1 /****************************************
2 * Computer Algebra System SINGULAR *
3 ****************************************/
4 /***************************************************************
5 * File: sbuckets.cc
6 * Purpose: implementation of routines for sorting polys using
7 * a bucket sort
8 * Author: obachman (Olaf Bachmann)
9 * Created: 9/00
10 *******************************************************************/
11 #include "misc/auxiliary.h"
12
13 #include "polys/sbuckets.h"
14
15 #include "polys/monomials/ring.h"
16 #include "polys/monomials/p_polys.h"
17
18 //////////////////////////////////////////////////////////////////////////
19 // Declarations
20 //
21
22 class sBucketPoly
23 {
24 public:
25 poly p;
26 long length;
27 };
28
29 class sBucket
30 {
31 public:
32 ring bucket_ring;
33 long max_bucket;
34 sBucketPoly buckets[BIT_SIZEOF_LONG - 3];
35 }
36 ;
37
38 STATIC_VAR omBin sBucket_bin = omGetSpecBin(sizeof(sBucket));
39
40
41 //////////////////////////////////////////////////////////////////////////
42 // New API:
43 //
44
45 /// Returns bucket ring
sBucketGetRing(const sBucket_pt bucket)46 ring sBucketGetRing(const sBucket_pt bucket)
47 { return bucket->bucket_ring; }
48
49
sIsEmpty(const sBucket_pt bucket)50 bool sIsEmpty(const sBucket_pt bucket)
51 {
52 for(int i = 0; i < (BIT_SIZEOF_LONG - 3); i++)
53 {
54 assume( i < (BIT_SIZEOF_LONG - 3) );
55 assume( pLength(bucket->buckets[i].p) == bucket->buckets[i].length );
56
57 if( bucket->buckets[i].p != NULL )
58 return false;
59
60 if( bucket->buckets[i].length != 0 )
61 return false;
62 }
63
64 return( bucket->max_bucket == 0 );
65
66 }
67
68
69 /// Copy sBucket non-intrusive!!!
sBucketCopy(const sBucket_pt bucket)70 sBucket_pt sBucketCopy(const sBucket_pt bucket)
71 {
72 sBucketCanonicalize(bucket);
73 const ring r = bucket->bucket_ring;
74
75 sBucket_pt newbucket = sBucketCreate(r);
76
77 newbucket->max_bucket = bucket->max_bucket;
78
79 for(int i = 0; i <= bucket->max_bucket; i++)
80 {
81 assume( i < (BIT_SIZEOF_LONG - 3) );
82 assume( pLength(bucket->buckets[i].p) == bucket->buckets[i].length );
83
84 newbucket->buckets[i].p = p_Copy(bucket->buckets[i].p, r);
85 newbucket->buckets[i].length = bucket->buckets[i].length;
86
87 assume( pLength(newbucket->buckets[i].p) == newbucket->buckets[i].length );
88 }
89
90 return newbucket;
91 }
92
93 //////////////////////////////////////////////////////////////////////////
94 // Creation/Destruction of buckets
95 //
sBucketCreate(const ring r)96 sBucket_pt sBucketCreate(const ring r)
97 {
98 sBucket_pt bucket = (sBucket_pt) omAlloc0Bin(sBucket_bin);
99 bucket->bucket_ring = r;
100 return bucket;
101 }
102
sBucketDestroy(sBucket_pt * bucket)103 void sBucketDestroy(sBucket_pt *bucket)
104 {
105 assume(bucket != NULL);
106 omFreeBin(*bucket, sBucket_bin);
107 *bucket = NULL;
108 }
109
sBucketDeleteAndDestroy(sBucket_pt * bucket_pt)110 void sBucketDeleteAndDestroy(sBucket_pt *bucket_pt)
