Re: [perl #24071] Typo in description of binmode

[perl5.git] / hv.h

diff --git a/hv.h b/hv.h
index 688663a..4fa4239 100644 (file)
--- a/hv.h
+++ b/hv.h
@@ -1,6 +1,7 @@
 /*    hv.h
  *
- *    Copyright (c) 1991-2002, Larry Wall
+ *    Copyright (C) 1991, 1992, 1993, 1996, 1997, 1998, 1999,
+ *    2000, 2001, 2002, by Larry Wall and others
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
@@ -23,6 +24,9 @@ struct hek {
     U32                hek_hash;       /* hash of key */
     I32                hek_len;        /* length of hash key */
     char       hek_key[1];     /* variable-length hash key */
+    /* the hash-key is \0-terminated */
+    /* after the \0 there is a byte for flags, such as whether the key
+       is UTF-8 */
 };
 
 /* hash structure: */
@@ -44,14 +48,37 @@ struct xpvhv {
 };
 
 /* 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) */
+/* 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 signed, 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 erl.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) \
      STMT_START        { \
-       register const char *s_PeRlHaSh = str; \
+       register const char *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 = 0; \
+       register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
        while (i_PeRlHaSh--) { \
            hash_PeRlHaSh += *s_PeRlHaSh++; \
            hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
@@ -157,11 +184,21 @@ C<SV*>.
 #define HvTOTALKEYS(hv)                XHvTOTALKEYS((XPVHV*)  SvANY(hv))
 #define HvPLACEHOLDERS(hv)     XHvPLACEHOLDERS((XPVHV*)  SvANY(hv))
 
-
 #define HvSHAREKEYS(hv)                (SvFLAGS(hv) & SVphv_SHAREKEYS)
 #define HvSHAREKEYS_on(hv)     (SvFLAGS(hv) |= SVphv_SHAREKEYS)
 #define HvSHAREKEYS_off(hv)    (SvFLAGS(hv) &= ~SVphv_SHAREKEYS)
 
+/* This is an optimisation flag. It won't be set if all hash keys have a 0
+ * flag. Currently the only flags relate to utf8.
+ * Hence it won't be set if all keys are 8 bit only. It will be set if any key
+ * is utf8 (including 8 bit keys that were entered as utf8, and need upgrading
+ * when retrieved during iteration. It may still be set when there are no longer
+ * any utf8 keys.
+ */
+#define HvHASKFLAGS(hv)                (SvFLAGS(hv) & SVphv_HASKFLAGS)
+#define HvHASKFLAGS_on(hv)     (SvFLAGS(hv) |= SVphv_HASKFLAGS)
+#define HvHASKFLAGS_off(hv)    (SvFLAGS(hv) &= ~SVphv_HASKFLAGS)
+
 #define HvLAZYDEL(hv)          (SvFLAGS(hv) & SVphv_LAZYDEL)
 #define HvLAZYDEL_on(hv)       (SvFLAGS(hv) |= SVphv_LAZYDEL)
 #define HvLAZYDEL_off(hv)      (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
@@ -186,7 +223,9 @@ C<SV*>.
 #define HeKEY_sv(he)           (*(SV**)HeKEY(he))
 #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 HeKLEN_UTF8(he)  (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
+#define HeKFLAGS(he)  HEK_FLAGS(HeKEY_hek(he))
 #define HeVAL(he)              (he)->hent_val
 #define HeHASH(he)             HEK_HASH(HeKEY_hek(he))
 #define HePV(he,lp)            ((HeKLEN(he) == HEf_SVKEY) ?            \
@@ -211,7 +250,21 @@ C<SV*>.
 #define HEK_HASH(hek)          (hek)->hek_hash
 #define HEK_LEN(hek)           (hek)->hek_len
 #define HEK_KEY(hek)           (hek)->hek_key
-#define HEK_UTF8(hek)  (*(HEK_KEY(hek)+HEK_LEN(hek)))
+#define HEK_FLAGS(hek) (*((unsigned char *)(HEK_KEY(hek))+HEK_LEN(hek)+1))
+
+#define HVhek_UTF8     0x01 /* Key is utf8 encoded. */
+#define HVhek_WASUTF8  0x02 /* Key is bytes here, but was supplied as utf8. */
+#define HVhek_FREEKEY  0x100 /* Internal flag to say key is malloc()ed.  */
+#define HVhek_PLACEHOLD        0x200 /* Internal flag to create placeholder.
+                               * (may change, but Storable is a core module) */
+#define HVhek_MASK     0xFF
+
+#define HEK_UTF8(hek)          (HEK_FLAGS(hek) & HVhek_UTF8)
+#define HEK_UTF8_on(hek)       (HEK_FLAGS(hek) |= HVhek_UTF8)
+#define HEK_UTF8_off(hek)      (HEK_FLAGS(hek) &= ~HVhek_UTF8)
+#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)
 
 /* calculate HV array allocation */
 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
@@ -224,6 +277,9 @@ C<SV*>.
                         : (size) * sizeof(HE*) * 2 - MALLOC_OVERHEAD)
 #endif
 
+/* Flags for hv_iternext_flags.  */
+#define HV_ITERNEXT_WANTPLACEHOLDERS   0x01    /* Don't skip placeholders.  */
+
 /* available as a function in hv.c */
 #define Perl_sharepvn(sv, len, hash) HEK_KEY(share_hek(sv, len, hash))
 #define sharepvn(sv, len, hash)             Perl_sharepvn(sv, len, hash)