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ruby--ruby/include/ruby/st.h
nobu c0ff5f4dd7 st.c: fix st_hash* functions [Bug #13019]
Previous implementation had an issues:
- macros murmur1 assumes murmur_step takes rotation value
  as a second argument
- but murmur_step second argument is "next block"
- this makes st_hash_uint and st_hash_end to not mix high bits of
  hash value into lower bits
- this leads to pure hash behavior on doubles and mixing hashes using
  st_hash_uint.
  It didn't matter when bins amount were prime numbers, but it hurts
  when bins are powers of two.

Mistake were created cause of attempt to co-exist Murmur1 and Murmur2
in a same code.

Change it to single hash-function implementation.
- block function is in a spirit of Murmur functions,
  but handles inter-block dependency a bit better (imho).
- final block is read in bit more optimal way on CPU with unaligned word access,
- final block is mixed in simple way,
- finalizer is taken from MurmurHash3 (it makes most of magic :) )
  (64bit finalizer is taken from
  http://zimbry.blogspot.ru/2011/09/better-bit-mixing-improving-on.html)

Also remove ST_USE_FNV1: it lacks implementation of many functions,
and looks to be abandoned

Author: Sokolov Yura aka funny_falcon <funny.falcon@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57134 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2016-12-21 06:22:16 +00:00

155 lines
5.4 KiB
C

/* This is a public domain general purpose hash table package
originally written by Peter Moore @ UCB.
The hash table data strutures were redesigned and the package was
rewritten by Vladimir Makarov <vmakarov@redhat.com>. */
#ifndef RUBY_ST_H
#define RUBY_ST_H 1
#if defined(__cplusplus)
extern "C" {
#if 0
} /* satisfy cc-mode */
#endif
#endif
#include "ruby/defines.h"
RUBY_SYMBOL_EXPORT_BEGIN
#if SIZEOF_LONG == SIZEOF_VOIDP
typedef unsigned long st_data_t;
#elif SIZEOF_LONG_LONG == SIZEOF_VOIDP
typedef unsigned LONG_LONG st_data_t;
#else
# error ---->> st.c requires sizeof(void*) == sizeof(long) or sizeof(LONG_LONG) to be compiled. <<----
#endif
#define ST_DATA_T_DEFINED
#ifndef CHAR_BIT
# ifdef HAVE_LIMITS_H
# include <limits.h>
# else
# define CHAR_BIT 8
# endif
#endif
#ifndef _
# define _(args) args
#endif
#ifndef ANYARGS
# ifdef __cplusplus
# define ANYARGS ...
# else
# define ANYARGS
# endif
#endif
typedef struct st_table st_table;
typedef st_data_t st_index_t;
/* Maximal value of unsigned integer type st_index_t. */
#define MAX_ST_INDEX_VAL (~(st_index_t) 0)
typedef int st_compare_func(st_data_t, st_data_t);
typedef st_index_t st_hash_func(st_data_t);
typedef char st_check_for_sizeof_st_index_t[SIZEOF_VOIDP == (int)sizeof(st_index_t) ? 1 : -1];
#define SIZEOF_ST_INDEX_T SIZEOF_VOIDP
struct st_hash_type {
int (*compare)(ANYARGS /*st_data_t, st_data_t*/); /* st_compare_func* */
st_index_t (*hash)(ANYARGS /*st_data_t*/); /* st_hash_func* */
};
#define ST_INDEX_BITS (SIZEOF_ST_INDEX_T * CHAR_BIT)
#if defined(HAVE_BUILTIN___BUILTIN_CHOOSE_EXPR) && defined(HAVE_BUILTIN___BUILTIN_TYPES_COMPATIBLE_P)
# define ST_DATA_COMPATIBLE_P(type) \
__builtin_choose_expr(__builtin_types_compatible_p(type, st_data_t), 1, 0)
#else
# define ST_DATA_COMPATIBLE_P(type) 0
#endif
typedef struct st_table_entry st_table_entry;
struct st_table_entry; /* defined in st.c */
struct st_table {
/* Cached features of the table -- see st.c for more details. */
unsigned char entry_power, bin_power, size_ind;
/* How many times the table was rebuilt. */
unsigned int rebuilds_num;
const struct st_hash_type *type;
/* Number of entries currently in the table. */
st_index_t num_entries;
/* Array of bins used for access by keys. */
st_index_t *bins;
/* Start and bound index of entries in array entries.
entries_starts and entries_bound are in interval
[0,allocated_entries]. */
st_index_t entries_start, entries_bound;
/* Array of size 2^entry_power. */
st_table_entry *entries;
};
#define st_is_member(table,key) st_lookup((table),(key),(st_data_t *)0)
enum st_retval {ST_CONTINUE, ST_STOP, ST_DELETE, ST_CHECK};
st_table *st_init_table(const struct st_hash_type *);
st_table *st_init_table_with_size(const struct st_hash_type *, st_index_t);
st_table *st_init_numtable(void);
st_table *st_init_numtable_with_size(st_index_t);
st_table *st_init_strtable(void);
st_table *st_init_strtable_with_size(st_index_t);
st_table *st_init_strcasetable(void);
st_table *st_init_strcasetable_with_size(st_index_t);
int st_delete(st_table *, st_data_t *, st_data_t *); /* returns 0:notfound 1:deleted */
int st_delete_safe(st_table *, st_data_t *, st_data_t *, st_data_t);
int st_shift(st_table *, st_data_t *, st_data_t *); /* returns 0:notfound 1:deleted */
int st_insert(st_table *, st_data_t, st_data_t);
int st_insert2(st_table *, st_data_t, st_data_t, st_data_t (*)(st_data_t));
int st_lookup(st_table *, st_data_t, st_data_t *);
int st_get_key(st_table *, st_data_t, st_data_t *);
typedef int st_update_callback_func(st_data_t *key, st_data_t *value, st_data_t arg, int existing);
/* *key may be altered, but must equal to the old key, i.e., the
* results of hash() are same and compare() returns 0, otherwise the
* behavior is undefined */
int st_update(st_table *table, st_data_t key, st_update_callback_func *func, st_data_t arg);
int st_foreach(st_table *, int (*)(ANYARGS), st_data_t);
int st_foreach_check(st_table *, int (*)(ANYARGS), st_data_t, st_data_t);
st_index_t st_keys(st_table *table, st_data_t *keys, st_index_t size);
st_index_t st_keys_check(st_table *table, st_data_t *keys, st_index_t size, st_data_t never);
st_index_t st_values(st_table *table, st_data_t *values, st_index_t size);
st_index_t st_values_check(st_table *table, st_data_t *values, st_index_t size, st_data_t never);
void st_add_direct(st_table *, st_data_t, st_data_t);
void st_free_table(st_table *);
void st_cleanup_safe(st_table *, st_data_t);
void st_clear(st_table *);
st_table *st_copy(st_table *);
CONSTFUNC(int st_numcmp(st_data_t, st_data_t));
CONSTFUNC(st_index_t st_numhash(st_data_t));
PUREFUNC(int st_locale_insensitive_strcasecmp(const char *s1, const char *s2));
PUREFUNC(int st_locale_insensitive_strncasecmp(const char *s1, const char *s2, size_t n));
#define st_strcasecmp st_locale_insensitive_strcasecmp
#define st_strncasecmp st_locale_insensitive_strncasecmp
PUREFUNC(size_t st_memsize(const st_table *));
PUREFUNC(st_index_t st_hash(const void *ptr, size_t len, st_index_t h));
CONSTFUNC(st_index_t st_hash_uint32(st_index_t h, uint32_t i));
CONSTFUNC(st_index_t st_hash_uint(st_index_t h, st_index_t i));
CONSTFUNC(st_index_t st_hash_end(st_index_t h));
CONSTFUNC(st_index_t st_hash_start(st_index_t h));
#define st_hash_start(h) ((st_index_t)(h))
RUBY_SYMBOL_EXPORT_END
#if defined(__cplusplus)
#if 0
{ /* satisfy cc-mode */
#endif
} /* extern "C" { */
#endif
#endif /* RUBY_ST_H */