111 {
112 sBucket_pt bucket = *bucket_pt;
113 int i;
114 for (i=0; i<= bucket->max_bucket; i++)
115 {
116 p_Delete(&(bucket->buckets[i].p), bucket->bucket_ring);
117 }
118 omFreeBin(bucket, sBucket_bin);
119 *bucket_pt = NULL;
120 }
121
122
123 /////////////////////////////////////////////////////////////////////////////
124 // Convertion from/to SBpolys
125 //
126
sBucket_Merge_m(sBucket_pt bucket,poly p)127 void sBucket_Merge_m(sBucket_pt bucket, poly p)
128 {
129 assume(p != NULL && pNext(p) == NULL);
130 int length = 1;
131 int i = 0;
132
133 while (bucket->buckets[i].p != NULL)
134 {
135 p = p_Merge_q(p, bucket->buckets[i].p, bucket->bucket_ring);
136 length += bucket->buckets[i].length;
137 bucket->buckets[i].p = NULL;
138 bucket->buckets[i].length = 0;
139 i++;
140 assume(SI_LOG2(length) == i);
141 }
142
143 bucket->buckets[i].p = p;
144 bucket->buckets[i].length = length;
145 if (i > bucket->max_bucket) bucket->max_bucket = i;
146 }
147
sBucket_Merge_p(sBucket_pt bucket,poly p,int length)148 void sBucket_Merge_p(sBucket_pt bucket, poly p, int length)
149 {
150 assume(bucket != NULL);
151 assume(length <= 0 || length == pLength(p));
152
153 if (p == NULL) return;
154 if (length <= 0) length = pLength(p);
155
156 int i = SI_LOG2(length);
157
158 while (bucket->buckets[i].p != NULL)
159 {
160 p = p_Merge_q(p, bucket->buckets[i].p, bucket->bucket_ring);
161 length += bucket->buckets[i].length;
162 bucket->buckets[i].p = NULL;
163 bucket->buckets[i].length = 0;
164 i++;
165 assume(SI_LOG2(length) == i);
166 }
167
168 bucket->buckets[i].p = p;
169 bucket->buckets[i].length = length;
170 if (i > bucket->max_bucket) bucket->max_bucket = i;
171 }
172
sBucket_Add_m(sBucket_pt bucket,poly p)173 void sBucket_Add_m(sBucket_pt bucket, poly p)
174 {
175 assume(bucket != NULL);
176 assume(1 == pLength(p));
177
178 int length = 1;
179
180 int i = 0; //SI_LOG2(length);
181
182 while (bucket->buckets[i].p != NULL)
183 {
184 int shorter;
185 p = bucket->bucket_ring->p_Procs->p_Add_q(p, bucket->buckets[i].p,
186 shorter, bucket->bucket_ring);
187 length+=bucket->buckets[i].length-shorter;
188 bucket->buckets[i].p = NULL;
189 bucket->buckets[i].length = 0;
190 if (p==NULL)
191 {
192 if (i > bucket->max_bucket) bucket->max_bucket = i;
193 return;
194 }
195 i = SI_LOG2(length);
196 }
197
198 bucket->buckets[i].p = p;
199 bucket->buckets[i].length = length;
200 if (i > bucket->max_bucket) bucket->max_bucket = i;
201 }
202
sBucket_Add_p(sBucket_pt bucket,poly p,int length)203 void sBucket_Add_p(sBucket_pt bucket, poly p, int length)
204 {
205 assume(bucket != NULL);
206 assume(length <= 0 || length == pLength(p));
207
208 if (p == NULL) return;
209 p_Test(p,bucket->bucket_ring);
210 if (length <= 0) length = pLength(p);
211
212 int i = SI_LOG2(length);
213
214 while (bucket->buckets[i].p != NULL)
215 {
216 int shorter;
217 p = bucket->bucket_ring->p_Procs->p_Add_q(p, bucket->buckets[i].p, shorter,
