khash.h

Includes: "khash.h", <stdint.h>, <stdlib.h>, <string.h>

Discussion

Generic hash table library.

Functions

__ac_X31_hash_string: const char* hash function

__ac_X31_hash_string

const char* hash function

static inline khint_t __ac_X31_hash_string(
    const char *s)

Parameters

s: Pointer to a null terminated string

Return Value

The hash value

#defines

kh_int_hash_func

Integer hash function

#define kh_int_hash_func(key)

Parameters

key: The integer [uint32_t]

Return Value

The hash value [khint_t]

kh_int_hash_equal

Integer comparison function

#define kh_int_hash_equal(a, b)

kh_int64_hash_func

64-bit integer hash function

#define kh_int64_hash_func(key)

Parameters

key: The integer [uint64_t]

Return Value

The hash value [khint_t]

kh_int64_hash_equal

64-bit integer comparison function

#define kh_int64_hash_equal(a, b)

kh_str_hash_func

Another interface to const char* hash function

#define kh_str_hash_func(key) __ac_X31_hash_string(key)

Parameters

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

Return Value

The hash value [khint_t]

kh_str_hash_equal

Const char* comparison function

#define kh_str_hash_equal(a, b)

khash_t

Type of the hash table.

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

Parameters

name: Name of the hash table [symbol]

kh_init

Initiate a hash table.

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

Parameters

name: Name of the hash table [symbol]

Return Value

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

kh_destroy

Destroy a hash table.

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

Parameters

name: Name of the hash table [symbol]
h: Pointer to the hash table [khash_t(name)*]

kh_clear

Reset a hash table without deallocating memory.

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

Parameters

name: Name of the hash table [symbol]
h: Pointer to the hash table [khash_t(name)*]

kh_resize

Resize a hash table.

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

Parameters

name: Name of the hash table [symbol]
h: Pointer to the hash table [khash_t(name)*]
s: New size [khint_t]

kh_put

Insert a key to the hash table.

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

Parameters

name: Name of the hash table [symbol]
h: Pointer to the hash table [khash_t(name)*]
k: Key [type of keys]
r: Extra return code: 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 Value

Iterator to the inserted element [khint_t]

kh_get

Retrieve a key from the hash table.

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

Parameters

name: Name of the hash table [symbol]
h: Pointer to the hash table [khash_t(name)*]
k: Key [type of keys]

Return Value

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

kh_del

Remove a key from the hash table.

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

Parameters

name: Name of the hash table [symbol]
h: Pointer to the hash table [khash_t(name)*]
k: Iterator to the element to be deleted [khint_t]

kh_exist

Test whether a bucket contains data.

#define kh_exist(h, x)

Parameters

h: Pointer to the hash table [khash_t(name)*]
x: Iterator to the bucket [khint_t]

Return Value

1 if containing data; 0 otherwise [int]

kh_key

Get key given an iterator

#define kh_key(h, x)

Parameters

h: Pointer to the hash table [khash_t(name)*]
x: Iterator to the bucket [khint_t]

Return Value

Key [type of keys]

kh_val

Get value given an iterator

#define kh_val(h, x)

Parameters

h: Pointer to the hash table [khash_t(name)*]
x: Iterator to the bucket [khint_t]

Return Value

Value [type of values]

Discussion

For hash sets, calling this results in segfault.

kh_value

Alias of kh_val()

#define kh_value(h, x)

kh_begin

Get the start iterator

#define kh_begin(h)

Parameters

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

Return Value

The start iterator [khint_t]

kh_end

Get the end iterator

#define kh_end(h)

Parameters

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

Return Value

The end iterator [khint_t]

kh_size

Get the number of elements in the hash table

#define kh_size(h)

Parameters

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

Return Value

Number of elements in the hash table [khint_t]

kh_n_buckets

Get the number of buckets in the hash table

#define kh_n_buckets(h)

Parameters

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

Return Value

Number of buckets in the hash table [khint_t]

KHASH_SET_INIT_INT

Instantiate a hash set containing integer keys

#define KHASH_SET_INIT_INT(name) \ 
    KHASH_INIT(name, uint32_t, char, 0, kh_int_hash_func, kh_int_hash_equal)

Parameters

name: Name of the hash table [symbol]

KHASH_MAP_INIT_INT

Instantiate a hash map containing integer keys

#define KHASH_MAP_INIT_INT(name, khval_t) \ 
    KHASH_INIT(name, uint32_t, khval_t, 1, kh_int_hash_func, kh_int_hash_equal)

Parameters

name: Name of the hash table [symbol]
khval_t: Type of values [type]

KHASH_SET_INIT_INT64

Instantiate a hash map containing 64-bit integer keys

#define KHASH_SET_INIT_INT64(name) \ 
    KHASH_INIT(name, uint64_t, char, 0, kh_int64_hash_func, kh_int64_hash_equal)

Parameters

name: Name of the hash table [symbol]

KHASH_MAP_INIT_INT64

Instantiate a hash map containing 64-bit integer keys

#define KHASH_MAP_INIT_INT64(name, khval_t) \ 
    KHASH_INIT(name, uint64_t, khval_t, 1, kh_int64_hash_func, kh_int64_hash_equal)

Parameters

name: Name of the hash table [symbol]
khval_t: Type of values [type]

KHASH_SET_INIT_STR

Instantiate a hash map containing const char* keys

#define KHASH_SET_INIT_STR(name) \ 
    KHASH_INIT(name, kh_cstr_t, char, 0, kh_str_hash_func, kh_str_hash_equal)

Parameters

name: Name of the hash table [symbol]

KHASH_MAP_INIT_STR

Instantiate a hash map containing const char* keys

#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)

Parameters

name: Name of the hash table [symbol]
khval_t: Type of values [type]