diff options
Diffstat (limited to 'plugins/MirOTR/ekhtml/include/hash.h')
| -rw-r--r-- | plugins/MirOTR/ekhtml/include/hash.h | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/plugins/MirOTR/ekhtml/include/hash.h b/plugins/MirOTR/ekhtml/include/hash.h index ddb3869477..5b6333e264 100644 --- a/plugins/MirOTR/ekhtml/include/hash.h +++ b/plugins/MirOTR/ekhtml/include/hash.h @@ -14,8 +14,6 @@ * into proprietary software; there is no requirement for such software to * contain a copyright notice related to this source. * - * $Id: hash.h,v 1.1 2002/09/17 02:49:36 jick Exp $ - * $Name: EKHTML_RELEASE_0_3_2 $ */ #ifndef HASH_H @@ -40,8 +38,6 @@ typedef unsigned long hashcount_t; typedef unsigned long hash_val_t; #define HASH_VAL_T_MAX ULONG_MAX -extern int hash_val_t_bit; - #ifndef HASH_VAL_T_BIT #define HASH_VAL_T_BIT ((int) hash_val_t_bit) #endif @@ -233,6 +229,33 @@ extern void hnode_destroy(hnode_t *); #define hnode_put(N, V) ((N)->hash_data = (V)) #endif +/* + * Compute the number of bits in the hash_val_t type. We know that hash_val_t + * is an unsigned integral type. Thus the highest value it can hold is a + * Mersenne number (power of two, less one). We initialize a hash_val_t + * object with this value and then shift bits out one by one while counting. + * Notes: + * 1. HASH_VAL_T_MAX is a Mersenne number---one that is one less than a power + * of two. This means that its binary representation consists of all one + * bits, and hence ``val'' is initialized to all one bits. + * 2. While bits remain in val, we increment the bit count and shift it to the + * right, replacing the topmost bit by zero. + */ + +static int compute_bits(void) +{ + hash_val_t val = HASH_VAL_T_MAX; /* 1 */ + int bits = 0; + + while (val) { /* 2 */ + bits++; + val >>= 1; + } + + return bits; +} + + #ifdef __cplusplus } #endif |