218 bucket->bucket_ring);
219 length+= bucket->buckets[i].length-shorter;
220 bucket->buckets[i].p = NULL;
221 bucket->buckets[i].length = 0;
222 if (p==NULL)
223 {
224 if (i > bucket->max_bucket) bucket->max_bucket = i;
225 return;
226 }
227 i = SI_LOG2(length);
228 }
229
230 bucket->buckets[i].p = p;
231 bucket->buckets[i].length = length;
232 if (i > bucket->max_bucket) bucket->max_bucket = i;
233 }
234
235 // Converts SBpoly into a poly and clears bucket
236 // i.e., afterwards SBpoly == 0
sBucketClearMerge(sBucket_pt bucket,poly * p,int * length)237 void sBucketClearMerge(sBucket_pt bucket, poly *p, int *length)
238 {
239 poly pr = NULL;
240 int lr = 0;
241 int i = 0;
242
243 while (bucket->buckets[i].p == NULL)
244 {
245 i++;
246 if (i > bucket->max_bucket) goto done;
247 }
248
249 pr = bucket->buckets[i].p;
250 lr = bucket->buckets[i].length;
251 bucket->buckets[i].p = NULL;
252 bucket->buckets[i].length = 0;
253 i++;
254
255 while (i <= bucket->max_bucket)
256 {
257 if (bucket->buckets[i].p != NULL)
258 {
259 pr = p_Merge_q(pr, bucket->buckets[i].p,bucket->bucket_ring);
260 lr += bucket->buckets[i].length;
261 bucket->buckets[i].p = NULL;
262 bucket->buckets[i].length = 0;
263 }
264 i++;
265 }
266
267 done:
268 *p = pr;
269 *length = lr;
270 bucket->max_bucket = 0;
271 }
272
273 // Converts SBpoly into a poly and clears bucket
274 // i.e., afterwards SBpoly == 0
sBucketClearAdd(sBucket_pt bucket,poly * p,int * length)275 void sBucketClearAdd(sBucket_pt bucket, poly *p, int *length)
276 {
277 poly pr = NULL;
278 int lr = 0;
279 int i = 0;
280
281 while (bucket->buckets[i].p == NULL)
282 {
283 assume( bucket->buckets[i].length == 0 );
284 i++;
285 if (i > bucket->max_bucket) goto done;
286 }
287
288 pr = bucket->buckets[i].p;
289 lr = bucket->buckets[i].length;
290
291 assume( pr != NULL && (lr > 0) );
292
293 bucket->buckets[i].p = NULL;
294 bucket->buckets[i].length = 0;
295 i++;
296
297 while (i <= bucket->max_bucket)
298 {
299 if (bucket->buckets[i].p != NULL)
300 {
301 assume( bucket->buckets[i].length == pLength(bucket->buckets[i].p) );
302
303 pr = p_Add_q(pr, bucket->buckets[i].p, lr, bucket->buckets[i].length,
304 bucket->bucket_ring);
305
306 bucket->buckets[i].p = NULL;
307 bucket->buckets[i].length = 0;
308 }
309
310 assume( bucket->buckets[i].p == NULL );
311 assume( bucket->buckets[i].length == 0 );
312 i++;
313 }
314
315 done:
316
317 *p = pr;
318 *length = lr;
319
320 bucket->max_bucket = 0;
321
322 assume( sIsEmpty(bucket) );
323 }
324
325
326
327
328 /////////////////////////////////////////////////////////////////////////////
329 // Sorts a poly using BucketSort
330 //
331
sBucketSortMerge(poly p,const ring r)332 poly sBucketSortMerge(poly p, const ring r)
333 {
334 if (p == NULL || pNext(p) == NULL) return p;
335
336 #ifndef SING_NDEBUG
337 int l_in = pLength(p);
338 #endif
339 sBucket_pt bucket = sBucketCreate(r);
340 poly pn = pNext(p);
