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] = $val;>.
288 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
289 more information on how to use this function on tied arrays.
295 Perl_av_store(pTHX_ register AV *av, I32 key, SV *val)
300 PERL_ARGS_ASSERT_AV_STORE;
301 assert(SvTYPE(av) == SVt_PVAV);
303 /* S_regclass relies on being able to pass in a NULL sv
304 (unicode_alternate may be NULL).
310 if (SvRMAGICAL(av)) {
311 const MAGIC * const tied_magic = mg_find((const SV *)av, PERL_MAGIC_tied);
313 /* Handle negative array indices 20020222 MJD */
315 bool adjust_index = 1;
316 SV * const * const negative_indices_glob =
317 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
319 NEGATIVE_INDICES_VAR, 16, 0);
320 if (negative_indices_glob
321 && SvTRUE(GvSV(*negative_indices_glob)))
324 key += AvFILL(av) + 1;
329 if (val != &PL_sv_undef) {
330 mg_copy(MUTABLE_SV(av), val, 0, key);
338 key += AvFILL(av) + 1;
343 if (SvREADONLY(av) && key >= AvFILL(av))
344 Perl_croak_no_modify(aTHX);
346 if (!AvREAL(av) && AvREIFY(av))
351 if (AvFILLp(av) < key) {
353 if (av == PL_curstack && key > PL_stack_sp - PL_stack_base)
354 PL_stack_sp = PL_stack_base + key; /* XPUSH in disguise */
356 ary[++AvFILLp(av)] = &PL_sv_undef;
357 } while (AvFILLp(av) < key);
362 SvREFCNT_dec(ary[key]);
364 if (SvSMAGICAL(av)) {
365 const MAGIC *mg = SvMAGIC(av);
367 for (; mg; mg = mg->mg_moremagic) {
368 const int eletype = toLOWER(mg->mg_type);
369 if (eletype == mg->mg_type) continue;
370 if (val != &PL_sv_undef) {
371 sv_magic(val, MUTABLE_SV(av), toLOWER(mg->mg_type), 0, key);
373 if (PL_delaymagic && mg->mg_type == PERL_MAGIC_isa) {
374 PL_delaymagic |= DM_ARRAY_ISA;
379 mg_set(MUTABLE_SV(av));
387 Creates a new AV and populates it with a list of SVs. The SVs are copied
388 into the array, so they may be freed after the call to av_make. The new AV
389 will have a reference count of 1.
391 Perl equivalent: C<my @new_array = ($scalar1, $scalar2, $scalar3...);>
397 Perl_av_make(pTHX_ register I32 size, register SV **strp)
399 register AV * const av = MUTABLE_AV(newSV_type(SVt_PVAV));
400 /* sv_upgrade does AvREAL_only() */
401 PERL_ARGS_ASSERT_AV_MAKE;
402 assert(SvTYPE(av) == SVt_PVAV);
404 if (size) { /* "defined" was returning undef for size==0 anyway. */
410 AvFILLp(av) = AvMAX(av) = size - 1;
411 for (i = 0; i < size; i++) {
414 /* Don't let sv_setsv swipe, since our source array might
415 have multiple references to the same temp scalar (e.g.
416 from a list slice) */
419 sv_setsv_flags(ary[i], *strp,
420 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
430 Clears an array, making it empty. Does not free the memory used by the
431 array itself. Perl equivalent: C<@myarray = ();>.
