Array-Heap/Heap.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

/* pre-5.10 compatibility */
#ifndef GV_NOTQUAL
# define GV_NOTQUAL 1
#endif
#ifndef gv_fetchpvs
# define gv_fetchpvs gv_fetchpv
#endif

/* pre-5.8 compatibility */
#ifndef PERL_MAGIC_tied
# define PERL_MAGIC_tied 'P'
#endif

#include "multicall.h"

/* workaround for buggy multicall API */
#ifndef cxinc
# define cxinc() Perl_cxinc (aTHX)
#endif

#define dCMP                    \
  dMULTICALL;                   \
  void *cmp_data;               \
  I32 gimme = G_SCALAR;

#define CMP_PUSH(sv)            \
  PUSH_MULTICALL (cmp_push_ (sv));\
  cmp_data = multicall_cop;

#define CMP_POP                 \
  POP_MULTICALL;

#define dCMP_CALL(data)         \
  OP *multicall_cop = (OP *)data;

static void *
cmp_push_ (SV *sv)
{
  HV *st;
  GV *gvp;
  CV *cv;

  cv = sv_2cv (sv, &st, &gvp, 0);

  if (!cv)
    croak ("%s: callback must be a CODE reference or another callable object", SvPV_nolen (sv));

  if (!PL_firstgv)  PL_firstgv  = gv_fetchpvs ("a", GV_ADD | GV_NOTQUAL, SVt_PV);
  if (!PL_secondgv) PL_secondgv = gv_fetchpvs ("b", GV_ADD | GV_NOTQUAL, SVt_PV);

  SAVESPTR (GvSV (PL_firstgv));
  SAVESPTR (GvSV (PL_secondgv));

  return cv;
}

/*****************************************************************************/

static SV *
sv_first (SV *sv)
{
  if (SvROK (sv) && SvTYPE (SvRV (sv)) == SVt_PVAV)
    {
      AV *av = (AV *)SvRV (sv);

      sv = AvFILLp (av) < 0 ? &PL_sv_undef : AvARRAY (av)[0];
    }

  return sv;
}

static int
cmp_nv (SV *a, SV *b, void *cmp_data)
{
  a = sv_first (a);
  b = sv_first (b);

  return SvNV (a) > SvNV (b);
}

static int
cmp_sv (SV *a, SV *b, void *cmp_data)
{
  a = sv_first (a);
  b = sv_first (b);

  return sv_cmp (a, b) > 0;
}

static int
cmp_custom (SV *a, SV *b, void *cmp_data)
{
  dCMP_CALL (cmp_data);

  GvSV (PL_firstgv)  = a;
  GvSV (PL_secondgv) = b;

  MULTICALL;

  if (SvTRUE (ERRSV))
    croak (NULL);

  {
    dSP;
    return TOPi > 0;
  }
}

/*****************************************************************************/

typedef int (*f_cmp)(SV *a, SV *b, void *cmp_data);

static AV *
array (SV *ref)
{
  if (SvROK (ref)
      && SvTYPE (SvRV (ref)) == SVt_PVAV
      && !SvTIED_mg (SvRV (ref), PERL_MAGIC_tied))
    return (AV *)SvRV (ref);

  croak ("argument 'heap' must be a (non-tied) array");
}

#define gt(a,b) cmp ((a), (b), cmp_data)

/*****************************************************************************/

/* away from the root */
static void
downheap (AV *av, f_cmp cmp, void *cmp_data, int N, int k)
{
  SV **heap = AvARRAY (av);
  SV *he = heap [k];

  for (;;)
    {
      int c = (k << 1) + 1;

      if (c >= N)
        break;

      c += c + 1 < N && gt (heap [c], heap [c + 1])
           ? 1 : 0;

      if (!(gt (he, heap [c])))
        break;

      heap [k] = heap [c];

      k = c;
    }

  heap [k] = he;
}

/* towards the root */
static void
upheap (AV *av, f_cmp cmp, void *cmp_data, int k)
{
  SV **heap = AvARRAY (av);
  SV *he = heap [k];

