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string_res.cfa @ 6f7aff3

ADTast-experimentalenumpthread-emulationqualifiedEnum

Last change on this file since 6f7aff3 was 6f7aff3, checked in by Michael Brooks <mlbrooks@…>, 3 years ago
String hybrid assignment to unshared now optimizes to overwrite instead of copy.
Property mode set to `100644`
File size: 37.5 KB

Line
1	//
2	// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3	//
4	// The contents of this file are covered under the licence agreement in the
5	// file "LICENCE" distributed with Cforall.
6	//
7	// string_res -- variable-length, mutable run of text, with resource semantics
8	//
9	// Author : Michael L. Brooks
10	// Created On : Fri Sep 03 11:00:00 2021
11	// Last Modified By : Michael L. Brooks
12	// Last Modified On : Fri Sep 03 11:00:00 2021
13	// Update Count : 1
14	//
15
16	#include "string_res.hfa"
17	#include "string_sharectx.hfa"
18
19	#include <stdlib.hfa> // e.g. malloc
20	#include <string.h> // e.g. strlen
21	#include <assert.h>
22
23	//######################### VbyteHeap "header" #########################
24
25	#ifdef VbyteDebug
26	HandleNode *HeaderPtr;
27	#endif // VbyteDebug
28
29	struct VbyteHeap {
30
31	int NoOfCompactions; // number of compactions of the byte area
32	int NoOfExtensions; // number of extensions in the size of the byte area
33	int NoOfReductions; // number of reductions in the size of the byte area
34
35	int InitSize; // initial number of bytes in the byte-string area
36	int CurrSize; // current number of bytes in the byte-string area
37	char *StartVbyte; // pointer to the `st byte of the start of the byte-string area
38	char *EndVbyte; // pointer to the next byte after the end of the currently used portion of byte-string area
39	void *ExtVbyte; // pointer to the next byte after the end of the byte-string area
40
41	HandleNode Header; // header node for handle list
42	}; // VbyteHeap
43
44
45	static inline void compaction( VbyteHeap & ); // compaction of the byte area
46	static inline void garbage( VbyteHeap &, int ); // garbage collect the byte area
47	static inline void extend( VbyteHeap &, int ); // extend the size of the byte area
48	static inline void reduce( VbyteHeap &, int ); // reduce the size of the byte area
49
50	static inline void ?{}( VbyteHeap &, size_t = 1000 );
51	static inline void ^?{}( VbyteHeap & );
52	static inline void ByteCopy( char , int, int, char , int, int ); // copy a block of bytes from one location in the heap to another
53	static inline int ByteCmp( char , int, int, char , int, int ); // compare 2 blocks of bytes
54	static inline char *VbyteAlloc( VbyteHeap &, int ); // allocate a block bytes in the heap
55	static inline char *VbyteTryAdjustLast( VbyteHeap &, int );
56
57	static inline void AddThisAfter( HandleNode &, HandleNode & );
58	static inline void DeleteNode( HandleNode & );
59	static inline void MoveThisAfter( HandleNode &, const HandleNode & ); // move current handle after parameter handle
60
61
62	// Allocate the storage for the variable sized area and intialize the heap variables.
63
64	static inline void ?{}( VbyteHeap & this, size_t Size ) with(this) {
65	#ifdef VbyteDebug
66	serr \| "enter:VbyteHeap::VbyteHeap, this:" \| &this \| " Size:" \| Size;
67	#endif // VbyteDebug
68	NoOfCompactions = NoOfExtensions = NoOfReductions = 0;
69	InitSize = CurrSize = Size;
70	StartVbyte = EndVbyte = alloc(CurrSize);
71	ExtVbyte = (void *)( StartVbyte + CurrSize );
72	Header.flink = Header.blink = &Header;
73	Header.ulink = & this;
74	#ifdef VbyteDebug
75	HeaderPtr = &Header;
76	serr \| "exit:VbyteHeap::VbyteHeap, this:" \| &this;
77	#endif // VbyteDebug
78	} // VbyteHeap
79
80
81	// Release the dynamically allocated storage for the byte area.
82
83	static inline void ^?{}( VbyteHeap & this ) with(this) {
84	free( StartVbyte );
85	} // ~VbyteHeap
86
87
88	//######################### HandleNode #########################
89
90
91	// Create a handle node. The handle is not linked into the handle list. This is the responsibilitiy of the handle
92	// creator.
93
94	static inline void ?{}( HandleNode & this ) with(this) {
95	#ifdef VbyteDebug
96	serr \| "enter:HandleNode::HandleNode, this:" \| &this;
97	#endif // VbyteDebug
98	s = 0;
99	lnth = 0;
100	#ifdef VbyteDebug
101	serr \| "exit:HandleNode::HandleNode, this:" \| &this;
102	#endif // VbyteDebug
103	} // HandleNode
104
105	// Create a handle node. The handle is linked into the handle list at the end. This means that this handle will NOT be
106	// in order by string address, but this is not a problem because a string with length zero does nothing during garbage
107	// collection.
108
109	static inline void ?{}( HandleNode & this, VbyteHeap & vh ) with(this) {
110	#ifdef VbyteDebug
111	serr \| "enter:HandleNode::HandleNode, this:" \| &this;
112	#endif // VbyteDebug
113	s = 0;
114	lnth = 0;
115	ulink = &vh;
116	AddThisAfter( this, *vh.Header.blink );
117	#ifdef VbyteDebug
118	serr \| "exit:HandleNode::HandleNode, this:" \| &this;
119	#endif // VbyteDebug
120	} // HandleNode
121
122
123	// Delete a node from the handle list by unchaining it from the list. If the handle node was allocated dynamically, it
124	// is the responsibility of the creator to destroy it.
