-/* Copyright (C) 1995,1996,1997, 2000, 2001, 2003, 2004 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1997, 2000, 2001, 2003, 2004, 2006, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
*
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
*/
\f
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#ifdef HAVE_WCHAR_H
+#include <wchar.h>
+#endif
+
+#include <math.h>
+#include <unistr.h>
#include "libguile/_scm.h"
#include "libguile/chars.h"
#endif
+/* This hash function is originally from
+ http://burtleburtle.net/bob/c/lookup3.c by Bob Jenkins, May 2006,
+ Public Domain. No warranty. */
+
+#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
+#define mix(a,b,c) \
+{ \
+ a -= c; a ^= rot(c, 4); c += b; \
+ b -= a; b ^= rot(a, 6); a += c; \
+ c -= b; c ^= rot(b, 8); b += a; \
+ a -= c; a ^= rot(c,16); c += b; \
+ b -= a; b ^= rot(a,19); a += c; \
+ c -= b; c ^= rot(b, 4); b += a; \
+}
+
+#define final(a,b,c) \
+{ \
+ c ^= b; c -= rot(b,14); \
+ a ^= c; a -= rot(c,11); \
+ b ^= a; b -= rot(a,25); \
+ c ^= b; c -= rot(b,16); \
+ a ^= c; a -= rot(c,4); \
+ b ^= a; b -= rot(a,14); \
+ c ^= b; c -= rot(b,24); \
+}
+
+#define JENKINS_LOOKUP3_HASHWORD2(k, length, ret) \
+ do { \
+ scm_t_uint32 a, b, c; \
+ \
+ /* Set up the internal state. */ \
+ a = b = c = 0xdeadbeef + ((scm_t_uint32)(length<<2)) + 47; \
+ \
+ /* Handle most of the key. */ \
+ while (length > 3) \
+ { \
+ a += k[0]; \
+ b += k[1]; \
+ c += k[2]; \
+ mix (a, b, c); \
+ length -= 3; \
+ k += 3; \
+ } \
+ \
+ /* Handle the last 3 elements. */ \
+ switch(length) /* All the case statements fall through. */ \
+ { \
+ case 3 : c += k[2]; \
+ case 2 : b += k[1]; \
+ case 1 : a += k[0]; \
+ final (a, b, c); \
+ case 0: /* case 0: nothing left to add */ \
+ break; \
+ } \
+ \
+ if (sizeof (ret) == 8) \
+ ret = (((unsigned long) c) << 32) | b; \
+ else \
+ ret = c; \
+ } while (0)
+
+
+static unsigned long
+narrow_string_hash (const scm_t_uint8 *str, size_t len)
+{
+ unsigned long ret;
+ JENKINS_LOOKUP3_HASHWORD2 (str, len, ret);
+ ret >>= 2; /* Ensure that it fits in a fixnum. */
+ return ret;
+}
+
+static unsigned long
+wide_string_hash (const scm_t_wchar *str, size_t len)
+{
+ unsigned long ret;
+ JENKINS_LOOKUP3_HASHWORD2 (str, len, ret);
+ ret >>= 2; /* Ensure that it fits in a fixnum. */
+ return ret;
+}
+
unsigned long
scm_string_hash (const unsigned char *str, size_t len)
{
- /* from suggestion at: */
- /* http://srfi.schemers.org/srfi-13/mail-archive/msg00112.html */
+ return narrow_string_hash (str, len);
+}
+
+unsigned long
+scm_i_string_hash (SCM str)
+{
+ size_t len = scm_i_string_length (str);
- unsigned long h = 0;
- while (len-- > 0)
- h = *str++ + h*37;
- return h;
+ if (scm_i_is_narrow_string (str))
+ return narrow_string_hash ((const scm_t_uint8 *) scm_i_string_chars (str),
+ len);
+ else
+ return wide_string_hash (scm_i_string_wide_chars (str), len);
}
+unsigned long
+scm_i_locale_string_hash (const char *str, size_t len)
+{
+ return scm_i_string_hash (scm_from_locale_stringn (str, len));
+}
-/* Dirk:FIXME:: why downcase for characters? (2x: scm_hasher, scm_ihashv) */
-/* Dirk:FIXME:: scm_hasher could be made static. */
+unsigned long
+scm_i_latin1_string_hash (const char *str, size_t len)
+{
+ if (len == (size_t) -1)
+ len = strlen (str);
+ return narrow_string_hash ((const scm_t_uint8 *) str, len);
+}
-unsigned long
-scm_hasher(SCM obj, unsigned long n, size_t d)
-{
- switch (SCM_ITAG3 (obj)) {
- case scm_tc3_int_1:
- case scm_tc3_int_2:
- return SCM_I_INUM(obj) % n; /* SCM_INUMP(obj) */
- case scm_tc3_imm24:
- if (SCM_CHARP(obj))
- return (unsigned)(scm_c_downcase(SCM_CHAR(obj))) % n;
- switch (SCM_UNPACK (obj)) {
-#ifndef SICP
- case SCM_UNPACK(SCM_EOL):
- d = 256;
- break;
-#endif
- case SCM_UNPACK(SCM_BOOL_T):
- d = 257;
- break;
- case SCM_UNPACK(SCM_BOOL_F):
- d = 258;
- break;
- case SCM_UNPACK(SCM_EOF_VAL):
- d = 259;
- break;
- default:
- d = 263; /* perhaps should be error */
+/* A tricky optimization, but probably worth it. */
+unsigned long
+scm_i_utf8_string_hash (const char *str, size_t len)
+{
+ const scm_t_uint8 *end, *ustr = (const scm_t_uint8 *) str;
+ unsigned long ret;
+
+ /* The length of the string in characters. This name corresponds to
+ Jenkins' original name. */
+ size_t length;
+
+ scm_t_uint32 a, b, c, u32;
+
+ if (len == (size_t) -1)
+ len = strlen (str);
+
+ end = ustr + len;
+
+ if (u8_check (ustr, len) != NULL)
+ /* Invalid UTF-8; punt. */
+ return scm_i_string_hash (scm_from_utf8_stringn (str, len));
+
+ length = u8_strnlen (ustr, len);
+
+ /* Set up the internal state. */
+ a = b = c = 0xdeadbeef + ((scm_t_uint32)(length<<2)) + 47;
+
+ /* Handle most of the key. */
+ while (length > 3)
+ {
+ ustr += u8_mbtouc_unsafe (&u32, ustr, end - ustr);
+ a += u32;
+ ustr += u8_mbtouc_unsafe (&u32, ustr, end - ustr);
+ b += u32;
+ ustr += u8_mbtouc_unsafe (&u32, ustr, end - ustr);
+ c += u32;
+ mix (a, b, c);
+ length -= 3;
+ }
+
+ /* Handle the last 3 elements's. */
+ ustr += u8_mbtouc_unsafe (&u32, ustr, end - ustr);
+ a += u32;
+ if (--length)
+ {
+ ustr += u8_mbtouc_unsafe (&u32, ustr, end - ustr);
+ b += u32;
+ if (--length)
+ {
+ ustr += u8_mbtouc_unsafe (&u32, ustr, end - ustr);
+ c += u32;
+ }
}
- return d % n;
- default:
- return 263 % n; /* perhaps should be error */
- case scm_tc3_cons:
- switch SCM_TYP7(obj) {
- default:
- return 263 % n;
+
+ final (a, b, c);
+
+ if (sizeof (unsigned long) == 8)
+ ret = (((unsigned long) c) << 32) | b;
+ else
+ ret = c;
+
+ ret >>= 2; /* Ensure that it fits in a fixnum. */
+ return ret;
+}
+
+
+/* Thomas Wang's integer hasher, from
+ http://www.cris.com/~Ttwang/tech/inthash.htm. */
+static unsigned long
+scm_raw_ihashq (scm_t_bits key)
+{
+ if (sizeof (key) < 8)
+ {
+ key = (key ^ 61) ^ (key >> 16);
+ key = key + (key << 3);
+ key = key ^ (key >> 4);
+ key = key * 0x27d4eb2d;
+ key = key ^ (key >> 15);
+ }
+ else
+ {
+ key = (~key) + (key << 21); // key = (key << 21) - key - 1;
+ key = key ^ (key >> 24);
+ key = (key + (key << 3)) + (key << 8); // key * 265
+ key = key ^ (key >> 14);
+ key = (key + (key << 2)) + (key << 4); // key * 21
+ key = key ^ (key >> 28);
+ key = key + (key << 31);
+ }
+ key >>= 2; /* Ensure that it fits in a fixnum. */
+ return key;
+}
+
+/* `depth' is used to limit recursion. */
+static unsigned long
+scm_raw_ihash (SCM obj, size_t depth)
+{
+ if (SCM_IMP (obj))
+ return scm_raw_ihashq (SCM_UNPACK (obj));
+
+ switch (SCM_TYP7(obj))
+ {
+ /* FIXME: do better for structs, variables, ... Also the hashes
+ are currently associative, which ain't the right thing. */
case scm_tc7_smob:
- return 263 % n;
+ return scm_raw_ihashq (SCM_TYP16 (obj));
case scm_tc7_number:
- switch SCM_TYP16 (obj) {
- case scm_tc16_big:
- return scm_to_ulong (scm_modulo (obj, scm_from_ulong (n)));
- case scm_tc16_real:
- {
- double r = SCM_REAL_VALUE (obj);
- if (floor (r) == r)
- {
- obj = scm_inexact_to_exact (obj);
- return scm_to_ulong (scm_modulo (obj, scm_from_ulong (n)));
- }
- }
- /* Fall through */
- case scm_tc16_complex:
- case scm_tc16_fraction:
- obj = scm_number_to_string (obj, scm_from_int (10));
- /* Fall through */
- }
- /* Fall through */
+ if (scm_is_integer (obj))
+ {
+ SCM n = SCM_I_MAKINUM (SCM_MOST_POSITIVE_FIXNUM);
+ if (scm_is_inexact (obj))
+ obj = scm_inexact_to_exact (obj);
+ return scm_raw_ihashq (scm_to_ulong (scm_modulo (obj, n)));
+ }
+ else
+ return scm_i_string_hash (scm_number_to_string (obj, scm_from_int (10)));
case scm_tc7_string:
- return scm_string_hash (SCM_STRING_UCHARS (obj), SCM_STRING_LENGTH (obj)) % n;
+ return scm_i_string_hash (obj);
case scm_tc7_symbol:
- return SCM_SYMBOL_HASH (obj) % n;
+ return scm_i_symbol_hash (obj);
+ case scm_tc7_pointer:
+ return scm_raw_ihashq ((scm_t_uintptr) SCM_POINTER_VALUE (obj));
case scm_tc7_wvect:
case scm_tc7_vector:
{
- size_t len = SCM_VECTOR_LENGTH(obj);
- SCM const *data = SCM_VELTS(obj);
- if (len > 5)
- {
- size_t i = d/2;
- unsigned long h = 1;
- while (i--) h = ((h << 8) + (scm_hasher (data[h % len], n, 2))) % n;
- return h;
- }
- else
- {
- size_t i = len;
- unsigned long h = (n)-1;
- while (i--) h = ((h << 8) + (scm_hasher (data[i], n, d/len))) % n;
- return h;
- }
+ size_t len = SCM_SIMPLE_VECTOR_LENGTH (obj);
+ size_t i = depth / 2;
+ unsigned long h = scm_raw_ihashq (SCM_CELL_WORD_0 (obj));
+ if (len)
+ while (i--)
+ h ^= scm_raw_ihash (scm_c_vector_ref (obj, h % len), i);
+ return h;
}
case scm_tcs_cons_imcar:
case scm_tcs_cons_nimcar:
- if (d) return (scm_hasher (SCM_CAR (obj), n, d/2)
- + scm_hasher (SCM_CDR (obj), n, d/2)) % n;
- else return 1;
- case scm_tc7_port:
- return ((SCM_RDNG & SCM_CELL_WORD_0 (obj)) ? 260 : 261) % n;
- case scm_tcs_closures:
- case scm_tcs_subrs:
- return 262 % n;
+ if (depth)
+ return (scm_raw_ihash (SCM_CAR (obj), depth / 2)
+ ^ scm_raw_ihash (SCM_CDR (obj), depth / 2));
+ else
+ return scm_raw_ihashq (scm_tc3_cons);
+ default:
+ return scm_raw_ihashq (SCM_CELL_WORD_0 (obj));
}
- }
}
\f
-
unsigned long
scm_ihashq (SCM obj, unsigned long n)
{
- return (SCM_UNPACK (obj) >> 1) % n;
+ return scm_raw_ihashq (SCM_UNPACK (obj)) % n;
}
unsigned long
scm_ihashv (SCM obj, unsigned long n)
{
- if (SCM_CHARP(obj))
- return ((unsigned long) (scm_c_downcase (SCM_CHAR (obj)))) % n; /* downcase!?!! */
-
if (SCM_NUMP(obj))
- return (unsigned long) scm_hasher(obj, n, 10);
+ return scm_raw_ihash (obj, 10) % n;
else
- return SCM_UNPACK (obj) % n;
+ return scm_raw_ihashq (SCM_UNPACK (obj)) % n;
}
unsigned long
scm_ihash (SCM obj, unsigned long n)
{
- return (unsigned long) scm_hasher (obj, n, 10);
+ return (unsigned long) scm_raw_ihash (obj, 10) % n;
}
SCM_DEFINE (scm_hash, "hash", 2, 0, 0,
HCoop / bpt / guile.git / blobdiff