  while (k)
    {
      int p = (k - 1) >> 1;

      if (!(gt (heap [p], he)))
        break;

      heap [k] = heap [p];
      k = p;
    }

  heap [k] = he;
}

/* move an element suitably so it is in a correct place */
static void
adjustheap (AV *av, f_cmp cmp, void *cmp_data, int N, int k)
{
  SV **heap = AvARRAY (av);

  if (k > 0 && !gt (heap [k], heap [(k - 1) >> 1]))
    upheap (av, cmp, cmp_data, k);
  else
    downheap (av, cmp, cmp_data, N, k);
}

/*****************************************************************************/

static void
make_heap (AV *av, f_cmp cmp, void *cmp_data)
{
  int i, len = AvFILLp (av);

  /* do not use floyds algorithm, as I expect the simpler and more cache-efficient */
  /* upheap is actually faster */
  for (i = 0; i <= len; ++i)
    upheap (av, cmp, cmp_data, i);
}

static void
push_heap (AV *av, f_cmp cmp, void *cmp_data, SV **elems, int nelems)
{
  int i;

  av_extend (av, AvFILLp (av) + nelems);

  /* we do it in two steps, as the perl cmp function might copy the stack */
  for (i = 0; i < nelems; ++i)
    AvARRAY (av)[++AvFILLp (av)] = newSVsv (elems [i]);

  for (i = 0; i < nelems; ++i)
    upheap (av, cmp, cmp_data, AvFILLp (av) - i);
}

static SV *
pop_heap (AV *av, f_cmp cmp, void *cmp_data)
{
  int len = AvFILLp (av);

  if (len < 0)
    return &PL_sv_undef;
  else if (len == 0)
    return av_pop (av);
  else
    {
      SV *top = av_pop (av);
      SV *result = AvARRAY (av)[0];
      AvARRAY (av)[0] = top;
      downheap (av, cmp, cmp_data, len, 0);
      return result;
    }
}

static SV *
splice_heap (AV *av, f_cmp cmp, void *cmp_data, int idx)
{
  int len = AvFILLp (av);

  if (len < 0 || idx > len)
    return &PL_sv_undef;
  else if (len == 0 || idx == len)
    return av_pop (av); /* the only or last element */
  else
    {
      SV *top = av_pop (av);
      SV *result = AvARRAY (av)[idx];
      AvARRAY (av)[idx] = top;
      adjustheap (av, cmp, cmp_data, len, idx);
      return result;
    }
}

static void
adjust_heap (AV *av, f_cmp cmp, void *cmp_data, int idx)
{
  adjustheap (av, cmp, cmp_data, AvFILLp (av) + 1, idx);
}

MODULE = Array::Heap            PACKAGE = Array::Heap

void
make_heap (SV *heap)
        PROTOTYPE: \@
        CODE:
        make_heap (array (heap), cmp_nv, 0);

void
make_heap_lex (SV *heap)
        PROTOTYPE: \@
        CODE:
        make_heap (array (heap), cmp_sv, 0);

void
make_heap_cmp (SV *cmp, SV *heap)
        PROTOTYPE: &\@
        CODE:
{
        dCMP;
        CMP_PUSH (cmp);
        make_heap (array (heap), cmp_custom, cmp_data);
        CMP_POP;
}

void
push_heap (SV *heap, ...)
        PROTOTYPE: \@@
        CODE:
        push_heap (array (heap), cmp_nv, 0, &(ST(1)), items - 1);

void
push_heap_lex (SV *heap, ...)
        PROTOTYPE: \@@
        CODE:
        push_heap (array (heap), cmp_sv, 0, &(ST(1)), items - 1);

void
push_heap_cmp (SV *cmp, SV *heap, ...)
        PROTOTYPE: &\@@
        CODE:
{
        SV **st_2 = &(ST(2)); /* multicall.h uses PUSHSTACK */
        dCMP;
        CMP_PUSH (cmp);
        push_heap (array (heap), cmp_custom, cmp_data, st_2, items - 2);
        CMP_POP;
}

