3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * '...for the Entwives desired order, and plenty, and peace (by which they
13 * meant that things should remain where they had set them).' --Treebeard
15 * [p.476 of _The Lord of the Rings_, III/iv: "Treebeard"]
19 =head1 Array Manipulation Functions
27 Perl_av_reify(pTHX_ AV *av)
32 PERL_ARGS_ASSERT_AV_REIFY;
33 assert(SvTYPE(av) == SVt_PVAV);
38 if (SvTIED_mg((const SV *)av, PERL_MAGIC_tied))
39 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEBUGGING), "av_reify called on tied array");
42 while (key > AvFILLp(av) + 1)
43 AvARRAY(av)[--key] = &PL_sv_undef;
45 SV * const sv = AvARRAY(av)[--key];
47 if (sv != &PL_sv_undef)
48 SvREFCNT_inc_simple_void_NN(sv);
50 key = AvARRAY(av) - AvALLOC(av);
52 AvALLOC(av)[--key] = &PL_sv_undef;
60 Pre-extend an array. The C<key> is the index to which the array should be
67 Perl_av_extend(pTHX_ AV *av, I32 key)
72 PERL_ARGS_ASSERT_AV_EXTEND;
73 assert(SvTYPE(av) == SVt_PVAV);
75 mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied);
77 SV *arg1 = sv_newmortal();
78 sv_setiv(arg1, (IV)(key + 1));
79 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "EXTEND", G_DISCARD, 1,
83 if (key > AvMAX(av)) {
88 if (AvALLOC(av) != AvARRAY(av)) {
89 ary = AvALLOC(av) + AvFILLp(av) + 1;
90 tmp = AvARRAY(av) - AvALLOC(av);
91 Move(AvARRAY(av), AvALLOC(av), AvFILLp(av)+1, SV*);
93 AvARRAY(av) = AvALLOC(av);
96 ary[--tmp] = &PL_sv_undef;
98 if (key > AvMAX(av) - 10) {
99 newmax = key + AvMAX(av);
104 #ifdef PERL_MALLOC_WRAP
105 static const char oom_array_extend[] =
106 "Out of memory during array extend"; /* Duplicated in pp_hot.c */
110 #if !defined(STRANGE_MALLOC) && !defined(MYMALLOC)
115 #ifdef Perl_safesysmalloc_size
116 /* Whilst it would be quite possible to move this logic around
117 (as I did in the SV code), so as to set AvMAX(av) early,
118 based on calling Perl_safesysmalloc_size() immediately after
119 allocation, I'm not convinced that it is a great idea here.
120 In an array we have to loop round setting everything to
121 &PL_sv_undef, which means writing to memory, potentially lots
122 of it, whereas for the SV buffer case we don't touch the
123 "bonus" memory. So there there is no cost in telling the
124 world about it, whereas here we have to do work before we can
125 tell the world about it, and that work involves writing to
126 memory that might never be read. So, I feel, better to keep
127 the current lazy system of only writing to it if our caller
128 has a need for more space. NWC */
129 newmax = Perl_safesysmalloc_size((void*)AvALLOC(av)) /
130 sizeof(const SV *) - 1;
135 newmax = key + AvMAX(av) / 5;
137 MEM_WRAP_CHECK_1(newmax+1, SV*, oom_array_extend);
138 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
139 Renew(AvALLOC(av),newmax+1, SV*);
141 bytes = (newmax + 1) * sizeof(const SV *);
142 #define MALLOC_OVERHEAD 16
143 itmp = MALLOC_OVERHEAD;
144 while ((MEM_SIZE)(itmp - MALLOC_OVERHEAD) < bytes)
146 itmp -= MALLOC_OVERHEAD;
147 itmp /= sizeof(const SV *);
148 assert(itmp > newmax);
150 assert(newmax >= AvMAX(av));
151 Newx(ary, newmax+1, SV*);
152 Copy(AvALLOC(av), ary, AvMAX(av)+1, SV*);
153 Safefree(AvALLOC(av));
156 #ifdef Perl_safesysmalloc_size
159 ary = AvALLOC(av) + AvMAX(av) + 1;
160 tmp = newmax - AvMAX(av);
161 if (av == PL_curstack) { /* Oops, grew stack (via av_store()?) */
162 PL_stack_sp = AvALLOC(av) + (PL_stack_sp - PL_stack_base);
163 PL_stack_base = AvALLOC(av);
164 PL_stack_max = PL_stack_base + newmax;
168 newmax = key < 3 ? 3 : key;
169 MEM_WRAP_CHECK_1(newmax+1, SV*, oom_array_extend);
170 Newx(AvALLOC(av), newmax+1, SV*);
171 ary = AvALLOC(av) + 1;
173 AvALLOC(av)[0] = &PL_sv_undef; /* For the stacks */
177 ary[--tmp] = &PL_sv_undef;
180 AvARRAY(av) = AvALLOC(av);
189 Returns the SV at the specified index in the array. The C<key> is the
190 index. If lval is true, you are guaranteed to get a real SV back (in case
191 it wasn't real before), which you can then modify. Check that the return
192 value is non-null before dereferencing it to a C<SV*>.