437 Perl_av_clear(pTHX_ register AV *av)
442 PERL_ARGS_ASSERT_AV_CLEAR;
443 assert(SvTYPE(av) == SVt_PVAV);
446 if (SvREFCNT(av) == 0) {
447 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEBUGGING), "Attempt to clear deleted array");
452 Perl_croak_no_modify(aTHX);
454 /* Give any tie a chance to cleanup first */
455 if (SvRMAGICAL(av)) {
456 const MAGIC* const mg = SvMAGIC(av);
457 if (PL_delaymagic && mg && mg->mg_type == PERL_MAGIC_isa)
458 PL_delaymagic |= DM_ARRAY_ISA;
460 mg_clear(MUTABLE_SV(av));
467 SV** const ary = AvARRAY(av);
468 I32 index = AvFILLp(av) + 1;
470 SV * const sv = ary[--index];
471 /* undef the slot before freeing the value, because a
472 * destructor might try to modify this array */
473 ary[index] = &PL_sv_undef;
477 extra = AvARRAY(av) - AvALLOC(av);
480 AvARRAY(av) = AvALLOC(av);
489 Undefines the array. Frees the memory used by the array itself.
495 Perl_av_undef(pTHX_ register AV *av)
497 PERL_ARGS_ASSERT_AV_UNDEF;
498 assert(SvTYPE(av) == SVt_PVAV);
500 /* Give any tie a chance to cleanup first */
501 if (SvTIED_mg((const SV *)av, PERL_MAGIC_tied))
505 register I32 key = AvFILLp(av) + 1;
507 SvREFCNT_dec(AvARRAY(av)[--key]);
510 Safefree(AvALLOC(av));
513 AvMAX(av) = AvFILLp(av) = -1;
515 if(SvRMAGICAL(av)) mg_clear(MUTABLE_SV(av));
520 =for apidoc av_create_and_push
522 Push an SV onto the end of the array, creating the array if necessary.
523 A small internal helper function to remove a commonly duplicated idiom.
529 Perl_av_create_and_push(pTHX_ AV **const avp, SV *const val)
531 PERL_ARGS_ASSERT_AV_CREATE_AND_PUSH;
541 Pushes an SV onto the end of the array. The array will grow automatically
542 to accommodate the addition. This takes ownership of one reference count.
544 Perl equivalent: C<push @myarray, $elem;>.
550 Perl_av_push(pTHX_ register AV *av, SV *val)
555 PERL_ARGS_ASSERT_AV_PUSH;
556 assert(SvTYPE(av) == SVt_PVAV);
559 Perl_croak_no_modify(aTHX);
561 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
562 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "PUSH", G_DISCARD, 1,
566 av_store(av,AvFILLp(av)+1,val);
572 Pops an SV off the end of the array. Returns C<&PL_sv_undef> if the array
575 Perl equivalent: C<pop(@myarray);>
581 Perl_av_pop(pTHX_ register AV *av)
587 PERL_ARGS_ASSERT_AV_POP;
588 assert(SvTYPE(av) == SVt_PVAV);
591 Perl_croak_no_modify(aTHX);
592 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
593 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "POP", 0, 0);
595 retval = newSVsv(retval);
600 retval = AvARRAY(av)[AvFILLp(av)];
601 AvARRAY(av)[AvFILLp(av)--] = &PL_sv_undef;
603 mg_set(MUTABLE_SV(av));
609 =for apidoc av_create_and_unshift_one
611 Unshifts an SV onto the beginning of the array, creating the array if
613 A small internal helper function to remove a commonly duplicated idiom.
619 Perl_av_create_and_unshift_one(pTHX_ AV **const avp, SV *const val)
621 PERL_ARGS_ASSERT_AV_CREATE_AND_UNSHIFT_ONE;
626 return av_store(*avp, 0, val);
630 =for apidoc av_unshift
632 Unshift the given number of C<undef> values onto the beginning of the
633 array. The array will grow automatically to accommodate the addition. You
634 must then use C<av_store> to assign values to these new elements.
