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] = $val;>.
288 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
289 more information on how to use this function on tied arrays.
295 Perl_av_store(pTHX_ register AV *av, I32 key, SV *val)
300 PERL_ARGS_ASSERT_AV_STORE;
301 assert(SvTYPE(av) == SVt_PVAV);
303 /* S_regclass relies on being able to pass in a NULL sv
304 (unicode_alternate may be NULL).
310 if (SvRMAGICAL(av)) {
311 const MAGIC * const tied_magic = mg_find((const SV *)av, PERL_MAGIC_tied);
313 /* Handle negative array indices 20020222 MJD */
315 bool adjust_index = 1;
316 SV * const * const negative_indices_glob =
317 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
319 NEGATIVE_INDICES_VAR, 16, 0);
320 if (negative_indices_glob
321 && SvTRUE(GvSV(*negative_indices_glob)))
324 key += AvFILL(av) + 1;
329 if (val != &PL_sv_undef) {
330 mg_copy(MUTABLE_SV(av), val, 0, key);
338 key += AvFILL(av) + 1;
343 if (SvREADONLY(av) && key >= AvFILL(av))
344 Perl_croak_no_modify(aTHX);
346 if (!AvREAL(av) && AvREIFY(av))
351 if (AvFILLp(av) < key) {
353 if (av == PL_curstack && key > PL_stack_sp - PL_stack_base)
354 PL_stack_sp = PL_stack_base + key; /* XPUSH in disguise */
356 ary[++AvFILLp(av)] = &PL_sv_undef;
357 } while (AvFILLp(av) < key);
362 SvREFCNT_dec(ary[key]);
364 if (SvSMAGICAL(av)) {
365 const MAGIC* const mg = SvMAGIC(av);
366 if (val != &PL_sv_undef) {
367 sv_magic(val, MUTABLE_SV(av), toLOWER(mg->mg_type), 0, key);
369 if (PL_delaymagic && mg->mg_type == PERL_MAGIC_isa)
370 PL_delaymagic |= DM_ARRAY_ISA;
372 mg_set(MUTABLE_SV(av));
380 Creates a new AV and populates it with a list of SVs. The SVs are copied
381 into the array, so they may be freed after the call to av_make. The new AV
382 will have a reference count of 1.
384 Perl equivalent: C<my @new_array = ($scalar1, $scalar2, $scalar3...);>
390 Perl_av_make(pTHX_ register I32 size, register SV **strp)
392 register AV * const av = MUTABLE_AV(newSV_type(SVt_PVAV));
393 /* sv_upgrade does AvREAL_only() */
394 PERL_ARGS_ASSERT_AV_MAKE;
395 assert(SvTYPE(av) == SVt_PVAV);
397 if (size) { /* "defined" was returning undef for size==0 anyway. */
403 AvFILLp(av) = AvMAX(av) = size - 1;
404 for (i = 0; i < size; i++) {
407 /* Don't let sv_setsv swipe, since our source array might
408 have multiple references to the same temp scalar (e.g.
409 from a list slice) */
412 sv_setsv_flags(ary[i], *strp,
413 SV_GMAGIC|SV_DO_COW_SVSETSV|SV_NOSTEAL);
423 Clears an array, making it empty. Does not free the memory used by the
424 array itself. Perl equivalent: C<@myarray = ();>.
430 Perl_av_clear(pTHX_ register AV *av)
435 PERL_ARGS_ASSERT_AV_CLEAR;
436 assert(SvTYPE(av) == SVt_PVAV);
439 if (SvREFCNT(av) == 0) {
440 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEBUGGING), "Attempt to clear deleted array");
445 Perl_croak_no_modify(aTHX);
447 /* Give any tie a chance to cleanup first */
448 if (SvRMAGICAL(av)) {
449 const MAGIC* const mg = SvMAGIC(av);
450 if (PL_delaymagic && mg && mg->mg_type == PERL_MAGIC_isa)
451 PL_delaymagic |= DM_ARRAY_ISA;
453 mg_clear(MUTABLE_SV(av));
460 SV** const ary = AvARRAY(av);
461 I32 index = AvFILLp(av) + 1;
463 SV * const sv = ary[--index];
464 /* undef the slot before freeing the value, because a
465 * destructor might try to modify this array */
466 ary[index] = &PL_sv_undef;
470 extra = AvARRAY(av) - AvALLOC(av);