194 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
195 more information on how to use this function on tied arrays.
197 The rough perl equivalent is C<$myarray[$idx]>.
203 Perl_av_fetch(pTHX_ register AV *av, I32 key, I32 lval)
207 PERL_ARGS_ASSERT_AV_FETCH;
208 assert(SvTYPE(av) == SVt_PVAV);
210 if (SvRMAGICAL(av)) {
211 const MAGIC * const tied_magic
212 = mg_find((const SV *)av, PERL_MAGIC_tied);
213 if (tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata)) {
216 I32 adjust_index = 1;
218 /* Handle negative array indices 20020222 MJD */
219 SV * const * const negative_indices_glob =
220 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
222 NEGATIVE_INDICES_VAR, 16, 0);
224 if (negative_indices_glob && SvTRUE(GvSV(*negative_indices_glob)))
229 key += AvFILL(av) + 1;
236 sv_upgrade(sv, SVt_PVLV);
237 mg_copy(MUTABLE_SV(av), sv, 0, key);
238 if (!tied_magic) /* for regdata, force leavesub to make copies */
241 LvTARG(sv) = sv; /* fake (SV**) */
242 return &(LvTARG(sv));
247 key += AvFILL(av) + 1;
252 if (key > AvFILLp(av)) {
255 return av_store(av,key,newSV(0));
257 if (AvARRAY(av)[key] == &PL_sv_undef) {
260 return av_store(av,key,newSV(0));
264 && (!AvARRAY(av)[key] /* eg. @_ could have freed elts */
265 || SvIS_FREED(AvARRAY(av)[key]))) {
266 AvARRAY(av)[key] = &PL_sv_undef; /* 1/2 reify */
269 return &AvARRAY(av)[key];
275 Stores an SV in an array. The array index is specified as C<key>. The
276 return value will be NULL if the operation failed or if the value did not
277 need to be actually stored within the array (as in the case of tied
278 arrays). Otherwise, it can be dereferenced
279 to get the C<SV*> that was stored
282 Note that the caller is responsible for suitably incrementing the reference
283 count of C<val> before the call, and decrementing it if the function
286 Approximate Perl equivalent: C<$myarray[$key] = $val;>.
288 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
289 more information on how to use this function on tied arrays.
295 Perl_av_store(pTHX_ register AV *av, I32 key, SV *val)
300 PERL_ARGS_ASSERT_AV_STORE;
301 assert(SvTYPE(av) == SVt_PVAV);
303 /* S_regclass relies on being able to pass in a NULL sv
304 (unicode_alternate may be NULL).
310 if (SvRMAGICAL(av)) {
311 const MAGIC * const tied_magic = mg_find((const SV *)av, PERL_MAGIC_tied);
313 /* Handle negative array indices 20020222 MJD */
315 bool adjust_index = 1;
316 SV * const * const negative_indices_glob =
317 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
319 NEGATIVE_INDICES_VAR, 16, 0);
320 if (negative_indices_glob
321 && SvTRUE(GvSV(*negative_indices_glob)))
324 key += AvFILL(av) + 1;
329 if (val != &PL_sv_undef) {
330 mg_copy(MUTABLE_SV(av), val, 0, key);
338 key += AvFILL(av) + 1;
343 if (SvREADONLY(av) && key >= AvFILL(av))
344 Perl_croak_no_modify(aTHX);
346 if (!AvREAL(av) && AvREIFY(av))
351 if (AvFILLp(av) < key) {
353 if (av == PL_curstack && key > PL_stack_sp - PL_stack_base)
354 PL_stack_sp = PL_stack_base + key; /* XPUSH in disguise */
356 ary[++AvFILLp(av)] = &PL_sv_undef;
357 } while (AvFILLp(av) < key);
362 SvREFCNT_dec(ary[key]);
364 if (SvSMAGICAL(av)) {
365 const MAGIC *mg = SvMAGIC(av);
367 for (; mg; mg = mg->mg_moremagic) {
368 if (!isUPPER(mg->mg_type)) continue;
369 if (val != &PL_sv_undef) {
370 sv_magic(val, MUTABLE_SV(av), toLOWER(mg->mg_type), 0, key);
372 if (PL_delaymagic && mg->mg_type == PERL_MAGIC_isa) {
373 PL_delaymagic |= DM_ARRAY_ISA;
378 mg_set(MUTABLE_SV(av));
386 Creates a new AV and populates it with a list of SVs. The SVs are copied
387 into the array, so they may be freed after the call to av_make. The new AV
388 will have a reference count of 1.