125
126	static inline void ^?{}( HandleNode & this ) with(this) {
127	#ifdef VbyteDebug
128	serr \| "enter:HandleNode::~HandleNode, this:" \| & this;
129	{
130	serr \| nlOff;
131	serr \| " lnth:" \| lnth \| " s:" \| (void *)s \| ",\"";
132	for ( int i = 0; i < lnth; i += 1 ) {
133	serr \| s[i];
134	} // for
135	serr \| "\" flink:" \| flink \| " blink:" \| blink \| nl;
136	serr \| nlOn;
137	}
138	#endif // VbyteDebug
139	DeleteNode( this );
140	} // ~HandleNode
141
142
143	//######################### String Sharing Context #########################
144
145	static string_sharectx * ambient_string_sharectx; // fickle top of stack
146	static string_sharectx default_string_sharectx = {NEW_SHARING}; // stable bottom of stack
147
148	void ?{}( string_sharectx & this, StringSharectx_Mode mode ) with( this ) {
149	(older){ ambient_string_sharectx };
150	if ( mode == NEW_SHARING ) {
151	(activeHeap){ new( (size_t) 1000 ) };
152	} else {
153	verify( mode == NO_SHARING );
154	(activeHeap){ 0p };
155	}
156	ambient_string_sharectx = & this;
157	}
158
159	void ^?{}( string_sharectx & this ) with( this ) {
160	if ( activeHeap ) delete( activeHeap );
161
162	// unlink this from older-list starting from ambient_string_sharectx
163	// usually, this==ambient_string_sharectx and the loop runs zero times
164	string_sharectx *& c = ambient_string_sharectx;
165	while ( c != &this ) &c = &c->older; // find this
166	c = this.older; // unlink
167	}
168
169	//######################### String Resource #########################
170
171
172	VbyteHeap * DEBUG_string_heap() {
173	assert( ambient_string_sharectx->activeHeap && "No sharing context is active" );
174	return ambient_string_sharectx->activeHeap;
175	}
176
177	size_t DEBUG_string_bytes_avail_until_gc( VbyteHeap * heap ) {
178	return ((char*)heap->ExtVbyte) - heap->EndVbyte;
179	}
180
181	size_t DEBUG_string_bytes_in_heap( VbyteHeap * heap ) {
182	return heap->CurrSize;
183	}
184
185	const char * DEBUG_string_heap_start( VbyteHeap * heap ) {
186	return heap->StartVbyte;
187	}
188
189	// Returns the size of the string in bytes
190	size_t size(const string_res &s) with(s) {
191	return Handle.lnth;
192	}
193
194	// Output operator
195	ofstream & ?\|?(ofstream &out, const string_res &s) {
196	// Store auto-newline state so it can be restored
197	bool anl = getANL$(out);
198	nlOff(out);
199	for (size_t i = 0; i < s.Handle.lnth; i++) {
200	out \| s[i];
201	}
202	out \| sep;
203	// Re-apply newlines after done, for chaining version
204	if (anl) nlOn(out);
205	return out;
206	}
207
208	void ?\|?(ofstream &out, const string_res &s) {
209	// Store auto-newline state so it can be restored
210	bool anl = getANL$(out);
211	nlOff(out);
212	for (size_t i = 0; i < s.Handle.lnth; i++) {
213	// Need to re-apply on the last output operator, for whole-statement version
214	if (anl && i == s.Handle.lnth-1) nlOn(out);
215	out \| s[i];
216	}
217	return out;
218	}
219
220	// Empty constructor
221	void ?{}(string_res &s) with(s) {
222	if( ambient_string_sharectx->activeHeap ) {
223	(Handle){ * ambient_string_sharectx->activeHeap };
224	(shareEditSet_owns_ulink){ false };
225	} else {
226	(Handle){ * new( (size_t) 10 ) }; // TODO: can I lazily avoid allocating for empty string
227	(shareEditSet_owns_ulink){ true };
228	}
229	s.shareEditSet_prev = &s;
230	s.shareEditSet_next = &s;
231	}
232
233	static inline void eagerCopyCtorHelper(string_res &s, const char* rhs, size_t rhslnth) with(s) {
234	if( ambient_string_sharectx->activeHeap ) {
235	(Handle){ * ambient_string_sharectx->activeHeap };
236	(shareEditSet_owns_ulink){ false };
237	} else {
238	(Handle){ * new( rhslnth ) };
239	(shareEditSet_owns_ulink){ true };
240	}
241	Handle.s = VbyteAlloc(*Handle.ulink, rhslnth);
242	Handle.lnth = rhslnth;
243	for ( int i = 0; i < rhslnth; i += 1 ) { // copy characters
244	Handle.s[i] = rhs[i];
245	} // for
246	s.shareEditSet_prev = &s;
247	s.shareEditSet_next = &s;
248	}
249
250	// Constructor from a raw buffer and size
251	void ?{}(string_res &s, const char* rhs, size_t rhslnth) with(s) {
252	eagerCopyCtorHelper(s, rhs, rhslnth);
253	}
254
255	// String literal constructor
256	void ?{}(string_res &s, const char* rhs) {
257	(s){ rhs, strlen(rhs) };
258	}
259
260	// General copy constructor
261	void ?{}(string_res &s, const string_res & s2, StrResInitMode mode, size_t start, size_t end ) {
262
263	verify( start <= end && end <= s2.Handle.lnth );
264
265	if (s2.Handle.ulink == ambient_string_sharectx->activeHeap) {
266	// same heap: allow overlap
267	(s.Handle){};
268	s.Handle.s = s2.Handle.s + start;
269	s.Handle.lnth = end - start;
270	s.Handle.ulink = ambient_string_sharectx->activeHeap;
271	(s.shareEditSet_owns_ulink){ false };
272	AddThisAfter(s.Handle, s2.Handle ); // insert this handle after rhs handle
273	// ^ bug? skip others at early point in string
274
275	if (mode == COPY_VALUE) {
276	// make s alone in its shareEditSet