SV *
pop_heap (SV *heap)
        PROTOTYPE: \@
        CODE:
        RETVAL = pop_heap (array (heap), cmp_nv, 0);
        OUTPUT:
        RETVAL

SV *
pop_heap_lex (SV *heap)
        PROTOTYPE: \@
        CODE:
        RETVAL = pop_heap (array (heap), cmp_sv, 0);
        OUTPUT:
        RETVAL

SV *
pop_heap_cmp (SV *cmp, SV *heap)
        PROTOTYPE: &\@
        CODE:
{
        dCMP;
        CMP_PUSH (cmp);
        RETVAL = pop_heap (array (heap), cmp_custom, cmp_data);
        CMP_POP;
}
        OUTPUT:
        RETVAL

SV *
splice_heap (SV *heap, int idx)
        PROTOTYPE: \@$
        CODE:
        RETVAL = splice_heap (array (heap), cmp_nv, 0, idx);
        OUTPUT:
        RETVAL

SV *
splice_heap_lex (SV *heap, int idx)
        PROTOTYPE: \@$
        CODE:
        RETVAL = splice_heap (array (heap), cmp_sv, 0, idx);
        OUTPUT:
        RETVAL

SV *
splice_heap_cmp (SV *cmp, SV *heap, int idx)
        PROTOTYPE: &\@$
        CODE:
{
        dCMP;
        CMP_PUSH (cmp);
        RETVAL = splice_heap (array (heap), cmp_custom, cmp_data, idx);
        CMP_POP;
}
        OUTPUT:
        RETVAL

void
adjust_heap (SV *heap, int idx)
        PROTOTYPE: \@$
        CODE:
        adjust_heap (array (heap), cmp_nv, 0, idx);

void
adjust_heap_lex (SV *heap, int idx)
        PROTOTYPE: \@$
        CODE:
        adjust_heap (array (heap), cmp_sv, 0, idx);

void
adjust_heap_cmp (SV *cmp, SV *heap, int idx)
        PROTOTYPE: &\@$
        CODE:
{
        dCMP;
        CMP_PUSH (cmp);
        adjust_heap (array (heap), cmp_custom, cmp_data, idx);
        CMP_POP;
}