636 Perl equivalent: C<unshift @myarray, ( (undef) x $n );>
642 Perl_av_unshift(pTHX_ register AV *av, register I32 num)
648 PERL_ARGS_ASSERT_AV_UNSHIFT;
649 assert(SvTYPE(av) == SVt_PVAV);
652 Perl_croak_no_modify(aTHX);
654 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
655 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "UNSHIFT",
656 G_DISCARD | G_UNDEF_FILL, num);
662 if (!AvREAL(av) && AvREIFY(av))
664 i = AvARRAY(av) - AvALLOC(av);
672 AvARRAY(av) = AvARRAY(av) - i;
676 const I32 i = AvFILLp(av);
677 /* Create extra elements */
678 const I32 slide = i > 0 ? i : 0;
680 av_extend(av, i + num);
683 Move(ary, ary + num, i + 1, SV*);
685 ary[--num] = &PL_sv_undef;
687 /* Make extra elements into a buffer */
689 AvFILLp(av) -= slide;
690 AvARRAY(av) = AvARRAY(av) + slide;
697 Shifts an SV off the beginning of the
698 array. Returns C<&PL_sv_undef> if the
701 Perl equivalent: C<shift(@myarray);>
707 Perl_av_shift(pTHX_ register AV *av)
713 PERL_ARGS_ASSERT_AV_SHIFT;
714 assert(SvTYPE(av) == SVt_PVAV);
717 Perl_croak_no_modify(aTHX);
718 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
719 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "SHIFT", 0, 0);
721 retval = newSVsv(retval);
726 retval = *AvARRAY(av);
728 *AvARRAY(av) = &PL_sv_undef;
729 AvARRAY(av) = AvARRAY(av) + 1;
733 mg_set(MUTABLE_SV(av));
740 Returns the highest index in the array. The number of elements in the
741 array is C<av_len(av) + 1>. Returns -1 if the array is empty.
743 The Perl equivalent for this is C<$#myarray>.
749 Perl_av_len(pTHX_ AV *av)
751 PERL_ARGS_ASSERT_AV_LEN;
752 assert(SvTYPE(av) == SVt_PVAV);
760 Set the highest index in the array to the given number, equivalent to
761 Perl's C<$#array = $fill;>.
763 The number of elements in the an array will be C<fill + 1> after
764 av_fill() returns. If the array was previously shorter, then the
765 additional elements appended are set to C<PL_sv_undef>. If the array
766 was longer, then the excess elements are freed. C<av_fill(av, -1)> is
767 the same as C<av_clear(av)>.
772 Perl_av_fill(pTHX_ register AV *av, I32 fill)
777 PERL_ARGS_ASSERT_AV_FILL;
778 assert(SvTYPE(av) == SVt_PVAV);
782 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
783 SV *arg1 = sv_newmortal();
784 sv_setiv(arg1, (IV)(fill + 1));
785 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "STORESIZE", G_DISCARD,
789 if (fill <= AvMAX(av)) {
790 I32 key = AvFILLp(av);
791 SV** const ary = AvARRAY(av);
795 SvREFCNT_dec(ary[key]);
796 ary[key--] = &PL_sv_undef;
801 ary[++key] = &PL_sv_undef;
806 mg_set(MUTABLE_SV(av));
809 (void)av_store(av,fill,&PL_sv_undef);
813 =for apidoc av_delete
815 Deletes the element indexed by C<key> from the array, makes the element mortal,
816 and returns it. If C<flags> equals C<G_DISCARD>, the element is freed and null
817 is returned. Perl equivalent: C<my $elem = delete($myarray[$idx]);> for the
818 non-C<G_DISCARD> version and a void-context C<delete($myarray[$idx]);> for the