473 AvARRAY(av) = AvALLOC(av);
482 Undefines the array. Frees the memory used by the array itself.
488 Perl_av_undef(pTHX_ register AV *av)
490 PERL_ARGS_ASSERT_AV_UNDEF;
491 assert(SvTYPE(av) == SVt_PVAV);
493 /* Give any tie a chance to cleanup first */
494 if (SvTIED_mg((const SV *)av, PERL_MAGIC_tied))
498 register I32 key = AvFILLp(av) + 1;
500 SvREFCNT_dec(AvARRAY(av)[--key]);
503 Safefree(AvALLOC(av));
506 AvMAX(av) = AvFILLp(av) = -1;
508 if(SvRMAGICAL(av)) mg_clear(MUTABLE_SV(av));
513 =for apidoc av_create_and_push
515 Push an SV onto the end of the array, creating the array if necessary.
516 A small internal helper function to remove a commonly duplicated idiom.
522 Perl_av_create_and_push(pTHX_ AV **const avp, SV *const val)
524 PERL_ARGS_ASSERT_AV_CREATE_AND_PUSH;
534 Pushes an SV onto the end of the array. The array will grow automatically
535 to accommodate the addition. This takes ownership of one reference count.
537 Perl equivalent: C<push @myarray, $elem;>.
543 Perl_av_push(pTHX_ register AV *av, SV *val)
548 PERL_ARGS_ASSERT_AV_PUSH;
549 assert(SvTYPE(av) == SVt_PVAV);
552 Perl_croak_no_modify(aTHX);
554 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
555 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "PUSH", G_DISCARD, 1,
559 av_store(av,AvFILLp(av)+1,val);
565 Pops an SV off the end of the array. Returns C<&PL_sv_undef> if the array
568 Perl equivalent: C<pop(@myarray);>
574 Perl_av_pop(pTHX_ register AV *av)
580 PERL_ARGS_ASSERT_AV_POP;
581 assert(SvTYPE(av) == SVt_PVAV);
584 Perl_croak_no_modify(aTHX);
585 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
586 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "POP", 0, 0);
588 retval = newSVsv(retval);
593 retval = AvARRAY(av)[AvFILLp(av)];
594 AvARRAY(av)[AvFILLp(av)--] = &PL_sv_undef;
596 mg_set(MUTABLE_SV(av));
602 =for apidoc av_create_and_unshift_one
604 Unshifts an SV onto the beginning of the array, creating the array if
606 A small internal helper function to remove a commonly duplicated idiom.
612 Perl_av_create_and_unshift_one(pTHX_ AV **const avp, SV *const val)
614 PERL_ARGS_ASSERT_AV_CREATE_AND_UNSHIFT_ONE;
619 return av_store(*avp, 0, val);
623 =for apidoc av_unshift
625 Unshift the given number of C<undef> values onto the beginning of the
626 array. The array will grow automatically to accommodate the addition. You
627 must then use C<av_store> to assign values to these new elements.
