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RUBY_KHASH_INCLUDES = {$(VPATH)}ruby_khash.h {$(VPATH)}khash.h

$(PROBES_H_INCLUDES) $(RUBY_KHASH_INCLUDES)

/* The MIT License

Copyright (c) 2008, 2009, 2011 by Attractive Chaos <attractor@live.co.uk>

Permission is hereby granted, free of charge, to any person obtaining

a copy of this software and associated documentation files (the

"Software"), to deal in the Software without restriction, including

without limitation the rights to use, copy, modify, merge, publish,

distribute, sublicense, and/or sell copies of the Software, and to

permit persons to whom the Software is furnished to do so, subject to

the following conditions:

The above copyright notice and this permission notice shall be

included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

SOFTWARE.

*/

/*

An example:

#include "khash.h"

KHASH_MAP_INIT_INT(32, char)

int main() {

int ret, is_missing;

khiter_t k;

khash_t(32) *h = kh_init(32);

k = kh_put(32, h, 5, &ret);

kh_value(h, k) = 10;

k = kh_get(32, h, 10);

is_missing = (k == kh_end(h));

k = kh_get(32, h, 5);

kh_del(32, h, k);

for (k = kh_begin(h); k != kh_end(h); ++k)

if (kh_exist(h, k)) kh_value(h, k) = 1;

kh_destroy(32, h);

return 0;

}

*/

/*

2013-05-02 (0.2.8):

* Use quadratic probing. When the capacity is power of 2, stepping function

i*(i+1)/2 guarantees to traverse each bucket. It is better than double

hashing on cache performance and is more robust than linear probing.

In theory, double hashing should be more robust than quadratic probing.

However, my implementation is probably not for large hash tables, because

the second hash function is closely tied to the first hash function,

which reduce the effectiveness of double hashing.

Reference: http://research.cs.vt.edu/AVresearch/hashing/quadratic.php

2011-12-29 (0.2.7):

* Minor code clean up; no actual effect.

2011-09-16 (0.2.6):

* The capacity is a power of 2. This seems to dramatically improve the

speed for simple keys. Thank Zilong Tan for the suggestion. Reference:

- http://code.google.com/p/ulib/

- http://nothings.org/computer/judy/

* Allow to optionally use linear probing which usually has better

performance for random input. Double hashing is still the default as it

is more robust to certain non-random input.

* Added Wang's integer hash function (not used by default). This hash

function is more robust to certain non-random input.

2011-02-14 (0.2.5):

* Allow to declare global functions.

2009-09-26 (0.2.4):

* Improve portability

2008-09-19 (0.2.3):

* Corrected the example

* Improved interfaces

2008-09-11 (0.2.2):

* Improved speed a little in kh_put()

2008-09-10 (0.2.1):

* Added kh_clear()

* Fixed a compiling error

2008-09-02 (0.2.0):

* Changed to token concatenation which increases flexibility.

2008-08-31 (0.1.2):

* Fixed a bug in kh_get(), which has not been tested previously.

2008-08-31 (0.1.1):

* Added destructor

*/

#ifndef __AC_KHASH_H

#define __AC_KHASH_H

/*!

@header

Generic hash table library.

*/

#define AC_VERSION_KHASH_H "0.2.8"

#include <stdlib.h>

#include <string.h>

#include <limits.h>

/* compiler specific configuration */

#if UINT_MAX == 0xffffffffu

typedef unsigned int khint32_t;

#elif ULONG_MAX == 0xffffffffu

typedef unsigned long khint32_t;

#endif

#if ULONG_MAX == ULLONG_MAX

typedef unsigned long khint64_t;

#else

typedef unsigned long long khint64_t;

#endif

#ifdef _MSC_VER

#define kh_inline __inline

#else

#define kh_inline inline

#endif

typedef khint32_t khint_t;

typedef khint_t khiter_t;

#define __ac_isempty(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&2)

#define __ac_isdel(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&1)

#define __ac_iseither(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&3)

#define __ac_set_isdel_false(flag, i) (flag[i>>4]&=~(1ul<<((i&0xfU)<<1)))

#define __ac_set_isempty_false(flag, i) (flag[i>>4]&=~(2ul<<((i&0xfU)<<1)))

#define __ac_set_isboth_false(flag, i) (flag[i>>4]&=~(3ul<<((i&0xfU)<<1)))

#define __ac_set_isdel_true(flag, i) (flag[i>>4]|=1ul<<((i&0xfU)<<1))

#define __ac_fsize(m) ((m) < 16? 1 : (m)>>4)

#ifndef kroundup32

#define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))

#endif

#ifndef kcalloc

#define kcalloc(N,Z) calloc(N,Z)

#endif

#ifndef kmalloc

#define kmalloc(Z) malloc(Z)

#endif

#ifndef krealloc

#define krealloc(P,Z) realloc(P,Z)

#endif

#ifndef kfree

#define kfree(P) free(P)

#endif

static const double __ac_HASH_UPPER = 0.77;

#define __KHASH_TYPE(name, khkey_t, khval_t) \

typedef struct { \

khint_t n_buckets, size, n_occupied, upper_bound; \

khint32_t *flags; \

khkey_t *keys; \

khval_t *vals; \

} kh_##name##_t;

#define __KHASH_PROTOTYPES(name, khkey_t, khval_t) \

extern kh_##name##_t *kh_init_##name(void); \

extern void kh_destroy_##name(kh_##name##_t *h); \

extern void kh_clear_##name(kh_##name##_t *h); \

extern khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key); \

extern int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \

extern khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); \

extern void kh_del_##name(kh_##name##_t *h, khint_t x);

#define __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \

SCOPE kh_##name##_t *kh_init_##name(void) { \

return (kh_##name##_t*)kcalloc(1, sizeof(kh_##name##_t)); \

} \

SCOPE void kh_destroy_##name(kh_##name##_t *h) \

{ \

if (h) { \

kfree((void *)h->keys); kfree(h->flags); \

kfree((void *)h->vals); \

kfree(h); \

} \

} \

SCOPE void kh_clear_##name(kh_##name##_t *h) \

{ \

if (h && h->flags) { \

memset(h->flags, 0xaa, __ac_fsize(h->n_buckets) * sizeof(khint32_t)); \

h->size = h->n_occupied = 0; \

} \

} \

SCOPE khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key) \

{ \

if (h->n_buckets) { \

khint_t k, i, last, mask, step = 0; \

mask = h->n_buckets - 1; \

k = __hash_func(key); i = k & mask; \

last = i; \

while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \

i = (i + (++step)) & mask; \

if (i == last) return h->n_buckets; \

} \

return __ac_iseither(h->flags, i)? h->n_buckets : i; \

} else return 0; \

} \

SCOPE int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \

{ /* This function uses 0.25*n_buckets bytes of working space instead of [sizeof(key_t+val_t)+.25]*n_buckets. */ \

khint32_t *new_flags = 0; \

khint_t j = 1; \

{ \

kroundup32(new_n_buckets); \

if (new_n_buckets < 4) new_n_buckets = 4; \

if (h->size >= (khint_t)(new_n_buckets * __ac_HASH_UPPER + 0.5)) j = 0; /* requested size is too small */ \

else { /* hash table size to be changed (shrink or expand); rehash */ \

new_flags = (khint32_t*)kmalloc(__ac_fsize(new_n_buckets) * sizeof(khint32_t)); \

if (!new_flags) return -1; \

memset(new_flags, 0xaa, __ac_fsize(new_n_buckets) * sizeof(khint32_t)); \

if (h->n_buckets < new_n_buckets) { /* expand */ \

khkey_t *new_keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \

if (!new_keys) return -1; \

h->keys = new_keys; \

if (kh_is_map) { \

khval_t *new_vals = (khval_t*)krealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \

if (!new_vals) return -1; \

h->vals = new_vals; \

} \

} /* otherwise shrink */ \

} \

} \

if (j) { /* rehashing is needed */ \

for (j = 0; j != h->n_buckets; ++j) { \

if (__ac_iseither(h->flags, j) == 0) { \

khkey_t key = h->keys[j]; \

khval_t val; \

khint_t new_mask; \

new_mask = new_n_buckets - 1; \

if (kh_is_map) val = h->vals[j]; \

__ac_set_isdel_true(h->flags, j); \

while (1) { /* kick-out process; sort of like in Cuckoo hashing */ \

khint_t k, i, step = 0; \

k = __hash_func(key); \

i = k & new_mask; \

while (!__ac_isempty(new_flags, i)) i = (i + (++step)) & new_mask; \

__ac_set_isempty_false(new_flags, i); \

if (i < h->n_buckets && __ac_iseither(h->flags, i) == 0) { /* kick out the existing element */ \

{ khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \

if (kh_is_map) { khval_t tmp = h->vals[i]; h->vals[i] = val; val = tmp; } \

__ac_set_isdel_true(h->flags, i); /* mark it as deleted in the old hash table */ \

} else { /* write the element and jump out of the loop */ \

h->keys[i] = key; \

if (kh_is_map) h->vals[i] = val; \

break; \

} \

} \

} \

} \

if (h->n_buckets > new_n_buckets) { /* shrink the hash table */ \

h->keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \

if (kh_is_map) h->vals = (khval_t*)krealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \

} \

kfree(h->flags); /* free the working space */ \

h->flags = new_flags; \

h->n_buckets = new_n_buckets; \

h->n_occupied = h->size; \

h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \

} \

return 0; \

} \

SCOPE khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \

{ \

khint_t x; \

if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \

if (h->n_buckets > (h->size<<1)) { \

if (kh_resize_##name(h, h->n_buckets - 1) < 0) { /* clear "deleted" elements */ \

*ret = -1; return h->n_buckets; \

} \

} else if (kh_resize_##name(h, h->n_buckets + 1) < 0) { /* expand the hash table */ \

*ret = -1; return h->n_buckets; \

} \

} /* TODO: to implement automatically shrinking; resize() already support shrinking */ \

{ \

khint_t k, i, site, last, mask = h->n_buckets - 1, step = 0; \

x = site = h->n_buckets; k = __hash_func(key); i = k & mask; \

if (__ac_isempty(h->flags, i)) x = i; /* for speed up */ \

else { \

last = i; \

while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \

if (__ac_isdel(h->flags, i)) site = i; \

i = (i + (++step)) & mask; \

if (i == last) { x = site; break; } \

} \

if (x == h->n_buckets) { \

if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \

else x = i; \

} \

} \

} \

if (__ac_isempty(h->flags, x)) { /* not present at all */ \

h->keys[x] = key; \

__ac_set_isboth_false(h->flags, x); \

++h->size; ++h->n_occupied; \

*ret = 1; \

} else if (__ac_isdel(h->flags, x)) { /* deleted */ \

h->keys[x] = key; \

__ac_set_isboth_false(h->flags, x); \

++h->size; \

*ret = 2; \

} else *ret = 0; /* Don't touch h->keys[x] if present and not deleted */ \

return x; \

} \

SCOPE void kh_del_##name(kh_##name##_t *h, khint_t x) \

{ \

if (x != h->n_buckets && !__ac_iseither(h->flags, x)) { \

__ac_set_isdel_true(h->flags, x); \

--h->size; \

} \

}

#define KHASH_DECLARE(name, khkey_t, khval_t) \

__KHASH_TYPE(name, khkey_t, khval_t) \

__KHASH_PROTOTYPES(name, khkey_t, khval_t)

#define KHASH_INIT2(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \

__KHASH_TYPE(name, khkey_t, khval_t) \

__KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)

#define KHASH_INIT(name, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \

KHASH_INIT2(name, static kh_inline, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)

/* --- BEGIN OF HASH FUNCTIONS --- */

/*! @function

@abstract Integer hash function

@param key The integer [khint32_t]

@return The hash value [khint_t]

*/

#define kh_int_hash_func(key) (khint32_t)(key)

/*! @function

@abstract Integer comparison function

*/

#define kh_int_hash_equal(a, b) ((a) == (b))

/*! @function

@abstract 64-bit integer hash function

@param key The integer [khint64_t]

@return The hash value [khint_t]

*/

#define kh_int64_hash_func(key) (khint32_t)((key)>>33^(key)^(key)<<11)

/*! @function

@abstract 64-bit integer comparison function

*/

#define kh_int64_hash_equal(a, b) ((a) == (b))

/*! @function

@abstract const char* hash function

@param s Pointer to a null terminated string

@return The hash value

*/

static kh_inline khint_t __ac_X31_hash_string(const char *s)

{

khint_t h = (khint_t)*s;

if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)*s;

return h;

}

/*! @function

@abstract Another interface to const char* hash function

@param key Pointer to a null terminated string [const char*]

@return The hash value [khint_t]

*/

#define kh_str_hash_func(key) __ac_X31_hash_string(key)

/*! @function

@abstract Const char* comparison function

*/

#define kh_str_hash_equal(a, b) (strcmp(a, b) == 0)

static kh_inline khint_t __ac_Wang_hash(khint_t key)

{

key += ~(key << 15);

key ^= (key >> 10);

key += (key << 3);

key ^= (key >> 6);

key += ~(key << 11);

key ^= (key >> 16);

return key;

}

#define kh_int_hash_func2(k) __ac_Wang_hash((khint_t)key)

/* --- END OF HASH FUNCTIONS --- */

/* Other convenient macros... */

/*!

@abstract Type of the hash table.

@param name Name of the hash table [symbol]

*/

#define khash_t(name) kh_##name##_t

/*! @function

@abstract Initiate a hash table.

@param name Name of the hash table [symbol]

@return Pointer to the hash table [khash_t(name)*]

*/

#define kh_init(name) kh_init_##name()

/*! @function

@abstract Destroy a hash table.

@param name Name of the hash table [symbol]

@param h Pointer to the hash table [khash_t(name)*]

*/

#define kh_destroy(name, h) kh_destroy_##name(h)

/*! @function

@abstract Reset a hash table without deallocating memory.

@param name Name of the hash table [symbol]

@param h Pointer to the hash table [khash_t(name)*]

*/

#define kh_clear(name, h) kh_clear_##name(h)

/*! @function

@abstract Resize a hash table.

@param name Name of the hash table [symbol]

@param h Pointer to the hash table [khash_t(name)*]

@param s New size [khint_t]

*/

#define kh_resize(name, h, s) kh_resize_##name(h, s)

/*! @function

@abstract Insert a key to the hash table.

@param name Name of the hash table [symbol]

@param h Pointer to the hash table [khash_t(name)*]

@param k Key [type of keys]

@param r Extra return code: -1 if the operation failed;

0 if the key is present in the hash table;

1 if the bucket is empty (never used); 2 if the element in

the bucket has been deleted [int*]

@return Iterator to the inserted element [khint_t]

*/

#define kh_put(name, h, k, r) kh_put_##name(h, k, r)

/*! @function

@abstract Retrieve a key from the hash table.

@param name Name of the hash table [symbol]

@param h Pointer to the hash table [khash_t(name)*]

@param k Key [type of keys]

@return Iterator to the found element, or kh_end(h) if the element is absent [khint_t]

*/

#define kh_get(name, h, k) kh_get_##name(h, k)

/*! @function

@abstract Remove a key from the hash table.

@param name Name of the hash table [symbol]

@param h Pointer to the hash table [khash_t(name)*]

@param k Iterator to the element to be deleted [khint_t]

*/

#define kh_del(name, h, k) kh_del_##name(h, k)

/*! @function

@abstract Test whether a bucket contains data.

@param h Pointer to the hash table [khash_t(name)*]

@param x Iterator to the bucket [khint_t]

@return 1 if containing data; 0 otherwise [int]

*/

#define kh_exist(h, x) (!__ac_iseither((h)->flags, (x)))

/*! @function

@abstract Get key given an iterator

@param h Pointer to the hash table [khash_t(name)*]

@param x Iterator to the bucket [khint_t]

@return Key [type of keys]

*/

#define kh_key(h, x) ((h)->keys[x])

/*! @function

@abstract Get value given an iterator

@param h Pointer to the hash table [khash_t(name)*]

@param x Iterator to the bucket [khint_t]

@return Value [type of values]

@discussion For hash sets, calling this results in segfault.

*/

#define kh_val(h, x) ((h)->vals[x])

/*! @function

@abstract Alias of kh_val()

*/

#define kh_value(h, x) ((h)->vals[x])

/*! @function

@abstract Get the start iterator

@param h Pointer to the hash table [khash_t(name)*]

@return The start iterator [khint_t]

*/

#define kh_begin(h) (khint_t)(0)

/*! @function

@abstract Get the end iterator

@param h Pointer to the hash table [khash_t(name)*]

@return The end iterator [khint_t]

*/

#define kh_end(h) ((h)->n_buckets)

/*! @function

@abstract Get the number of elements in the hash table

@param h Pointer to the hash table [khash_t(name)*]

@return Number of elements in the hash table [khint_t]

*/

#define kh_size(h) ((h)->size)

/*! @function

@abstract Get the number of buckets in the hash table

@param h Pointer to the hash table [khash_t(name)*]

@return Number of buckets in the hash table [khint_t]

*/

#define kh_n_buckets(h) ((h)->n_buckets)

/*! @function

@abstract Iterate over the entries in the hash table

@param h Pointer to the hash table [khash_t(name)*]

@param kvar Variable to which key will be assigned

@param vvar Variable to which value will be assigned

@param code Block of code to execute

*/

#define kh_foreach(h, kvar, vvar, code) { khint_t __i; \

for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \

if (!kh_exist(h,__i)) continue; \

(kvar) = kh_key(h,__i); \

(vvar) = kh_val(h,__i); \

code; \

} }

/*! @function

@abstract Iterate over the values in the hash table

@param h Pointer to the hash table [khash_t(name)*]

@param vvar Variable to which value will be assigned

@param code Block of code to execute

*/

#define kh_foreach_value(h, vvar, code) { khint_t __i; \

for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \

if (!kh_exist(h,__i)) continue; \

(vvar) = kh_val(h,__i); \

code; \

} }

/* More conenient interfaces */

/*! @function

@abstract Instantiate a hash set containing integer keys

@param name Name of the hash table [symbol]

*/

#define KHASH_SET_INIT_INT(name) \

KHASH_INIT(name, khint32_t, char, 0, kh_int_hash_func, kh_int_hash_equal)

/*! @function

@abstract Instantiate a hash map containing integer keys

@param name Name of the hash table [symbol]

@param khval_t Type of values [type]

*/

#define KHASH_MAP_INIT_INT(name, khval_t) \

KHASH_INIT(name, khint32_t, khval_t, 1, kh_int_hash_func, kh_int_hash_equal)

/*! @function

@abstract Instantiate a hash map containing 64-bit integer keys

@param name Name of the hash table [symbol]

*/

#define KHASH_SET_INIT_INT64(name) \

KHASH_INIT(name, khint64_t, char, 0, kh_int64_hash_func, kh_int64_hash_equal)

/*! @function

@abstract Instantiate a hash map containing 64-bit integer keys

@param name Name of the hash table [symbol]

@param khval_t Type of values [type]

*/

#define KHASH_MAP_INIT_INT64(name, khval_t) \

KHASH_INIT(name, khint64_t, khval_t, 1, kh_int64_hash_func, kh_int64_hash_equal)

typedef const char *kh_cstr_t;

/*! @function

@abstract Instantiate a hash map containing const char* keys

@param name Name of the hash table [symbol]

*/

#define KHASH_SET_INIT_STR(name) \

KHASH_INIT(name, kh_cstr_t, char, 0, kh_str_hash_func, kh_str_hash_equal)

/*! @function

@abstract Instantiate a hash map containing const char* keys

@param name Name of the hash table [symbol]

@param khval_t Type of values [type]

*/

#define KHASH_MAP_INIT_STR(name, khval_t) \

KHASH_INIT(name, kh_cstr_t, khval_t, 1, kh_str_hash_func, kh_str_hash_equal)

#endif /* __AC_KHASH_H */

#ifndef RUBY_KHASH_H

#define RUBY_KHASH_H

#include "ruby/ruby.h"

/*

* Avoid modifying khash.h directly since that is imported from

* https://github.com/attractivechaos/klib.git

*/

/* override klib defaults to do GC accounting */

#define kcalloc(N,Z) ruby_xcalloc((N),(Z))

#define kmalloc(N) ruby_xmalloc((N))

#define krealloc(P,Z) ruby_xrealloc((P),(Z))

#define kfree(P) ruby_xfree((P))

#include "khash.h"

static inline khint_t

rb_khash_str(VALUE str)

{

st_index_t h = rb_str_hash(str);

if (sizeof(st_index_t) == (sizeof(khint_t) * 2)) {

union { st_index_t in; khint_t out[2]; } tmp;

tmp.in = h;

return tmp.out[0] ^ tmp.out[1];

}

return (khint_t)h;

}

/*

* TODO: send this to khash upstream if it works well

* This is based on kh_foreach_value, but for keys.

*/

#define rb_kh_foreach_key(h, kvar, code) do { khint_t __i; \

for (__i = kh_begin(h); __i != kh_end(h); ++__i) { \

if (!kh_exist(h,__i)) continue; \

(kvar) = kh_key(h,__i); \

code; \

} } while (0)

#endif /* RUBY_KHASH_H */

#include "ruby_khash.h"

static int fstring_eq(VALUE a, VALUE b);

KHASH_INIT(fstring, VALUE, char, 0, rb_khash_str, fstring_eq);

static khash_t(fstring) *frozen_strings;

static int

fstring_eq(VALUE a, VALUE b)

{

int cmp = rb_str_hash_cmp(a, b);

if (cmp == 0) {

return (ENCODING_GET(b) - ENCODING_GET(a)) == 0;

}

return 0;

}

static inline khash_t(fstring) *

VALUE

rb_fstring(VALUE str)

khash_t(fstring) *tbl = rb_vm_fstring_table();

VALUE fstr;

khint_t k;

int ret;

Check_Type(str, T_STRING);

if (FL_TEST(str, RSTRING_FSTR))

return str;

again:

k = kh_get(fstring, tbl, str);

if (k != kh_end(tbl)) { /* existing */

fstr = kh_key(tbl, k);

/* because of lazy sweep, fstr may be unmarked already and swept

if (rb_objspace_garbage_object_p(fstr)) {

kh_del(fstring, tbl, k);

goto again;

fstr = rb_enc_str_new(RSTRING_PTR(str), RSTRING_LEN(str), STR_ENC_GET(str));

OBJ_FREEZE(fstr);

fstr = rb_str_new_frozen(str);

RBASIC(fstr)->flags |= RSTRING_FSTR;

kh_put(fstring, tbl, fstr, &ret);

if (ret < 0) rb_memerror();

return fstr;

khash_t(fstring) *tbl = rb_vm_fstring_table();

khint_t k = kh_get(fstring, tbl, str);

if (k != kh_end(tbl)) {

kh_del(fstring, tbl, k);

}

{

VALUE str;

assert(rb_vm_fstring_table());

rb_kh_foreach_key(rb_vm_fstring_table(), str, do {

RBASIC_SET_CLASS(str, rb_cString);

} while (0));

}

frozen_strings = kh_init(fstring);