819 C<G_DISCARD> version.
824 Perl_av_delete(pTHX_ AV *av, I32 key, I32 flags)
829 PERL_ARGS_ASSERT_AV_DELETE;
830 assert(SvTYPE(av) == SVt_PVAV);
833 Perl_croak_no_modify(aTHX);
835 if (SvRMAGICAL(av)) {
836 const MAGIC * const tied_magic
837 = mg_find((const SV *)av, PERL_MAGIC_tied);
838 if ((tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata))) {
839 /* Handle negative array indices 20020222 MJD */
842 unsigned adjust_index = 1;
844 SV * const * const negative_indices_glob =
845 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
847 NEGATIVE_INDICES_VAR, 16, 0);
848 if (negative_indices_glob
849 && SvTRUE(GvSV(*negative_indices_glob)))
853 key += AvFILL(av) + 1;
858 svp = av_fetch(av, key, TRUE);
862 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
863 sv_unmagic(sv, PERL_MAGIC_tiedelem); /* No longer an element */
872 key += AvFILL(av) + 1;
877 if (key > AvFILLp(av))
880 if (!AvREAL(av) && AvREIFY(av))
882 sv = AvARRAY(av)[key];
883 if (key == AvFILLp(av)) {
884 AvARRAY(av)[key] = &PL_sv_undef;
887 } while (--key >= 0 && AvARRAY(av)[key] == &PL_sv_undef);
890 AvARRAY(av)[key] = &PL_sv_undef;
892 mg_set(MUTABLE_SV(av));
894 if (flags & G_DISCARD) {
904 =for apidoc av_exists
906 Returns true if the element indexed by C<key> has been initialized.
908 This relies on the fact that uninitialized array elements are set to
911 Perl equivalent: C<exists($myarray[$key])>.
916 Perl_av_exists(pTHX_ AV *av, I32 key)
919 PERL_ARGS_ASSERT_AV_EXISTS;
920 assert(SvTYPE(av) == SVt_PVAV);
922 if (SvRMAGICAL(av)) {
923 const MAGIC * const tied_magic
924 = mg_find((const SV *)av, PERL_MAGIC_tied);
925 const MAGIC * const regdata_magic
926 = mg_find((const SV *)av, PERL_MAGIC_regdata);
927 if (tied_magic || regdata_magic) {
928 SV * const sv = sv_newmortal();
930 /* Handle negative array indices 20020222 MJD */
932 unsigned adjust_index = 1;
934 SV * const * const negative_indices_glob =
935 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
937 NEGATIVE_INDICES_VAR, 16, 0);
938 if (negative_indices_glob
939 && SvTRUE(GvSV(*negative_indices_glob)))
943 key += AvFILL(av) + 1;
951 if(key >= 0 && regdata_magic) {
952 if (key <= AvFILL(av))
958 mg_copy(MUTABLE_SV(av), sv, 0, key);
959 mg = mg_find(sv, PERL_MAGIC_tiedelem);
961 magic_existspack(sv, mg);
962 return cBOOL(SvTRUE(sv));
969 key += AvFILL(av) + 1;
974 if (key <= AvFILLp(av) && AvARRAY(av)[key] != &PL_sv_undef
984 S_get_aux_mg(pTHX_ AV *av) {
988 PERL_ARGS_ASSERT_GET_AUX_MG;
989 assert(SvTYPE(av) == SVt_PVAV);
991 mg = mg_find((const SV *)av, PERL_MAGIC_arylen_p);
994 mg = sv_magicext(MUTABLE_SV(av), 0, PERL_MAGIC_arylen_p,
995 &PL_vtbl_arylen_p, 0, 0);
997 /* sv_magicext won't set this for us because we pass in a NULL obj */
998 mg->mg_flags |= MGf_REFCOUNTED;
1004 Perl_av_arylen_p(pTHX_ AV *av) {
1005 MAGIC *const mg = get_aux_mg(av);
1007 PERL_ARGS_ASSERT_AV_ARYLEN_P;
1008 assert(SvTYPE(av) == SVt_PVAV);
1010 return &(mg->mg_obj);
1014 Perl_av_iter_p(pTHX_ AV *av) {
1015 MAGIC *const mg = get_aux_mg(av);
1017 PERL_ARGS_ASSERT_AV_ITER_P;
1018 assert(SvTYPE(av) == SVt_PVAV);
1020 #if IVSIZE == I32SIZE
1021 return (IV *)&(mg->mg_len);
1025 mg->mg_len = IVSIZE;
1027 mg->mg_ptr = (char *) temp;
1029 return (IV *)mg->mg_ptr;
1035 * c-indentation-style: bsd
1037 * indent-tabs-mode: t
1040 * ex: set ts=8 sts=4 sw=4 noet: