mirror of
https://git.savannah.gnu.org/git/guile.git
synced 2025-04-30 03:40:34 +02:00
fa980bcc0f
Moved scm_i_struct_hash from struct.c to hash.c and made it static. The port's alist is now a field of 'scm_t_port'. Conflicts: libguile/arrays.c libguile/hash.c libguile/ports.c libguile/print.h libguile/read.c
456 lines
14 KiB
C
456 lines
14 KiB
C
/* Copyright (C) 1995, 1996, 1997, 2000, 2001, 2003, 2004, 2006, 2008,
|
||
* 2009, 2010, 2011, 2012 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 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
|
||
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
|
||
* 02110-1301 USA
|
||
*/
|
||
|
||
|
||
|
||
#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"
|
||
#include "libguile/ports.h"
|
||
#include "libguile/strings.h"
|
||
#include "libguile/symbols.h"
|
||
#include "libguile/vectors.h"
|
||
|
||
#include "libguile/validate.h"
|
||
#include "libguile/hash.h"
|
||
|
||
|
||
#ifndef floor
|
||
extern double floor();
|
||
#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)
|
||
{
|
||
return narrow_string_hash (str, len);
|
||
}
|
||
|
||
unsigned long
|
||
scm_i_string_hash (SCM str)
|
||
{
|
||
size_t len = scm_i_string_length (str);
|
||
|
||
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));
|
||
}
|
||
|
||
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);
|
||
}
|
||
|
||
/* 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;
|
||
}
|
||
}
|
||
|
||
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;
|
||
}
|
||
|
||
static unsigned long scm_raw_ihashq (scm_t_bits key);
|
||
static unsigned long scm_raw_ihash (SCM obj, size_t depth);
|
||
|
||
/* Return the hash of struct OBJ. Traverse OBJ's fields to compute the
|
||
result, unless DEPTH is zero. Assumes that OBJ is a struct. */
|
||
static unsigned long
|
||
scm_i_struct_hash (SCM obj, size_t depth)
|
||
{
|
||
SCM layout;
|
||
scm_t_bits *data;
|
||
size_t struct_size, field_num;
|
||
unsigned long hash;
|
||
|
||
layout = SCM_STRUCT_LAYOUT (obj);
|
||
struct_size = scm_i_symbol_length (layout) / 2;
|
||
data = SCM_STRUCT_DATA (obj);
|
||
|
||
hash = scm_raw_ihashq (SCM_UNPACK (SCM_STRUCT_VTABLE (obj)));
|
||
if (depth > 0)
|
||
for (field_num = 0; field_num < struct_size; field_num++)
|
||
{
|
||
int protection;
|
||
|
||
protection = scm_i_symbol_ref (layout, field_num * 2 + 1);
|
||
if (protection != 'h' && protection != 'o')
|
||
{
|
||
int type;
|
||
type = scm_i_symbol_ref (layout, field_num * 2);
|
||
switch (type)
|
||
{
|
||
case 'p':
|
||
hash ^= scm_raw_ihash (SCM_PACK (data[field_num]),
|
||
depth / 2);
|
||
break;
|
||
case 'u':
|
||
hash ^= scm_raw_ihashq (data[field_num]);
|
||
break;
|
||
default:
|
||
/* Ignore 's' fields. */;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* FIXME: Tail elements should be taken into account. */
|
||
|
||
return hash;
|
||
}
|
||
|
||
/* 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 scm_raw_ihashq (SCM_TYP16 (obj));
|
||
case scm_tc7_number:
|
||
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_i_string_hash (obj);
|
||
case scm_tc7_symbol:
|
||
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_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 (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);
|
||
case scm_tcs_struct:
|
||
return scm_i_struct_hash (obj, depth);
|
||
default:
|
||
return scm_raw_ihashq (SCM_CELL_WORD_0 (obj));
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|
||
unsigned long
|
||
scm_ihashq (SCM obj, unsigned long n)
|
||
{
|
||
return scm_raw_ihashq (SCM_UNPACK (obj)) % n;
|
||
}
|
||
|
||
|
||
SCM_DEFINE (scm_hashq, "hashq", 2, 0, 0,
|
||
(SCM key, SCM size),
|
||
"Determine a hash value for @var{key} that is suitable for\n"
|
||
"lookups in a hashtable of size @var{size}, where @code{eq?} is\n"
|
||
"used as the equality predicate. The function returns an\n"
|
||
"integer in the range 0 to @var{size} - 1. Note that\n"
|
||
"@code{hashq} may use internal addresses. Thus two calls to\n"
|
||
"hashq where the keys are @code{eq?} are not guaranteed to\n"
|
||
"deliver the same value if the key object gets garbage collected\n"
|
||
"in between. This can happen, for example with symbols:\n"
|
||
"@code{(hashq 'foo n) (gc) (hashq 'foo n)} may produce two\n"
|
||
"different values, since @code{foo} will be garbage collected.")
|
||
#define FUNC_NAME s_scm_hashq
|
||
{
|
||
unsigned long sz = scm_to_unsigned_integer (size, 1, ULONG_MAX);
|
||
return scm_from_ulong (scm_ihashq (key, sz));
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
|
||
|
||
|
||
unsigned long
|
||
scm_ihashv (SCM obj, unsigned long n)
|
||
{
|
||
if (SCM_NUMP(obj))
|
||
return scm_raw_ihash (obj, 10) % n;
|
||
else
|
||
return scm_raw_ihashq (SCM_UNPACK (obj)) % n;
|
||
}
|
||
|
||
|
||
SCM_DEFINE (scm_hashv, "hashv", 2, 0, 0,
|
||
(SCM key, SCM size),
|
||
"Determine a hash value for @var{key} that is suitable for\n"
|
||
"lookups in a hashtable of size @var{size}, where @code{eqv?} is\n"
|
||
"used as the equality predicate. The function returns an\n"
|
||
"integer in the range 0 to @var{size} - 1. Note that\n"
|
||
"@code{(hashv key)} may use internal addresses. Thus two calls\n"
|
||
"to hashv where the keys are @code{eqv?} are not guaranteed to\n"
|
||
"deliver the same value if the key object gets garbage collected\n"
|
||
"in between. This can happen, for example with symbols:\n"
|
||
"@code{(hashv 'foo n) (gc) (hashv 'foo n)} may produce two\n"
|
||
"different values, since @code{foo} will be garbage collected.")
|
||
#define FUNC_NAME s_scm_hashv
|
||
{
|
||
unsigned long sz = scm_to_unsigned_integer (size, 1, ULONG_MAX);
|
||
return scm_from_ulong (scm_ihashv (key, sz));
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
|
||
|
||
|
||
unsigned long
|
||
scm_ihash (SCM obj, unsigned long n)
|
||
{
|
||
return (unsigned long) scm_raw_ihash (obj, 10) % n;
|
||
}
|
||
|
||
SCM_DEFINE (scm_hash, "hash", 2, 0, 0,
|
||
(SCM key, SCM size),
|
||
"Determine a hash value for @var{key} that is suitable for\n"
|
||
"lookups in a hashtable of size @var{size}, where @code{equal?}\n"
|
||
"is used as the equality predicate. The function returns an\n"
|
||
"integer in the range 0 to @var{size} - 1.")
|
||
#define FUNC_NAME s_scm_hash
|
||
{
|
||
unsigned long sz = scm_to_unsigned_integer (size, 1, ULONG_MAX);
|
||
return scm_from_ulong (scm_ihash (key, sz));
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
|
||
|
||
|
||
void
|
||
scm_init_hash ()
|
||
{
|
||
#include "libguile/hash.x"
|
||
}
|
||
|
||
|
||
/*
|
||
Local Variables:
|
||
c-file-style: "gnu"
|
||
End:
|
||
*/
|