277	s.shareEditSet_prev = &s;
278	s.shareEditSet_next = &s;
279	} else {
280	verify( mode == SHARE_EDITS );
281
282	// s2 is logically const but not implementation const
283	string_res & s2mod = (string_res &) s2;
284
285	// insert s after s2 on shareEditSet
286	s.shareEditSet_next = s2mod.shareEditSet_next;
287	s.shareEditSet_prev = &s2mod;
288	s.shareEditSet_next->shareEditSet_prev = &s;
289	s.shareEditSet_prev->shareEditSet_next = &s;
290	}
291	} else {
292	// crossing heaps: eager copy
293	assert( mode == COPY_VALUE && "need to solidify context-crossing rules for requesting shared edits");
294	eagerCopyCtorHelper(s, s2.Handle.s + start, end - start);
295	verify(s.shareEditSet_prev == &s);
296	verify(s.shareEditSet_next == &s);
297	}
298	}
299
300	static void assignEditSet(string_res & this, string_res * shareEditSetStartPeer, string_res * shareEditSetEndPeer,
301	char * resultSesStart,
302	size_t resultSesLnth,
303	HandleNode * resultPadPosition, size_t bsize ) {
304
305	char * beforeBegin = shareEditSetStartPeer->Handle.s;
306	size_t beforeLen = this.Handle.s - beforeBegin;
307
308	char * afterBegin = this.Handle.s + this.Handle.lnth;
309	size_t afterLen = shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth - afterBegin;
310
311	size_t oldLnth = this.Handle.lnth;
312
313	this.Handle.s = resultSesStart + beforeLen;
314	this.Handle.lnth = bsize;
315	if (resultPadPosition)
316	MoveThisAfter( this.Handle, *resultPadPosition );
317
318	// adjust all substring string and handle locations, and check if any substring strings are outside the new base string
319	char *limit = resultSesStart + resultSesLnth;
320	for (string_res * p = this.shareEditSet_next; p != &this; p = p->shareEditSet_next) {
321	verify (p->Handle.s >= beforeBegin);
322	if ( p->Handle.s >= afterBegin ) {
323	verify ( p->Handle.s <= afterBegin + afterLen );
324	verify ( p->Handle.s + p->Handle.lnth <= afterBegin + afterLen );
325	// p starts after the edit
326	// take start and end as end-anchored
327	size_t startOffsetFromEnd = afterBegin + afterLen - p->Handle.s;
328	p->Handle.s = limit - startOffsetFromEnd;
329	// p->Handle.lnth unaffected
330	} else if ( p->Handle.s <= beforeBegin + beforeLen ) {
331	// p starts before, or at the start of, the edit
332	if ( p->Handle.s + p->Handle.lnth <= beforeBegin + beforeLen ) {
333	// p ends before the edit
334	// take end as start-anchored too
335	// p->Handle.lnth unaffected
336	} else if ( p->Handle.s + p->Handle.lnth < afterBegin ) {
337	// p ends during the edit; p does not include the last character replaced
338	// clip end of p to end at start of edit
339	p->Handle.lnth = beforeLen - ( p->Handle.s - beforeBegin );
340	} else {
341	// p ends after the edit
342	verify ( p->Handle.s + p->Handle.lnth <= afterBegin + afterLen );
343	// take end as end-anchored
344	// stretch-shrink p according to the edit
345	p->Handle.lnth += this.Handle.lnth;
346	p->Handle.lnth -= oldLnth;
347	}
348	// take start as start-anchored
349	size_t startOffsetFromStart = p->Handle.s - beforeBegin;
350	p->Handle.s = resultSesStart + startOffsetFromStart;
351	} else {
352	verify ( p->Handle.s < afterBegin );
353	// p starts during the edit
354	verify( p->Handle.s + p->Handle.lnth >= beforeBegin + beforeLen );
355	if ( p->Handle.s + p->Handle.lnth < afterBegin ) {
356	// p ends during the edit; p does not include the last character replaced
357	// set p to empty string at start of edit
358	p->Handle.s = this.Handle.s;
359	p->Handle.lnth = 0;
360	} else {
361	// p includes the end of the edit
362	// clip start of p to start at end of edit
363	int charsToClip = afterBegin - p->Handle.s;
364	p->Handle.s = this.Handle.s + this.Handle.lnth;
365	p->Handle.lnth -= charsToClip;
366	}
367	}
368	if (resultPadPosition)
369	MoveThisAfter( p->Handle, *resultPadPosition ); // move substring handle to maintain sorted order by string position
370	}
371	}
372
373	static void assign_(string_res &this, const char* buffer, size_t bsize, const string_res & valSrc) {
374
375	// traverse the incumbent share-edit set (SES) to recover the range of a base string to which `this` belongs
376	string_res * shareEditSetStartPeer = & this;
377	string_res * shareEditSetEndPeer = & this;
378	for (string_res * editPeer = this.shareEditSet_next; editPeer != &this; editPeer = editPeer->shareEditSet_next) {
379	if ( editPeer->Handle.s < shareEditSetStartPeer->Handle.s ) {
380	shareEditSetStartPeer = editPeer;
381	}
382	if ( shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth < editPeer->Handle.s + editPeer->Handle.lnth) {
383	shareEditSetEndPeer = editPeer;
384	}
385	}
386
387	verify( shareEditSetEndPeer->Handle.s >= shareEditSetStartPeer->Handle.s );
388	size_t editSetLength = shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth - shareEditSetStartPeer->Handle.s;
389	verify( editSetLength >= this.Handle.lnth );
390
391	if ( this.shareEditSet_owns_ulink ) { // assigning to private context
392	// ok to overwrite old value within LHS
393	char * prefixStartOrig = shareEditSetStartPeer->Handle.s;
394	int prefixLen = this.Handle.s - prefixStartOrig;
395	char * suffixStartOrig = this.Handle.s + this.Handle.lnth;
396	int suffixLen = shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth - suffixStartOrig;
397
398	int delta = bsize - this.Handle.lnth;
399	if ( char * oldBytes = VbyteTryAdjustLast( *this.Handle.ulink, delta ) ) {
400	// growing: copy from old to new
401	char * dest = VbyteAlloc( *this.Handle.ulink, editSetLength );
402	char *destCursor = dest; memcpy(destCursor, prefixStartOrig, prefixLen);
403	destCursor += prefixLen; memcpy(destCursor, buffer , bsize );
404	destCursor += this.Handle.lnth; memcpy(destCursor, suffixStartOrig, suffixLen);
405	assignEditSet(this, shareEditSetStartPeer, shareEditSetEndPeer,
406	dest,
407	editSetLength,
408	0p, bsize);
409	free( oldBytes );
410	} else {
411	// room is already allocated in-place: bubble suffix and overwite middle
412	memmove( suffixStartOrig + delta, suffixStartOrig, suffixLen );
413	memcpy( this.Handle.s, buffer, bsize );
414
415	assignEditSet(this, shareEditSetStartPeer, shareEditSetEndPeer,
416	shareEditSetStartPeer->Handle.s,
417	editSetLength,
418	0p, bsize);
419	}
420
421	} else if ( // assigning to shared context
422	this.Handle.lnth == editSetLength && // overwriting entire run of SES
423	& valSrc && // sourcing from a managed string
424	valSrc.Handle.ulink == this.Handle.ulink ) { // sourcing from same heap
425
426	// SES's result will only use characters from the source string => reuse source
427	assignEditSet(this, shareEditSetStartPeer, shareEditSetEndPeer,
428	valSrc.Handle.s,
429	valSrc.Handle.lnth,
430	&((string_res&)valSrc).Handle, bsize);
431
432	} else {
433	// overwriting a proper substring of some string: mash characters from old and new together (copy on write)
434	// OR we are importing characters: need to copy eagerly (can't refer to source)
435
436	// full string is from start of shareEditSetStartPeer thru end of shareEditSetEndPeer
437	// `this` occurs in the middle of it, to be replaced
438	// build up the new text in `pasting`
439
440	// super private string ctor: ignore ambient context
441	void ?{}( string_res &s, VbyteHeap & heap, const char* rhs, size_t rhslnth ) with(s) {
442	(Handle){ heap };
443	Handle.s = VbyteAlloc(*Handle.ulink, rhslnth);
444	Handle.lnth = rhslnth;
445	(s.shareEditSet_owns_ulink){ false };
446	for ( int i = 0; i < rhslnth; i += 1 ) { // copy characters
447	Handle.s[i] = rhs[i];
448	} // for
449	s.shareEditSet_prev = &s;
450	s.shareEditSet_next = &s;
451	}
452
453	string_res pasting = {
454	* this.Handle.ulink, // maintain same heap, regardless of context
455	shareEditSetStartPeer->Handle.s, // start of SES
456	this.Handle.s - shareEditSetStartPeer->Handle.s }; // length of SES, before this
457	append( pasting,
458	buffer, // start of replacement for this
459	bsize ); // length of replacement for this
460	append( pasting,
461	this.Handle.s + this.Handle.lnth, // start of SES after this
462	shareEditSetEndPeer->Handle.s + shareEditSetEndPeer->Handle.lnth -
463	(this.Handle.s + this.Handle.lnth) ); // length of SES, after this
464
465	// The above string building can trigger compaction.
466	// The reference points (that are arguments of the string building) may move during that building.
467	// From this point on, they are stable.
468
469	assignEditSet(this, shareEditSetStartPeer, shareEditSetEndPeer,
470	pasting.Handle.s,
471	pasting.Handle.lnth,
472	&pasting.Handle, bsize);
473	}
474	}
475
476	void assign(string_res &this, const char* buffer, size_t bsize) {
477	assign_(this, buffer, bsize, *0p);
478	}
479
480	void ?=?(string_res &s, const char* other) {
481	assign(s, other, strlen(other));
482	}
483
484	void ?=?(string_res &s, char other) {
485	assign(s, &other, 1);
486	}
487
488	// Copy assignment operator
489	void ?=?(string_res & this, const string_res & rhs) with( this ) {
490	assign_(this, rhs.Handle.s, rhs.Handle.lnth, rhs);
491	}
492
493	void ?=?(string_res & this, string_res & rhs) with( this ) {
494	const string_res & rhs2 = rhs;
495	this = rhs2;
496	}
497
498
499	// Destructor
500	void ^?{}(string_res &s) with(s) {
501	// much delegated to implied ^VbyteSM
502
503	// sever s from its share-edit peers, if any (four no-ops when already solo)
504	s.shareEditSet_prev->shareEditSet_next = s.shareEditSet_next;
505	s.shareEditSet_next->shareEditSet_prev = s.shareEditSet_prev;
506	// s.shareEditSet_next = &s;
507	// s.shareEditSet_prev = &s;
508
509	if (shareEditSet_owns_ulink && s.shareEditSet_next == &s) { // last one out
510	delete( s.Handle.ulink );
511	}
512	}
513
514
515	// Returns the character at the given index
516	// With unicode support, this may be different from just the byte at the given
517	// offset from the start of the string.