Revision:	1.4
Committed:	Sun Jul 26 05:25:18 2009 UTC (14 years, 9 months ago) by root
Branch:	MAIN
CVS Tags:	rel-2_0
Changes since 1.3:	+20 -17 lines
Log Message:	2.0
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5	root	1.3	/* pre-5.10 compatibility */
6			#ifndef GV_NOTQUAL
7			# define GV_NOTQUAL 1
8			#endif
9			#ifndef gv_fetchpvs
10			# define gv_fetchpvs gv_fetchpv
11			#endif
12
13	root	1.4	/* pre-5.8 compatibility */
14			#ifndef PERL_MAGIC_tied
15			# define PERL_MAGIC_tied 'P'
16			#endif
17
18	root	1.3	#include "multicall.h"
19
20			/* workaround for buggy multicall API */
21			#ifndef cxinc
22			# define cxinc() Perl_cxinc (aTHX)
23			#endif
24
25			#define dCMP \
26			dMULTICALL; \
27			void *cmp_data; \
28			I32 gimme = G_SCALAR;
29
30			#define CMP_PUSH(sv) \
31			PUSH_MULTICALL (cmp_push_ (sv));\
32			cmp_data = multicall_cop;
33
34			#define CMP_POP \
35			POP_MULTICALL;
36
37			#define dCMP_CALL(data) \
38			OP multicall_cop = (OP )data;
39
40			static void *
41			cmp_push_ (SV *sv)
42			{
43			HV *st;
44			GV *gvp;
45			CV *cv;
46
47			cv = sv_2cv (sv, &st, &gvp, 0);
48
49			if (!cv)
50			croak ("%s: callback must be a CODE reference or another callable object", SvPV_nolen (sv));
51
52			if (!PL_firstgv) PL_firstgv = gv_fetchpvs ("a", GV_ADD \| GV_NOTQUAL, SVt_PV);
53			if (!PL_secondgv) PL_secondgv = gv_fetchpvs ("b", GV_ADD \| GV_NOTQUAL, SVt_PV);
54
55			SAVESPTR (GvSV (PL_firstgv));
56			SAVESPTR (GvSV (PL_secondgv));
57
58			return cv;
59			}
60
61			/*****************************************************************************/
62
63			static SV *
64			sv_first (SV *sv)
65			{
66			if (SvROK (sv) && SvTYPE (SvRV (sv)) == SVt_PVAV)
67			{
68			AV av = (AV )SvRV (sv);
69
70			sv = AvFILLp (av) < 0 ? &PL_sv_undef : AvARRAY (av)[0];
71			}
72
73			return sv;
74			}
75
76	root	1.1	static int
77	root	1.3	cmp_nv (SV a, SV b, void *cmp_data)
78	root	1.1	{
79	root	1.3	a = sv_first (a);
80			b = sv_first (b);
81	root	1.1
82			return SvNV (a) > SvNV (b);
83			}
84
85			static int
86	root	1.3	cmp_sv (SV a, SV b, void *cmp_data)
87	root	1.1	{
88	root	1.3	a = sv_first (a);
89			b = sv_first (b);
90	root	1.1
91	root	1.3	return sv_cmp (a, b) > 0;
92	root	1.1	}
93
94			static int
95	root	1.3	cmp_custom (SV a, SV b, void *cmp_data)
96	root	1.1	{
97	root	1.3	dCMP_CALL (cmp_data);
98	root	1.1
99			GvSV (PL_firstgv) = a;
100			GvSV (PL_secondgv) = b;
101
102	root	1.3	MULTICALL;
103	root	1.1
104			if (SvTRUE (ERRSV))
105			croak (NULL);
106
107	root	1.3	{
108			dSP;
109			return TOPi > 0;
110			}
111			}
112	root	1.1
113	root	1.3	/*****************************************************************************/
114	root	1.1
115	root	1.3	typedef int (f_cmp)(SV a, SV b, void cmp_data);
116	root	1.1
117			static AV *
118			array (SV *ref)
119			{
120	root	1.3	if (SvROK (ref)
121			&& SvTYPE (SvRV (ref)) == SVt_PVAV
122			&& !SvTIED_mg (SvRV (ref), PERL_MAGIC_tied))
123	root	1.1	return (AV *)SvRV (ref);
124
125	root	1.3	croak ("argument 'heap' must be a (non-tied) array");
126	root	1.1	}
127
128	root	1.3	#define gt(a,b) cmp ((a), (b), cmp_data)
129	root	1.1
130	root	1.3	/*****************************************************************************/
131	root	1.1
132	root	1.3	/* away from the root */
133	root	1.1	static void
134	root	1.3	downheap (AV av, f_cmp cmp, void cmp_data, int N, int k)
135	root	1.1	{
136	root	1.3	SV **heap = AvARRAY (av);
137			SV *he = heap [k];
138	root	1.1
139	root	1.3	for (;;)
140	root	1.1	{
141	root	1.3	int c = (k << 1) + 1;
142
143			if (c >= N)
144			break;
145
146			c += c + 1 < N && gt (heap [c], heap [c + 1])
147			? 1 : 0;
148
149			if (!(gt (he, heap [c])))
150			break;
151
152			heap [k] = heap [c];
153
154			k = c;
155	root	1.1	}
156
157	root	1.3	heap [k] = he;
158	root	1.1	}
159
160	root	1.3	/* towards the root */
161	root	1.1	static void
162	root	1.3	upheap (AV av, f_cmp cmp, void cmp_data, int k)
163	root	1.1	{
164	root	1.3	SV **heap = AvARRAY (av);
165			SV *he = heap [k];
166	root	1.1
167	root	1.3	while (k)
168	root	1.1	{
169	root	1.3	int p = (k - 1) >> 1;
170	root	1.1
171	root	1.3	if (!(gt (heap [p], he)))
172			break;
173
174			heap [k] = heap [p];
175			k = p;
176	root	1.1	}
177
178	root	1.3	heap [k] = he;
179			}
180
181			/* move an element suitably so it is in a correct place */
182			static void
183			adjustheap (AV av, f_cmp cmp, void cmp_data, int N, int k)
184			{
185			SV **heap = AvARRAY (av);
186	root	1.1
187	root	1.3	if (k > 0 && !gt (heap [k], heap [(k - 1) >> 1]))
188			upheap (av, cmp, cmp_data, k);
189			else
190			downheap (av, cmp, cmp_data, N, k);
191	root	1.1	}
192
193	root	1.3	/*****************************************************************************/
194
195	root	1.1	static void
196	root	1.3	make_heap (AV av, f_cmp cmp, void cmp_data)
197	root	1.1	{
198	root	1.3	int i, len = AvFILLp (av);
199	root	1.1
200	root	1.3	/* do not use floyds algorithm, as I expect the simpler and more cache-efficient */
201			/* upheap is actually faster */
202			for (i = 0; i <= len; ++i)
203			upheap (av, cmp, cmp_data, i);
204	root	1.1	}
205
206			static void
207	root	1.4	push_heap (AV av, f_cmp cmp, void cmp_data, SV **elems, int nelems)
208	root	1.1	{
209	root	1.4	int i;
210
211			av_extend (av, AvFILLp (av) + nelems);
212
213			/* we do it in two steps, as the perl cmp function might copy the stack */
214			for (i = 0; i < nelems; ++i)
215			AvARRAY (av)[++AvFILLp (av)] = newSVsv (elems [i]);
216
217			for (i = 0; i < nelems; ++i)
218			upheap (av, cmp, cmp_data, AvFILLp (av) - i);
219	root	1.1	}
220
221			static SV *
222	root	1.3	pop_heap (AV av, f_cmp cmp, void cmp_data)
223	root	1.1	{
224	root	1.3	int len = AvFILLp (av);
225
226			if (len < 0)
227	root	1.1	return &PL_sv_undef;
228	root	1.3	else if (len == 0)
229	root	1.1	return av_pop (av);
230			else
231			{
232			SV *top = av_pop (av);
233	root	1.3	SV *result = AvARRAY (av)[0];
234			AvARRAY (av)[0] = top;
235			downheap (av, cmp, cmp_data, len, 0);
236			return result;
237			}
238			}
239	root	1.1
240	root	1.3	static SV *
241			splice_heap (AV av, f_cmp cmp, void cmp_data, int idx)
242			{
243			int len = AvFILLp (av);
244	root	1.1
245	root	1.3	if (len < 0 \|\| idx > len)
246			return &PL_sv_undef;
247			else if (len == 0 \|\| idx == len)
248			return av_pop (av); /* the only or last element */
249			else
250			{
251			SV *top = av_pop (av);
252			SV *result = AvARRAY (av)[idx];
253			AvARRAY (av)[idx] = top;