629 Perl equivalent: C<unshift @myarray, ( (undef) x $n );>
635 Perl_av_unshift(pTHX_ register AV *av, register I32 num)
641 PERL_ARGS_ASSERT_AV_UNSHIFT;
642 assert(SvTYPE(av) == SVt_PVAV);
645 Perl_croak_no_modify(aTHX);
647 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
648 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "UNSHIFT",
649 G_DISCARD | G_UNDEF_FILL, num);
655 if (!AvREAL(av) && AvREIFY(av))
657 i = AvARRAY(av) - AvALLOC(av);
665 AvARRAY(av) = AvARRAY(av) - i;
669 const I32 i = AvFILLp(av);
670 /* Create extra elements */
671 const I32 slide = i > 0 ? i : 0;
673 av_extend(av, i + num);
676 Move(ary, ary + num, i + 1, SV*);
678 ary[--num] = &PL_sv_undef;
680 /* Make extra elements into a buffer */
682 AvFILLp(av) -= slide;
683 AvARRAY(av) = AvARRAY(av) + slide;
690 Shifts an SV off the beginning of the
691 array. Returns C<&PL_sv_undef> if the
694 Perl equivalent: C<shift(@myarray);>
700 Perl_av_shift(pTHX_ register AV *av)
706 PERL_ARGS_ASSERT_AV_SHIFT;
707 assert(SvTYPE(av) == SVt_PVAV);
710 Perl_croak_no_modify(aTHX);
711 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
712 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "SHIFT", 0, 0);
714 retval = newSVsv(retval);
719 retval = *AvARRAY(av);
721 *AvARRAY(av) = &PL_sv_undef;
722 AvARRAY(av) = AvARRAY(av) + 1;
726 mg_set(MUTABLE_SV(av));
733 Returns the highest index in the array. The number of elements in the
734 array is C<av_len(av) + 1>. Returns -1 if the array is empty.
736 The Perl equivalent for this is C<$#myarray>.
742 Perl_av_len(pTHX_ AV *av)
744 PERL_ARGS_ASSERT_AV_LEN;
745 assert(SvTYPE(av) == SVt_PVAV);
753 Set the highest index in the array to the given number, equivalent to
754 Perl's C<$#array = $fill;>.
756 The number of elements in the an array will be C<fill + 1> after
757 av_fill() returns. If the array was previously shorter, then the
758 additional elements appended are set to C<PL_sv_undef>. If the array
759 was longer, then the excess elements are freed. C<av_fill(av, -1)> is
760 the same as C<av_clear(av)>.
765 Perl_av_fill(pTHX_ register AV *av, I32 fill)
770 PERL_ARGS_ASSERT_AV_FILL;
771 assert(SvTYPE(av) == SVt_PVAV);
775 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
776 SV *arg1 = sv_newmortal();
777 sv_setiv(arg1, (IV)(fill + 1));
778 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, "STORESIZE", G_DISCARD,
782 if (fill <= AvMAX(av)) {
783 I32 key = AvFILLp(av);
784 SV** const ary = AvARRAY(av);
788 SvREFCNT_dec(ary[key]);
789 ary[key--] = &PL_sv_undef;
794 ary[++key] = &PL_sv_undef;
799 mg_set(MUTABLE_SV(av));
802 (void)av_store(av,fill,&PL_sv_undef);
806 =for apidoc av_delete
808 Deletes the element indexed by C<key> from the array, makes the element mortal,
809 and returns it. If C<flags> equals C<G_DISCARD>, the element is freed and null
810 is returned. Perl equivalent: C<my $elem = delete($myarray[$idx]);> for the
811 non-C<G_DISCARD> version and a void-context C<delete($myarray[$idx]);> for the
812 C<G_DISCARD> version.
817 Perl_av_delete(pTHX_ AV *av, I32 key, I32 flags)
822 PERL_ARGS_ASSERT_AV_DELETE;
823 assert(SvTYPE(av) == SVt_PVAV);
826 Perl_croak_no_modify(aTHX);
828 if (SvRMAGICAL(av)) {
829 const MAGIC * const tied_magic
830 = mg_find((const SV *)av, PERL_MAGIC_tied);
831 if ((tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata))) {
832 /* Handle negative array indices 20020222 MJD */
835 unsigned adjust_index = 1;
837 SV * const * const negative_indices_glob =
838 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
840 NEGATIVE_INDICES_VAR, 16, 0);
841 if (negative_indices_glob
842 && SvTRUE(GvSV(*negative_indices_glob)))
846 key += AvFILL(av) + 1;
851 svp = av_fetch(av, key, TRUE);
855 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
856 sv_unmagic(sv, PERL_MAGIC_tiedelem); /* No longer an element */
865 key += AvFILL(av) + 1;
870 if (key > AvFILLp(av))
873 if (!AvREAL(av) && AvREIFY(av))
875 sv = AvARRAY(av)[key];
876 if (key == AvFILLp(av)) {
877 AvARRAY(av)[key] = &PL_sv_undef;
880 } while (--key >= 0 && AvARRAY(av)[key] == &PL_sv_undef);
883 AvARRAY(av)[key] = &PL_sv_undef;
885 mg_set(MUTABLE_SV(av));