518	char ?[?](const string_res &s, size_t index) with(s) {
519	//TODO: Check if index is valid (no exceptions yet)
520	return Handle.s[index];
521	}
522
523	void assignAt(const string_res &s, size_t index, char val) {
524	string_res editZone = { s, SHARE_EDITS, index, index+1 };
525	assign(editZone, &val, 1);
526	}
527
528
529	///////////////////////////////////////////////////////////////////
530	// Concatenation
531
532	void append(string_res &str1, const char * buffer, size_t bsize) {
533	size_t clnth = size(str1) + bsize;
534	if ( str1.Handle.s + size(str1) == buffer ) { // already juxtapose ?
535	// no-op
536	} else { // must copy some text
537	if ( str1.Handle.s + size(str1) == VbyteAlloc(*str1.Handle.ulink, 0) ) { // str1 at end of string area ?
538	VbyteAlloc( *str1.Handle.ulink, bsize ); // create room for 2nd part at the end of string area
539	} else { // copy the two parts
540	char * str1oldBuf = str1.Handle.s;
541	str1.Handle.s = VbyteAlloc( *str1.Handle.ulink, clnth );
542	ByteCopy( str1.Handle.s, 0, str1.Handle.lnth, str1oldBuf, 0, str1.Handle.lnth);
543	} // if
544	ByteCopy( str1.Handle.s, str1.Handle.lnth, bsize, (char*)buffer, 0, (int)bsize);
545	// VbyteHeap & this, char Dst, int DstStart, int DstLnth, char Src, int SrcStart, int SrcLnth
546	} // if
547	str1.Handle.lnth = clnth;
548	}
549
550	void ?+=?(string_res &str1, const string_res &str2) {
551	append( str1, str2.Handle.s, str2.Handle.lnth );
552	}
553
554	void ?+=?(string_res &s, char other) {
555	append( s, &other, 1 );
556	}
557
558	void ?+=?(string_res &s, const char* other) {
559	append( s, other, strlen(other) );
560	}
561
562
563
564
565	//////////////////////////////////////////////////////////
566	// Comparisons
567
568
569	bool ?==?(const string_res &s1, const string_res &s2) {
570	return ByteCmp( s1.Handle.s, 0, s1.Handle.lnth, s2.Handle.s, 0, s2.Handle.lnth) == 0;
571	}
572
573	bool ?!=?(const string_res &s1, const string_res &s2) {
574	return !(s1 == s2);
575	}
576	bool ?==?(const string_res &s, const char* other) {
577	string_res sother = other;
578	return s == sother;
579	}
580	bool ?!=?(const string_res &s, const char* other) {
581	return !(s == other);
582	}
583
584
585	//////////////////////////////////////////////////////////
586	// Search
587
588	bool contains(const string_res &s, char ch) {
589	for (i; size(s)) {
590	if (s[i] == ch) return true;
591	}
592	return false;
593	}
594
595	int find(const string_res &s, char search) {
596	for (i; size(s)) {
597	if (s[i] == search) return i;
598	}
599	return size(s);
600	}
601
602	/* Remaining implementations essentially ported from Sunjay's work */
603
604	int find(const string_res &s, const string_res &search) {
605	return find(s, search.Handle.s, search.Handle.lnth);
606	}
607
608	int find(const string_res &s, const char* search) {
609	return find(s, search, strlen(search));
610	}
611
612	int find(const string_res &s, const char* search, size_t searchsize) {
613	// FIXME: This is a naive algorithm. We probably want to switch to someting
614	// like Boyer-Moore in the future.
615	// https://en.wikipedia.org/wiki/String_searching_algorithm
616
617	// Always find the empty string
618	if (searchsize == 0) {
619	return 0;
620	}
621
622	for (size_t i = 0; i < s.Handle.lnth; i++) {
623	size_t remaining = s.Handle.lnth - i;
624	// Never going to find the search string if the remaining string is
625	// smaller than search
626	if (remaining < searchsize) {
627	break;
628	}
629
630	bool matched = true;
631	for (size_t j = 0; j < searchsize; j++) {
632	if (search[j] != s.Handle.s[i + j]) {
633	matched = false;
634	break;
635	}
636	}
637	if (matched) {
638	return i;
639	}
640	}
641
642	return s.Handle.lnth;
643	}
644
645	bool includes(const string_res &s, const string_res &search) {
646	return includes(s, search.Handle.s, search.Handle.lnth);
647	}
648
649	bool includes(const string_res &s, const char* search) {
650	return includes(s, search, strlen(search));
651	}
652
653	bool includes(const string_res &s, const char* search, size_t searchsize) {
654	return find(s, search, searchsize) < s.Handle.lnth;
655	}
656
657	bool startsWith(const string_res &s, const string_res &prefix) {
658	return startsWith(s, prefix.Handle.s, prefix.Handle.lnth);
659	}
660
661	bool startsWith(const string_res &s, const char* prefix) {
662	return startsWith(s, prefix, strlen(prefix));
663	}
664
665	bool startsWith(const string_res &s, const char* prefix, size_t prefixsize) {
666	if (s.Handle.lnth < prefixsize) {
667	return false;
668	}
669	return memcmp(s.Handle.s, prefix, prefixsize) == 0;
670	}
671
672	bool endsWith(const string_res &s, const string_res &suffix) {
673	return endsWith(s, suffix.Handle.s, suffix.Handle.lnth);
674	}
675
676	bool endsWith(const string_res &s, const char* suffix) {
677	return endsWith(s, suffix, strlen(suffix));
678	}
679
680	bool endsWith(const string_res &s, const char* suffix, size_t suffixsize) {
681	if (s.Handle.lnth < suffixsize) {
682	return false;
683	}
684	// Amount to offset the bytes pointer so that we are comparing the end of s
685	// to suffix. s.bytes + offset should be the first byte to compare against suffix
686	size_t offset = s.Handle.lnth - suffixsize;
687	return memcmp(s.Handle.s + offset, suffix, suffixsize) == 0;
688	}
689
690	/* Back to Mike's work */
691
692
693	///////////////////////////////////////////////////////////////////////////
694	// charclass, include, exclude
695
696	void ?{}( charclass_res & this, const string_res & chars) {
697	(this){ chars.Handle.s, chars.Handle.lnth };
698	}
699
700	void ?{}( charclass_res & this, const char * chars ) {
701	(this){ chars, strlen(chars) };
702	}
703
704	void ?{}( charclass_res & this, const char * chars, size_t charssize ) {
705	(this.chars){ chars, charssize };
706	// now sort it ?
707	}
708
709	void ^?{}( charclass_res & this ) {
710	^(this.chars){};
711	}
712
713	static bool test( const charclass_res & mask, char c ) {
714	// instead, use sorted char list?
715	return contains( mask.chars, c );
716	}
717
718	int exclude(const string_res &s, const charclass_res &mask) {
719	for (int i = 0; i < size(s); i++) {
720	if ( test(mask, s[i]) ) return i;
721	}
722	return size(s);
723	}
724
725	int include(const string_res &s, const charclass_res &mask) {
726	for (int i = 0; i < size(s); i++) {
727	if ( ! test(mask, s[i]) ) return i;
728	}
729	return size(s);
730	}
731
732	//######################### VbyteHeap "implementation" #########################
733
734
735	// Add a new HandleNode node n after the current HandleNode node.
736
737	static inline void AddThisAfter( HandleNode & this, HandleNode & n ) with(this) {
738	#ifdef VbyteDebug
739	serr \| "enter:AddThisAfter, this:" \| &this \| " n:" \| &n;
740	#endif // VbyteDebug
741	verify( n.ulink != 0p );
742	verify( this.ulink == n.ulink );
743	flink = n.flink;
744	blink = &n;
745	n.flink->blink = &this;
746	n.flink = &this;
747	#ifdef VbyteDebug
748	{
749	serr \| "HandleList:";
750	serr \| nlOff;
751	for ( HandleNode *ni = HeaderPtr->flink; ni != HeaderPtr; ni = ni->flink ) {
752	serr \| "\tnode:" \| ni \| " lnth:" \| ni->lnth \| " s:" \| (void *)ni->s \| ",\"";
753	for ( int i = 0; i < ni->lnth; i += 1 ) {
754	serr \| ni->s[i];
755	} // for
756	serr \| "\" flink:" \| ni->flink \| " blink:" \| ni->blink \| nl;
757	} // for
758	serr \| nlOn;
759	}
760	serr \| "exit:AddThisAfter";
761	#endif // VbyteDebug
762	} // AddThisAfter
763
764
765	// Delete the current HandleNode node.
766
767	static inline void DeleteNode( HandleNode & this ) with(this) {
768	#ifdef VbyteDebug
769	serr \| "enter:DeleteNode, this:" \| &this;
770	#endif // VbyteDebug
771	flink->blink = blink;
772	blink->flink = flink;
773	#ifdef VbyteDebug
774	serr \| "exit:DeleteNode";
775	#endif // VbyteDebug
776	} // DeleteNode
777
778
779
780	// Allocates specified storage for a string from byte-string area. If not enough space remains to perform the
781	// allocation, the garbage collection routine is called.
782
783	static inline char * VbyteAlloc( VbyteHeap & this, int size ) with(this) {
784	#ifdef VbyteDebug
785	serr \| "enter:VbyteAlloc, size:" \| size;
786	#endif // VbyteDebug
787	uintptr_t NoBytes;
788	char *r;
789
790	NoBytes = ( uintptr_t )EndVbyte + size;
791	if ( NoBytes > ( uintptr_t )ExtVbyte ) { // enough room for new byte-string ?
792	garbage( this, size ); // firer up the garbage collector
793	NoBytes = ( uintptr_t )EndVbyte + size; // try again
794	if ( NoBytes > ( uintptr_t )ExtVbyte ) { // enough room for new byte-string ?
795	assert( 0 && "garbage run did not free up required space" );
796	} // if
797	} // if
798	r = EndVbyte;
799	EndVbyte += size;
800	#ifdef VbyteDebug
801	serr \| "exit:VbyteAlloc, r:" \| (void )r \| " EndVbyte:" \| (void )EndVbyte \| " ExtVbyte:" \| ExtVbyte;
802	#endif // VbyteDebug
803	return r;
804	} // VbyteAlloc
805
806
807	// Adjusts the last allocation in this heap by delta bytes, or resets this heap to be able to offer
808	// new allocations of its original size + delta bytes. Positive delta means bigger;
809	// negative means smaller. A null return indicates that the original heap location has room for
810	// the requested growth. A non-null return indicates that copying to a new location is required
811	// but has not been done; the returned value is the old heap storage location; `this` heap is
812	// modified to reference the new location. In the copy-requred case, the caller should use
813	// VbyteAlloc to claim the new space, while doing optimal copying from old to new, then free old.