254			adjustheap (av, cmp, cmp_data, len, idx);
255	root	1.1	return result;
256			}
257			}
258
259	root	1.3	static void
260			adjust_heap (AV av, f_cmp cmp, void cmp_data, int idx)
261			{
262			adjustheap (av, cmp, cmp_data, AvFILLp (av) + 1, idx);
263			}
264
265	root	1.1	MODULE = Array::Heap PACKAGE = Array::Heap
266
267			void
268	root	1.3	make_heap (SV *heap)
269	root	1.1	PROTOTYPE: \@
270			CODE:
271			make_heap (array (heap), cmp_nv, 0);
272
273			void
274	root	1.3	make_heap_lex (SV *heap)
275	root	1.1	PROTOTYPE: \@
276			CODE:
277			make_heap (array (heap), cmp_sv, 0);
278
279			void
280	root	1.3	make_heap_cmp (SV cmp, SV heap)
281	root	1.1	PROTOTYPE: &\@
282			CODE:
283	root	1.3	{
284			dCMP;
285			CMP_PUSH (cmp);
286			make_heap (array (heap), cmp_custom, cmp_data);
287			CMP_POP;
288			}
289	root	1.1
290			void
291	root	1.3	push_heap (SV *heap, ...)
292	root	1.1	PROTOTYPE: \@@
293			CODE:
294	root	1.4	push_heap (array (heap), cmp_nv, 0, &(ST(1)), items - 1);
295	root	1.1
296			void
297	root	1.3	push_heap_lex (SV *heap, ...)
298	root	1.1	PROTOTYPE: \@@
299			CODE:
300	root	1.4	push_heap (array (heap), cmp_sv, 0, &(ST(1)), items - 1);
301	root	1.1
302			void
303	root	1.3	push_heap_cmp (SV cmp, SV heap, ...)
304	root	1.1	PROTOTYPE: &\@@
305			CODE:
306	root	1.3	{
307	root	1.4	SV *st_2 = &(ST(2)); / multicall.h uses PUSHSTACK */
308	root	1.3	dCMP;
309			CMP_PUSH (cmp);
310	root	1.4	push_heap (array (heap), cmp_custom, cmp_data, st_2, items - 2);
311	root	1.3	CMP_POP;
312			}
313	root	1.1
314			SV *
315	root	1.3	pop_heap (SV *heap)
316	root	1.1	PROTOTYPE: \@
317			CODE:
318			RETVAL = pop_heap (array (heap), cmp_nv, 0);
319			OUTPUT:
320			RETVAL
321
322			SV *
323	root	1.3	pop_heap_lex (SV *heap)
324	root	1.1	PROTOTYPE: \@
325			CODE:
326			RETVAL = pop_heap (array (heap), cmp_sv, 0);
327			OUTPUT:
328			RETVAL
329
330			SV *
331	root	1.3	pop_heap_cmp (SV cmp, SV heap)
332	root	1.1	PROTOTYPE: &\@
333			CODE:
334	root	1.3	{
335			dCMP;
336			CMP_PUSH (cmp);
337			RETVAL = pop_heap (array (heap), cmp_custom, cmp_data);
338			CMP_POP;
339			}
340			OUTPUT:
341			RETVAL
342
343			SV *
344			splice_heap (SV *heap, int idx)
345			PROTOTYPE: \@$
346			CODE:
347			RETVAL = splice_heap (array (heap), cmp_nv, 0, idx);
348			OUTPUT:
349			RETVAL
350
351			SV *
352			splice_heap_lex (SV *heap, int idx)
353			PROTOTYPE: \@$
354			CODE:
355			RETVAL = splice_heap (array (heap), cmp_sv, 0, idx);
356			OUTPUT:
357			RETVAL
358
359			SV *
360			splice_heap_cmp (SV cmp, SV heap, int idx)
361			PROTOTYPE: &\@$
362			CODE:
363			{
364			dCMP;
365			CMP_PUSH (cmp);
366			RETVAL = splice_heap (array (heap), cmp_custom, cmp_data, idx);
367			CMP_POP;
368			}
369	root	1.1	OUTPUT:
370			RETVAL
371
372	root	1.3	void
373			adjust_heap (SV *heap, int idx)
374			PROTOTYPE: \@$
375			CODE:
376			adjust_heap (array (heap), cmp_nv, 0, idx);
377
378			void
379			adjust_heap_lex (SV *heap, int idx)
380			PROTOTYPE: \@$
381			CODE:
382			adjust_heap (array (heap), cmp_sv, 0, idx);
383
384			void
385			adjust_heap_cmp (SV cmp, SV heap, int idx)
386			PROTOTYPE: &\@$
387			CODE:
388			{
389			dCMP;
390			CMP_PUSH (cmp);
391			adjust_heap (array (heap), cmp_custom, cmp_data, idx);
392			CMP_POP;
393			}
394	root	1.1