341
342 do
343 {
344 pNext(p) = NULL;
345 sBucket_Merge_m(bucket, p);
346 p = pn;
347 if (p == NULL) break;
348 pn = pNext(pn);
349 }
350 while (1);
351
352 int l_dummy;
353 sBucketClearMerge(bucket, &pn, &l_dummy);
354 sBucketDestroy(&bucket);
355
356 p_Test(pn, r);
357 assume(l_dummy == pLength(pn));
358 #ifndef SING_NDEBUG
359 assume(l_in == l_dummy);
360 #endif
361 return pn;
362 }
363
364 /////////////////////////////////////////////////////////////////////////////
365 // Sorts a poly using BucketSort
366 //
367
sBucketSortAdd(poly p,const ring r)368 poly sBucketSortAdd(poly p, const ring r)
369 {
370 #ifndef SING_NDEBUG
371 int l_in = pLength(p);
372 #endif
373
374 if (p == NULL || pNext(p) == NULL) return p;
375
376 sBucket_pt bucket = sBucketCreate(r);
377 poly pn = pNext(p);
378
379 do
380 {
381 pNext(p) = NULL;
382 sBucket_Add_m(bucket, p);
383 p = pn;
384 if (p == NULL) break;
385 pn = pNext(pn);
386 }
387 while (1);
388
389 int l_dummy;
390 sBucketClearAdd(bucket, &pn, &l_dummy);
391 sBucketDestroy(&bucket);
392
393 p_Test(pn, r);
394 #ifndef SING_NDEBUG
395 assume(l_dummy == pLength(pn));
396 assume(l_in >= l_dummy);
397 #endif
398 return pn;
399 }
400
sBucketCanonicalize(sBucket_pt bucket)401 void sBucketCanonicalize(sBucket_pt bucket)
402 {
403 poly pr = NULL;
404 int lr = 0;
405 int i = 0;
406
407 while (bucket->buckets[i].p == NULL)
408 {
409 assume( bucket->buckets[i].length == 0 );
410 i++;
411 if (i > bucket->max_bucket) goto done;
412 }
413
414 pr = bucket->buckets[i].p;
415 lr = bucket->buckets[i].length;
416
417 assume( pr != NULL && (lr > 0) );
418
419 bucket->buckets[i].p = NULL;
420 bucket->buckets[i].length = 0;
421 i++;
422
423 while (i <= bucket->max_bucket)
424 {
425 if (bucket->buckets[i].p != NULL)
426 {
427 p_Test(pr,bucket->bucket_ring);
428 assume( bucket->buckets[i].length == pLength(bucket->buckets[i].p) );
429
430 p_Test(bucket->buckets[i].p,bucket->bucket_ring);
431 //pr = p_Add_q(pr, bucket->buckets[i].p, lr, bucket->buckets[i].length,
432 // bucket->bucket_ring);
433 pr = p_Add_q(pr, bucket->buckets[i].p, bucket->bucket_ring);
434
435 bucket->buckets[i].p = NULL;
436 bucket->buckets[i].length = 0;
437 }
438
439 assume( bucket->buckets[i].p == NULL );
440 assume( bucket->buckets[i].length == 0 );
441 i++;
442 }
443
444 done:
445 lr=pLength(pr);
446 if (pr!=NULL)
447 {
448 i = SI_LOG2(lr);
449 bucket->buckets[i].p = pr;
450 bucket->buckets[i].length = lr;
451 bucket->max_bucket = i;
452 }
453 }
454
sBucketPeek(sBucket_pt b)455 poly sBucketPeek(sBucket_pt b)
456 {
457 sBucketCanonicalize(b);
458 return b->buckets[b->max_bucket].p;
459 }
460
sBucketString(sBucket_pt bucket)461 char* sBucketString(sBucket_pt bucket)
462 {
463 return (p_String(sBucketPeek(bucket),sBucketGetRing(bucket)));
464 }
465
sBucketPrint(sBucket_pt bucket)466 void sBucketPrint(sBucket_pt bucket)
467 {
468 p_Write0(sBucketPeek(bucket),sBucketGetRing(bucket));
469 }
470
471