386     rope<_CharT,_Alloc> __remainder_rope;
1387 
1388     if (0 == __n)
1389       return;
1390 
1391     __exponent = __n / __exponentiate_threshold;
1392     __rest = __n % __exponentiate_threshold;
1393     if (0 == __rest) {
1394 	__remainder = 0;
1395     } else {
1396 	__rest_buffer = _Data_allocate(_S_rounded_up_size(__rest));
1397 	uninitialized_fill_n(__rest_buffer, __rest, __c);
1398 	_S_cond_store_eos(__rest_buffer[__rest]);
1399 	try {
1400 	    __remainder = _S_new_RopeLeaf(__rest_buffer, __rest, __a);
1401         }
1402 	catch(...)
1403 	  {
1404 	    _RopeRep::__STL_FREE_STRING(__rest_buffer, __rest, __a);
1405 	    __throw_exception_again;
1406 	  }
1407     }
1408     __remainder_rope._M_tree_ptr = __remainder;
1409     if (__exponent != 0) {
1410 	_CharT* __base_buffer =
1411 	  _Data_allocate(_S_rounded_up_size(__exponentiate_threshold));
1412 	_RopeLeaf* __base_leaf;
1413 	rope __base_rope;
1414 	uninitialized_fill_n(__base_buffer, __exponentiate_threshold, __c);
1415 	_S_cond_store_eos(__base_buffer[__exponentiate_threshold]);
1416 	try {
1417           __base_leaf = _S_new_RopeLeaf(__base_buffer,
1418                                         __exponentiate_threshold, __a);
1419         }
1420 	catch(...)
1421 	  {
1422 	    _RopeRep::__STL_FREE_STRING(__base_buffer,
1423 					__exponentiate_threshold, __a);
1424 	    __throw_exception_again;
1425 	  }
1426 	__base_rope._M_tree_ptr = __base_leaf;
1427  	if (1 == __exponent) {
1428 	  __result = __base_rope;
1429 	} else {
1430 	  __result = power(__base_rope, __exponent,
1431 			   _Rope_Concat_fn<_CharT,_Alloc>());
1432 	}
1433 	if (0 != __remainder) {
1434 	  __result += __remainder_rope;
1435 	}
1436     } else {
1437 	__result = __remainder_rope;
1438     }
1439     _M_tree_ptr = __result._M_tree_ptr;
1440     _M_tree_ptr->_M_ref_nonnil();
1441 }
1442 
1443 template<class _CharT, class _Alloc>
1444   _CharT rope<_CharT,_Alloc>::_S_empty_c_str[1];
1445 
1446 template<class _CharT, class _Alloc>
1447 const _CharT* rope<_CharT,_Alloc>::c_str() const {
1448     if (0 == _M_tree_ptr) {
1449         _S_empty_c_str[0] = _S_eos((_CharT*)0);  // Possibly redundant,
1450 					     // but probably fast.
1451         return _S_empty_c_str;
1452     }
1453     __GC_CONST _CharT* __old_c_string = _M_tree_ptr->_M_c_string;
1454     if (0 != __old_c_string) return(__old_c_string);
1455     size_t __s = size();
1456     _CharT* __result = _Data_allocate(__s + 1);
1457     _S_flatten(_M_tree_ptr, __result);
1458     __result[__s] = _S_eos((_CharT*)0);
1459 #   ifdef __GC
1460 	_M_tree_ptr->_M_c_string = __result;
1461 #   else
1462       if ((__old_c_string = (__GC_CONST _CharT*)
1463              std::_Atomic_swap((unsigned long *)(&(_M_tree_ptr->_M_c_string)),
1464 			  (unsigned long)__result)) != 0) {
1465 	// It must have been added in the interim.  Hence it had to have been
1466 	// separately allocated.  Deallocate the old copy, since we just
1467 	// replaced it.
1468 	_Destroy(__old_c_string, __old_c_string + __s + 1);
1469 	_Data_deallocate(__old_c_string, __s + 1);
1470       }
1471 #   endif
1472     return(__result);
1473 }
1474 
1475 template<class _CharT, class _Alloc>
1476 const _CharT* rope<_CharT,_Alloc>::replace_with_c_str() {
1477     if (0 == _M_tree_ptr) {
1478         _S_empty_c_str[0] = _S_eos((_CharT*)0);
1479         return _S_empty_c_str;
1480     }
1481     __GC_CONST _CharT* __old_c_string = _M_tree_ptr->_M_c_string;
1482     if (_RopeRep::_S_leaf == _M_tree_ptr->_M_tag && 0 != __old_c_string) {
1483 	return(__old_c_string);
1484     }
1485     size_t __s = size();
1486     _CharT* __result = _Data_allocate(_S_rounded_up_size(__s));
1487     _S_flatten(_M_tree_ptr, __result);
1488     __result[__s] = _S_eos((_CharT*)0);
1489     _M_tree_ptr->_M_unref_nonnil();
1490     _M_tree_ptr = _S_new_RopeLeaf(__result, __s, get_allocator());
1491     return(__result);
1492 }
1493 
1494 // Algorithm specializations.  More should be added.
1495 
1496 template<class _Rope_iterator>  // was templated on CharT and Alloc
1497 void				// VC++ workaround
1498 _Rope_rotate(_Rope_iterator __first,
1499              _Rope_iterator __middle,
1500              _Rope_iterator __last)
1501 {
1502   typedef typename _Rope_iterator::value_type _CharT;
1503   typedef typename _Rope_iterator::_allocator_type _Alloc;
1504 
1505   rope<_CharT,_Alloc>& __r(__first.container());
1506   rope<_CharT,_Alloc> __prefix = __r.substr(0, __first.index());
1507   rope<_CharT,_Alloc> __suffix =
1508     __r.substr(__last.index(), __r.size() - __last.index());
1509   rope<_CharT,_Alloc> __part1 =
1510     __r.substr(__middle.index(), __last.index() - __middle.index());
1511   rope<_CharT,_Alloc> __part2 =
1512     __r.substr(__first.index(), __middle.index() - __first.index());
1513   __r = __prefix;
1514   __r += __part1;
1515   __r += __part2;
1516   __r += __suffix;
1517 }
1518 
1519 #if !defined(__GNUC__)
1520 // Appears to confuse g++
1521 inline void rotate(_Rope_iterator<char,__STL_DEFAULT_ALLOCATOR(char)> __first,
1522                    _Rope_iterator<char,__STL_DEFAULT_ALLOCATOR(char)> __middle,
1523                    _Rope_iterator<char,__STL_DEFAULT_ALLOCATOR(char)> __last) {
1524     _Rope_rotate(__first, __middle, __last);
1525 }
1526 #endif
1527 
1528 # if 0
1529 // Probably not useful for several reasons:
1530 // - for SGIs 7.1 compiler and probably some others,
1531 //   this forces lots of rope<wchar_t, ...> instantiations, creating a
1532 //   code bloat and compile time problem.  (Fixed in 7.2.)
1533 // - wchar_t is 4 bytes wide on most UNIX platforms, making it unattractive
1534 //   for unicode strings.  Unsigned short may be a better character
1535 //   type.
1536 inline void rotate(
1537 		_Rope_iterator<wchar_t,__STL_DEFAULT_ALLOCATOR(char)> __first,
1538                 _Rope_iterator<wchar_t,__STL_DEFAULT_ALLOCATOR(char)> __middle,
1539                 _Rope_iterator<wchar_t,__STL_DEFAULT_ALLOCATOR(char)> __last) {
1540     _Rope_rotate(__first, __middle, __last);
1541 }
1542 # endif
1543 
1544 } // namespace __gnu_cxx
1545 
1546 // Local Variables:
1547 // mode:C++
1548 // End:
1549