887 if (flags & G_DISCARD) {
897 =for apidoc av_exists
899 Returns true if the element indexed by C<key> has been initialized.
901 This relies on the fact that uninitialized array elements are set to
904 Perl equivalent: C<exists($myarray[$key])>.
909 Perl_av_exists(pTHX_ AV *av, I32 key)
912 PERL_ARGS_ASSERT_AV_EXISTS;
913 assert(SvTYPE(av) == SVt_PVAV);
915 if (SvRMAGICAL(av)) {
916 const MAGIC * const tied_magic
917 = mg_find((const SV *)av, PERL_MAGIC_tied);
918 const MAGIC * const regdata_magic
919 = mg_find((const SV *)av, PERL_MAGIC_regdata);
920 if (tied_magic || regdata_magic) {
921 SV * const sv = sv_newmortal();
923 /* Handle negative array indices 20020222 MJD */
925 unsigned adjust_index = 1;
927 SV * const * const negative_indices_glob =
928 hv_fetch(SvSTASH(SvRV(SvTIED_obj(MUTABLE_SV(av),
930 NEGATIVE_INDICES_VAR, 16, 0);
931 if (negative_indices_glob
932 && SvTRUE(GvSV(*negative_indices_glob)))
936 key += AvFILL(av) + 1;
944 if(key >= 0 && regdata_magic) {
945 if (key <= AvFILL(av))
951 mg_copy(MUTABLE_SV(av), sv, 0, key);
952 mg = mg_find(sv, PERL_MAGIC_tiedelem);
954 magic_existspack(sv, mg);
955 return cBOOL(SvTRUE(sv));
962 key += AvFILL(av) + 1;
967 if (key <= AvFILLp(av) && AvARRAY(av)[key] != &PL_sv_undef
977 S_get_aux_mg(pTHX_ AV *av) {
981 PERL_ARGS_ASSERT_GET_AUX_MG;
982 assert(SvTYPE(av) == SVt_PVAV);
984 mg = mg_find((const SV *)av, PERL_MAGIC_arylen_p);
987 mg = sv_magicext(MUTABLE_SV(av), 0, PERL_MAGIC_arylen_p,
988 &PL_vtbl_arylen_p, 0, 0);
990 /* sv_magicext won't set this for us because we pass in a NULL obj */
991 mg->mg_flags |= MGf_REFCOUNTED;
997 Perl_av_arylen_p(pTHX_ AV *av) {
998 MAGIC *const mg = get_aux_mg(av);
1000 PERL_ARGS_ASSERT_AV_ARYLEN_P;
1001 assert(SvTYPE(av) == SVt_PVAV);
1003 return &(mg->mg_obj);
1007 Perl_av_iter_p(pTHX_ AV *av) {
1008 MAGIC *const mg = get_aux_mg(av);
1010 PERL_ARGS_ASSERT_AV_ITER_P;
1011 assert(SvTYPE(av) == SVt_PVAV);
1013 #if IVSIZE == I32SIZE
1014 return (IV *)&(mg->mg_len);
1018 mg->mg_len = IVSIZE;
1020 mg->mg_ptr = (char *) temp;
1022 return (IV *)mg->mg_ptr;
1028 * c-indentation-style: bsd
1030 * indent-tabs-mode: t
1033 * ex: set ts=8 sts=4 sw=4 noet: