3 * Copyright (c) 1991-2002, Larry Wall
5 * You may distribute under the terms of either the GNU General Public
6 * License or the Artistic License, as specified in the README file.
10 /* typedefs to eliminate some typing */
12 typedef struct hek HEK;
14 /* entry in hash value chain */
16 HE *hent_next; /* next entry in chain */
17 HEK *hent_hek; /* hash key */
18 SV *hent_val; /* scalar value that was hashed */
21 /* hash key -- defined separately for use as shared pointer */
23 U32 hek_hash; /* hash of key */
24 I32 hek_len; /* length of hash key */
25 char hek_key[1]; /* variable-length hash key */
26 /* the hash-key is \0-terminated */
27 /* after the \0 there is a byte for flags, such as whether the key is
32 /* This structure must match the beginning of struct xpvmg in sv.h. */
34 char * xhv_array; /* pointer to malloced string */
35 STRLEN xhv_fill; /* how full xhv_array currently is */
36 STRLEN xhv_max; /* subscript of last element of xhv_array */
37 IV xhv_keys; /* how many elements in the array */
38 NV xnv_nv; /* numeric value, if any */
39 #define xhv_placeholders xnv_nv
40 MAGIC* xmg_magic; /* magic for scalar array */
41 HV* xmg_stash; /* class package */
43 I32 xhv_riter; /* current root of iterator */
44 HE *xhv_eiter; /* current entry of iterator */
45 PMOP *xhv_pmroot; /* list of pm's for this package */
46 char *xhv_name; /* name, if a symbol table */
50 /* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins */
51 /* from requirements by Colin Plumb. */
52 /* (http://burtleburtle.net/bob/hash/doobs.html) */
53 #define PERL_HASH(hash,str,len) \
55 register const char *s_PeRlHaSh = str; \
56 register I32 i_PeRlHaSh = len; \
57 register U32 hash_PeRlHaSh = 0; \
58 while (i_PeRlHaSh--) { \
59 hash_PeRlHaSh += *s_PeRlHaSh++; \
60 hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
61 hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
63 hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
64 hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
65 (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
69 =head1 Hash Manipulation Functions
71 =for apidoc AmU||HEf_SVKEY
72 This flag, used in the length slot of hash entries and magic structures,
73 specifies the structure contains an C<SV*> pointer where a C<char*> pointer
74 is to be expected. (For information only--not to be used).
78 =for apidoc AmU||Nullhv
81 =head1 Hash Manipulation Functions
83 =for apidoc Am|char*|HvNAME|HV* stash
84 Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
86 =for apidoc Am|void*|HeKEY|HE* he
87 Returns the actual pointer stored in the key slot of the hash entry. The
88 pointer may be either C<char*> or C<SV*>, depending on the value of
89 C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
90 usually preferable for finding the value of a key.
92 =for apidoc Am|STRLEN|HeKLEN|HE* he
93 If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
94 holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
95 be assigned to. The C<HePV()> macro is usually preferable for finding key
98 =for apidoc Am|SV*|HeVAL|HE* he
99 Returns the value slot (type C<SV*>) stored in the hash entry.
101 =for apidoc Am|U32|HeHASH|HE* he
102 Returns the computed hash stored in the hash entry.
104 =for apidoc Am|char*|HePV|HE* he|STRLEN len
105 Returns the key slot of the hash entry as a C<char*> value, doing any
106 necessary dereferencing of possibly C<SV*> keys. The length of the string
107 is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
108 not care about what the length of the key is, you may use the global
109 variable C<PL_na>, though this is rather less efficient than using a local
110 variable. Remember though, that hash keys in perl are free to contain
111 embedded nulls, so using C<strlen()> or similar is not a good way to find
112 the length of hash keys. This is very similar to the C<SvPV()> macro
113 described elsewhere in this document.
115 =for apidoc Am|SV*|HeSVKEY|HE* he
116 Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
117 contain an C<SV*> key.
119 =for apidoc Am|SV*|HeSVKEY_force|HE* he
120 Returns the key as an C<SV*>. Will create and return a temporary mortal
121 C<SV*> if the hash entry contains only a C<char*> key.
123 =for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv
124 Sets the key to a given C<SV*>, taking care to set the appropriate flags to
125 indicate the presence of an C<SV*> key, and returns the same
131 /* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
132 #define HEf_SVKEY -2 /* hent_key is an SV* */
135 #define Nullhv Null(HV*)
136 #define HvARRAY(hv) (*(HE***)&((XPVHV*) SvANY(hv))->xhv_array)
137 #define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
138 #define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
139 #define HvRITER(hv) ((XPVHV*) SvANY(hv))->xhv_riter
140 #define HvEITER(hv) ((XPVHV*) SvANY(hv))->xhv_eiter
141 #define HvPMROOT(hv) ((XPVHV*) SvANY(hv))->xhv_pmroot
142 #define HvNAME(hv) ((XPVHV*) SvANY(hv))->xhv_name
144 /* the number of keys (including any placeholers) */
145 #define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
147 /* The number of placeholders in the enumerated-keys hash */
148 #define XHvPLACEHOLDERS(xhv) ((xhv)->xhv_placeholders)
150 /* the number of keys that exist() (i.e. excluding placeholders) */
151 #define XHvUSEDKEYS(xhv) (XHvTOTALKEYS(xhv) - (IV)XHvPLACEHOLDERS(xhv))
154 * HvKEYS gets the number of keys that actually exist(), and is provided
155 * for backwards compatibility with old XS code. The core uses HvUSEDKEYS
156 * (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders)
158 #define HvKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv))
159 #define HvUSEDKEYS(hv) XHvUSEDKEYS((XPVHV*) SvANY(hv))
160 #define HvTOTALKEYS(hv) XHvTOTALKEYS((XPVHV*) SvANY(hv))
161 #define HvPLACEHOLDERS(hv) XHvPLACEHOLDERS((XPVHV*) SvANY(hv))
163 #define HvSHAREKEYS(hv) (SvFLAGS(hv) & SVphv_SHAREKEYS)
164 #define HvSHAREKEYS_on(hv) (SvFLAGS(hv) |= SVphv_SHAREKEYS)
165 #define HvSHAREKEYS_off(hv) (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
167 /* This is an optimisation flag. It won't be set if all hash keys have a 0
168 * flag. Currently the only flags relate to utf8.
169 * Hence it won't be set if all keys are 8 bit only. It will be set if any key
170 * is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
171 * when retrieved during iteration. It may still be set when there are no longer
174 #define HvHASKFLAGS(hv) (SvFLAGS(hv) & SVphv_HASKFLAGS)
175 #define HvHASKFLAGS_on(hv) (SvFLAGS(hv) |= SVphv_HASKFLAGS)
176 #define HvHASKFLAGS_off(hv) (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
178 #define HvLAZYDEL(hv) (SvFLAGS(hv) & SVphv_LAZYDEL)
179 #define HvLAZYDEL_on(hv) (SvFLAGS(hv) |= SVphv_LAZYDEL)
180 #define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
182 /* Maybe amagical: */
183 /* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM | SVpgv_AM)) */
185 #define HV_AMAGIC(hv) (SvFLAGS(hv) & SVpgv_AM)
186 #define HV_AMAGIC_on(hv) (SvFLAGS(hv) |= SVpgv_AM)
187 #define HV_AMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_AM)
190 #define HV_AMAGICbad(hv) (SvFLAGS(hv) & SVpgv_badAM)
191 #define HV_badAMAGIC_on(hv) (SvFLAGS(hv) |= SVpgv_badAM)
192 #define HV_badAMAGIC_off(hv) (SvFLAGS(hv) &= ~SVpgv_badAM)
195 #define Nullhe Null(HE*)
196 #define HeNEXT(he) (he)->hent_next
197 #define HeKEY_hek(he) (he)->hent_hek
198 #define HeKEY(he) HEK_KEY(HeKEY_hek(he))
199 #define HeKEY_sv(he) (*(SV**)HeKEY(he))
200 #define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
201 #define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
202 #define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
203 #define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
204 #define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
205 #define HeVAL(he) (he)->hent_val
206 #define HeHASH(he) HEK_HASH(HeKEY_hek(he))
207 #define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
208 SvPV(HeKEY_sv(he),lp) : \
209 (((lp = HeKLEN(he)) >= 0) ? \
212 #define HeSVKEY(he) ((HeKEY(he) && \
213 HeKLEN(he) == HEf_SVKEY) ? \
214 HeKEY_sv(he) : Nullsv)
216 #define HeSVKEY_force(he) (HeKEY(he) ? \
217 ((HeKLEN(he) == HEf_SVKEY) ? \
219 sv_2mortal(newSVpvn(HeKEY(he), \
222 #define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
224 #define Nullhek Null(HEK*)
225 #define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
226 #define HEK_HASH(hek) (hek)->hek_hash
227 #define HEK_LEN(hek) (hek)->hek_len
228 #define HEK_KEY(hek) (hek)->hek_key
229 #define HEK_FLAGS(hek) (*((unsigned char *)(HEK_KEY(hek))+HEK_LEN(hek)+1))
231 #define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
232 #define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
233 #define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
234 #define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
235 * (may change, but Storable is a core module) */
236 #define HVhek_MASK 0xFF
238 #define HEK_UTF8(hek) (HEK_FLAGS(hek) & HVhek_UTF8)
239 #define HEK_UTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_UTF8)
240 #define HEK_UTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_UTF8)
241 #define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
242 #define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_WASUTF8)
243 #define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
245 /* calculate HV array allocation */
246 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
247 # define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
249 # define MALLOC_OVERHEAD 16
250 # define PERL_HV_ARRAY_ALLOC_BYTES(size) \
252 ? (size) * sizeof(HE*) \
253 : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD)
256 /* Flags for hv_iternext_flags. */
257 #define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
259 /* available as a function in hv.c */
260 #define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
261 #define sharepvn(sv, len, hash) Perl_sharepvn(sv, len, hash)