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stb/stb_ds.h
Rafael Sachetto 89bccdd567 Small documentation correction
2019-02-26 09:37:16 -03:00

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/* stb_ds.h - v0.3 - public domain data structures - Sean Barrett 2019
This is a single-header-file library that provides easy-to-use
dynamic arrays and hash tables for C (also works in C++).
For a gentle introduction:
http://nothings.org/stb_ds
To use this library, do this in *one* C or C++ file:
#define STB_DS_IMPLEMENTATION
#include "stb_ds.h"
TABLE OF CONTENTS
Table of Contents
Compile-time options
License
Documentation
Notes
Notes - Dynamic arrays
Notes - Hash maps
Credits
COMPILE-TIME OPTIONS
#define STBDS_NO_SHORT_NAMES
This flag needs to be set globally.
By default stb_ds exposes shorter function names that are not qualified
with the "stbds_" prefix. If these names conflict with the names in your
code, define this flag.
#define STBDS_SIPHASH_2_4
This flag only needs to be set in the file containing #define STB_DS_IMPLEMENTATION.
By default stb_ds.h hashes using a weaker variant of SipHash and a custom hash for
4- and 8-byte keys. On 64-bit platforms, you can define the above flag to force
stb_ds.h to use specification-compliant SipHash-2-4 for all keys. Doing so makes
hash table insertion about 20% slower on 4- and 8-byte keys, 5% slower on
64-byte keys, and 10% slower on 256-byte keys on my test computer.
LICENSE
Placed in the public domain and also MIT licensed.
See end of file for detailed license information.
DOCUMENTATION
Dynamic Arrays
Non-function interface:
Declare an empty dynamic array of type T
T* foo = NULL;
Access the i'th item of a dynamic array 'foo' of type T, T* foo:
foo[i]
Functions (actually macros)
arrfree:
void arrfree(T*);
Frees the array.
arrlen:
ptrdiff_t arrlen(T*);
Returns the number of elements in the array.
arrlenu:
size_t arrlenu(T*);
Returns the number of elements in the array as an unsigned type.
arrput:
T arrput(T* a, T b);
Appends the item b to the end of array a. Returns b.
arrins:
T arrins(T* a, int p, T b);
Inserts the item b into the middle of array a, into a[p],
moving the rest of the array over. Returns b.
arrinsn:
void arrins(T* a, int p, int n);
Inserts n uninitialized items into array a starting at a[p],
moving the rest of the array over.
arrdel:
void arrdel(T* a, int p);
Deletes the element at a[p], moving the rest of the array over.
arrdeln:
void arrdel(T* a, int p, int n);
Deletes n elements starting at a[p], moving the rest of the array over.
arrdelswap:
void arrdelswap(T* a, int p);
Deletes the element at a[p], replacing it with the element from
the end of the array. O(1) performance.
arrsetlen:
void arrsetlen(T* a, int n);
Changes the length of the array to n. Allocates uninitialized
slots at the end if necessary.
arrsetcap:
size_t arrsetcap(T* a, int n);
Sets the length of allocated storage to at least n. It will not
change the length of the array.
arrcap:
size_t arrcap(T* a);
Returns the number of total elements the array can contain without
needing to be reallocated.
Hash maps & String hash maps
Given T is a structure type: struct { TK key; TV value; }. Note that some
functions do not require TV value and can have other fields. For string
hash maps, TK must be 'char *'.
Special interface:
stbds_rand_seed:
void stbds_rand_seed(size_t seed);
For security against adversarially chosen data, you should seed the
library with a strong random number. Or at least seed it with time().
stbds_hash_string:
size_t stbds_hash_string(char *str, size_t seed);
Returns a hash value for a string.
stbds_hash_bytes:
size_t stbds_hash_bytes(void *p, size_t len, size_t seed);
These functions hash an arbitrary number of bytes. The function
uses a custom hash for 4- and 8-byte data, and a weakened version
of SipHash for everything else. On 64-bit platforms you can get
specification-compliant SipHash-2-4 on all data by defining
STBDS_SIPHASH_2_4, at a significant cost in speed.
Non-function interface:
Declare an empty hash map of type T
T* foo = NULL;
Access the i'th entry in a hash table T* foo:
foo[i]
Function interface (actually macros):
hmfree
shfree
void hmfree(T*);
void shfree(T*);
Frees the hashmap and sets the pointer to NULL.
hmlen
shlen
ptrdiff_t hmlen(T*)
ptrdiff_t shlen(T*)
Returns the number of elements in the hashmap.
hmlenu
shlenu
size_t hmlenu(T*)
size_t shlenu(T*)
Returns the number of elements in the hashmap.
hmgeti
shgeti
ptrdiff_t hmgeti(T*, TK key)
ptrdiff_t shgeti(T*, char* key)
Returns the index in the hashmap which has the key 'key', or -1
if the key is not present.
hmget
shget
TV hmget(T*, TK key)
TV shget(T*, char* key)
Returns the value corresponding to 'key' in the hashmap.
The structure must have a 'value' field
hmgets
shgets
T hmgets(T*, TK key)
T shgets(T*, char* key)
Returns the structure corresponding to 'key' in the hashmap.
hmdefault
shdefault
TV hmdefault(T*, TV value)
TV shdefault(T*, TV value)
Sets the default value for the hashmap, the value which will be
returned by hmget/shget if the key is not present.
hmdefaults
shdefaults
TV hmdefaults(T*, T item)
TV shdefaults(T*, T item)
Sets the default struct for the hashmap, the contents which will be
returned by hmgets/shgets if the key is not present.
hmput
shput
TV hmput(T*, TK key, TV value)
TV shput(T*, char* key, TV value)
Inserts a <key,value> pair into the hashmap. If the key is already
present in the hashmap, updates its value.
hmputs
shputs
T hmputs(T*, T item)
T shputs(T*, T item)
Inserts a struct with T.key and T.value into the hashmap. If the struct is already
present in the hashmap, updates it.
hmdel
shdel
int hmdel(T*, TK key)
int shdel(T*, char* key)
If 'key' is in the hashmap, deletes its entry and returns 1.
Otherwise returns 0.
Function interface (actually macros) for strings only:
sh_new_strdup
void sh_new_strdup(T*);
Overwrites the existing pointer with a newly allocated
string hashmap which will automatically allocate and free
each string key using malloc/free
sh_new_arena
void sh_new_arena(T*);
Overwrites the existing pointer with a newly allocated
string hashmap which will automatically allocate each string
key to a string arena. Every string key ever used by this
hash table remains in the arena until the arena is freed.
Additionally, any key which is deleted and reinserted will
be allocated multiple times in the string arena.
NOTES
* These data structures are realloc'd when they grow, and the macro "functions"
write to the provided pointer. This means: (a) the pointer must be an lvalue,
and (b) the pointer to the data structure is not stable, and you must maintain
it the same as you would a realloc'd pointer. For example, if you pass a pointer
to a dynamic array to a function which updates it, the function must return
back the new pointer to the caller. This is the price of trying to do this in C.
* You iterate over the contents of a dynamic array and a hashmap in exactly
the same way, using arrlen/hmlen/shlen:
for (i=0; i < arrlen(foo); ++i)
... foo[i] ...
* All operations except arrins/arrdel are O(1) amortized, but individual
operations can be slow, so these data structures may not be suitable
for real time use. Dynamic arrays double in capacity as needed, so
elements are copied an average of once. Hash tables double/halve
their size as needed, with appropriate hysteresis to maintain O(1)
performance.
NOTES - DYNAMIC ARRAY
* If you know how long a dynamic array is going to be in advance, you can avoid
extra memory allocations by using arrsetlen to allocate it to that length in
advance and use foo[n] while filling it out, or arrsetcap to allocate the memory
for that length and use arrput/arrpush as normal.
* Unlike some other versions of the dynamic array, this version should
be safe to use with strict-aliasing optimizations.
NOTES - HASH MAP
* For compilers other than GCC and clang (e.g. Visual Studio), for hmput/hmget/hmdel
and variants, the key must be an lvalue (so the macro can take the address of it).
For GCC and clang, extensions are used that eliminate this requirement if you're
using C99 and later or using C++.
* To test for presence of a key in a hashmap, just do 'hmget(foo,key) >= 0'.
* The iteration order of your data in the hashmap is determined solely by the
order of insertions and deletions. In particular, if you never delete, new
keys are always added at the end of the array. This will be consistent
across all platforms and versions of the library. However, you should not
attempt to serialize the internal hash table, as the hash is not consistent
between different platforms, and may change with future versions of the library.
* Use sh_new_arena() for string hashmaps that you never delete from. Initialize
with NULL if you're managing the memory for your strings, or your strings are
never freed (at least until the hashmap is freed). Otherwise, use sh_new_strdup().
@TODO: make an arena variant that garbage collects the strings with a trivial
copy collector into a new arena whenever the table shrinks / rebuilds. Since
current arena recommendation is to only use arena if it never deletes, then
this can just replace current arena implementation.
* If adversarial input is a serious concern and you're on a 64-bit platform,
enable STBDS_SIPHASH_2_4 (see the 'Compile-time options' section), and pass
a strong random number to stbds_rand_seed.
* The default value for the hash table is stored in foo[-1], so if you
use code like 'hmget(T,k)->value = 5' you can overwrite the value
stored by hmdefault if 'k' is not present.
CREDITS
Sean Barrett -- library, idea for dynamic array API/implementation
Per Vognsen -- idea for hash table API/implementation
*/
#ifndef INCLUDE_STB_DS_H
#define INCLUDE_STB_DS_H
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#ifndef STBDS_NO_SHORT_NAMES
#define arrlen stbds_arrlen
#define arrlenu stbds_arrlenu
#define arrput stbds_arrput
#define arrpush stbds_arrput
#define arrfree stbds_arrfree
#define arraddn stbds_arraddn
#define arrsetlen stbds_arrsetlen
#define arrlast stbds_arrlast
#define arrins stbds_arrins
#define arrinsn stbds_arrinsn
#define arrdel stbds_arrdel
#define arrdeln stbds_arrdeln
#define arrdelswap stbds_arrdelswap
#define arrcap stbds_arrcap
#define arrsetcap stbds_arrsetcap
#define hmput stbds_hmput
#define hmputs stbds_hmputs
#define hmget stbds_hmget
#define hmgets stbds_hmgets
#define hmgetp stbds_hmgetp
#define hmgeti stbds_hmgeti
#define hmdel stbds_hmdel
#define hmlen stbds_hmlen
#define hmlenu stbds_hmlenu
#define hmfree stbds_hmfree
#define hmdefault stbds_hmdefault
#define hmdefaults stbds_hmdefaults
#define shput stbds_shput
#define shputs stbds_shputs
#define shget stbds_shget
#define shgets stbds_shgets
#define shgetp stbds_shgetp
#define shgeti stbds_shgeti
#define shdel stbds_shdel
#define shlen stbds_shlen
#define shlenu stbds_shlenu
#define shfree stbds_shfree
#define shdefault stbds_shdefault
#define shdefaults stbds_shdefaults
#define sh_new_arena stbds_sh_new_arena
#define sh_new_strdup stbds_sh_new_strdup
#define stralloc stbds_stralloc
#define strreset stbds_strreset
#endif
#ifdef __cplusplus
extern "C" {
#endif
// for security against attackers, seed the library with a random number, at least time() but stronger is better
extern void stbds_rand_seed(size_t seed);
// these are the hash functions used internally if you want to test them or use them for other purposes
extern size_t stbds_hash_bytes(void *p, size_t len, size_t seed);
extern size_t stbds_hash_string(char *str, size_t seed);
// this is a simple string arena allocator, initialize with e.g. 'stbds_string_arena my_arena={0}'.
typedef struct stbds_string_arena stbds_string_arena;
extern char * stbds_stralloc(stbds_string_arena *a, char *str);
extern void stbds_strreset(stbds_string_arena *a);
// have to #define STBDS_UNIT_TESTS to call this
extern void stbds_unit_tests(void);
///////////////
//
// Everything below here is implementation details
//
extern void * stbds_arrgrowf(void *a, size_t elemsize, size_t addlen, size_t min_cap);
extern void stbds_hmfree_func(void *p, size_t elemsize, size_t keyoff);
extern void * stbds_hmget_key(void *a, size_t elemsize, void *key, size_t keysize, int mode);
extern void * stbds_hmput_default(void *a, size_t elemsize);
extern void * stbds_hmput_key(void *a, size_t elemsize, void *key, size_t keysize, int mode);
extern void * stbds_hmdel_key(void *a, size_t elemsize, void *key, size_t keysize, size_t keyoffset, int mode);
extern void * stbds_shmode_func(size_t elemsize, int mode);
#ifdef __cplusplus
}
#endif
#if defined(__GNUC__) || defined(__clang__)
#define STBDS_HAS_TYPEOF
#ifdef __cplusplus
//#define STBDS_HAS_LITERAL_ARRAY // this is currently broken for clang
#endif
#endif
#if !defined(__cplusplus)
#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
#define STBDS_HAS_LITERAL_ARRAY
#endif
#endif
// this macro takes the address of the argument, but on gcc/clang can accept rvalues
#if defined(STBDS_HAS_LITERAL_ARRAY) && defined(STBDS_HAS_TYPEOF)
#if __clang__
#define STBDS_ADDRESSOF(typevar, value) ((__typeof__(typevar)[1]){value}) // literal array decays to pointer to value
#else
#define STBDS_ADDRESSOF(typevar, value) ((typeof(typevar)[]){value}) // literal array decays to pointer to value
#endif
#else
#define STBDS_ADDRESSOF(typevar, value) &(value)
#endif
#define STBDS_OFFSETOF(var,field) ((char *) &(var)->field - (char *) (var))
#define stbds_header(t) ((stbds_array_header *) (t) - 1)
#define stbds_temp(t) stbds_header(t)->temp
#define stbds_arrsetcap(a,n) (stbds_arrgrow(a,0,n))
#define stbds_arrsetlen(a,n) ((stbds_arrcap(a) < n ? stbds_arrsetcap(a,n),0 : 0), (a) ? stbds_header(a)->length = (n) : 0)
#define stbds_arrcap(a) ((a) ? stbds_header(a)->capacity : 0)
#define stbds_arrlen(a) ((a) ? (ptrdiff_t) stbds_header(a)->length : 0)
#define stbds_arrlenu(a) ((a) ? stbds_header(a)->length : 0)
#define stbds_arrput(a,v) (stbds_arrmaybegrow(a,1), (a)[stbds_header(a)->length++] = (v))
#define stbds_arrpush stbds_arrput // synonym
#define stbds_arraddn(a,n) (stbds_arrmaybegrow(a,n), stbds_header(a)->length += (n))
#define stbds_arrlast(a) ((a)[stbds_header(a)->length-1])
#define stbds_arrfree(a) ((void) ((a) ? realloc(stbds_header(a),0) : 0), (a)=NULL)
#define stbds_arrdel(a,i) stbds_arrdeln(a,i,1)
#define stbds_arrdeln(a,i,n) (memmove(&(a)[i], &(a)[(i)+(n)], sizeof *(a) * (stbds_header(a)->length-(n)-(i))), stbds_header(a)->length -= (n))
#define stbds_arrdelswap(a,i) ((a)[i] = stbds_arrlast(a), stbds_header(a)->length -= 1)
#define stbds_arrinsn(a,i,n) (stbds_arraddn((a),(n)), memmove(&(a)[(i)+(n)], &(a)[i], sizeof *(a) * (stbds_header(a)->length-(n)-(i))))
#define stbds_arrins(a,i,v) (stbds_arrinsn((a),(i),1), (a)[i]=(v))
#define stbds_arrmaybegrow(a,n) ((!(a) || stbds_header(a)->length + (n) > stbds_header(a)->capacity) \
? (stbds_arrgrow(a,n,0),0) : 0)
#define stbds_arrgrow(a,b,c) ((a) = stbds_arrgrowf_wrapper((a), sizeof *(a), (b), (c)))
#define stbds_hmput(t, k, v) \
((t) = stbds_hmput_key_wrapper((t), sizeof *(t), (void*) STBDS_ADDRESSOF((t)->key, (k)), sizeof (t)->key, 0), \
(t)[stbds_temp((t)-1)].key = (k), \
(t)[stbds_temp((t)-1)].value = (v))
#define stbds_hmputs(t, s) \
((t) = stbds_hmput_key_wrapper((t), sizeof *(t), &(s).key, sizeof (s).key, STBDS_HM_BINARY), \
(t)[stbds_temp((t)-1)] = (s))
#define stbds_hmgeti(t,k) \
((t) = stbds_hmget_key_wrapper((t), sizeof *(t), (void*) STBDS_ADDRESSOF((t)->key, (k)), sizeof (t)->key, STBDS_HM_BINARY), \
stbds_temp((t)-1))
#define stbds_hmgetp(t, k) \
((void) stbds_hmgeti(t,k), &(t)[stbds_temp((t)-1)])
#define stbds_hmdel(t,k) \
(((t) = stbds_hmdel_key_wrapper((t),sizeof *(t), (void*) STBDS_ADDRESSOF((t)->key, (k)), sizeof (t)->key, STBDS_OFFSETOF((t),key), STBDS_HM_BINARY)),(t)?stbds_temp((t)-1):0)
#define stbds_hmdefault(t, v) \
((t) = stbds_hmput_default_wrapper((t), sizeof *(t)), (t)[-1].value = (v))
#define stbds_hmdefaults(t, s) \
((t) = stbds_hmput_default_wrapper((t), sizeof *(t)), (t)[-1] = (s))
#define stbds_hmfree(p) \
((void) ((p) != NULL ? stbds_hmfree_func((p)-1,sizeof*(p),STBDS_OFFSETOF((p),key)),0 : 0),(p)=NULL)
#define stbds_hmgets(t, k) (*stbds_hmgetp(t,k))
#define stbds_hmget(t, k) (stbds_hmgetp(t,k)->value)
#define stbds_hmlen(t) (stbds_arrlen((t)-1)-1)
#define stbds_hmlenu(t) (stbds_arrlenu((t)-1)-1)
#define stbds_shput(t, k, v) \
((t) = stbds_hmput_key_wrapper((t), sizeof *(t), (void*) (k), sizeof (t)->key, STBDS_HM_STRING), \
(t)[stbds_temp(t-1)].value = (v))
#define stbds_shputs(t, s) \
((t) = stbds_hmput_key_wrapper((t), sizeof *(t), (void*) (s).key, sizeof (s).key, STBDS_HM_STRING), \
(t)[stbds_temp(t-1)] = (s))
#define stbds_shgeti(t,k) \
((t) = stbds_hmget_key_wrapper((t), sizeof *(t), (void*) (k), sizeof (t)->key, STBDS_HM_STRING), \
stbds_temp(t))
#define stbds_shgetp(t, k) \
((void) stbds_shgeti(t,k), &(t)[stbds_temp(t-1)])
#define stbds_shdel(t,k) \
(((t) = stbds_hmdel_key_wrapper((t),sizeof *(t), (void*) (k), sizeof (t)->key, STBDS_OFFSETOF((t),key), STBDS_HM_STRING)),(t)?stbds_temp((t)-1):0)
#define stbds_sh_new_arena(t) \
((t) = stbds_shmode_func_wrapper(t, sizeof *(t), STBDS_SH_ARENA))
#define stbds_sh_new_strdup(t) \
((t) = stbds_shmode_func_wrapper(t, sizeof *(t), STBDS_SH_STRDUP))
#define stbds_shdefault(t, v) stbds_hmdefault(t,v)
#define stbds_shdefaults(t, s) stbds_hmdefaults(t,s)
#define stbds_shfree stbds_hmfree
#define stbds_shlenu stbds_hmlenu
#define stbds_shgets(t, k) (*stbds_shgetp(t,k))
#define stbds_shget(t, k) (stbds_shgetp(t,k)->value)
#define stbds_shlen stbds_hmlen
typedef struct
{
size_t length;
size_t capacity;
void * hash_table;
ptrdiff_t temp;
} stbds_array_header;
typedef struct stbds_string_block
{
struct stbds_string_block *next;
char storage[8];
} stbds_string_block;
struct stbds_string_arena
{
stbds_string_block *storage;
size_t remaining;
unsigned char block;
unsigned char mode; // this isn't used by the string arena itself
};
enum
{
STBDS_HM_BINARY,
STBDS_HM_STRING,
};
enum
{
STBDS_SH_NONE,
STBDS_SH_STRDUP,
STBDS_SH_ARENA
};
#ifdef __cplusplus
// in C we use implicit assignment from these void*-returning functions to T*.
// in C++ these templates make the same code work
template<class T> static T * stbds_arrgrowf_wrapper(T *a, size_t elemsize, size_t addlen, size_t min_cap) {
return (T*)stbds_arrgrowf((void *)a, elemsize, addlen, min_cap);
}
template<class T> static T * stbds_hmget_key_wrapper(T *a, size_t elemsize, void *key, size_t keysize, int mode) {
return (T*)stbds_hmget_key((void*)a, elemsize, key, keysize, mode);
}
template<class T> static T * stbds_hmput_default_wrapper(T *a, size_t elemsize) {
return (T*)stbds_hmput_default((void *)a, elemsize);
}
template<class T> static T * stbds_hmput_key_wrapper(T *a, size_t elemsize, void *key, size_t keysize, int mode) {
return (T*)stbds_hmput_key((void*)a, elemsize, key, keysize, mode);
}
template<class T> static T * stbds_hmdel_key_wrapper(T *a, size_t elemsize, void *key, size_t keysize, size_t keyoffset, int mode){
return (T*)stbds_hmdel_key((void*)a, elemsize, key, keysize, keyoffset, mode);
}
template<class T> static T * stbds_shmode_func_wrapper(T *, size_t elemsize, int mode) {
return (T*)stbds_shmode_func(elemsize, mode);
}
#else
#define stbds_arrgrowf_wrapper stbds_arrgrowf
#define stbds_hmget_key_wrapper stbds_hmget_key
#define stbds_hmput_default_wrapper stbds_hmput_default
#define stbds_hmput_key_wrapper stbds_hmput_key
#define stbds_hmdel_key_wrapper stbds_hmdel_key
#define stbds_shmode_func_wrapper(t,e,m) stbds_shmode_func(e,m)
#endif
#endif // INCLUDE_STB_DS_H
//////////////////////////////////////////////////////////////////////////////
//
// IMPLEMENTATION
//
#ifdef STB_DS_IMPLEMENTATION
#include <assert.h>
#include <string.h>
#ifndef STBDS_ASSERT
#define STBDS_ASSERT(x) ((void) 0)
#endif
#ifdef STBDS_STATISTICS