390 Perl equivalent: C<my @new_array = ($scalar1, $scalar2, $scalar3...);>
396 Perl_av_make(pTHX_ register I32 size, register SV **strp)
398 register AV * const av = MUTABLE_AV(newSV_type(SVt_PVAV));
399 /* sv_upgrade does AvREAL_only() */
400 PERL_ARGS_ASSERT_AV_MAKE;
401 assert(SvTYPE(av) == SVt_PVAV);
403 if (size) { /* "defined" was returning undef for size==0 anyway. */
409 AvFILLp(av) = AvMAX(av) = size - 1;
410 for (i = 0; i < size; i++) {
413 /* Don't let sv_setsv swipe, since our source array might
414 have multiple references to the same temp scalar (e.g.
415 from a list slice) */
418 sv_setsv_flags(ary[i], *strp,
419 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
429 Clears an array, making it empty. Does not free the memory used by the
430 array itself. Perl equivalent: C<@myarray = ();>.
436 Perl_av_clear(pTHX_ register AV *av)
441 PERL_ARGS_ASSERT_AV_CLEAR;
442 assert(SvTYPE(av) == SVt_PVAV);
445 if (SvREFCNT(av) == 0) {
446 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEBUGGING), "Attempt to clear deleted array");
451 Perl_croak_no_modify(aTHX);
453 /* Give any tie a chance to cleanup first */
454 if (SvRMAGICAL(av)) {
455 const MAGIC* const mg = SvMAGIC(av);
456 if (PL_delaymagic && mg && mg->mg_type == PERL_MAGIC_isa)
457 PL_delaymagic |= DM_ARRAY_ISA;
459 mg_clear(MUTABLE_SV(av));
466 SV** const ary = AvARRAY(av);
467 I32 index = AvFILLp(av) + 1;
469 SV * const sv = ary[--index];
470 /* undef the slot before freeing the value, because a
471 * destructor might try to modify this array */
472 ary[index] = &PL_sv_undef;
476 extra = AvARRAY(av) - AvALLOC(av);
479 AvARRAY(av) = AvALLOC(av);
488 Undefines the array. Frees the memory used by the array itself.
494 Perl_av_undef(pTHX_ register AV *av)
496 PERL_ARGS_ASSERT_AV_UNDEF;
497 assert(SvTYPE(av) == SVt_PVAV);
499 /* Give any tie a chance to cleanup first */
500 if (SvTIED_mg((const SV *)av, PERL_MAGIC_tied))
504 register I32 key = AvFILLp(av) + 1;
506 SvREFCNT_dec(AvARRAY(av)[--key]);
509 Safefree(AvALLOC(av));
512 AvMAX(av) = AvFILLp(av) = -1;
514 if(SvRMAGICAL(av)) mg_clear(MUTABLE_SV(av));
519 =for apidoc av_create_and_push
521 Push an SV onto the end of the array, creating the array if necessary.
522 A small internal helper function to remove a commonly duplicated idiom.
528 Perl_av_create_and_push(pTHX_ AV **const avp, SV *const val)
530 PERL_ARGS_ASSERT_AV_CREATE_AND_PUSH;
540 Pushes an SV onto the end of the array. The array will grow automatically
541 to accommodate the addition. This takes ownership of one reference count.
543 Perl equivalent: C<push @myarray, $elem;>.
549 Perl_av_push(pTHX_ register AV *av, SV *val)
554 PERL_ARGS_ASSERT_AV_PUSH;
555 assert(SvTYPE(av) == SVt_PVAV);
558 Perl_croak_no_modify(aTHX);
560 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
561 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "PUSH", G_DISCARD, 1,
565 av_store(av,AvFILLp(av)+1,val);
571 Pops an SV off the end of the array. Returns C<&PL_sv_undef> if the array
574 Perl equivalent: C<pop(@myarray);>
580 Perl_av_pop(pTHX_ register AV *av)
586 PERL_ARGS_ASSERT_AV_POP;
587 assert(SvTYPE(av) == SVt_PVAV);
590 Perl_croak_no_modify(aTHX);
591 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
592 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "POP", 0, 0);
594 retval = newSVsv(retval);
599 retval = AvARRAY(av)[AvFILLp(av)];
600 AvARRAY(av)[AvFILLp(av)--] = &PL_sv_undef;
602 mg_set(MUTABLE_SV(av));