814
815	static inline char * VbyteTryAdjustLast( VbyteHeap & this, int delta ) with(this) {
816
817	if ( ( uintptr_t )EndVbyte + delta <= ( uintptr_t )ExtVbyte ) {
818	// room available
819	EndVbyte += delta;
820	return 0p;
821	}
822
823	char *oldBytes = StartVbyte;
824
825	NoOfExtensions += 1;
826	CurrSize *= 2;
827	StartVbyte = EndVbyte = alloc(CurrSize);
828	ExtVbyte = StartVbyte + CurrSize;
829
830	return oldBytes;
831	}
832
833
834	// Move an existing HandleNode node h somewhere after the current HandleNode node so that it is in ascending order by
835	// the address in the byte string area.
836
837	static inline void MoveThisAfter( HandleNode & this, const HandleNode & h ) with(this) {
838	#ifdef VbyteDebug
839	serr \| "enter:MoveThisAfter, this:" \| & this \| " h:" \| & h;
840	#endif // VbyteDebug
841	verify( h.ulink != 0p );
842	verify( this.ulink == h.ulink );
843	if ( s < h.s ) { // check argument values
844	// serr \| "VbyteSM: Error - Cannot move byte string starting at:" \| s \| " after byte string starting at:"
845	// \| ( h->s ) \| " and keep handles in ascending order";
846	// exit(-1 );
847	verify( 0 && "VbyteSM: Error - Cannot move byte strings as requested and keep handles in ascending order");
848	} // if
849
850	HandleNode *i;
851	for ( i = h.flink; i->s != 0 && s > ( i->s ); i = i->flink ); // find the position for this node after h
852	if ( & this != i->blink ) {
853	DeleteNode( this );
854	AddThisAfter( this, *i->blink );
855	} // if
856	#ifdef VbyteDebug
857	{
858	serr \| "HandleList:";
859	serr \| nlOff;
860	for ( HandleNode *n = HeaderPtr->flink; n != HeaderPtr; n = n->flink ) {
861	serr \| "\tnode:" \| n \| " lnth:" \| n->lnth \| " s:" \| (void *)n->s \| ",\"";
862	for ( int i = 0; i < n->lnth; i += 1 ) {
863	serr \| n->s[i];
864	} // for
865	serr \| "\" flink:" \| n->flink \| " blink:" \| n->blink \| nl;
866	} // for
867	serr \| nlOn;
868	}
869	serr \| "exit:MoveThisAfter";
870	#endif // VbyteDebug
871	} // MoveThisAfter
872
873
874
875
876
877	//######################### VbyteHeap #########################
878
879	// Move characters from one location in the byte-string area to another. The routine handles the following situations:
880	//
881	// if the \|Src\| > \|Dst\| => truncate
882	// if the \|Dst\| > \|Src\| => pad Dst with blanks
883
884	void ByteCopy( char Dst, int DstStart, int DstLnth, char Src, int SrcStart, int SrcLnth ) {
885	for ( int i = 0; i < DstLnth; i += 1 ) {
886	if ( i == SrcLnth ) { // \|Dst\| > \|Src\|
887	for ( ; i < DstLnth; i += 1 ) { // pad Dst with blanks
888	Dst[DstStart + i] = ' ';
889	} // for
890	break;
891	} // exit
892	Dst[DstStart + i] = Src[SrcStart + i];
893	} // for
894	} // ByteCopy
895
896	// Compare two byte strings in the byte-string area. The routine returns the following values:
897	//
898	// 1 => Src1-byte-string > Src2-byte-string
899	// 0 => Src1-byte-string = Src2-byte-string
900	// -1 => Src1-byte-string < Src2-byte-string
901
902	int ByteCmp( char Src1, int Src1Start, int Src1Lnth, char Src2, int Src2Start, int Src2Lnth ) {
903	#ifdef VbyteDebug
904	serr \| "enter:ByteCmp, Src1Start:" \| Src1Start \| " Src1Lnth:" \| Src1Lnth \| " Src2Start:" \| Src2Start \| " Src2Lnth:" \| Src2Lnth;
905	#endif // VbyteDebug
906	int cmp;
907
908	CharZip: for ( int i = 0; ; i += 1 ) {
909	if ( i == Src2Lnth - 1 ) {
910	for ( ; ; i += 1 ) {
911	if ( i == Src1Lnth - 1 ) {
912	cmp = 0;
913	break CharZip;
914	} // exit
915	if ( Src1[Src1Start + i] != ' ') {
916	// SUSPECTED BUG: this could be be why Peter got the bug report about == " " (why is this case here at all?)
917	cmp = 1;
918	break CharZip;
919	} // exit
920	} // for
921	} // exit
922	if ( i == Src1Lnth - 1 ) {
923	for ( ; ; i += 1 ) {
924	if ( i == Src2Lnth - 1 ) {
925	cmp = 0;
926	break CharZip;
927	} // exit
928	if ( Src2[Src2Start + i] != ' ') {
929	cmp = -1;
930	break CharZip;
931	} // exit
932	} // for
933	} // exit
934	if ( Src2[Src2Start + i] != Src1[Src1Start+ i]) {
935	cmp = Src1[Src1Start + i] > Src2[Src2Start + i] ? 1 : -1;
936	break CharZip;
937	} // exit
938	} // for
939	#ifdef VbyteDebug
940	serr \| "exit:ByteCmp, cmp:" \| cmp;
941	#endif // VbyteDebug
942	return cmp;
943	} // ByteCmp
944
945
946	// The compaction moves all of the byte strings currently in use to the beginning of the byte-string area and modifies
947	// the handles to reflect the new positions of the byte strings. Compaction assumes that the handle list is in ascending
948	// order by pointers into the byte-string area. The strings associated with substrings do not have to be moved because
949	// the containing string has been moved. Hence, they only require that their string pointers be adjusted.
