#include "duk_internal.h"

Macros
#define	DUK__HASH_SIZE_RATIO 1177 /* floor(1.15 * (1 << 10)) */

Functions
DUK_INTERNAL duk_uint32_t	duk_util_get_hash_prime (duk_uint32_t size)

Variables
DUK_LOCAL const duk_int8_t	duk__hash_size_corrections []

DUK_INTERNAL duk_uint8_t	duk_util_probe_steps [32]

Macro Definition Documentation

◆ DUK__HASH_SIZE_RATIO

#define DUK__HASH_SIZE_RATIO 1177 /* floor(1.15 * (1 << 10)) */

Definition at line 22 of file duktape-1.8.0/src-separate/duk_util_hashprime.c.

Referenced by duk_util_get_hash_prime().

Function Documentation

◆ duk_util_get_hash_prime()

DUK_INTERNAL duk_uint32_t duk_util_get_hash_prime ( duk_uint32_t size )

Definition at line 45 of file duktape-1.8.0/src-separate/duk_util_hashprime.c.

                                                                     {
    const duk_int8_t *p = duk__hash_size_corrections;
    duk_uint32_t curr;
 
    curr = (duk_uint32_t) *p++;
    for (;;) {
        duk_small_int_t t = (duk_small_int_t) *p++;
        if (t < 0) {
            /* may happen if size is very close to 2^32-1 */
            break;
        }
 
        /* prediction: portable variant using doubles if 64-bit values not available */
#ifdef DUK_USE_64BIT_OPS
        curr = (duk_uint32_t) ((((duk_uint64_t) curr) * ((duk_uint64_t) DUK__HASH_SIZE_RATIO)) >> 10);
#else
        /* 32-bit x 11-bit = 43-bit, fits accurately into a double */
        curr = (duk_uint32_t) DUK_FLOOR(((double) curr) * ((double) DUK__HASH_SIZE_RATIO) / 1024.0);
#endif
 
        /* correction */
        curr += t;
 
        DUK_DDD(DUK_DDDPRINT("size=%ld, curr=%ld", (long) size, (long) curr));
 
        if (curr >= size) {
            return curr;
        }
    }
    return 0;
}

References duk__hash_size_corrections, DUK__HASH_SIZE_RATIO, DUK_DDD, DUK_DDDPRINT, and DUK_FLOOR.

Variable Documentation

◆ duk__hash_size_corrections

DUK_LOCAL const duk_int8_t duk__hash_size_corrections[]

Initial value:

= {
    17,  
    4, 3, 4, 1, 4, 1, 1, 2, 2, 2, 2, 1, 6, 6, 9, 5, 1, 2, 2, 5, 1, 3, 3, 3,
    5, 4, 4, 2, 4, 8, 3, 4, 23, 2, 4, 7, 8, 11, 2, 12, 15, 10, 1, 1, 5, 1, 5,
    8, 9, 17, 14, 10, 7, 5, 2, 46, 21, 1, 9, 9, 4, 4, 10, 23, 36, 6, 20, 29,
    18, 6, 19, 21, 16, 11, 5, 5, 48, 9, 1, 39, 14, 8, 4, 29, 9, 1, 15, 48, 12,
    22, 6, 15, 27, 4, 2, 17, 28, 8, 9, 4, 5, 8, 3, 3, 8, 37, 11, 15, 8, 30,
    43, 6, 33, 41, 5, 20, 32, 41, 38, 24, 77, 14, 19, 11, 4, 35, 18, 19, 41,
    10, 23, 16, 9, 2,
    -1
}

Definition at line 25 of file duktape-1.8.0/src-separate/duk_util_hashprime.c.

                                                          {
    17,  /* minimum prime */
    4, 3, 4, 1, 4, 1, 1, 2, 2, 2, 2, 1, 6, 6, 9, 5, 1, 2, 2, 5, 1, 3, 3, 3,
    5, 4, 4, 2, 4, 8, 3, 4, 23, 2, 4, 7, 8, 11, 2, 12, 15, 10, 1, 1, 5, 1, 5,
    8, 9, 17, 14, 10, 7, 5, 2, 46, 21, 1, 9, 9, 4, 4, 10, 23, 36, 6, 20, 29,
    18, 6, 19, 21, 16, 11, 5, 5, 48, 9, 1, 39, 14, 8, 4, 29, 9, 1, 15, 48, 12,
    22, 6, 15, 27, 4, 2, 17, 28, 8, 9, 4, 5, 8, 3, 3, 8, 37, 11, 15, 8, 30,
    43, 6, 33, 41, 5, 20, 32, 41, 38, 24, 77, 14, 19, 11, 4, 35, 18, 19, 41,
    10, 23, 16, 9, 2,
    -1
};

Referenced by duk_util_get_hash_prime().

◆ duk_util_probe_steps

DUK_INTERNAL duk_uint8_t duk_util_probe_steps[32]

Initial value:

= {
    2, 3, 5, 7, 11, 13, 19, 31, 41, 47, 59, 67, 73, 79, 89, 101, 103, 107,
    109, 127, 137, 139, 149, 157, 163, 167, 173, 181, 191, 193, 197, 199
}

Definition at line 40 of file duktape-1.8.0/src-separate/duk_util_hashprime.c.

                                                    {
    2, 3, 5, 7, 11, 13, 19, 31, 41, 47, 59, 67, 73, 79, 89, 101, 103, 107,
    109, 127, 137, 139, 149, 157, 163, 167, 173, 181, 191, 193, 197, 199
};

Macros

Functions