perl5.git.perl.org Git - perl5.git/blame_incremental

... / ...

Commit	Line	Data
	1	/* hv.h
	2	*
	3	* Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
	4	* 2000, 2001, 2002, 2003, 2005, 2006, 2007, 2008, by Larry Wall and others
	5	*
	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.
	8	*
	9	*/
	10
	11	/* entry in hash value chain */
	12	struct he {
	13	/* Keep hent_next first in this structure, because sv_free_arenas take
	14	advantage of this to share code between the he arenas and the SV
	15	body arenas */
	16	HE hent_next; / next entry in chain */
	17	HEK hent_hek; / hash key */
	18	union {
	19	SV hent_val; / scalar value that was hashed */
	20	Size_t hent_refcount; /* references for this shared hash key */
	21	} he_valu;
	22	};
	23
	24	/* hash key -- defined separately for use as shared pointer */
	25	struct hek {
	26	U32 hek_hash; /* hash of key */
	27	I32 hek_len; /* length of hash key */
	28	char hek_key[1]; /* variable-length hash key */
	29	/* the hash-key is \0-terminated */
	30	/* after the \0 there is a byte for flags, such as whether the key
	31	is UTF-8 */
	32	};
	33
	34	struct shared_he {
	35	struct he shared_he_he;
	36	struct hek shared_he_hek;
	37	};
	38
	39	/* Subject to change.
	40	Don't access this directly.
	41	Use the funcs in mro.c
	42	*/
	43
	44	struct mro_alg {
	45	AV (resolve)(pTHX_ HV* stash, U32 level);
	46	const char *name;
	47	U16 length;
	48	U16 kflags; /* For the hash API - set HVhek_UTF8 if name is UTF-8 */
	49	U32 hash; /* or 0 */
	50	};
	51
	52	struct mro_meta {
	53	/* a hash holding the different MROs private data. */
	54	HV *mro_linear_all;
	55	/* a pointer directly to the current MROs private data. If mro_linear_all
	56	is NULL, this owns the SV reference, else it is just a pointer to a
	57	value stored in and owned by mro_linear_all. */
	58	SV *mro_linear_current;
	59	HV mro_nextmethod; / next::method caching */
	60	U32 cache_gen; /* Bumping this invalidates our method cache */
	61	U32 pkg_gen; /* Bumps when local methods/@ISA change */
	62	const struct mro_alg mro_which; / which mro alg is in use? */
	63	HV isa; / Everything this class @ISA */
	64	};
	65
	66	#define MRO_GET_PRIVATE_DATA(smeta, which) \
	67	(((smeta)->mro_which && (which) == (smeta)->mro_which) \
	68	? (smeta)->mro_linear_current \
	69	: Perl_mro_get_private_data(aTHX_ (smeta), (which)))
	70
	71	/* Subject to change.
	72	Don't access this directly.
	73	*/
	74
	75	union _xhvnameu {
	76	HEK xhvnameu_name; / When xhv_name_count is 0 */
	77	HEK *xhvnameu_names; / When xhv_name_count is non-0 */
	78	};
	79
	80	struct xpvhv_aux {
	81	union _xhvnameu xhv_name_u; /* name, if a symbol table */
	82	AV xhv_backreferences; / back references for weak references */
	83	HE xhv_eiter; / current entry of iterator */
	84	I32 xhv_riter; /* current root of iterator */
	85
	86	/* Concerning xhv_name_count: When non-zero, xhv_name_u contains a pointer
	87	* to an array of HEK pointers, this being the length. The first element is
	88	* the name of the stash, which may be NULL. If xhv_name_count is positive,
	89	* then *xhv_name is one of the effective names. If xhv_name_count is nega-
	90	* tive, then xhv_name_u.xhvnameu_names[1] is the first effective name.
	91	*/
	92	I32 xhv_name_count;
	93	struct mro_meta *xhv_mro_meta;
	94	HV * xhv_super; /* SUPER method cache */
	95	};
	96
	97	/* hash structure: */
	98	/* This structure must match the beginning of struct xpvmg in sv.h. */
	99	struct xpvhv {
	100	HV* xmg_stash; /* class package */
	101	union _xmgu xmg_u;
	102	STRLEN xhv_keys; /* total keys, including placeholders */
	103	STRLEN xhv_max; /* subscript of last element of xhv_array */
	104	};
	105
	106	/* hash a key */
	107	/* The use of a temporary pointer and the casting games
	108	* is needed to serve the dual purposes of
	109	* (a) the hashed data being interpreted as "unsigned char" (new since 5.8,
	110	* a "char" can be either signed or unsigned, depending on the compiler)
	111	* (b) catering for old code that uses a "char"
	112	*
	113	* The "hash seed" feature was added in Perl 5.8.1 to perturb the results
	114	* to avoid "algorithmic complexity attacks".
	115	*
	116	* If USE_HASH_SEED is defined, hash randomisation is done by default
	117	* If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
	118	* only if the environment variable PERL_HASH_SEED is set.
	119	* (see also perl.c:perl_parse() and S_init_tls_and_interp() and util.c:get_hash_seed())
	120	*/
	121	#ifndef PERL_HASH_SEED
	122	# if defined(USE_HASH_SEED) \|\| defined(USE_HASH_SEED_EXPLICIT)
	123	# define PERL_HASH_SEED PL_hash_seed
	124	# else
	125	# define PERL_HASH_SEED "PeRlHaShhAcKpErl"
	126	# endif
	127	#endif
	128
	129	#define PERL_HASH_SEED_U32 ((U32)PERL_HASH_SEED)
	130	#define PERL_HASH_SEED_U64_1 (((U64*)PERL_HASH_SEED)[0])
	131	#define PERL_HASH_SEED_U64_2 (((U64*)PERL_HASH_SEED)[1])
	132	#define PERL_HASH_SEED_U16_x(idx) (((U16*)PERL_HASH_SEED)[idx])
	133
	134	/* legacy - only mod_perl should be doing this. */
	135	#ifdef PERL_HASH_INTERNAL_ACCESS
	136	#define PERL_HASH_INTERNAL(hash,str,len) PERL_HASH(hash,str,len)
	137	#endif
	138
	139	/* Uncomment one of the following lines to use an alternative hash algorithm.
	140	#define PERL_HASH_FUNC_SDBM
	141	#define PERL_HASH_FUNC_DJB2
	142	#define PERL_HASH_FUNC_SUPERFAST
	143	#define PERL_HASH_FUNC_MURMUR3
	144	#define PERL_HASH_FUNC_SIPHASH
	145	#define PERL_HASH_FUNC_ONE_AT_A_TIME
	146	#define PERL_HASH_FUNC_ONE_AT_A_TIME_OLD
	147	#define PERL_HASH_FUNC_BUZZHASH16
	148	*/
	149
	150	#if !( 0 \
	151	\|\| defined(PERL_HASH_FUNC_SDBM) \
	152	\|\| defined(PERL_HASH_FUNC_DJB2) \
	153	\|\| defined(PERL_HASH_FUNC_SUPERFAST) \
	154	\|\| defined(PERL_HASH_FUNC_MURMUR3) \
	155	\|\| defined(PERL_HASH_FUNC_ONE_AT_A_TIME) \
	156	\|\| defined(PERL_HASH_FUNC_ONE_AT_A_TIME_OLD) \
	157	\|\| defined(PERL_HASH_FUNC_BUZZHASH16) \
	158	)
	159	#ifdef U64
	160	#define PERL_HASH_FUNC_SIPHASH
	161	#else
	162	#define PERL_HASH_FUNC_ONE_AT_A_TIME
	163	#endif
	164	#endif
	165
	166	#if defined(PERL_HASH_FUNC_BUZZHASH16)
	167	/* "BUZZHASH16"
	168	*
	169	* I whacked this together while just playing around.
	170	*
	171	* The idea is that instead of hashing the actual string input we use the
	172	* bytes of the string as an index into a table of randomly generated
	173	* 16 bit values.
	174	*
	175	* A left rotate is used to "mix" in previous bits as we go, and I borrowed
	176	* the avalanche function from one-at-a-time for the final step. A lookup
	177	* into the table based on the lower 8 bits of the length combined with
	178	* the length itself is used as an itializer.
	179	*
	180	* The resulting hash value has no actual bits fed in from the string so
	181	* I would guess it is pretty secure, although I am not a cryptographer
	182	* and have no idea for sure. Nor has it been rigorously tested. On the
	183	* other hand it is reasonably fast, and seems to produce reasonable
	184	* distributions.
	185	*
	186	* Yves Orton
	187	*/
	188
	189
	190	#define PERL_HASH_FUNC "BUZZHASH16"
	191	#define PERL_HASH_SEED_BYTES 512 /* 2 bytes per octet value, 2 * 256 */
	192	/* Find best way to ROTL32 */
	193	#if defined(_MSC_VER)
	194	#include <stdlib.h> /* Microsoft put _rotl declaration in here */
	195	#define BUZZHASH_ROTL32(x,r) _rotl(x,r)
	196	#else
	197	/* gcc recognises this code and generates a rotate instruction for CPUs with one */
	198	#define BUZZHASH_ROTL32(x,r) (((U32)x << r) \| ((U32)x >> (32 - r)))
	199	#endif
	200
	201	#define PERL_HASH(hash,str,len) \
	202	STMT_START { \
	203	const char * const s_PeRlHaSh_tmp = (str); \
	204	const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	205	const unsigned char end_PeRlHaSh = (const unsigned char )s_PeRlHaSh + len; \
	206	U32 hash_PeRlHaSh = (PERL_HASH_SEED_U16_x(len & 0xff) << 16) + len; \
	207	while (s_PeRlHaSh < end_PeRlHaSh) { \
	208	hash_PeRlHaSh ^= PERL_HASH_SEED_U16_x((U8)*s_PeRlHaSh++); \
	209	hash_PeRlHaSh += BUZZHASH_ROTL32(hash_PeRlHaSh,11); \
	210	} \
	211	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	212	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	213	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	214	} STMT_END
	215
	216	#elif defined(PERL_HASH_FUNC_SIPHASH)
	217	#define PERL_HASH_FUNC "SIPHASH"
	218	#define PERL_HASH_SEED_BYTES 16
	219
	220	/* This is SipHash by Jean-Philippe Aumasson and Daniel J. Bernstein.
	221	* The authors claim it is relatively secure compared to the alternatives
	222	* and that performance wise it is a suitable hash for languages like Perl.
	223	* See:
	224	*
	225	* https://www.131002.net/siphash/
	226	*
	227	* This implementation seems to perform slightly slower than one-at-a-time for
	228	* short keys, but degrades slower for longer keys. Murmur Hash outperforms it
	229	* regardless of keys size.
	230	*
	231	* It is 64 bit only.
	232	*/
	233
	234	#define PERL_HASH_NEEDS_TWO_SEEDS
	235
	236	#ifndef U64
	237	#define U64 uint64_t
	238	#endif
	239
	240	#define ROTL(x,b) (U64)( ((x) << (b)) \| ( (x) >> (64 - (b))) )
	241
	242	#define U32TO8_LE(p, v) \
	243	(p)[0] = (U8)((v) ); (p)[1] = (U8)((v) >> 8); \
	244	(p)[2] = (U8)((v) >> 16); (p)[3] = (U8)((v) >> 24);
	245
	246	#define U64TO8_LE(p, v) \
	247	U32TO8_LE((p), (U32)((v) )); \
	248	U32TO8_LE((p) + 4, (U32)((v) >> 32));
	249
	250	#define U8TO64_LE(p) \
	251	(((U64)((p)[0]) ) \| \
	252	((U64)((p)[1]) << 8) \| \
	253	((U64)((p)[2]) << 16) \| \
	254	((U64)((p)[3]) << 24) \| \
	255	((U64)((p)[4]) << 32) \| \
	256	((U64)((p)[5]) << 40) \| \
	257	((U64)((p)[6]) << 48) \| \
	258	((U64)((p)[7]) << 56))
	259
	260	#define SIPROUND \
	261	do { \
	262	v0_PeRlHaSh += v1_PeRlHaSh; v1_PeRlHaSh=ROTL(v1_PeRlHaSh,13); v1_PeRlHaSh ^= v0_PeRlHaSh; v0_PeRlHaSh=ROTL(v0_PeRlHaSh,32); \
	263	v2_PeRlHaSh += v3_PeRlHaSh; v3_PeRlHaSh=ROTL(v3_PeRlHaSh,16); v3_PeRlHaSh ^= v2_PeRlHaSh; \
	264	v0_PeRlHaSh += v3_PeRlHaSh; v3_PeRlHaSh=ROTL(v3_PeRlHaSh,21); v3_PeRlHaSh ^= v0_PeRlHaSh; \
	265	v2_PeRlHaSh += v1_PeRlHaSh; v1_PeRlHaSh=ROTL(v1_PeRlHaSh,17); v1_PeRlHaSh ^= v2_PeRlHaSh; v2_PeRlHaSh=ROTL(v2_PeRlHaSh,32); \
	266	} while(0)
	267
	268	/* SipHash-2-4 */
	269	#define PERL_HASH(hash,str,len) STMT_START { \
	270	const char * const strtmp_PeRlHaSh = (str); \
	271	const unsigned char in_PeRlHaSh = (const unsigned char )strtmp_PeRlHaSh; \
	272	const U32 inlen_PeRlHaSh = (len); \
	273	/* "somepseudorandomlygeneratedbytes" */ \
	274	U64 v0_PeRlHaSh = 0x736f6d6570736575ULL; \
	275	U64 v1_PeRlHaSh = 0x646f72616e646f6dULL; \
	276	U64 v2_PeRlHaSh = 0x6c7967656e657261ULL; \
	277	U64 v3_PeRlHaSh = 0x7465646279746573ULL; \
	278	\
	279	U64 b_PeRlHaSh; \
	280	U64 k0_PeRlHaSh = PERL_HASH_SEED_U64_1; \
	281	U64 k1_PeRlHaSh = PERL_HASH_SEED_U64_2; \
	282	U64 m_PeRlHaSh; \
	283	const int left_PeRlHaSh = inlen_PeRlHaSh & 7; \
	284	const U8 *end_PeRlHaSh = in_PeRlHaSh + inlen_PeRlHaSh - left_PeRlHaSh; \
	285	\
	286	b_PeRlHaSh = ( ( U64 )(len) ) << 56; \
	287	v3_PeRlHaSh ^= k1_PeRlHaSh; \
	288	v2_PeRlHaSh ^= k0_PeRlHaSh; \
	289	v1_PeRlHaSh ^= k1_PeRlHaSh; \
	290	v0_PeRlHaSh ^= k0_PeRlHaSh; \
	291	\
	292	for ( ; in_PeRlHaSh != end_PeRlHaSh; in_PeRlHaSh += 8 ) \
	293	{ \
	294	m_PeRlHaSh = U8TO64_LE( in_PeRlHaSh ); \
	295	v3_PeRlHaSh ^= m_PeRlHaSh; \
	296	SIPROUND; \
	297	SIPROUND; \
	298	v0_PeRlHaSh ^= m_PeRlHaSh; \
	299	} \
	300	\
	301	switch( left_PeRlHaSh ) \
	302	{ \
	303	case 7: b_PeRlHaSh \|= ( ( U64 )in_PeRlHaSh[ 6] ) << 48; \
	304	case 6: b_PeRlHaSh \|= ( ( U64 )in_PeRlHaSh[ 5] ) << 40; \
	305	case 5: b_PeRlHaSh \|= ( ( U64 )in_PeRlHaSh[ 4] ) << 32; \
	306	case 4: b_PeRlHaSh \|= ( ( U64 )in_PeRlHaSh[ 3] ) << 24; \
	307	case 3: b_PeRlHaSh \|= ( ( U64 )in_PeRlHaSh[ 2] ) << 16; \
	308	case 2: b_PeRlHaSh \|= ( ( U64 )in_PeRlHaSh[ 1] ) << 8; \
	309	case 1: b_PeRlHaSh \|= ( ( U64 )in_PeRlHaSh[ 0] ); break; \
	310	case 0: break; \
	311	} \
	312	\
	313	v3_PeRlHaSh ^= b_PeRlHaSh; \
	314	SIPROUND; \
	315	SIPROUND; \
	316	v0_PeRlHaSh ^= b_PeRlHaSh; \
	317	\
	318	v2_PeRlHaSh ^= 0xff; \
	319	SIPROUND; \
	320	SIPROUND; \
	321	SIPROUND; \
	322	SIPROUND; \
	323	b_PeRlHaSh = v0_PeRlHaSh ^ v1_PeRlHaSh ^ v2_PeRlHaSh ^ v3_PeRlHaSh; \
	324	(hash)= (U32)(b_PeRlHaSh & U32_MAX); \
	325	} STMT_END
	326
	327	#elif defined(PERL_HASH_FUNC_SUPERFAST)
	328	#define PERL_HASH_FUNC "SUPERFAST"
	329	#define PERL_HASH_SEED_BYTES 4
	330	/* FYI: This is the "Super-Fast" algorithm mentioned by Bob Jenkins in
	331	* (http://burtleburtle.net/bob/hash/doobs.html)
	332	* It is by Paul Hsieh (c) 2004 and is analysed here
	333	* http://www.azillionmonkeys.com/qed/hash.html
	334	* license terms are here:
	335	* http://www.azillionmonkeys.com/qed/weblicense.html
	336	*/
	337	#undef get16bits
	338	#if (defined(__GNUC__) && defined(__i386__)) \|\| defined(__WATCOMC__) \
	339	\|\| defined(_MSC_VER) \|\| defined (__BORLANDC__) \|\| defined (__TURBOC__)
	340	#define get16bits(d) (((const U16 ) (d)))
	341	#endif
	342
	343	#if !defined (get16bits)
	344	#define get16bits(d) ((((const U8 *)(d))[1] << UINT32_C(8))\
	345	+((const U8 *)(d))[0])
	346	#endif
	347	#define PERL_HASH(hash,str,len) \
	348	STMT_START { \
	349	const char * const strtmp_PeRlHaSh = (str); \
	350	const unsigned char str_PeRlHaSh = (const unsigned char )strtmp_PeRlHaSh; \
	351	U32 len_PeRlHaSh = (len); \
	352	U32 hash_PeRlHaSh = PERL_HASH_SEED_U32 ^ len; \
	353	U32 tmp_PeRlHaSh; \
	354	int rem_PeRlHaSh= len_PeRlHaSh & 3; \
	355	len_PeRlHaSh >>= 2; \
	356	\
	357	for (;len_PeRlHaSh > 0; len_PeRlHaSh--) { \
	358	hash_PeRlHaSh += get16bits (str_PeRlHaSh); \
	359	tmp_PeRlHaSh = (get16bits (str_PeRlHaSh+2) << 11) ^ hash_PeRlHaSh; \
	360	hash_PeRlHaSh = (hash_PeRlHaSh << 16) ^ tmp_PeRlHaSh; \
	361	str_PeRlHaSh += 2 * sizeof (U16); \
	362	hash_PeRlHaSh += hash_PeRlHaSh >> 11; \
	363	} \
	364	\
	365	/* Handle end cases */ \
	366	switch (rem_PeRlHaSh) { \
	367	case 3: hash_PeRlHaSh += get16bits (str_PeRlHaSh); \
	368	hash_PeRlHaSh ^= hash_PeRlHaSh << 16; \
	369	hash_PeRlHaSh ^= str_PeRlHaSh[sizeof (U16)] << 18; \
	370	hash_PeRlHaSh += hash_PeRlHaSh >> 11; \
	371	break; \
	372	case 2: hash_PeRlHaSh += get16bits (str_PeRlHaSh); \
	373	hash_PeRlHaSh ^= hash_PeRlHaSh << 11; \
	374	hash_PeRlHaSh += hash_PeRlHaSh >> 17; \
	375	break; \
	376	case 1: hash_PeRlHaSh += *str_PeRlHaSh; \
	377	hash_PeRlHaSh ^= hash_PeRlHaSh << 10; \
	378	hash_PeRlHaSh += hash_PeRlHaSh >> 1; \
	379	} \
	380	\
	381	/* Force "avalanching" of final 127 bits */ \
	382	hash_PeRlHaSh ^= hash_PeRlHaSh << 3; \
	383	hash_PeRlHaSh += hash_PeRlHaSh >> 5; \
	384	hash_PeRlHaSh ^= hash_PeRlHaSh << 4; \
	385	hash_PeRlHaSh += hash_PeRlHaSh >> 17; \
	386	hash_PeRlHaSh ^= hash_PeRlHaSh << 25; \
	387	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh >> 6)); \
	388	} STMT_END
	389
	390	#elif defined(PERL_HASH_FUNC_MURMUR3)
	391	#define PERL_HASH_FUNC "MURMUR3"
	392	#define PERL_HASH_SEED_BYTES 4
	393
	394	/*-----------------------------------------------------------------------------
	395	* MurmurHash3 was written by Austin Appleby, and is placed in the public
	396	* domain.
	397	*
	398	* This implementation was originally written by Shane Day, and is also public domain,
	399	* and was modified to function as a macro similar to other perl hash functions by
	400	* Yves Orton.
	401	*
	402	* This is a portable ANSI C implementation of MurmurHash3_x86_32 (Murmur3A)
	403	* with support for progressive processing.
	404	*
	405	* If you want to understand the MurmurHash algorithm you would be much better
	406	* off reading the original source. Just point your browser at:
	407	* http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
	408	*
	409	* How does it work?
	410	*
	411	* We can only process entire 32 bit chunks of input, except for the very end
	412	* that may be shorter.
	413	*
	414	* To handle endianess I simply use a macro that reads a U32 and define
	415	* that macro to be a direct read on little endian machines, a read and swap
	416	* on big endian machines, or a byte-by-byte read if the endianess is unknown.
	417	*/
	418
	419
	420	/*-----------------------------------------------------------------------------
	421	* Endianess, misalignment capabilities and util macros
	422	*
	423	* The following 3 macros are defined in this section. The other macros defined
	424	* are only needed to help derive these 3.
	425	*
	426	* MURMUR_READ_UINT32(x) Read a little endian unsigned 32-bit int
	427	* MURMUR_UNALIGNED_SAFE Defined if READ_UINT32 works on non-word boundaries
	428	* MURMUR_ROTL32(x,r) Rotate x left by r bits
	429	*/
	430
	431	/* Now find best way we can to READ_UINT32 */
	432	#if (BYTEORDER == 0x1234 \|\| BYTEORDER == 0x12345678) && U32SIZE == 4
	433	/* CPU endian matches murmurhash algorithm, so read 32-bit word directly */
	434	#define MURMUR_READ_UINT32(ptr) (((U32)(ptr)))
	435	#elif BYTEORDER == 0x4321 \|\| BYTEORDER == 0x87654321
	436	/* TODO: Add additional cases below where a compiler provided bswap32 is available */
	437	#if defined(__GNUC__) && (__GNUC__>4 \|\| (__GNUC__==4 && __GNUC_MINOR__>=3))
	438	#define MURMUR_READ_UINT32(ptr) (__builtin_bswap32(((U32)(ptr))))
	439	#else
	440	/* Without a known fast bswap32 we're just as well off doing this */
	441	#define MURMUR_READ_UINT32(ptr) (ptr[0]\|ptr[1]<<8\|ptr[2]<<16\|ptr[3]<<24)
	442	#define MURMUR_UNALIGNED_SAFE
	443	#endif
	444	#else
	445	/* Unknown endianess so last resort is to read individual bytes */
	446	#define MURMUR_READ_UINT32(ptr) (ptr[0]\|ptr[1]<<8\|ptr[2]<<16\|ptr[3]<<24)
	447
	448	/* Since we're not doing word-reads we can skip the messing about with realignment */
	449	#define MURMUR_UNALIGNED_SAFE
	450	#endif
	451
	452	/* Find best way to ROTL32 */
	453	#if defined(_MSC_VER)
	454	#include <stdlib.h> /* Microsoft put _rotl declaration in here */
	455	#define MURMUR_ROTL32(x,r) _rotl(x,r)
	456	#else
	457	/* gcc recognises this code and generates a rotate instruction for CPUs with one */
	458	#define MURMUR_ROTL32(x,r) (((U32)x << r) \| ((U32)x >> (32 - r)))
	459	#endif
	460
	461
	462	/*-----------------------------------------------------------------------------
	463	* Core murmurhash algorithm macros */
	464
	465	#define MURMUR_C1 (0xcc9e2d51)
	466	#define MURMUR_C2 (0x1b873593)
	467	#define MURMUR_C3 (0xe6546b64)
	468	#define MURMUR_C4 (0x85ebca6b)
	469	#define MURMUR_C5 (0xc2b2ae35)
	470
	471	/* This is the main processing body of the algorithm. It operates
	472	* on each full 32-bits of input. */
	473	#define MURMUR_DOBLOCK(h1, k1) STMT_START { \
	474	k1 *= MURMUR_C1; \
	475	k1 = MURMUR_ROTL32(k1,15); \
	476	k1 *= MURMUR_C2; \
	477	\
	478	h1 ^= k1; \
	479	h1 = MURMUR_ROTL32(h1,13); \
	480	h1 = h1 * 5 + MURMUR_C3; \
	481	} STMT_END
	482
	483
	484	/* Append unaligned bytes to carry, forcing hash churn if we have 4 bytes */
	485	/* cnt=bytes to process, h1=name of h1 var, c=carry, n=bytes in c, ptr/len=payload */
	486	#define MURMUR_DOBYTES(cnt, h1, c, n, ptr, len) STMT_START { \
	487	int MURMUR_DOBYTES_i = cnt; \
	488	while(MURMUR_DOBYTES_i--) { \
	489	c = c>>8 \| *ptr++<<24; \
	490	n++; len--; \
	491	if(n==4) { \
	492	MURMUR_DOBLOCK(h1, c); \
	493	n = 0; \
	494	} \
	495	} \
	496	} STMT_END
	497
	498	/* process the last 1..3 bytes and finalize */
	499	#define MURMUR_FINALIZE(hash, PeRlHaSh_len, PeRlHaSh_k1, PeRlHaSh_h1, PeRlHaSh_carry, PeRlHaSh_bytes_in_carry, PeRlHaSh_ptr, PeRlHaSh_total_length) STMT_START { \
	500	/* Advance over whole 32-bit chunks, possibly leaving 1..3 bytes */\
	501	PeRlHaSh_len -= PeRlHaSh_len/4*4; \
	502	\
	503	/* Append any remaining bytes into carry */ \
	504	MURMUR_DOBYTES(PeRlHaSh_len, PeRlHaSh_h1, PeRlHaSh_carry, PeRlHaSh_bytes_in_carry, PeRlHaSh_ptr, PeRlHaSh_len); \
	505	\
	506	if (PeRlHaSh_bytes_in_carry) { \
	507	PeRlHaSh_k1 = PeRlHaSh_carry >> ( 4 - PeRlHaSh_bytes_in_carry ) * 8; \
	508	PeRlHaSh_k1 *= MURMUR_C1; \
	509	PeRlHaSh_k1 = MURMUR_ROTL32(PeRlHaSh_k1,15); \
	510	PeRlHaSh_k1 *= MURMUR_C2; \
	511	PeRlHaSh_h1 ^= PeRlHaSh_k1; \
	512	} \
	513	PeRlHaSh_h1 ^= PeRlHaSh_total_length; \
	514	\
	515	/* fmix */ \
	516	PeRlHaSh_h1 ^= PeRlHaSh_h1 >> 16; \
	517	PeRlHaSh_h1 *= MURMUR_C4; \
	518	PeRlHaSh_h1 ^= PeRlHaSh_h1 >> 13; \
	519	PeRlHaSh_h1 *= MURMUR_C5; \
	520	PeRlHaSh_h1 ^= PeRlHaSh_h1 >> 16; \
	521	(hash)= PeRlHaSh_h1; \
	522	} STMT_END
	523
	524	/* now we create the hash function */
	525
	526	#if defined(UNALIGNED_SAFE)
	527	#define PERL_HASH(hash,str,len) STMT_START { \
	528	const char * const s_PeRlHaSh_tmp = (str); \
	529	const unsigned char PeRlHaSh_ptr = (const unsigned char )s_PeRlHaSh_tmp; \
	530	I32 PeRlHaSh_len = len; \
	531	\
	532	U32 PeRlHaSh_h1 = PERL_HASH_SEED_U32; \
	533	U32 PeRlHaSh_k1; \
	534	U32 PeRlHaSh_carry = 0; \
	535	\
	536	const unsigned char *PeRlHaSh_end; \
	537	\
	538	int PeRlHaSh_bytes_in_carry = 0; /* bytes in carry */ \
	539	I32 PeRlHaSh_total_length= PeRlHaSh_len; \
	540	\
	541	/* This CPU handles unaligned word access */ \
	542	/* Process 32-bit chunks */ \
	543	PeRlHaSh_end = PeRlHaSh_ptr + PeRlHaSh_len/4*4; \
	544	for( ; PeRlHaSh_ptr < PeRlHaSh_end ; PeRlHaSh_ptr+=4) { \
	545	PeRlHaSh_k1 = MURMUR_READ_UINT32(PeRlHaSh_ptr); \
	546	MURMUR_DOBLOCK(PeRlHaSh_h1, PeRlHaSh_k1); \
	547	} \
	548	\
	549	MURMUR_FINALIZE(hash, PeRlHaSh_len, PeRlHaSh_k1, PeRlHaSh_h1, PeRlHaSh_carry, PeRlHaSh_bytes_in_carry, PeRlHaSh_ptr, PeRlHaSh_total_length);\
	550	} STMT_END
	551	#else
	552	#define PERL_HASH(hash,str,len) STMT_START { \
	553	const char * const s_PeRlHaSh_tmp = (str); \
	554	const unsigned char PeRlHaSh_ptr = (const unsigned char )s_PeRlHaSh_tmp; \
	555	I32 PeRlHaSh_len = len; \
	556	\
	557	U32 PeRlHaSh_h1 = PERL_HASH_SEED_U32; \
	558	U32 PeRlHaSh_k1; \
	559	U32 PeRlHaSh_carry = 0; \
	560	\
	561	const unsigned char *PeRlHaSh_end; \
	562	\
	563	int PeRlHaSh_bytes_in_carry = 0; /* bytes in carry */ \
	564	I32 PeRlHaSh_total_length= PeRlHaSh_len; \
	565	\
	566	/* This CPU does not handle unaligned word access */ \
	567	\
	568	/* Consume enough so that the next data byte is word aligned */ \
	569	int PeRlHaSh_i = -(long)PeRlHaSh_ptr & 3; \
	570	if(PeRlHaSh_i && PeRlHaSh_i <= PeRlHaSh_len) { \
	571	MURMUR_DOBYTES(PeRlHaSh_i, PeRlHaSh_h1, PeRlHaSh_carry, PeRlHaSh_bytes_in_carry, PeRlHaSh_ptr, PeRlHaSh_len);\
	572	} \
	573	\
	574	/* We're now aligned. Process in aligned blocks. Specialise for each possible carry count */ \
	575	PeRlHaSh_end = PeRlHaSh_ptr + PeRlHaSh_len/4*4; \
	576	switch(PeRlHaSh_bytes_in_carry) { /* how many bytes in carry */ \
	577	case 0: /* c=[----] w=[3210] b=[3210]=w c'=[----] */ \
	578	for( ; PeRlHaSh_ptr < PeRlHaSh_end ; PeRlHaSh_ptr+=4) { \
	579	PeRlHaSh_k1 = MURMUR_READ_UINT32(PeRlHaSh_ptr); \
	580	MURMUR_DOBLOCK(PeRlHaSh_h1, PeRlHaSh_k1); \
	581	} \
	582	break; \
	583	case 1: /* c=[0---] w=[4321] b=[3210]=c>>24\|w<<8 c'=[4---] */ \
	584	for( ; PeRlHaSh_ptr < PeRlHaSh_end ; PeRlHaSh_ptr+=4) { \
	585	PeRlHaSh_k1 = PeRlHaSh_carry>>24; \
	586	PeRlHaSh_carry = MURMUR_READ_UINT32(PeRlHaSh_ptr); \
	587	PeRlHaSh_k1 \|= PeRlHaSh_carry<<8; \
	588	MURMUR_DOBLOCK(PeRlHaSh_h1, PeRlHaSh_k1); \
	589	} \
	590	break; \
	591	case 2: /* c=[10--] w=[5432] b=[3210]=c>>16\|w<<16 c'=[54--] */ \
	592	for( ; PeRlHaSh_ptr < PeRlHaSh_end ; PeRlHaSh_ptr+=4) { \
	593	PeRlHaSh_k1 = PeRlHaSh_carry>>16; \
	594	PeRlHaSh_carry = MURMUR_READ_UINT32(PeRlHaSh_ptr); \
	595	PeRlHaSh_k1 \|= PeRlHaSh_carry<<16; \
	596	MURMUR_DOBLOCK(PeRlHaSh_h1, PeRlHaSh_k1); \
	597	} \
	598	break; \
	599	case 3: /* c=[210-] w=[6543] b=[3210]=c>>8\|w<<24 c'=[654-] */ \
	600	for( ; PeRlHaSh_ptr < PeRlHaSh_end ; PeRlHaSh_ptr+=4) { \
	601	PeRlHaSh_k1 = PeRlHaSh_carry>>8; \
	602	PeRlHaSh_carry = MURMUR_READ_UINT32(PeRlHaSh_ptr); \
	603	PeRlHaSh_k1 \|= PeRlHaSh_carry<<24; \
	604	MURMUR_DOBLOCK(PeRlHaSh_h1, PeRlHaSh_k1); \
	605	} \
	606	} \
	607	\
	608	MURMUR_FINALIZE(hash, PeRlHaSh_len, PeRlHaSh_k1, PeRlHaSh_h1, PeRlHaSh_carry, PeRlHaSh_bytes_in_carry, PeRlHaSh_ptr, PeRlHaSh_total_length);\
	609	} STMT_END
	610	#endif
	611
	612	#elif defined(PERL_HASH_FUNC_DJB2)
	613	#define PERL_HASH_FUNC "DJB2"
	614	#define PERL_HASH_SEED_BYTES 4
	615	#define PERL_HASH(hash,str,len) \
	616	STMT_START { \
	617	const char * const s_PeRlHaSh_tmp = (str); \
	618	const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	619	I32 i_PeRlHaSh = len; \
	620	U32 hash_PeRlHaSh = PERL_HASH_SEED_U32 ^ len; \
	621	while (i_PeRlHaSh--) { \
	622	hash_PeRlHaSh = ((hash_PeRlHaSh << 5) + hash_PeRlHaSh) + *s_PeRlHaSh++; \
	623	} \
	624	(hash) = hash_PeRlHaSh;\
	625	} STMT_END
	626
	627	#elif defined(PERL_HASH_FUNC_SDBM)
	628	#define PERL_HASH_FUNC "SDBM"
	629	#define PERL_HASH_SEED_BYTES 4
	630	#define PERL_HASH(hash,str,len) \
	631	STMT_START { \
	632	const char * const s_PeRlHaSh_tmp = (str); \
	633	const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	634	I32 i_PeRlHaSh = len; \
	635	U32 hash_PeRlHaSh = PERL_HASH_SEED_U32 ^ len; \
	636	while (i_PeRlHaSh--) { \
	637	hash_PeRlHaSh = (hash_PeRlHaSh << 6) + (hash_PeRlHaSh << 16) - hash_PeRlHaSh + *s_PeRlHaSh++; \
	638	} \
	639	(hash) = hash_PeRlHaSh;\
	640	} STMT_END
	641
	642	#elif defined(PERL_HASH_FUNC_ONE_AT_A_TIME) \|\| defined(PERL_HASH_FUNC_ONE_AT_A_TIME_OLD)
	643
	644	#define PERL_HASH_SEED_BYTES 4
	645
	646	#ifdef PERL_HASH_FUNC_ONE_AT_A_TIME
	647	/* new version, add the length to the seed so that adding characters changes the "seed" being used. */
	648	#define PERL_HASH_FUNC "ONE_AT_A_TIME"
	649	#define MIX_SEED_AND_LEN(seed,len) (seed + len)
	650	#else
	651	/* old version, just use the seed. - not recommended */
	652	#define PERL_HASH_FUNC "ONE_AT_A_TIME_OLD"
	653	#define MIX_SEED_AND_LEN(seed,len) (seed)
	654	#endif
	655
	656	/* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins
	657	* from requirements by Colin Plumb.
	658	* (http://burtleburtle.net/bob/hash/doobs.html) */
	659	#define PERL_HASH(hash,str,len) \
	660	STMT_START { \
	661	const char * const s_PeRlHaSh_tmp = (str); \
	662	const unsigned char s_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp; \
	663	const unsigned char end_PeRlHaSh = (const unsigned char )s_PeRlHaSh_tmp + (len); \
	664	U32 hash_PeRlHaSh = MIX_SEED_AND_LEN(PERL_HASH_SEED_U32, len); \
	665	while (s_PeRlHaSh < end_PeRlHaSh) { \
	666	hash_PeRlHaSh += (U8)*s_PeRlHaSh++; \
	667	hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
	668	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
	669	} \
	670	hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
	671	hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
	672	(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
	673	} STMT_END
	674	#endif
	675	#ifndef PERL_HASH
	676	#error "No hash function defined!"
	677	#endif
	678	/*
	679	=head1 Hash Manipulation Functions
	680
	681	=for apidoc AmU\|\|HEf_SVKEY
	682	This flag, used in the length slot of hash entries and magic structures,
	683	specifies the structure contains an C<SV> pointer where a C<char> pointer
	684	is to be expected. (For information only--not to be used).
	685
	686	=head1 Handy Values
	687
	688	=for apidoc AmU\|\|Nullhv
	689	Null HV pointer.
	690
	691	(deprecated - use C<(HV *)NULL> instead)
	692
	693	=head1 Hash Manipulation Functions
	694
	695	=for apidoc Am\|char\|HvNAME\|HV stash
	696	Returns the package name of a stash, or NULL if C<stash> isn't a stash.
	697	See C<SvSTASH>, C<CvSTASH>.
	698
	699	=for apidoc Am\|STRLEN\|HvNAMELEN\|HV *stash
	700	Returns the length of the stash's name.
	701
	702	=for apidoc Am\|unsigned char\|HvNAMEUTF8\|HV *stash
	703	Returns true if the name is in UTF8 encoding.
	704
	705	=for apidoc Am\|char\|HvENAME\|HV stash
	706	Returns the effective name of a stash, or NULL if there is none. The
	707	effective name represents a location in the symbol table where this stash
	708	resides. It is updated automatically when packages are aliased or deleted.
	709	A stash that is no longer in the symbol table has no effective name. This
	710	name is preferable to C<HvNAME> for use in MRO linearisations and isa
	711	caches.
	712
	713	=for apidoc Am\|STRLEN\|HvENAMELEN\|HV *stash
	714	Returns the length of the stash's effective name.
	715
	716	=for apidoc Am\|unsigned char\|HvENAMEUTF8\|HV *stash
	717	Returns true if the effective name is in UTF8 encoding.
	718
	719	=for apidoc Am\|void\|HeKEY\|HE he
	720	Returns the actual pointer stored in the key slot of the hash entry. The
	721	pointer may be either C<char> or C<SV>, depending on the value of
	722	C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
	723	usually preferable for finding the value of a key.
	724
	725	=for apidoc Am\|STRLEN\|HeKLEN\|HE* he
	726	If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
	727	holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
	728	be assigned to. The C<HePV()> macro is usually preferable for finding key
	729	lengths.
	730
	731	=for apidoc Am\|SV\|HeVAL\|HE he
	732	Returns the value slot (type C<SV*>) stored in the hash entry. Can be assigned
	733	to.
	734
	735	SV *foo= HeVAL(hv);
	736	HeVAL(hv)= sv;
	737
	738
	739	=for apidoc Am\|U32\|HeHASH\|HE* he
	740	Returns the computed hash stored in the hash entry.
	741
	742	=for apidoc Am\|char\|HePV\|HE he\|STRLEN len
	743	Returns the key slot of the hash entry as a C<char*> value, doing any
	744	necessary dereferencing of possibly C<SV*> keys. The length of the string
	745	is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
	746	not care about what the length of the key is, you may use the global
	747	variable C<PL_na>, though this is rather less efficient than using a local
	748	variable. Remember though, that hash keys in perl are free to contain
	749	embedded nulls, so using C<strlen()> or similar is not a good way to find
	750	the length of hash keys. This is very similar to the C<SvPV()> macro
	751	described elsewhere in this document. See also C<HeUTF8>.
	752
	753	If you are using C<HePV> to get values to pass to C<newSVpvn()> to create a
	754	new SV, you should consider using C<newSVhek(HeKEY_hek(he))> as it is more
	755	efficient.
	756
	757	=for apidoc Am\|char\|HeUTF8\|HE he
	758	Returns whether the C<char *> value returned by C<HePV> is encoded in UTF-8,
	759	doing any necessary dereferencing of possibly C<SV*> keys. The value returned
	760	will be 0 or non-0, not necessarily 1 (or even a value with any low bits set),
	761	so B<do not> blindly assign this to a C<bool> variable, as C<bool> may be a
	762	typedef for C<char>.
	763
	764	=for apidoc Am\|SV\|HeSVKEY\|HE he
	765	Returns the key as an C<SV*>, or C<NULL> if the hash entry does not
	766	contain an C<SV*> key.
	767
	768	=for apidoc Am\|SV\|HeSVKEY_force\|HE he
	769	Returns the key as an C<SV*>. Will create and return a temporary mortal
	770	C<SV> if the hash entry contains only a C<char> key.
	771
	772	=for apidoc Am\|SV\|HeSVKEY_set\|HE he\|SV* sv
	773	Sets the key to a given C<SV*>, taking care to set the appropriate flags to
	774	indicate the presence of an C<SV*> key, and returns the same
	775	C<SV*>.
	776
	777	=cut
	778	*/
	779
	780	/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
	781	#define HEf_SVKEY -2 /* hent_key is an SV* */
	782
	783	#ifndef PERL_CORE
	784	# define Nullhv Null(HV*)
	785	#endif
	786	#define HvARRAY(hv) ((hv)->sv_u.svu_hash)
	787	#define HvFILL(hv) Perl_hv_fill(aTHX_ (const HV *)(hv))
	788	#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
	789	/* This quite intentionally does no flag checking first. That's your
	790	responsibility. */
	791	#define HvAUX(hv) ((struct xpvhv_aux*)&(HvARRAY(hv)[HvMAX(hv)+1]))
	792	#define HvRITER(hv) (*Perl_hv_riter_p(aTHX_ MUTABLE_HV(hv)))
	793	#define HvEITER(hv) (*Perl_hv_eiter_p(aTHX_ MUTABLE_HV(hv)))
	794	#define HvRITER_set(hv,r) Perl_hv_riter_set(aTHX_ MUTABLE_HV(hv), r)
	795	#define HvEITER_set(hv,e) Perl_hv_eiter_set(aTHX_ MUTABLE_HV(hv), e)
	796	#define HvRITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_riter : -1)
	797	#define HvEITER_get(hv) (SvOOK(hv) ? HvAUX(hv)->xhv_eiter : NULL)
	798	#define HvNAME(hv) HvNAME_get(hv)
	799	#define HvNAMELEN(hv) HvNAMELEN_get(hv)
	800	#define HvENAME(hv) HvENAME_get(hv)
	801	#define HvENAMELEN(hv) HvENAMELEN_get(hv)
	802
	803	/* Checking that hv is a valid package stash is the
	804	caller's responsibility */
	805	#define HvMROMETA(hv) (HvAUX(hv)->xhv_mro_meta \
	806	? HvAUX(hv)->xhv_mro_meta \
	807	: Perl_mro_meta_init(aTHX_ hv))
	808
	809	#define HvNAME_HEK_NN(hv) \
	810	( \
	811	HvAUX(hv)->xhv_name_count \
	812	? *HvAUX(hv)->xhv_name_u.xhvnameu_names \
	813	: HvAUX(hv)->xhv_name_u.xhvnameu_name \
	814	)
	815	/* This macro may go away without notice. */
	816	#define HvNAME_HEK(hv) \
	817	(SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name ? HvNAME_HEK_NN(hv) : NULL)
	818	#define HvNAME_get(hv) \
	819	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvNAME_HEK_NN(hv)) \
	820	? HEK_KEY(HvNAME_HEK_NN(hv)) : NULL)
	821	#define HvNAMELEN_get(hv) \
	822	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvNAME_HEK_NN(hv)) \
	823	? HEK_LEN(HvNAME_HEK_NN(hv)) : 0)
	824	#define HvNAMEUTF8(hv) \
	825	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvNAME_HEK_NN(hv)) \
	826	? HEK_UTF8(HvNAME_HEK_NN(hv)) : 0)
	827	#define HvENAME_HEK_NN(hv) \
	828	( \
	829	HvAUX(hv)->xhv_name_count > 0 ? HvAUX(hv)->xhv_name_u.xhvnameu_names[0] : \
	830	HvAUX(hv)->xhv_name_count < -1 ? HvAUX(hv)->xhv_name_u.xhvnameu_names[1] : \
	831	HvAUX(hv)->xhv_name_count == -1 ? NULL : \
	832	HvAUX(hv)->xhv_name_u.xhvnameu_name \
	833	)
	834	#define HvENAME_HEK(hv) \
	835	(SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name ? HvENAME_HEK_NN(hv) : NULL)
	836	#define HvENAME_get(hv) \
	837	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvAUX(hv)->xhv_name_count != -1) \
	838	? HEK_KEY(HvENAME_HEK_NN(hv)) : NULL)
	839	#define HvENAMELEN_get(hv) \
	840	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvAUX(hv)->xhv_name_count != -1) \
	841	? HEK_LEN(HvENAME_HEK_NN(hv)) : 0)
	842	#define HvENAMEUTF8(hv) \
	843	((SvOOK(hv) && HvAUX(hv)->xhv_name_u.xhvnameu_name && HvAUX(hv)->xhv_name_count != -1) \
	844	? HEK_UTF8(HvENAME_HEK_NN(hv)) : 0)
	845
	846	/* the number of keys (including any placeholders) */
	847	#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
	848
	849	/*
	850	* HvKEYS gets the number of keys that actually exist(), and is provided
	851	* for backwards compatibility with old XS code. The core uses HvUSEDKEYS
	852	* (keys, excluding placeholders) and HvTOTALKEYS (including placeholders)
	853	*/
	854	#define HvKEYS(hv) HvUSEDKEYS(hv)
	855	#define HvUSEDKEYS(hv) (HvTOTALKEYS(hv) - HvPLACEHOLDERS_get(hv))
	856	#define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
	857	#define HvPLACEHOLDERS(hv) (*Perl_hv_placeholders_p(aTHX_ MUTABLE_HV(hv)))
	858	#define HvPLACEHOLDERS_get(hv) (SvMAGIC(hv) ? Perl_hv_placeholders_get(aTHX_ (const HV *)hv) : 0)
	859	#define HvPLACEHOLDERS_set(hv,p) Perl_hv_placeholders_set(aTHX_ MUTABLE_HV(hv), p)
	860
	861	#define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
	862	#define HvSHAREKEYS_on(hv) (SvFLAGS(hv) \|= SVphv_SHAREKEYS)
	863	#define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
	864
	865	/* This is an optimisation flag. It won't be set if all hash keys have a 0
	866	* flag. Currently the only flags relate to utf8.
	867	* Hence it won't be set if all keys are 8 bit only. It will be set if any key
	868	* is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
	869	* when retrieved during iteration. It may still be set when there are no longer
	870	* any utf8 keys.
	871	* See HVhek_ENABLEHVKFLAGS for the trigger.
	872	*/
	873	#define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
	874	#define HvHASKFLAGS_on(hv) (SvFLAGS(hv) \|= SVphv_HASKFLAGS)
	875	#define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
	876
	877	#define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
	878	#define HvLAZYDEL_on(hv) (SvFLAGS(hv) \|= SVphv_LAZYDEL)
	879	#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
	880
	881	#ifndef PERL_CORE
	882	# define Nullhe Null(HE*)
	883	#endif
	884	#define HeNEXT(he) (he)->hent_next
	885	#define HeKEY_hek(he) (he)->hent_hek
	886	#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
	887	#define HeKEY_sv(he) ((SV*)HeKEY(he))
	888	#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
	889	#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
	890	#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
	891	#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
	892	#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
	893	#define HeVAL(he) (he)->he_valu.hent_val
	894	#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
	895	#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
	896	SvPV(HeKEY_sv(he),lp) : \
	897	((lp = HeKLEN(he)), HeKEY(he)))
	898	#define HeUTF8(he) ((HeKLEN(he) == HEf_SVKEY) ? \
	899	SvUTF8(HeKEY_sv(he)) : \
	900	(U32)HeKUTF8(he))
	901
	902	#define HeSVKEY(he) ((HeKEY(he) && \
	903	HeKLEN(he) == HEf_SVKEY) ? \
	904	HeKEY_sv(he) : NULL)
	905
	906	#define HeSVKEY_force(he) (HeKEY(he) ? \
	907	((HeKLEN(he) == HEf_SVKEY) ? \
	908	HeKEY_sv(he) : \
	909	newSVpvn_flags(HeKEY(he), \
	910	HeKLEN(he), SVs_TEMP)) : \
	911	&PL_sv_undef)
	912	#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
	913
	914	#ifndef PERL_CORE
	915	# define Nullhek Null(HEK*)
	916	#endif
	917	#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
	918	#define HEK_HASH(hek) (hek)->hek_hash
	919	#define HEK_LEN(hek) (hek)->hek_len
	920	#define HEK_KEY(hek) (hek)->hek_key
	921	#define HEK_FLAGS(hek) (((unsigned char )(HEK_KEY(hek))+HEK_LEN(hek)+1))
	922
	923	#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
	924	#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
	925	#define HVhek_UNSHARED 0x08 /* This key isn't a shared hash key. */
	926	#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
	927	#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
	928	* (may change, but Storable is a core module) */
	929	#define HVhek_KEYCANONICAL 0x400 /* Internal flag - key is in canonical form.
	930	If the string is UTF-8, it cannot be
	931	converted to bytes. */
	932	#define HVhek_MASK 0xFF
	933
	934	#define HVhek_ENABLEHVKFLAGS (HVhek_MASK & ~(HVhek_UNSHARED))
	935
	936	#define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
	937	#define HEK_UTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_UTF8)
	938	#define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
	939	#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
	940	#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) \|= HVhek_WASUTF8)
	941	#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
	942
	943	/* calculate HV array allocation */
	944	#ifndef PERL_USE_LARGE_HV_ALLOC
	945	/* Default to allocating the correct size - default to assuming that malloc()
	946	is not broken and is efficient at allocating blocks sized at powers-of-two.
	947	*/
	948	# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
	949	#else
	950	# define MALLOC_OVERHEAD 16
	951	# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
	952	(((size) < 64) \
	953	? (size) * sizeof(HE*) \
	954	: (size) * sizeof(HE) 2 - MALLOC_OVERHEAD)
	955	#endif
	956
	957	/* Flags for hv_iternext_flags. */
	958	#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
	959
	960	#define hv_iternext(hv) hv_iternext_flags(hv, 0)
	961	#define hv_magic(hv, gv, how) sv_magic(MUTABLE_SV(hv), MUTABLE_SV(gv), how, NULL, 0)
	962	#define hv_undef(hv) Perl_hv_undef_flags(aTHX_ hv, 0)
	963
	964	#define Perl_sharepvn(pv, len, hash) HEK_KEY(share_hek(pv, len, hash))
	965	#define sharepvn(pv, len, hash) Perl_sharepvn(pv, len, hash)
	966
	967	#define share_hek_hek(hek) \
	968	(++(((struct shared_he )(((char )hek) \
	969	- STRUCT_OFFSET(struct shared_he, \
	970	shared_he_hek))) \
	971	->shared_he_he.he_valu.hent_refcount), \
	972	hek)
	973
	974	#define hv_store_ent(hv, keysv, val, hash) \
	975	((HE *) hv_common((hv), (keysv), NULL, 0, 0, HV_FETCH_ISSTORE, \
	976	(val), (hash)))
	977
	978	#define hv_exists_ent(hv, keysv, hash) \
	979	(hv_common((hv), (keysv), NULL, 0, 0, HV_FETCH_ISEXISTS, 0, (hash)) \
	980	? TRUE : FALSE)
	981	#define hv_fetch_ent(hv, keysv, lval, hash) \
	982	((HE *) hv_common((hv), (keysv), NULL, 0, 0, \
	983	((lval) ? HV_FETCH_LVALUE : 0), NULL, (hash)))
	984	#define hv_delete_ent(hv, key, flags, hash) \
	985	(MUTABLE_SV(hv_common((hv), (key), NULL, 0, 0, (flags) \| HV_DELETE, \
	986	NULL, (hash))))
	987
	988	#define hv_store_flags(hv, key, klen, val, hash, flags) \
	989	((SV**) hv_common((hv), NULL, (key), (klen), (flags), \
	990	(HV_FETCH_ISSTORE\|HV_FETCH_JUST_SV), (val), \
	991	(hash)))
	992
	993	#define hv_store(hv, key, klen, val, hash) \
	994	((SV**) hv_common_key_len((hv), (key), (klen), \
	995	(HV_FETCH_ISSTORE\|HV_FETCH_JUST_SV), \
	996	(val), (hash)))
	997
	998	#define hv_exists(hv, key, klen) \
	999	(hv_common_key_len((hv), (key), (klen), HV_FETCH_ISEXISTS, NULL, 0) \
	1000	? TRUE : FALSE)
	1001
	1002	#define hv_fetch(hv, key, klen, lval) \
	1003	((SV**) hv_common_key_len((hv), (key), (klen), (lval) \
	1004	? (HV_FETCH_JUST_SV \| HV_FETCH_LVALUE) \
	1005	: HV_FETCH_JUST_SV, NULL, 0))
	1006
	1007	#define hv_delete(hv, key, klen, flags) \
	1008	(MUTABLE_SV(hv_common_key_len((hv), (key), (klen), \
	1009	(flags) \| HV_DELETE, NULL, 0)))
	1010
	1011	/* This refcounted he structure is used for storing the hints used for lexical
	1012	pragmas. Without threads, it's basically struct he + refcount.
	1013	With threads, life gets more complex as the structure needs to be shared
	1014	between threads (because it hangs from OPs, which are shared), hence the
	1015	alternate definition and mutex. */
	1016
	1017	struct refcounted_he;
	1018
	1019	/* flags for the refcounted_he API */
	1020	#define REFCOUNTED_HE_KEY_UTF8 0x00000001
	1021	#ifdef PERL_CORE
	1022	# define REFCOUNTED_HE_EXISTS 0x00000002
	1023	#endif
	1024
	1025	#ifdef PERL_CORE
	1026
	1027	/* Gosh. This really isn't a good name any longer. */
	1028	struct refcounted_he {
	1029	struct refcounted_he refcounted_he_next; / next entry in chain */
	1030	#ifdef USE_ITHREADS
	1031	U32 refcounted_he_hash;
	1032	U32 refcounted_he_keylen;
	1033	#else
	1034	HEK refcounted_he_hek; / hint key */
	1035	#endif
	1036	union {
	1037	IV refcounted_he_u_iv;
	1038	UV refcounted_he_u_uv;
	1039	STRLEN refcounted_he_u_len;
	1040	void refcounted_he_u_ptr; / Might be useful in future */
	1041	} refcounted_he_val;
	1042	U32 refcounted_he_refcnt; /* reference count */
	1043	/* First byte is flags. Then NUL-terminated value. Then for ithreads,
	1044	non-NUL terminated key. */
	1045	char refcounted_he_data[1];
	1046	};
	1047
	1048	/*
	1049	=for apidoc m\|SV \|refcounted_he_fetch_pvs\|const struct refcounted_he chain\|const char *key\|U32 flags
	1050
	1051	Like L</refcounted_he_fetch_pvn>, but takes a literal string instead of
	1052	a string/length pair, and no precomputed hash.
	1053
	1054	=cut
	1055	*/
	1056
	1057	#define refcounted_he_fetch_pvs(chain, key, flags) \
	1058	Perl_refcounted_he_fetch_pvn(aTHX_ chain, STR_WITH_LEN(key), 0, flags)
	1059
	1060	/*
	1061	=for apidoc m\|struct refcounted_he \|refcounted_he_new_pvs\|struct refcounted_he parent\|const char key\|SV value\|U32 flags
	1062
	1063	Like L</refcounted_he_new_pvn>, but takes a literal string instead of
	1064	a string/length pair, and no precomputed hash.
	1065
	1066	=cut
	1067	*/
	1068
	1069	#define refcounted_he_new_pvs(parent, key, value, flags) \
	1070	Perl_refcounted_he_new_pvn(aTHX_ parent, STR_WITH_LEN(key), 0, value, flags)
	1071
	1072	/* Flag bits are HVhek_UTF8, HVhek_WASUTF8, then */
	1073	#define HVrhek_undef 0x00 /* Value is undef. */
	1074	#define HVrhek_delete 0x10 /* Value is placeholder - signifies delete. */
	1075	#define HVrhek_IV 0x20 /* Value is IV. */
	1076	#define HVrhek_UV 0x30 /* Value is UV. */
	1077	#define HVrhek_PV 0x40 /* Value is a (byte) string. */
	1078	#define HVrhek_PV_UTF8 0x50 /* Value is a (utf8) string. */
	1079	/* Two spare. As these have to live in the optree, you can't store anything
	1080	interpreter specific, such as SVs. :-( */
	1081	#define HVrhek_typemask 0x70
	1082
	1083	#ifdef USE_ITHREADS
	1084	/* A big expression to find the key offset */
	1085	#define REF_HE_KEY(chain) \
	1086	((((chain->refcounted_he_data[0] & 0x60) == 0x40) \
	1087	? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0) \
	1088	+ 1 + chain->refcounted_he_data)
	1089	#endif
	1090
	1091	# ifdef USE_ITHREADS
	1092	# define HINTS_REFCNT_LOCK MUTEX_LOCK(&PL_hints_mutex)
	1093	# define HINTS_REFCNT_UNLOCK MUTEX_UNLOCK(&PL_hints_mutex)
	1094	# else
	1095	# define HINTS_REFCNT_LOCK NOOP
	1096	# define HINTS_REFCNT_UNLOCK NOOP
	1097	# endif
	1098	#endif
	1099
	1100	#ifdef USE_ITHREADS
	1101	# define HINTS_REFCNT_INIT MUTEX_INIT(&PL_hints_mutex)
	1102	# define HINTS_REFCNT_TERM MUTEX_DESTROY(&PL_hints_mutex)
	1103	#else
	1104	# define HINTS_REFCNT_INIT NOOP
	1105	# define HINTS_REFCNT_TERM NOOP
	1106	#endif
	1107
	1108	/* Hash actions
	1109	* Passed in PERL_MAGIC_uvar calls
	1110	*/
	1111	#define HV_DISABLE_UVAR_XKEY 0x01
	1112	/* We need to ensure that these don't clash with G_DISCARD, which is 2, as it
	1113	is documented as being passed to hv_delete(). */
	1114	#define HV_FETCH_ISSTORE 0x04
	1115	#define HV_FETCH_ISEXISTS 0x08
	1116	#define HV_FETCH_LVALUE 0x10
	1117	#define HV_FETCH_JUST_SV 0x20
	1118	#define HV_DELETE 0x40
	1119	#define HV_FETCH_EMPTY_HE 0x80 /* Leave HeVAL null. */
	1120
	1121	/* Must not conflict with HVhek_UTF8 */
	1122	#define HV_NAME_SETALL 0x02
	1123
	1124	/*
	1125	=for apidoc newHV
	1126
	1127	Creates a new HV. The reference count is set to 1.
	1128
	1129	=cut
	1130	*/
	1131
	1132	#define newHV() MUTABLE_HV(newSV_type(SVt_PVHV))
	1133
	1134	/*
	1135	* Local variables:
	1136	* c-indentation-style: bsd
	1137	* c-basic-offset: 4
	1138	* indent-tabs-mode: nil
	1139	* End:
	1140	*
	1141	* ex: set ts=8 sts=4 sw=4 et:
	1142	*/