950
951	void compaction(VbyteHeap & this) with(this) {
952	HandleNode *h;
953	char obase, nbase, *limit;
954
955	NoOfCompactions += 1;
956	EndVbyte = StartVbyte;
957	h = Header.flink; // ignore header node
958	for (;;) {
959	ByteCopy( EndVbyte, 0, h->lnth, h->s, 0, h->lnth );
960	obase = h->s;
961	h->s = EndVbyte;
962	nbase = h->s;
963	EndVbyte += h->lnth;
964	limit = obase + h->lnth;
965	h = h->flink;
966
967	// check if any substrings are allocated within a string
968
969	for (;;) {
970	if ( h == &Header ) break; // end of header list ?
971	if ( h->s >= limit ) break; // outside of current string ?
972	h->s = nbase + (( uintptr_t )h->s - ( uintptr_t )obase );
973	h = h->flink;
974	} // for
975	if ( h == &Header ) break; // end of header list ?
976	} // for
977	} // compaction
978
979
980	// Garbage determines the amount of free space left in the heap and then reduces, leave the same, or extends the size of
981	// the heap. The heap is then compacted in the existing heap or into the newly allocated heap.
982
983	void garbage(VbyteHeap & this, int minreq ) with(this) {
984	#ifdef VbyteDebug
985	serr \| "enter:garbage";
986	{
987	serr \| "HandleList:";
988	for ( HandleNode *n = Header.flink; n != &Header; n = n->flink ) {
989	serr \| nlOff;
990	serr \| "\tnode:" \| n \| " lnth:" \| n->lnth \| " s:" \| (void *)n->s \| ",\"";
991	for ( int i = 0; i < n->lnth; i += 1 ) {
992	serr \| n->s[i];
993	} // for
994	serr \| nlOn;
995	serr \| "\" flink:" \| n->flink \| " blink:" \| n->blink;
996	} // for
997	}
998	#endif // VbyteDebug
999	int AmountUsed, AmountFree;
1000
1001	AmountUsed = 0;
1002	for ( HandleNode *i = Header.flink; i != &Header; i = i->flink ) { // calculate amount of byte area used
1003	AmountUsed += i->lnth;
1004	} // for
1005	AmountFree = ( uintptr_t )ExtVbyte - ( uintptr_t )StartVbyte - AmountUsed;
1006
1007	if ( ( double ) AmountFree < ( CurrSize * 0.1 ) \|\| AmountFree < minreq ) { // free space less than 10% or not enough to serve cur request
1008
1009	extend( this, max( CurrSize, minreq ) ); // extend the heap
1010
1011	// Peter says, "This needs work before it should be used."
1012	// } else if ( AmountFree > CurrSize / 2 ) { // free space greater than 3 times the initial allocation ?
1013	// reduce(( AmountFree / CurrSize - 3 ) * CurrSize ); // reduce the memory
1014
1015	} // if
1016	compaction(this); // compact the byte area, in the same or new heap area
1017	#ifdef VbyteDebug
1018	{
1019	serr \| "HandleList:";
1020	for ( HandleNode *n = Header.flink; n != &Header; n = n->flink ) {
1021	serr \| nlOff;
1022	serr \| "\tnode:" \| n \| " lnth:" \| n->lnth \| " s:" \| (void *)n->s \| ",\"";
1023	for ( int i = 0; i < n->lnth; i += 1 ) {
1024	serr \| n->s[i];
1025	} // for
1026	serr \| nlOn;
1027	serr \| "\" flink:" \| n->flink \| " blink:" \| n->blink;
1028	} // for
1029	}
1030	serr \| "exit:garbage";
1031	#endif // VbyteDebug
1032	} // garbage
1033
1034	#undef VbyteDebug
1035
1036
1037
1038	// Extend the size of the byte-string area by creating a new area and copying the old area into it. The old byte-string
1039	// area is deleted.
1040
1041	void extend( VbyteHeap & this, int size ) with (this) {
1042	#ifdef VbyteDebug
1043	serr \| "enter:extend, size:" \| size;
1044	#endif // VbyteDebug
1045	char *OldStartVbyte;
1046
1047	NoOfExtensions += 1;
1048	OldStartVbyte = StartVbyte; // save previous byte area
1049
1050	CurrSize += size > InitSize ? size : InitSize; // minimum extension, initial size
1051	StartVbyte = EndVbyte = alloc(CurrSize);
1052	ExtVbyte = (void *)( StartVbyte + CurrSize );
1053	compaction(this); // copy from old heap to new & adjust pointers to new heap
1054	free( OldStartVbyte ); // release old heap
1055	#ifdef VbyteDebug
1056	serr \| "exit:extend, CurrSize:" \| CurrSize;
1057	#endif // VbyteDebug
1058	} // extend
1059
1060	//WIP
1061	#if 0
1062
1063	// Extend the size of the byte-string area by creating a new area and copying the old area into it. The old byte-string
1064	// area is deleted.
1065
1066	void VbyteHeap::reduce( int size ) {
1067	#ifdef VbyteDebug
1068	serr \| "enter:reduce, size:" \| size;
1069	#endif // VbyteDebug
1070	char *OldStartVbyte;
1071
1072	NoOfReductions += 1;
1073	OldStartVbyte = StartVbyte; // save previous byte area
1074
1075	CurrSize -= size;
1076	StartVbyte = EndVbyte = new char[CurrSize];
1077	ExtVbyte = (void *)( StartVbyte + CurrSize );
1078	compaction(); // copy from old heap to new & adjust pointers to new heap
1079	delete OldStartVbyte; // release old heap
1080	#ifdef VbyteDebug
1081	serr \| "exit:reduce, CurrSize:" \| CurrSize;
1082	#endif // VbyteDebug
1083	} // reduce
1084
1085
1086	#endif

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