608 =for apidoc av_create_and_unshift_one
610 Unshifts an SV onto the beginning of the array, creating the array if
612 A small internal helper function to remove a commonly duplicated idiom.
618 Perl_av_create_and_unshift_one(pTHX_ AV **const avp, SV *const val)
620 PERL_ARGS_ASSERT_AV_CREATE_AND_UNSHIFT_ONE;
625 return av_store(*avp, 0, val);
629 =for apidoc av_unshift
631 Unshift the given number of C<undef> values onto the beginning of the
632 array. The array will grow automatically to accommodate the addition. You
633 must then use C<av_store> to assign values to these new elements.
635 Perl equivalent: C<unshift @myarray, ( (undef) x $n );>
641 Perl_av_unshift(pTHX_ register AV *av, register I32 num)
647 PERL_ARGS_ASSERT_AV_UNSHIFT;
648 assert(SvTYPE(av) == SVt_PVAV);
651 Perl_croak_no_modify(aTHX);
653 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
654 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "UNSHIFT",
655 G_DISCARD | G_UNDEF_FILL, num);
661 if (!AvREAL(av) && AvREIFY(av))
663 i = AvARRAY(av) - AvALLOC(av);
671 AvARRAY(av) = AvARRAY(av) - i;
675 const I32 i = AvFILLp(av);
676 /* Create extra elements */
677 const I32 slide = i > 0 ? i : 0;
679 av_extend(av, i + num);
682 Move(ary, ary + num, i + 1, SV*);
684 ary[--num] = &PL_sv_undef;
686 /* Make extra elements into a buffer */
688 AvFILLp(av) -= slide;
689 AvARRAY(av) = AvARRAY(av) + slide;
696 Shifts an SV off the beginning of the
697 array. Returns C<&PL_sv_undef> if the
700 Perl equivalent: C<shift(@myarray);>
706 Perl_av_shift(pTHX_ register AV *av)
712 PERL_ARGS_ASSERT_AV_SHIFT;
713 assert(SvTYPE(av) == SVt_PVAV);
716 Perl_croak_no_modify(aTHX);
717 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
718 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "SHIFT", 0, 0);
720 retval = newSVsv(retval);
725 retval = *AvARRAY(av);
727 *AvARRAY(av) = &PL_sv_undef;
728 AvARRAY(av) = AvARRAY(av) + 1;
732 mg_set(MUTABLE_SV(av));
739 Returns the highest index in the array. The number of elements in the
740 array is C<av_len(av) + 1>. Returns -1 if the array is empty.
742 The Perl equivalent for this is C<$#myarray>.
748 Perl_av_len(pTHX_ AV *av)
750 PERL_ARGS_ASSERT_AV_LEN;
751 assert(SvTYPE(av) == SVt_PVAV);
759 Set the highest index in the array to the given number, equivalent to
760 Perl's C<$#array = $fill;>.
762 The number of elements in the an array will be C<fill + 1> after
763 av_fill() returns. If the array was previously shorter, then the
764 additional elements appended are set to C<PL_sv_undef>. If the array
765 was longer, then the excess elements are freed. C<av_fill(av, -1)> is
766 the same as C<av_clear(av)>.
771 Perl_av_fill(pTHX_ register AV *av, I32 fill)
776 PERL_ARGS_ASSERT_AV_FILL;
777 assert(SvTYPE(av) == SVt_PVAV);
781 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
782 SV *arg1 = sv_newmortal();
783 sv_setiv(arg1, (IV)(fill + 1));
784 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "STORESIZE", G_DISCARD,
788 if (fill <= AvMAX(av)) {
789 I32 key = AvFILLp(av);
790 SV** const ary = AvARRAY(av);
794 SvREFCNT_dec(ary[key]);
795 ary[key--] = &PL_sv_undef;
800 ary[++key] = &PL_sv_undef;
805 mg_set(MUTABLE_SV(av));
808 (void)av_store(av,fill,&PL_sv_undef);
812 =for apidoc av_delete
814 Deletes the element indexed by C<key> from the array, makes the element mortal,
815 and returns it. If C<flags> equals C<G_DISCARD>, the element is freed and null
816 is returned. Perl equivalent: C<my $elem = delete($myarray[$idx]);> for the
817 non-C<G_DISCARD> version and a void-context C<delete($myarray[$idx]);> for the
818 C<G_DISCARD> version.
823 Perl_av_delete(pTHX_ AV *av, I32 key, I32 flags)
828 PERL_ARGS_ASSERT_AV_DELETE;
829 assert(SvTYPE(av) == SVt_PVAV);
832 Perl_croak_no_modify(aTHX);
834 if (SvRMAGICAL(av)) {
835 const MAGIC * const tied_magic
836 = mg_find((const SV *)av, PERL_MAGIC_tied);
837 if ((tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata))) {
838 /* Handle negative array indices 20020222 MJD */
841 unsigned adjust_index = 1;
843 SV * const * const negative_indices_glob =
844 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
846 NEGATIVE_INDICES_VAR, 16, 0);
847 if (negative_indices_glob
848 && SvTRUE(GvSV(*negative_indices_glob)))
852 key += AvFILL(av) + 1;
857 svp = av_fetch(av, key, TRUE);
861 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
862 sv_unmagic(sv, PERL_MAGIC_tiedelem); /* No longer an element */
871 key += AvFILL(av) + 1;
876 if (key > AvFILLp(av))
879 if (!AvREAL(av) && AvREIFY(av))
881 sv = AvARRAY(av)[key];
882 if (key == AvFILLp(av)) {
883 AvARRAY(av)[key] = &PL_sv_undef;
886 } while (--key >= 0 && AvARRAY(av)[key] == &PL_sv_undef);
889 AvARRAY(av)[key] = &PL_sv_undef;
891 mg_set(MUTABLE_SV(av));
893 if (flags & G_DISCARD) {
903 =for apidoc av_exists
905 Returns true if the element indexed by C<key> has been initialized.
907 This relies on the fact that uninitialized array elements are set to
910 Perl equivalent: C<exists($myarray[$key])>.
915 Perl_av_exists(pTHX_ AV *av, I32 key)
918 PERL_ARGS_ASSERT_AV_EXISTS;
919 assert(SvTYPE(av) == SVt_PVAV);
921 if (SvRMAGICAL(av)) {
922 const MAGIC * const tied_magic
923 = mg_find((const SV *)av, PERL_MAGIC_tied);
924 const MAGIC * const regdata_magic
925 = mg_find((const SV *)av, PERL_MAGIC_regdata);
926 if (tied_magic || regdata_magic) {
927 SV * const sv = sv_newmortal();
929 /* Handle negative array indices 20020222 MJD */
931 unsigned adjust_index = 1;
933 SV * const * const negative_indices_glob =
934 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
936 NEGATIVE_INDICES_VAR, 16, 0);
937 if (negative_indices_glob
938 && SvTRUE(GvSV(*negative_indices_glob)))
942 key += AvFILL(av) + 1;
950 if(key >= 0 && regdata_magic) {
951 if (key <= AvFILL(av))
957 mg_copy(MUTABLE_SV(av), sv, 0, key);
958 mg = mg_find(sv, PERL_MAGIC_tiedelem);
960 magic_existspack(sv, mg);
961 return cBOOL(SvTRUE(sv));
968 key += AvFILL(av) + 1;
973 if (key <= AvFILLp(av) && AvARRAY(av)[key] != &PL_sv_undef
983 S_get_aux_mg(pTHX_ AV *av) {
987 PERL_ARGS_ASSERT_GET_AUX_MG;
988 assert(SvTYPE(av) == SVt_PVAV);
990 mg = mg_find((const SV *)av, PERL_MAGIC_arylen_p);
993 mg = sv_magicext(MUTABLE_SV(av), 0, PERL_MAGIC_arylen_p,
994 &PL_vtbl_arylen_p, 0, 0);
996 /* sv_magicext won't set this for us because we pass in a NULL obj */
997 mg->mg_flags |= MGf_REFCOUNTED;
1003 Perl_av_arylen_p(pTHX_ AV *av) {
1004 MAGIC *const mg = get_aux_mg(av);
1006 PERL_ARGS_ASSERT_AV_ARYLEN_P;
1007 assert(SvTYPE(av) == SVt_PVAV);
1009 return &(mg->mg_obj);
1013 Perl_av_iter_p(pTHX_ AV *av) {
1014 MAGIC *const mg = get_aux_mg(av);
1016 PERL_ARGS_ASSERT_AV_ITER_P;
1017 assert(SvTYPE(av) == SVt_PVAV);
1019 #if IVSIZE == I32SIZE
1020 return (IV *)&(mg->mg_len);
1024 mg->mg_len = IVSIZE;
1026 mg->mg_ptr = (char *) temp;
1028 return (IV *)mg->mg_ptr;
1034 * c-indentation-style: bsd
1036 * indent-tabs-mode: t
1039 * ex: set ts=8 sts=4 sw=4 noet: