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a0d0e21e 1/* hv.h
79072805 2 *
be3c0a43 3 * Copyright (c) 1991-2002, Larry Wall
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4 *
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.
7 *
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8 */
9
5cbe4eec 10/* typedefs to eliminate some typing */
79072805 11typedef struct he HE;
ff68c719 12typedef struct hek HEK;
79072805 13
5cbe4eec 14/* entry in hash value chain */
79072805 15struct he {
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16 HE *hent_next; /* next entry in chain */
17 HEK *hent_hek; /* hash key */
18 SV *hent_val; /* scalar value that was hashed */
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19};
20
5cbe4eec 21/* hash key -- defined separately for use as shared pointer */
ff68c719 22struct hek {
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23 U32 hek_hash; /* hash of key */
24 I32 hek_len; /* length of hash key */
25 char hek_key[1]; /* variable-length hash key */
e05949c7 26 /* the hash-key is \0-terminated */
ddac11c4 27 /* after the \0 there is a byte for flags, such as whether the key is
19692e8d 28 UTF8 */
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29};
30
5cbe4eec 31/* hash structure: */
6ee623d5 32/* This structure must match the beginning of struct xpvmg in sv.h. */
79072805 33struct xpvhv {
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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 */
6ee623d5 37 IV xhv_keys; /* how many elements in the array */
65202027 38 NV xnv_nv; /* numeric value, if any */
8aacddc1 39#define xhv_placeholders xnv_nv
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40 MAGIC* xmg_magic; /* magic for scalar array */
41 HV* xmg_stash; /* class package */
42
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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 */
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47};
48
5cbe4eec 49/* hash a key */
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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) */
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53#define PERL_HASH(hash,str,len) \
54 STMT_START { \
ceea1387 55 register const unsigned char *s_PeRlHaSh = str; \
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56 register I32 i_PeRlHaSh = len; \
57 register U32 hash_PeRlHaSh = 0; \
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58 while (i_PeRlHaSh--) { \
59 hash_PeRlHaSh += *s_PeRlHaSh++; \
60 hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
61 hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
62 } \
63 hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
64 hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
4fee5c71 65 (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
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66 } STMT_END
67
954c1994 68/*
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69=head1 Hash Manipulation Functions
70
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71=for apidoc AmU||HEf_SVKEY
72This flag, used in the length slot of hash entries and magic structures,
d1be9408 73specifies the structure contains an C<SV*> pointer where a C<char*> pointer
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74is to be expected. (For information only--not to be used).
75
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76=head1 Handy Values
77
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78=for apidoc AmU||Nullhv
79Null HV pointer.
80
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81=head1 Hash Manipulation Functions
82
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83=for apidoc Am|char*|HvNAME|HV* stash
84Returns the package name of a stash. See C<SvSTASH>, C<CvSTASH>.
85
86=for apidoc Am|void*|HeKEY|HE* he
87Returns the actual pointer stored in the key slot of the hash entry. The
88pointer may be either C<char*> or C<SV*>, depending on the value of
89C<HeKLEN()>. Can be assigned to. The C<HePV()> or C<HeSVKEY()> macros are
90usually preferable for finding the value of a key.
91
92=for apidoc Am|STRLEN|HeKLEN|HE* he
93If this is negative, and amounts to C<HEf_SVKEY>, it indicates the entry
94holds an C<SV*> key. Otherwise, holds the actual length of the key. Can
95be assigned to. The C<HePV()> macro is usually preferable for finding key
96lengths.
97
98=for apidoc Am|SV*|HeVAL|HE* he
99Returns the value slot (type C<SV*>) stored in the hash entry.
100
101=for apidoc Am|U32|HeHASH|HE* he
102Returns the computed hash stored in the hash entry.
103
104=for apidoc Am|char*|HePV|HE* he|STRLEN len
105Returns the key slot of the hash entry as a C<char*> value, doing any
106necessary dereferencing of possibly C<SV*> keys. The length of the string
107is placed in C<len> (this is a macro, so do I<not> use C<&len>). If you do
108not care about what the length of the key is, you may use the global
109variable C<PL_na>, though this is rather less efficient than using a local
110variable. Remember though, that hash keys in perl are free to contain
111embedded nulls, so using C<strlen()> or similar is not a good way to find
112the length of hash keys. This is very similar to the C<SvPV()> macro
113described elsewhere in this document.
114
115=for apidoc Am|SV*|HeSVKEY|HE* he
116Returns the key as an C<SV*>, or C<Nullsv> if the hash entry does not
117contain an C<SV*> key.
118
119=for apidoc Am|SV*|HeSVKEY_force|HE* he
120Returns the key as an C<SV*>. Will create and return a temporary mortal
121C<SV*> if the hash entry contains only a C<char*> key.
122
123=for apidoc Am|SV*|HeSVKEY_set|HE* he|SV* sv
124Sets the key to a given C<SV*>, taking care to set the appropriate flags to
125indicate the presence of an C<SV*> key, and returns the same
126C<SV*>.
127
128=cut
129*/
bf6bd887 130
bf5b86ae 131/* these hash entry flags ride on hent_klen (for use only in magic/tied HVs) */
d1be9408 132#define HEf_SVKEY -2 /* hent_key is an SV* */
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133
134
79072805 135#define Nullhv Null(HV*)
4efcf9a2 136#define HvARRAY(hv) (*(HE***)&((XPVHV*) SvANY(hv))->xhv_array)
79072805 137#define HvFILL(hv) ((XPVHV*) SvANY(hv))->xhv_fill
463ee0b2 138#define HvMAX(hv) ((XPVHV*) SvANY(hv))->xhv_max
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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
a0d0e21e 143
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144/* the number of keys (including any placeholers) */
145#define XHvTOTALKEYS(xhv) ((xhv)->xhv_keys)
146
147/* The number of placeholders in the enumerated-keys hash */
205c8ad3 148#define XHvPLACEHOLDERS(xhv) ((xhv)->xhv_placeholders)
8aacddc1 149
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150/* the number of keys that exist() (i.e. excluding placeholders) */
151#define XHvUSEDKEYS(xhv) (XHvTOTALKEYS(xhv) - (IV)XHvPLACEHOLDERS(xhv))
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152
153/*
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)
157 */
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))
162
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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)
166
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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
172 * any utf8 keys.
173 */
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)
574c8022 177
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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)
181
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182/* Maybe amagical: */
183/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM | SVpgv_AM)) */
184
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)
188
189/*
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)
193*/
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194
195#define Nullhe Null(HE*)
196#define HeNEXT(he) (he)->hent_next
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197#define HeKEY_hek(he) (he)->hent_hek
198#define HeKEY(he) HEK_KEY(HeKEY_hek(he))
bbce6d69 199#define HeKEY_sv(he) (*(SV**)HeKEY(he))
ff68c719 200#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
da58a35d 201#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
19692e8d 202#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
da58a35d 203#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
19692e8d 204#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
bf6bd887 205#define HeVAL(he) (he)->hent_val
ff68c719 206#define HeHASH(he) HEK_HASH(HeKEY_hek(he))
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207#define HePV(he,lp) ((HeKLEN(he) == HEf_SVKEY) ? \
208 SvPV(HeKEY_sv(he),lp) : \
209 (((lp = HeKLEN(he)) >= 0) ? \
210 HeKEY(he) : Nullch))
211
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212#define HeSVKEY(he) ((HeKEY(he) && \
213 HeKLEN(he) == HEf_SVKEY) ? \
214 HeKEY_sv(he) : Nullsv)
215
216#define HeSVKEY_force(he) (HeKEY(he) ? \
217 ((HeKLEN(he) == HEf_SVKEY) ? \
218 HeKEY_sv(he) : \
79cb57f6 219 sv_2mortal(newSVpvn(HeKEY(he), \
bbce6d69 220 HeKLEN(he)))) : \
3280af22 221 &PL_sv_undef)
1e422769 222#define HeSVKEY_set(he,sv) ((HeKLEN(he) = HEf_SVKEY), (HeKEY_sv(he) = sv))
bbce6d69 223
ff68c719 224#define Nullhek Null(HEK*)
71be2cbc 225#define HEK_BASESIZE STRUCT_OFFSET(HEK, hek_key[0])
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226#define HEK_HASH(hek) (hek)->hek_hash
227#define HEK_LEN(hek) (hek)->hek_len
228#define HEK_KEY(hek) (hek)->hek_key
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229#define HEK_FLAGS(hek) (*((unsigned char *)(HEK_KEY(hek))+HEK_LEN(hek)+1))
230
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. */
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234#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
235 * (may change, but Storable is a core module) */
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236#define HVhek_MASK 0xFF
237
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)
d18c6117 244
5cbe4eec 245/* calculate HV array allocation */
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246#if defined(STRANGE_MALLOC) || defined(MYMALLOC)
247# define PERL_HV_ARRAY_ALLOC_BYTES(size) ((size) * sizeof(HE*))
248#else
249# define MALLOC_OVERHEAD 16
250# define PERL_HV_ARRAY_ALLOC_BYTES(size) \
251 (((size) < 64) \
252 ? (size) * sizeof(HE*) \
253 : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD)
254#endif
37d85e3a 255
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256/* Flags for hv_iternext_flags. */
257#define HV_ITERNEXT_WANTPLACEHOLDERS 0x01 /* Don't skip placeholders. */
258
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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)