#define STBDS_STATS(x) x
size_t stbds_array_grow;
size_t stbds_hash_grow;
size_t stbds_hash_shrink;
size_t stbds_hash_rebuild;
size_t stbds_hash_probes;
size_t stbds_hash_alloc;
size_t stbds_rehash_probes;
size_t stbds_rehash_items;
#else
#define STBDS_STATS(x)
#endif
//
// stbds_arr implementation
//
void *stbds_arrgrowf(void *a, size_t elemsize, size_t addlen, size_t min_cap)
{
void *b;
size_t min_len = stbds_arrlen(a) + addlen;
// compute the minimum capacity needed
if (min_len > min_cap)
min_cap = min_len;
if (min_cap <= stbds_arrcap(a))
return a;
// increase needed capacity to guarantee O(1) amortized
if (min_cap < 2 * stbds_arrcap(a))
min_cap = 2 * stbds_arrcap(a);
else if (min_cap < 4)
min_cap = 4;
b = realloc((a) ? stbds_header(a) : 0, elemsize * min_cap + sizeof(stbds_array_header));
b = (char *) b + sizeof(stbds_array_header);
if (a == NULL) {
stbds_header(b)->length = 0;
stbds_header(b)->hash_table = 0;
} else {
STBDS_STATS(++stbds_array_grow);
}
stbds_header(b)->capacity = min_cap;
return b;
}
//
// stbds_hm hash table implementation
//
#define STBDS_CACHE_LINE_SIZE 64
#define STBDS_BUCKET_LENGTH 8
#define STBDS_BUCKET_SHIFT 3
#define STBDS_BUCKET_MASK (STBDS_BUCKET_LENGTH-1)
#define STBDS_ALIGN_FWD(n,a) (((n) + (a) - 1) & ~((a)-1))
typedef struct
{
size_t hash [STBDS_BUCKET_LENGTH];
ptrdiff_t index[STBDS_BUCKET_LENGTH];
} stbds_hash_bucket; // in 32-bit, this is one 64-byte cache line; in 64-bit, each array is one 64-byte cache line
typedef struct
{
size_t slot_count;
size_t used_count;
size_t used_count_threshold;
size_t used_count_shrink_threshold;
size_t tombstone_count;
size_t tombstone_count_threshold;
size_t seed;
size_t slot_count_log2;
stbds_string_arena string;
stbds_hash_bucket *storage; // not a separate allocation, just 64-byte aligned storage after this struct
} stbds_hash_index;
#define STBDS_INDEX_EMPTY -1
#define STBDS_INDEX_DELETED -2
#define STBDS_INDEX_IN_USE(x) ((x) >= 0)
#define STBDS_HASH_EMPTY 0
#define STBDS_HASH_DELETED 1
static size_t stbds_hash_seed=0x31415926;
void stbds_rand_seed(size_t seed)
{
stbds_hash_seed = seed;
}
#define stbds_load_32_or_64(var, temp, v32, v64_hi, v64_lo) \
temp = v64_lo ^ v32, temp <<= 16, temp <<= 16, temp >>= 16, temp >>= 16, /* discard if 32-bit */ \
var = v64_hi, var <<= 16, var <<= 16, /* discard if 32-bit */ \
var ^= temp ^ v32
#define STBDS_SIZE_T_BITS ((sizeof (size_t)) * 8)
static size_t stbds_probe_position(size_t hash, size_t slot_count, size_t slot_log2)
{
#if 1
size_t pos = (hash >> (STBDS_SIZE_T_BITS-slot_log2));
STBDS_ASSERT(pos < slot_count);
return pos;
#else
return hash & (slot_count-1);
#endif
}
static size_t stbds_log2(size_t slot_count)
{
size_t n=0;
while (slot_count > 1) {
slot_count >>= 1;
++n;
}
return n;
}
static stbds_hash_index *stbds_make_hash_index(size_t slot_count, stbds_hash_index *ot)
{
stbds_hash_index *t;
t = (stbds_hash_index *) realloc(0,(slot_count >> STBDS_BUCKET_SHIFT) * sizeof(stbds_hash_bucket) + sizeof(stbds_hash_index) + STBDS_CACHE_LINE_SIZE-1);
t->storage = (stbds_hash_bucket *) STBDS_ALIGN_FWD((size_t) (t+1), STBDS_CACHE_LINE_SIZE);
t->slot_count = slot_count;
t->slot_count_log2 = stbds_log2(slot_count);
t->tombstone_count = 0;
t->used_count = 0;
#if 0 // A1
t->used_count_threshold = slot_count*12/16; // if 12/16th of table is occupied, grow
t->tombstone_count_threshold = slot_count* 2/16; // if tombstones are 2/16th of table, rebuild
t->used_count_shrink_threshold = slot_count* 4/16; // if table is only 4/16th full, shrink
#elif 1 // A2
//t->used_count_threshold = slot_count*12/16; // if 12/16th of table is occupied, grow
//t->tombstone_count_threshold = slot_count* 3/16; // if tombstones are 3/16th of table, rebuild
//t->used_count_shrink_threshold = slot_count* 4/16; // if table is only 4/16th full, shrink
// compute without overflowing
t->used_count_threshold = slot_count - (slot_count>>2);
t->tombstone_count_threshold = (slot_count>>3) + (slot_count>>4);
t->used_count_shrink_threshold = slot_count >> 2;
#elif 0 // B1
t->used_count_threshold = slot_count*13/16; // if 13/16th of table is occupied, grow
t->tombstone_count_threshold = slot_count* 2/16; // if tombstones are 2/16th of table, rebuild
t->used_count_shrink_threshold = slot_count* 5/16; // if table is only 5/16th full, shrink
#else // C1
t->used_count_threshold = slot_count*14/16; // if 14/16th of table is occupied, grow
t->tombstone_count_threshold = slot_count* 2/16; // if tombstones are 2/16th of table, rebuild
t->used_count_shrink_threshold = slot_count* 6/16; // if table is only 6/16th full, shrink
#endif
// Following statistics were measured on a Core i7-6700 @ 4.00Ghz, compiled with clang 7.0.1 -O2
// Note that the larger tables have high variance as they were run fewer times
// A1 A2 B1 C1
// 0.10ms : 0.10ms : 0.10ms : 0.11ms : 2,000 inserts creating 2K table
// 0.96ms : 0.95ms : 0.97ms : 1.04ms : 20,000 inserts creating 20K table
// 14.48ms : 14.46ms : 10.63ms : 11.00ms : 200,000 inserts creating 200K table
// 195.74ms : 196.35ms : 203.69ms : 214.92ms : 2,000,000 inserts creating 2M table
// 2193.88ms : 2209.22ms : 2285.54ms : 2437.17ms : 20,000,000 inserts creating 20M table
// 65.27ms : 53.77ms : 65.33ms : 65.47ms : 500,000 inserts & deletes in 2K table
// 72.78ms : 62.45ms : 71.95ms : 72.85ms : 500,000 inserts & deletes in 20K table
// 89.47ms : 77.72ms : 96.49ms : 96.75ms : 500,000 inserts & deletes in 200K table
// 97.58ms : 98.14ms : 97.18ms : 97.53ms : 500,000 inserts & deletes in 2M table
// 118.61ms : 119.62ms : 120.16ms : 118.86ms : 500,000 inserts & deletes in 20M table
// 192.11ms : 194.39ms : 196.38ms : 195.73ms : 500,000 inserts & deletes in 200M table
if (slot_count <= STBDS_BUCKET_LENGTH)
t->used_count_shrink_threshold = 0;
// to avoid infinite loop, we need to guarantee that at least one slot is empty and will terminate probes
STBDS_ASSERT(t->used_count_threshold + t->tombstone_count_threshold < t->slot_count);
STBDS_STATS(++stbds_hash_alloc);
if (ot) {
t->string = ot->string;
// reuse old seed so we can reuse old hashes so below "copy out old data" doesn't do any hashing
t->seed = ot->seed;
} else {
size_t a,b,temp;
memset(&t->string, 0, sizeof(t->string));
t->seed = stbds_hash_seed;
// LCG
// in 32-bit, a = 2147001325 b = 715136305
// in 64-bit, a = 2862933555777941757 b = 3037000493
stbds_load_32_or_64(a,temp, 2147001325, 0x27bb2ee6, 0x87b0b0fd);
stbds_load_32_or_64(b,temp, 715136305, 0, 0xb504f32d);
stbds_hash_seed = stbds_hash_seed * a + b;
}
{
size_t i,j;
for (i=0; i < slot_count >> STBDS_BUCKET_SHIFT; ++i) {
stbds_hash_bucket *b = &t->storage[i];
for (j=0; j < STBDS_BUCKET_LENGTH; ++j)
b->hash[j] = STBDS_HASH_EMPTY;
for (j=0; j < STBDS_BUCKET_LENGTH; ++j)
b->index[j] = STBDS_INDEX_EMPTY;
}
}
// copy out the old data, if any
if (ot) {
size_t i,j;
t->used_count = ot->used_count;
for (i=0; i < ot->slot_count >> STBDS_BUCKET_SHIFT; ++i) {
stbds_hash_bucket *ob = &ot->storage[i];
for (j=0; j < STBDS_BUCKET_LENGTH; ++j) {
if (STBDS_INDEX_IN_USE(ob->index[j])) {
size_t hash = ob->hash[j];
size_t pos = stbds_probe_position(hash, t->slot_count, t->slot_count_log2);
size_t step = STBDS_BUCKET_LENGTH;
STBDS_STATS(++stbds_rehash_items);
for (;;) {
size_t limit,z;
stbds_hash_bucket *bucket;
pos &= (t->slot_count-1);
bucket = &t->storage[pos >> STBDS_BUCKET_SHIFT];
STBDS_STATS(++stbds_rehash_probes);
for (z=pos & STBDS_BUCKET_MASK; z < STBDS_BUCKET_LENGTH; ++z) {
if (bucket->hash[z] == 0) {
bucket->hash[z] = hash;
bucket->index[z] = ob->index[j];
goto done;
}
}
limit = pos & STBDS_BUCKET_MASK;
for (z = 0; z < limit; ++z) {
if (bucket->hash[z] == 0) {
bucket->hash[z] = hash;
bucket->index[z] = ob->index[j];
goto done;
}
}
pos += step; // quadratic probing
step += STBDS_BUCKET_LENGTH;
}
}
done:
;
}
}
}
return t;
}
#define STBDS_ROTATE_LEFT(val, n) (((val) << (n)) | ((val) >> (STBDS_SIZE_T_BITS - (n))))
#define STBDS_ROTATE_RIGHT(val, n) (((val) >> (n)) | ((val) << (STBDS_SIZE_T_BITS - (n))))
size_t stbds_hash_string(char *str, size_t seed)
{
size_t hash = seed;
while (*str)
hash = STBDS_ROTATE_LEFT(hash, 9) + (unsigned char) *str++;
// Thomas Wang 64-to-32 bit mix function, hopefully also works in 32 bits
hash ^= seed;
hash = (~hash) + (hash << 18);
hash ^= hash ^ STBDS_ROTATE_RIGHT(hash,31);
hash = hash * 21;
hash ^= hash ^ STBDS_ROTATE_RIGHT(hash,11);
hash += (hash << 6);
hash ^= STBDS_ROTATE_RIGHT(hash,22);
return hash+seed;
}
#ifdef STBDS_SIPHASH_2_4
#define STBDS_SIPHASH_C_ROUNDS 2
#define STBDS_SIPHASH_D_ROUNDS 4
typedef int STBDS_SIPHASH_2_4_can_only_be_used_in_64_bit_builds[sizeof(size_t) == 8 ? 1 : -1];
#endif
#ifndef STBDS_SIPHASH_C_ROUNDS
#define STBDS_SIPHASH_C_ROUNDS 1
#endif
#ifndef STBDS_SIPHASH_D_ROUNDS
#define STBDS_SIPHASH_D_ROUNDS 1
#endif
static size_t stbds_siphash_bytes(void *p, size_t len, size_t seed)
{
unsigned char *d = (unsigned char *) p;
size_t i,j;
size_t v0,v1,v2,v3, data;
// hash that works on 32- or 64-bit registers without knowing which we have
// (computes different results on 32-bit and 64-bit platform)
// derived from siphash, but on 32-bit platforms very different as it uses 4 32-bit state not 4 64-bit
v0 = ((((size_t) 0x736f6d65 << 16) << 16) + 0x70736575) ^ seed;
v1 = ((((size_t) 0x646f7261 << 16) << 16) + 0x6e646f6d) ^ ~seed;
v2 = ((((size_t) 0x6c796765 << 16) << 16) + 0x6e657261) ^ seed;
v3 = ((((size_t) 0x74656462 << 16) << 16) + 0x79746573) ^ ~seed;
#ifdef STBDS_TEST_SIPHASH_2_4
// hardcoded with key material in the siphash test vectors
v0 ^= 0x0706050403020100ull ^ seed;
v1 ^= 0x0f0e0d0c0b0a0908ull ^ ~seed;
v2 ^= 0x0706050403020100ull ^ seed;
v3 ^= 0x0f0e0d0c0b0a0908ull ^ ~seed;
#endif
#define STBDS_SIPROUND() \
do { \
v0 += v1; v1 = STBDS_ROTATE_LEFT(v1, 13); v1 ^= v0; v0 = STBDS_ROTATE_LEFT(v0,STBDS_SIZE_T_BITS/2); \
v2 += v3; v3 = STBDS_ROTATE_LEFT(v3, 16); v3 ^= v2; \
v2 += v1; v1 = STBDS_ROTATE_LEFT(v1, 17); v1 ^= v2; v2 = STBDS_ROTATE_LEFT(v2,STBDS_SIZE_T_BITS/2); \
v0 += v3; v3 = STBDS_ROTATE_LEFT(v3, 21); v3 ^= v0; \
} while (0)
for (i=0; i+sizeof(size_t) <= len; i += sizeof(size_t), d += sizeof(size_t)) {
data = d[0] | (d[1] << 8) | (d[2] << 16) | (d[3] << 24);
data |= (size_t) (d[4] | (d[5] << 8) | (d[6] << 16) | (d[7] << 24)) << 16 << 16; // discarded if size_t == 4
v3 ^= data;
for (j=0; j < STBDS_SIPHASH_C_ROUNDS; ++j)
STBDS_SIPROUND();
v0 ^= data;
}
data = len << (STBDS_SIZE_T_BITS-8);
switch (len - i) {
case 7: data |= ((size_t) d[6] << 24) << 24;
case 6: data |= ((size_t) d[5] << 20) << 20;
case 5: data |= ((size_t) d[4] << 16) << 16;
case 4: data |= (d[3] << 24);
case 3: data |= (d[2] << 16);
case 2: data |= (d[1] << 8);
case 1: data |= d[0];
case 0: break;
}
v3 ^= data;
for (j=0; j < STBDS_SIPHASH_C_ROUNDS; ++j)
STBDS_SIPROUND();
v0 ^= data;
v2 ^= 0xff;
for (j=0; j < STBDS_SIPHASH_D_ROUNDS; ++j)
STBDS_SIPROUND();
#ifdef STBDS_SIPHASH_2_4
return v0^v1^v2^v3;
#else
return v1^v2^v3; // slightly stronger since v0^v3 in above cancels out final round operation
#endif
}
size_t stbds_hash_bytes(void *p, size_t len, size_t seed)
{
#ifdef STBDS_SIPHASH_2_4
return stbds_siphash_bytes(p,len,seed);
#else
unsigned char *d = (unsigned char *) p;
if (len == 4) {
unsigned int hash = d[0] | (d[1] << 8) | (d[2] << 16) | (d[3] << 24);
#if 0
// HASH32-A Bob Jenkin's hash function w/o large constants
hash ^= seed ^ len;
hash -= (hash<<6);
hash ^= (hash>>17);
hash -= (hash<<9);
hash ^= (hash<<4);
hash -= (hash<<3);
hash ^= (hash<<10);
hash ^= (hash>>15);
#elif 1
// HASH32-BB Bob Jenkin's presumably-accidental version of Thomas Wang hash with rotates turned into shifts.
// Note that converting these back to rotates makes it run a lot slower, presumably due to collisions, so I'm
// not really sure what's going on.
