X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/9d32539b56f03de1849acc6621b291c318729bc5..0064f8cc7c4421620a76af5ddcf6cee0e7cc4368:/hv.h diff --git a/hv.h b/hv.h index 2058fcd..95dde46 100644 --- a/hv.h +++ b/hv.h @@ -8,6 +8,26 @@ * */ +/* These control hash traversal randomization and the environment variable PERL_PERTURB_KEYS. + * Currently disabling this functionality will break a few tests, but should otherwise work fine. + * See perlrun for more details. */ + +#if defined(PERL_PERTURB_KEYS_DISABLED) +# define PL_HASH_RAND_BITS_ENABLED 0 +# define PERL_HASH_ITER_BUCKET(iter) ((iter)->xhv_riter) +#else +# define PERL_HASH_RANDOMIZE_KEYS 1 +# if defined(PERL_PERTURB_KEYS_RANDOM) +# define PL_HASH_RAND_BITS_ENABLED 1 +# elif defined(PERL_PERTURB_KEYS_DETERMINISTIC) +# define PL_HASH_RAND_BITS_ENABLED 2 +# else +# define USE_PERL_PERTURB_KEYS 1 +# define PL_HASH_RAND_BITS_ENABLED PL_hash_rand_bits_enabled +# endif +# define PERL_HASH_ITER_BUCKET(iter) (((iter)->xhv_riter) ^ ((iter)->xhv_rand)) +#endif + /* entry in hash value chain */ struct he { /* Keep hent_next first in this structure, because sv_free_arenas take @@ -61,6 +81,8 @@ struct mro_meta { U32 pkg_gen; /* Bumps when local methods/@ISA change */ const struct mro_alg *mro_which; /* which mro alg is in use? */ HV *isa; /* Everything this class @ISA */ + HV *super; /* SUPER method cache */ + U32 destroy_gen; /* Generation number of DESTROY cache */ }; #define MRO_GET_PRIVATE_DATA(smeta, which) \ @@ -82,6 +104,7 @@ struct xpvhv_aux { AV *xhv_backreferences; /* back references for weak references */ HE *xhv_eiter; /* current entry of iterator */ I32 xhv_riter; /* current root of iterator */ + /* Concerning xhv_name_count: When non-zero, xhv_name_u contains a pointer * to an array of HEK pointers, this being the length. The first element is * the name of the stash, which may be NULL. If xhv_name_count is positive, @@ -90,8 +113,18 @@ struct xpvhv_aux { */ I32 xhv_name_count; struct mro_meta *xhv_mro_meta; +#ifdef PERL_HASH_RANDOMIZE_KEYS + U32 xhv_rand; /* random value for hash traversal */ + U32 xhv_last_rand; /* last random value for hash traversal, + used to detect each() after insert for warnings */ +#endif + U32 xhv_fill_lazy; + U32 xhv_aux_flags; /* assorted extra flags */ }; +#define HvAUXf_SCAN_STASH 0x1 /* stash is being scanned by gv_check */ +#define HvAUXf_NO_DEREF 0x2 /* @{}, %{} etc (and nomethod) not present */ + /* hash structure: */ /* This structure must match the beginning of struct xpvmg in sv.h. */ struct xpvhv { @@ -101,66 +134,13 @@ struct xpvhv { STRLEN xhv_max; /* subscript of last element of xhv_array */ }; -/* hash a key */ -/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins - * from requirements by Colin Plumb. - * (http://burtleburtle.net/bob/hash/doobs.html) */ -/* The use of a temporary pointer and the casting games - * is needed to serve the dual purposes of - * (a) the hashed data being interpreted as "unsigned char" (new since 5.8, - * a "char" can be either signed or unsigned, depending on the compiler) - * (b) catering for old code that uses a "char" - * - * The "hash seed" feature was added in Perl 5.8.1 to perturb the results - * to avoid "algorithmic complexity attacks". - * - * If USE_HASH_SEED is defined, hash randomisation is done by default - * If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done - * only if the environment variable PERL_HASH_SEED is set. - * For maximal control, one can define PERL_HASH_SEED. - * (see also perl.c:perl_parse()). - */ -#ifndef PERL_HASH_SEED -# if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) -# define PERL_HASH_SEED PL_hash_seed -# else -# define PERL_HASH_SEED 0 -# endif -#endif - -#define PERL_HASH(hash,str,len) PERL_HASH_INTERNAL_(hash,str,len,0) - -/* Only hv.c and mod_perl should be doing this. */ -#ifdef PERL_HASH_INTERNAL_ACCESS -#define PERL_HASH_INTERNAL(hash,str,len) PERL_HASH_INTERNAL_(hash,str,len,1) -#endif - -/* Common base for PERL_HASH and PERL_HASH_INTERNAL that parameterises - * the source of the seed. Not for direct use outside of hv.c. */ - -#define PERL_HASH_INTERNAL_(hash,str,len,internal) \ - STMT_START { \ - register const char * const s_PeRlHaSh_tmp = str; \ - register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \ - register I32 i_PeRlHaSh = len; \ - register U32 hash_PeRlHaSh = (internal ? PL_rehash_seed : PERL_HASH_SEED); \ - while (i_PeRlHaSh--) { \ - hash_PeRlHaSh += *s_PeRlHaSh++; \ - hash_PeRlHaSh += (hash_PeRlHaSh << 10); \ - hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \ - } \ - hash_PeRlHaSh += (hash_PeRlHaSh << 3); \ - hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \ - (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \ - } STMT_END - /* =head1 Hash Manipulation Functions =for apidoc AmU||HEf_SVKEY This flag, used in the length slot of hash entries and magic structures, specifies the structure contains an C pointer where a C pointer -is to be expected. (For information only--not to be used). +is to be expected. (For information only--not to be used). =head1 Handy Values @@ -182,10 +162,10 @@ Returns the length of the stash's name. Returns true if the name is in UTF8 encoding. =for apidoc Am|char*|HvENAME|HV* stash -Returns the effective name of a stash, or NULL if there is none. The +Returns the effective name of a stash, or NULL if there is none. The effective name represents a location in the symbol table where this stash -resides. It is updated automatically when packages are aliased or deleted. -A stash that is no longer in the symbol table has no effective name. This +resides. It is updated automatically when packages are aliased or deleted. +A stash that is no longer in the symbol table has no effective name. This name is preferable to C for use in MRO linearisations and isa caches. @@ -196,7 +176,7 @@ Returns the length of the stash's effective name. Returns true if the effective name is in UTF8 encoding. =for apidoc Am|void*|HeKEY|HE* he -Returns the actual pointer stored in the key slot of the hash entry. The +Returns the actual pointer stored in the key slot of the hash entry. The pointer may be either C or C, depending on the value of C. Can be assigned to. The C or C macros are usually preferable for finding the value of a key. @@ -204,11 +184,17 @@ usually preferable for finding the value of a key. =for apidoc Am|STRLEN|HeKLEN|HE* he If this is negative, and amounts to C, it indicates the entry holds an C key. Otherwise, holds the actual length of the key. Can -be assigned to. The C macro is usually preferable for finding key +be assigned to. The C macro is usually preferable for finding key lengths. =for apidoc Am|SV*|HeVAL|HE* he -Returns the value slot (type C) stored in the hash entry. +Returns the value slot (type C) +stored in the hash entry. Can be assigned +to. + + SV *foo= HeVAL(hv); + HeVAL(hv)= sv; + =for apidoc Am|U32|HeHASH|HE* he Returns the computed hash stored in the hash entry. @@ -221,14 +207,14 @@ not care about what the length of the key is, you may use the global variable C, though this is rather less efficient than using a local variable. Remember though, that hash keys in perl are free to contain embedded nulls, so using C or similar is not a good way to find -the length of hash keys. This is very similar to the C macro -described elsewhere in this document. See also C. +the length of hash keys. This is very similar to the C macro +described elsewhere in this document. See also C. If you are using C to get values to pass to C to create a new SV, you should consider using C as it is more efficient. -=for apidoc Am|char*|HeUTF8|HE* he +=for apidoc Am|U32|HeUTF8|HE* he Returns whether the C value returned by C is encoded in UTF-8, doing any necessary dereferencing of possibly C keys. The value returned will be 0 or non-0, not necessarily 1 (or even a value with any low bits set), @@ -251,6 +237,20 @@ C. =cut */ +#define PERL_HASH_DEFAULT_HvMAX 7 + +/* During hsplit(), if HvMAX(hv)+1 (the new bucket count) is >= this value, + * we preallocate the HvAUX() struct. + * The assumption being that we are using so much space anyway we might + * as well allocate the extra bytes and speed up later keys() + * or each() operations. We don't do this to small hashes as we assume + * that a) it will be easy/fast to resize them to add the iterator, and b) that + * many of them will be objects which won't be traversed. Larger hashes however + * will take longer to extend, and the size of the aux struct is swamped by the + * overall length of the bucket array. + * */ +#define PERL_HV_ALLOC_AUX_SIZE (1 << 9) + /* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */ #define HEf_SVKEY -2 /* hent_key is an SV* */ @@ -258,7 +258,7 @@ C. # define Nullhv Null(HV*) #endif #define HvARRAY(hv) ((hv)->sv_u.svu_hash) -#define HvFILL(hv) Perl_hv_fill(aTHX_ (const HV *)(hv)) +#define HvFILL(hv) Perl_hv_fill(aTHX_ MUTABLE_HV(hv)) #define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max /* This quite intentionally does no flag checking first. That's your responsibility. */ @@ -269,6 +269,9 @@ C. #define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ MUTABLE_HV(hv), e) #define HvRITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1) #define HvEITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_eiter : NULL) +#define HvRAND_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_rand : 0) +#define HvLASTRAND_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_last_rand : 0) + #define HvNAME(hv) HvNAME_get(hv) #define HvNAMELEN(hv) HvNAMELEN_get(hv) #define HvENAME(hv) HvENAME_get(hv) @@ -352,10 +355,6 @@ C. #define HvLAZYDEL_on(hv) (SvFLAGS(hv) |= SVphv_LAZYDEL) #define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL) -#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH) -#define HvREHASH_on(hv) (SvFLAGS(hv) |= SVphv_REHASH) -#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH) - #ifndef PERL_CORE # define Nullhe Null(HE*) #endif @@ -366,7 +365,6 @@ C. #define HeKLEN(he) HEK_LEN(HeKEY_hek(he)) #define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he)) #define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he)) -#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he)) #define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he)) #define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he)) #define HeVAL(he) (he)->he_valu.hent_val @@ -386,7 +384,9 @@ C. ((HeKLEN(he) == HEf_SVKEY) ? \ HeKEY_sv(he) : \ newSVpvn_flags(HeKEY(he), \ - HeKLEN(he), SVs_TEMP)) : \ + HeKLEN(he), \ + SVs_TEMP | \ + ( HeKUTF8(he) ? SVf_UTF8 : 0 ))) : \ &PL_sv_undef) #define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv)) @@ -401,7 +401,6 @@ C. #define HVhek_UTF8 0x01 /* Key is utf8 encoded. */ #define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */ -#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */ #define HVhek_UNSHARED 0x08 /* This key isn't a shared hash key. */ #define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */ #define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder. @@ -411,16 +410,7 @@ C. converted to bytes. */ #define HVhek_MASK 0xFF -/* Which flags enable HvHASKFLAGS? Somewhat a hack on a hack, as - HVhek_REHASH is only needed because the rehash flag has to be duplicated - into all keys as hv_iternext has no access to the hash flags. At this - point Storable's tests get upset, because sometimes hashes are "keyed" - and sometimes not, depending on the order of data insertion, and whether - it triggered rehashing. So currently HVhek_REHASH is exempt. - Similarly UNSHARED -*/ - -#define HVhek_ENABLEHVKFLAGS (HVhek_MASK & ~(HVhek_REHASH|HVhek_UNSHARED)) +#define HVhek_ENABLEHVKFLAGS (HVhek_MASK & ~(HVhek_UNSHARED)) #define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8) #define HEK_UTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_UTF8) @@ -428,8 +418,6 @@ C. #define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8) #define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_WASUTF8) #define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8) -#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH) -#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) |= HVhek_REHASH) /* calculate HV array allocation */ #ifndef PERL_USE_LARGE_HV_ALLOC @@ -452,8 +440,8 @@ C. #define hv_magic(hv, gv, how) sv_magic(MUTABLE_SV(hv), MUTABLE_SV(gv), how, NULL, 0) #define hv_undef(hv) Perl_hv_undef_flags(aTHX_ hv, 0) -#define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash)) -#define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash) +#define Perl_sharepvn(pv, len, hash) HEK_KEY(share_hek(pv, len, hash)) +#define sharepvn(pv, len, hash) Perl_sharepvn(pv, len, hash) #define share_hek_hek(hek) \ (++(((struct shared_he *)(((char *)hek) \ @@ -499,6 +487,22 @@ C. (MUTABLE_SV(hv_common_key_len((hv), (key), (klen), \ (flags) | HV_DELETE, NULL, 0))) +#ifdef PERL_CORE +# define hv_storehek(hv, hek, val) \ + hv_common((hv), NULL, HEK_KEY(hek), HEK_LEN(hek), HEK_UTF8(hek), \ + HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, (val), HEK_HASH(hek)) +# define hv_fetchhek(hv, hek, lval) \ + ((SV **) \ + hv_common((hv), NULL, HEK_KEY(hek), HEK_LEN(hek), HEK_UTF8(hek), \ + (lval) \ + ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) \ + : HV_FETCH_JUST_SV, \ + NULL, HEK_HASH(hek))) +# define hv_deletehek(hv, hek, flags) \ + hv_common((hv), NULL, HEK_KEY(hek), HEK_LEN(hek), HEK_UTF8(hek), \ + (flags)|HV_DELETE, NULL, HEK_HASH(hek)) +#endif + /* This refcounted he structure is used for storing the hints used for lexical pragmas. Without threads, it's basically struct he + refcount. With threads, life gets more complex as the structure needs to be shared @@ -509,6 +513,9 @@ struct refcounted_he; /* flags for the refcounted_he API */ #define REFCOUNTED_HE_KEY_UTF8 0x00000001 +#ifdef PERL_CORE +# define REFCOUNTED_HE_EXISTS 0x00000002 +#endif #ifdef PERL_CORE @@ -619,12 +626,14 @@ Creates a new HV. The reference count is set to 1. #define newHV() MUTABLE_HV(newSV_type(SVt_PVHV)) +#include "hv_func.h" + /* * Local variables: * c-indentation-style: bsd * c-basic-offset: 4 - * indent-tabs-mode: t + * indent-tabs-mode: nil * End: * - * ex: set ts=8 sts=4 sw=4 noet: + * ex: set ts=8 sts=4 sw=4 et: */