hash ^= seed ^ len;
hash = (hash ^ 61) ^ (hash >> 16);
hash = hash + (hash << 3);
hash = hash ^ (hash >> 4);
hash = hash * 0x27d4eb2d;
hash = hash ^ (hash >> 15);
#else // HASH32-C - Murmur3
hash *= 0xcc9e2d51;
hash = (hash << 17) | (hash >> 15);
hash *= 0x1b873593;
hash ^= seed;
hash = (hash << 19) | (hash >> 13);
hash = hash*5 + 0xe6546b64;
hash ^= len;
hash ^= hash >> 16;
hash *= 0x85ebca6b;
hash ^= hash >> 13;
hash *= 0xc2b2ae35;
hash ^= hash >> 16;
#endif
// Following statistics were measured on a Core i7-6700 @ 4.00Ghz, compiled with clang 7.0.1 -O2
// Note that the larger tables have high variance as they were run fewer times
// HASH32-A // HASH32-BB // HASH32-C
// 0.10ms // 0.10ms // 0.10ms : 2,000 inserts creating 2K table
// 0.96ms // 0.95ms // 0.99ms : 20,000 inserts creating 20K table
// 14.69ms // 14.43ms // 14.97ms : 200,000 inserts creating 200K table
// 199.99ms // 195.36ms // 202.05ms : 2,000,000 inserts creating 2M table
// 2234.84ms // 2187.74ms // 2240.38ms : 20,000,000 inserts creating 20M table
// 55.68ms // 53.72ms // 57.31ms : 500,000 inserts & deletes in 2K table
// 63.43ms // 61.99ms // 65.73ms : 500,000 inserts & deletes in 20K table
// 80.04ms // 77.96ms // 81.83ms : 500,000 inserts & deletes in 200K table
// 100.42ms // 97.40ms // 102.39ms : 500,000 inserts & deletes in 2M table
// 119.71ms // 120.59ms // 121.63ms : 500,000 inserts & deletes in 20M table
// 185.28ms // 195.15ms // 187.74ms : 500,000 inserts & deletes in 200M table
// 15.58ms // 14.79ms // 15.52ms : 200,000 inserts creating 200K table with varying key spacing
return (((size_t) hash << 16 << 16) | hash) ^ seed;
} else if (len == 8 && sizeof(size_t) == 8) {
size_t hash = d[0] | (d[1] << 8) | (d[2] << 16) | (d[3] << 24);
hash |= (size_t) (d[4] | (d[5] << 8) | (d[6] << 16) | (d[7] << 24)) << 16 << 16; // avoid warning if size_t == 4
hash ^= seed ^ len;
hash = (~hash) + (hash << 21);
hash ^= STBDS_ROTATE_RIGHT(hash,24);
hash *= 265;
hash ^= STBDS_ROTATE_RIGHT(hash,14);
hash *= 21;
hash ^= STBDS_ROTATE_RIGHT(hash,28);
hash += (hash << 31);
hash = (~hash) + (hash << 18);
return hash^seed;
} else {
return stbds_siphash_bytes(p,len,seed);
}
#endif
}
static int stbds_is_key_equal(void *a, size_t elemsize, void *key, size_t keysize, int mode, size_t i)
{
if (mode >= STBDS_HM_STRING)
return 0==strcmp((char *) key, * (char **) ((char *) a + elemsize*i));
else
return 0==memcmp(key, (char *) a + elemsize*i, keysize);
}
#define STBDS_HASH_TO_ARR(x,elemsize) ((char*) (x) - (elemsize))
#define STBDS_ARR_TO_HASH(x,elemsize) ((char*) (x) + (elemsize))
#define STBDS_FREE(x) realloc(x,0)
#define stbds_hash_table(a) ((stbds_hash_index *) stbds_header(a)->hash_table)
void stbds_hmfree_func(void *a, size_t elemsize, size_t keyoff)
{
if (a == NULL) return;
if (stbds_hash_table(a) != NULL) {
if (stbds_hash_table(a)->string.mode == STBDS_SH_STRDUP) {
size_t i;
// skip 0th element, which is default
for (i=1; i < stbds_header(a)->length; ++i)
STBDS_FREE(*(char**) ((char *) a + elemsize*i));
}
stbds_strreset(&stbds_hash_table(a)->string);
}
STBDS_FREE(stbds_header(a)->hash_table);
STBDS_FREE(stbds_header(a));
}
static ptrdiff_t stbds_hm_find_slot(void *a, size_t elemsize, void *key, size_t keysize, int mode)
{
void *raw_a = STBDS_HASH_TO_ARR(a,elemsize);
stbds_hash_index *table = stbds_hash_table(raw_a);
size_t hash = mode >= STBDS_HM_STRING ? stbds_hash_string((char*)key,table->seed) : stbds_hash_bytes(key, keysize,table->seed);
size_t step = STBDS_BUCKET_LENGTH;
size_t limit,i;
size_t pos;
stbds_hash_bucket *bucket;
if (hash < 2) hash += 2; // stored hash values are forbidden from being 0, so we can detect empty slots
pos = stbds_probe_position(hash, table->slot_count, table->slot_count_log2);
for (;;) {
STBDS_STATS(++stbds_hash_probes);
bucket = &table->storage[pos >> STBDS_BUCKET_SHIFT];
// start searching from pos to end of bucket, this should help performance on small hash tables that fit in cache
for (i=pos & STBDS_BUCKET_MASK; i < STBDS_BUCKET_LENGTH; ++i) {
if (bucket->hash[i] == hash) {
if (stbds_is_key_equal(a, elemsize, key, keysize, mode, bucket->index[i])) {
return (pos & ~STBDS_BUCKET_MASK)+i;
}
} else if (bucket->hash[i] == STBDS_HASH_EMPTY) {
return -1;
}
}
// search from beginning of bucket to pos
limit = pos & STBDS_BUCKET_MASK;
for (i = 0; i < limit; ++i) {
if (bucket->hash[i] == hash) {
if (stbds_is_key_equal(a, elemsize, key, keysize, mode, bucket->index[i])) {
return (pos & ~STBDS_BUCKET_MASK)+i;
}
} else if (bucket->hash[i] == STBDS_HASH_EMPTY) {
return -1;
}
}
// quadratic probing
pos += step;
step += STBDS_BUCKET_LENGTH;
pos &= (table->slot_count-1);
}
/* NOTREACHED */
return -1;
}
void * stbds_hmget_key(void *a, size_t elemsize, void *key, size_t keysize, int mode)
{
if (a == NULL) {
// make it non-empty so we can return a temp
a = stbds_arrgrowf(0, elemsize, 0, 1);
stbds_header(a)->length += 1;
memset(a, 0, elemsize);
stbds_temp(a) = STBDS_INDEX_EMPTY;
// adjust a to point after the default element
return STBDS_ARR_TO_HASH(a,elemsize);
} else {
stbds_hash_index *table;
void *raw_a = STBDS_HASH_TO_ARR(a,elemsize);
// adjust a to point to the default element
table = (stbds_hash_index *) stbds_header(raw_a)->hash_table;
if (table == 0) {
stbds_temp(raw_a) = -1;
} else {
ptrdiff_t slot = stbds_hm_find_slot(a, elemsize, key, keysize, mode);
if (slot < 0) {
stbds_temp(raw_a) = STBDS_INDEX_EMPTY;
} else {
stbds_hash_bucket *b = &table->storage[slot >> STBDS_BUCKET_SHIFT];
stbds_temp(raw_a) = b->index[slot & STBDS_BUCKET_MASK];
}
}
return a;
}
}
void * stbds_hmput_default(void *a, size_t elemsize)
{
// three cases:
// a is NULL <- allocate
// a has a hash table but no entries, because of shmode <- grow
// a has entries <- do nothing
if (a == NULL || stbds_header(STBDS_HASH_TO_ARR(a,elemsize))->length == 0) {
a = stbds_arrgrowf(a ? STBDS_HASH_TO_ARR(a,elemsize) : NULL, elemsize, 0, 1);
stbds_header(a)->length += 1;
memset(a, 0, elemsize);
a=STBDS_ARR_TO_HASH(a,elemsize);
}
return a;
}
static char *stbds_strdup(char *str);
void *stbds_hmput_key(void *a, size_t elemsize, void *key, size_t keysize, int mode)
{
void *raw_a;
stbds_hash_index *table;
if (a == NULL) {
a = stbds_arrgrowf(0, elemsize, 0, 1);
memset(a, 0, elemsize);
stbds_header(a)->length += 1;
// adjust a to point AFTER the default element
a = STBDS_ARR_TO_HASH(a,elemsize);
}
// adjust a to point to the default element
raw_a = a;
a = STBDS_HASH_TO_ARR(a,elemsize);
table = (stbds_hash_index *) stbds_header(a)->hash_table;
if (table == NULL || table->used_count >= table->used_count_threshold) {
stbds_hash_index *nt;
size_t slot_count;
slot_count = (table == NULL) ? STBDS_BUCKET_LENGTH : table->slot_count*2;
nt = stbds_make_hash_index(slot_count, table);
if (table) {
STBDS_FREE(table);
}
stbds_header(a)->hash_table = table = nt;
STBDS_STATS(++stbds_hash_grow);
}
// we iterate hash table explicitly because we want to track if we saw a tombstone
{
size_t hash = mode >= STBDS_HM_STRING ? stbds_hash_string((char*)key,table->seed) : stbds_hash_bytes(key, keysize,table->seed);
size_t step = STBDS_BUCKET_LENGTH;
size_t limit,i;
size_t pos;
ptrdiff_t tombstone = -1;
stbds_hash_bucket *bucket;
// stored hash values are forbidden from being 0, so we can detect empty slots to early out quickly
if (hash < 2) hash += 2;
pos = stbds_probe_position(hash, table->slot_count, table->slot_count_log2);
for (;;) {
STBDS_STATS(++stbds_hash_probes);
bucket = &table->storage[pos >> STBDS_BUCKET_SHIFT];
// start searching from pos to end of bucket
for (i=pos & STBDS_BUCKET_MASK; i < STBDS_BUCKET_LENGTH; ++i) {
if (bucket->hash[i] == hash) {
if (stbds_is_key_equal(raw_a, elemsize, key, keysize, mode, bucket->index[i])) {
stbds_temp(a) = bucket->index[i];
return STBDS_ARR_TO_HASH(a,elemsize);
}
} else if (bucket->hash[i] == 0) {
pos = (pos & ~STBDS_BUCKET_MASK) + i;
goto found_empty_slot;
} else if (tombstone < 0) {
if (bucket->index[i] == STBDS_INDEX_DELETED)
tombstone = (ptrdiff_t) ((pos & ~STBDS_BUCKET_MASK) + i);
}
}
// search from beginning of bucket to pos
limit = pos & STBDS_BUCKET_MASK;
for (i = 0; i < limit; ++i) {
if (bucket->hash[i] == hash) {
if (stbds_is_key_equal(raw_a, elemsize, key, keysize, mode, bucket->index[i])) {
stbds_temp(a) = bucket->index[i];
return STBDS_ARR_TO_HASH(a,elemsize);
}
} else if (bucket->hash[i] == 0) {
pos = (pos & ~STBDS_BUCKET_MASK) + i;
goto found_empty_slot;
} else if (tombstone < 0) {
if (bucket->index[i] == STBDS_INDEX_DELETED)
tombstone = (ptrdiff_t) ((pos & ~STBDS_BUCKET_MASK) + i);
}
}
// quadratic probing
pos += step;
step += STBDS_BUCKET_LENGTH;
pos &= (table->slot_count-1);
}
found_empty_slot:
if (tombstone >= 0) {
pos = tombstone;
--table->tombstone_count;
}
++table->used_count;
{
ptrdiff_t i = (ptrdiff_t) stbds_arrlen(a);
// we want to do stbds_arraddn(1), but we can't use the macros since we don't have something of the right type
if ((size_t) i+1 > stbds_arrcap(a))
*(void **) &a = stbds_arrgrowf(a, elemsize, 1, 0);
raw_a = STBDS_ARR_TO_HASH(a,elemsize);
STBDS_ASSERT((size_t) i+1 <= stbds_arrcap(a));
stbds_header(a)->length = i+1;
bucket = &table->storage[pos >> STBDS_BUCKET_SHIFT];
bucket->hash[pos & STBDS_BUCKET_MASK] = hash;
bucket->index[pos & STBDS_BUCKET_MASK] = i-1;
stbds_temp(a) = i-1;
switch (table->string.mode) {
case STBDS_SH_STRDUP: *(char **) ((char *) a + elemsize*i) = stbds_strdup((char*) key); break;
case STBDS_SH_ARENA: *(char **) ((char *) a + elemsize*i) = stbds_stralloc(&table->string, (char*)key); break;
default: *(char **) ((char *) a + elemsize*i) = (char *) key; break;
}
}
return STBDS_ARR_TO_HASH(a,elemsize);
}
}
void * stbds_shmode_func(size_t elemsize, int mode)
{
void *a = stbds_arrgrowf(0, elemsize, 0, 1);
stbds_hash_index *h;
stbds_header(a)->hash_table = h = (stbds_hash_index *) stbds_make_hash_index(STBDS_BUCKET_LENGTH, NULL);
h->string.mode = mode;
return STBDS_ARR_TO_HASH(a,elemsize);
}
void * stbds_hmdel_key(void *a, size_t elemsize, void *key, size_t keysize, size_t keyoffset, int mode)
{
if (a == NULL) {
return 0;
} else {
stbds_hash_index *table;
void *raw_a = STBDS_HASH_TO_ARR(a,elemsize);
table = (stbds_hash_index *) stbds_header(raw_a)->hash_table;
stbds_temp(raw_a) = 0;
if (table == 0) {
return a;
} else {
ptrdiff_t slot;
slot = stbds_hm_find_slot(a, elemsize, key, keysize, mode);
if (slot < 0)
return a;
else {
stbds_hash_bucket *b = &table->storage[slot >> STBDS_BUCKET_SHIFT];
int i = slot & STBDS_BUCKET_MASK;
ptrdiff_t old_index = b->index[i];
ptrdiff_t final_index = (ptrdiff_t) stbds_arrlen(raw_a)-1-1; // minus one for the raw_a vs a, and minus one for 'last'
STBDS_ASSERT(slot < (ptrdiff_t) table->slot_count);
--table->used_count;
++table->tombstone_count;
stbds_temp(raw_a) = 1;
STBDS_ASSERT(table->used_count >= 0);
//STBDS_ASSERT(table->tombstone_count < table->slot_count/4);
b->hash[i] = STBDS_HASH_DELETED;
b->index[i] = STBDS_INDEX_DELETED;
if (mode == STBDS_HM_STRING && table->string.mode == STBDS_SH_STRDUP)
STBDS_FREE(*(char**) ((char *) a+elemsize*old_index));
// if indices are the same, memcpy is a no-op, but back-pointer-fixup will fail, so skip
if (old_index != final_index) {
// swap delete
memmove((char*) a + elemsize*old_index, (char*) a + elemsize*final_index, elemsize);
// now find the slot for the last element
if (mode == STBDS_HM_STRING)
slot = stbds_hm_find_slot(a, elemsize, *(char**) ((char *) a+elemsize*old_index + keyoffset), keysize, mode);
else
slot = stbds_hm_find_slot(a, elemsize, (char* ) a+elemsize*old_index + keyoffset, keysize, mode);
STBDS_ASSERT(slot >= 0);
b = &table->storage[slot >> STBDS_BUCKET_SHIFT];
i = slot & STBDS_BUCKET_MASK;
STBDS_ASSERT(b->index[i] == final_index);
b->index[i] = old_index;
}
stbds_header(raw_a)->length -= 1;
if (table->used_count < table->used_count_shrink_threshold && table->slot_count > STBDS_BUCKET_LENGTH) {
stbds_header(raw_a)->hash_table = stbds_make_hash_index(table->slot_count>>1, table);
STBDS_FREE(table);
STBDS_STATS(++stbds_hash_shrink);
} else if (table->tombstone_count > table->tombstone_count_threshold) {
stbds_header(raw_a)->hash_table = stbds_make_hash_index(table->slot_count , table);
STBDS_FREE(table);
STBDS_STATS(++stbds_hash_rebuild);
}
return a;
}
}
}
/* NOTREACHED */
return 0;
}
static char *stbds_strdup(char *str)
{
// to keep replaceable allocator simple, we don't want to use strdup.
// rolling our own also avoids problem of strdup vs _strdup
size_t len = strlen(str)+1;
char *p = (char*) realloc(0, len);
memmove(p, str, len);
return p;
}
#ifndef STBDS_STRING_ARENA_BLOCKSIZE_MIN
#define STBDS_STRING_ARENA_BLOCKSIZE_MIN 512
#endif
#ifndef STBDS_STRING_ARENA_BLOCKSIZE_MAX
#define STBDS_STRING_ARENA_BLOCKSIZE_MAX 1<<20
#endif
char *stbds_stralloc(stbds_string_arena *a, char *str)
{
char *p;
size_t len = strlen(str)+1;
if (len > a->remaining) {
// compute the next blocksize
size_t blocksize = a->block;
// size is 512, 512, 1024, 1024, 2048, 2048, 4096, 4096, etc., so that
// there are log(SIZE) allocations to free when we destroy the table
blocksize = (size_t) (STBDS_STRING_ARENA_BLOCKSIZE_MIN) << (blocksize>>1);
// if size is under 1M, advance to next blocktype
if (blocksize < (size_t)(STBDS_STRING_ARENA_BLOCKSIZE_MAX))
++a->block;
if (len > blocksize) {
// if string is larger than blocksize, then just allocate the full size.
// note that we still advance string_block so block size will continue
// increasing, so e.g. if somebody only calls this with 1000-long strings,
// eventually the arena will start doubling and handling those as well
stbds_string_block *sb = (stbds_string_block *) realloc(0, sizeof(*sb)-8 + len);
memmove(sb->storage, str, len);
if (a->storage) {
// insert it after the first element, so that we don't waste the space there
sb->next = a->storage->next;
a->storage->next = sb;
} else {
sb->next = 0;
a->storage = sb;
a->remaining = 0; // this is redundant, but good for clarity
}
return sb->storage;
} else {
stbds_string_block *sb = (stbds_string_block *) realloc(0, sizeof(*sb)-8 + blocksize);
sb->next = a->storage;
a->storage = sb;
a->remaining = blocksize;
}
}
STBDS_ASSERT(len <= a->remaining);
p = a->storage->storage + a->remaining - len;
a->remaining -= len;
memmove(p, str, len);
return p;
}
void stbds_strreset(stbds_string_arena *a)
{
stbds_string_block *x,*y;
x = a->storage;
while (x) {
y = x->next;
realloc(x,0);
x = y;
}
memset(a, 0, sizeof(*a));
}
#endif
//////////////////////////////////////////////////////////////////////////////
//
// UNIT TESTS
//
#ifdef STBDS_UNIT_TESTS
#include <stdio.h>
#ifndef STBDS_ASSERT
#define STBDS_ASSERT assert
#include <assert.h>
#endif
typedef struct { int key,b,c,d; } stbds_struct;
static char buffer[256];
char *strkey(int n)
{
sprintf(buffer, "test_%d", n);
return buffer;
}
void stbds_unit_tests(void)
{
#if defined(_MSC_VER) && _MSC_VER <= 1200 && defined(__cplusplus)
// VC6 C++ doesn't like the template<> trick on unnamed structures, so do nothing!
STBDS_ASSERT(0);
#else
const int testsize = 100000;
int *arr=NULL;
struct { int key; int value; } *intmap = NULL;
struct { char *key; int value; } *strmap = NULL;
struct { stbds_struct key; int value; } *map = NULL;
stbds_struct *map2 = NULL;
stbds_string_arena sa = { 0 };
int i,j;
for (i=0; i < 20000; i += 50) {
for (j=0; j < i; ++j)
arrpush(arr,j);
arrfree(arr);
}
for (i=0; i < 4; ++i) {
arrpush(arr,1); arrpush(arr,2); arrpush(arr,3); arrpush(arr,4);
arrdel(arr,i);
arrfree(arr);
arrpush(arr,1); arrpush(arr,2); arrpush(arr,3); arrpush(arr,4);
arrdelswap(arr,i);
arrfree(arr);
}
for (i=0; i < 5; ++i) {
arrpush(arr,1); arrpush(arr,2); arrpush(arr,3); arrpush(arr,4);
stbds_arrins(arr,i,5);
STBDS_ASSERT(arr[i] == 5);
if (i < 4)
STBDS_ASSERT(arr[4] == 4);
arrfree(arr);
}
hmdefault(intmap, -1);
i=1; STBDS_ASSERT(hmget(intmap, i) == -1);
for (i=0; i < testsize; i+=2)
hmput(intmap, i, i*5);
for (i=0; i < testsize; i+=1)
if (i & 1) STBDS_ASSERT(hmget(intmap, i) == -1 );
else STBDS_ASSERT(hmget(intmap, i) == i*5);
for (i=0; i < testsize; i+=2)
hmput(intmap, i, i*3);
for (i=0; i < testsize; i+=1)
if (i & 1) STBDS_ASSERT(hmget(intmap, i) == -1 );
else STBDS_ASSERT(hmget(intmap, i) == i*3);
for (i=2; i < testsize; i+=4)
hmdel(intmap, i); // delete half the entries
for (i=0; i < testsize; i+=1)
if (i & 3) STBDS_ASSERT(hmget(intmap, i) == -1 );
else STBDS_ASSERT(hmget(intmap, i) == i*3);
for (i=0; i < testsize; i+=1)
hmdel(intmap, i); // delete the rest of the entries
for (i=0; i < testsize; i+=1)
STBDS_ASSERT(hmget(intmap, i) == -1 );
hmfree(intmap);
for (i=0; i < testsize; i+=2)
hmput(intmap, i, i*3);
hmfree(intmap);
#if defined(__clang__) || defined(__GNUC__)
#ifndef __cplusplus
intmap = NULL;
hmput(intmap, 15, 7);
hmput(intmap, 11, 3);
hmput(intmap, 9, 5);
STBDS_ASSERT(hmget(intmap, 9) == 5);
STBDS_ASSERT(hmget(intmap, 11) == 3);
STBDS_ASSERT(hmget(intmap, 15) == 7);
#endif
#endif
for (i=0; i < testsize; ++i)
stralloc(&sa, strkey(i));
strreset(&sa);
for (j=0; j < 2; ++j) {
if (j == 0)
sh_new_strdup(strmap);
else
sh_new_arena(strmap);
shdefault(strmap, -1);
for (i=0; i < testsize; i+=2)
shput(strmap, strkey(i), i*3);
for (i=0; i < testsize; i+=1)
if (i & 1) STBDS_ASSERT(shget(strmap, strkey(i)) == -1 );
else STBDS_ASSERT(shget(strmap, strkey(i)) == i*3);
for (i=2; i < testsize; i+=4)
shdel(strmap, strkey(i)); // delete half the entries
for (i=0; i < testsize; i+=1)
if (i & 3) STBDS_ASSERT(shget(strmap, strkey(i)) == -1 );
else STBDS_ASSERT(shget(strmap, strkey(i)) == i*3);
for (i=0; i < testsize; i+=1)
shdel(strmap, strkey(i)); // delete the rest of the entries
for (i=0; i < testsize; i+=1)
STBDS_ASSERT(shget(strmap, strkey(i)) == -1 );
shfree(strmap);
}
{
struct { char *key; char value; } *hash = NULL;
char name[4] = "jen";
shput(hash, "bob" , 'h');
shput(hash, "sally" , 'e');
shput(hash, "fred" , 'l');
shput(hash, "jen" , 'x');
shput(hash, "doug" , 'o');
shput(hash, name , 'l');
shfree(hash);
}
for (i=0; i < testsize; i += 2) {
stbds_struct s = { i,i*2,i*3,i*4 };
hmput(map, s, i*5);
}
for (i=0; i < testsize; i += 1) {
stbds_struct s = { i,i*2,i*3 ,i*4 };
stbds_struct t = { i,i*2,i*3+1,i*4 };
if (i & 1) STBDS_ASSERT(hmget(map, s) == 0);
else STBDS_ASSERT(hmget(map, s) == i*5);
STBDS_ASSERT(hmget(map, t) == 0);
}
for (i=0; i < testsize; i += 2) {
stbds_struct s = { i,i*2,i*3,i*4 };
hmputs(map2, s);
}
hmfree(map);
for (i=0; i < testsize; i += 1) {
stbds_struct s = { i,i*2,i*3,i*4 };
stbds_struct t = { i,i*2,i*3,i*4 };
if (i & 1) STBDS_ASSERT(hmgets(map2, s.key).d == 0);
else STBDS_ASSERT(hmgets(map2, s.key).d == i*4);
}
hmfree(map2);
#endif
}
#endif
/*
------------------------------------------------------------------------------
This software is available under 2 licenses -- choose whichever you prefer.
------------------------------------------------------------------------------
ALTERNATIVE A - MIT License
Copyright (c) 2019 Sean Barrett
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.
------------------------------------------------------------------------------
ALTERNATIVE B - Public Domain (www.unlicense.org)
This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
software, either in source code form or as a compiled binary, for any purpose,
commercial or non-commercial, and by any means.
In jurisdictions that recognize copyright laws, the author or authors of this
software dedicate any and all copyright interest in the software to the public
domain. We make this dedication for the benefit of the public at large and to
the detriment of our heirs and successors. We intend this dedication to be an
overt act of relinquishment in perpetuity of all present and future rights to
this software under copyright law.
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 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.
------------------------------------------------------------------------------
*/
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