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FS-9803 #resolve [Add support for arbitrary data as hash keys]

This commit is contained in:
Anthony Minessale 2016-12-01 18:11:01 -06:00
parent 44d69cb2b9
commit a0180288cf
5 changed files with 450 additions and 12 deletions
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350
libs/libks/src/include/ks_hash.h
View File

@ -106,7 +106,8 @@ typedef enum {
KS_HASH_MODE_CASE_INSENSITIVE, KS_HASH_MODE_CASE_INSENSITIVE,
KS_HASH_MODE_INT, KS_HASH_MODE_INT,
KS_HASH_MODE_INT64, KS_HASH_MODE_INT64,
KS_HASH_MODE_PTR KS_HASH_MODE_PTR,
KS_HASH_MODE_ARBITRARY
} ks_hash_mode_t; } ks_hash_mode_t;
@ -157,6 +158,7 @@ KS_DECLARE(int) ks_hash_insert_ex(ks_hash_t *h, void *k, void *v, ks_hash_flag_t
KS_DECLARE(void) ks_hash_set_flags(ks_hash_t *h, ks_hash_flag_t flags); KS_DECLARE(void) ks_hash_set_flags(ks_hash_t *h, ks_hash_flag_t flags);
KS_DECLARE(void) ks_hash_set_keysize(ks_hash_t *h, ks_size_t keysize);
KS_DECLARE(void) ks_hash_set_destructor(ks_hash_t *h, ks_hash_destructor_t destructor); KS_DECLARE(void) ks_hash_set_destructor(ks_hash_t *h, ks_hash_destructor_t destructor);
/***************************************************************************** /*****************************************************************************
@ -318,6 +320,352 @@ static __inline uint32_t ks_hash_default_ci(void *ky)
return hash; return hash;
} }
#define hashsize(n) ((uint32_t)1<<(n))
#define hashmask(n) (hashsize(n)-1)
#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
/*
-------------------------------------------------------------------------------
mix -- mix 3 32-bit values reversibly.
This is reversible, so any information in (a,b,c) before mix() is
still in (a,b,c) after mix().
If four pairs of (a,b,c) inputs are run through mix(), or through
mix() in reverse, there are at least 32 bits of the output that
are sometimes the same for one pair and different for another pair.
This was tested for:
* pairs that differed by one bit, by two bits, in any combination
of top bits of (a,b,c), or in any combination of bottom bits of
(a,b,c).
* "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
is commonly produced by subtraction) look like a single 1-bit
difference.
* the base values were pseudorandom, all zero but one bit set, or
all zero plus a counter that starts at zero.
Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that
satisfy this are
4 6 8 16 19 4
9 15 3 18 27 15
14 9 3 7 17 3
Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing
for "differ" defined as + with a one-bit base and a two-bit delta. I
used http://burtleburtle.net/bob/hash/avalanche.html to choose
the operations, constants, and arrangements of the variables.
This does not achieve avalanche. There are input bits of (a,b,c)
that fail to affect some output bits of (a,b,c), especially of a. The
most thoroughly mixed value is c, but it doesn't really even achieve
avalanche in c.
This allows some parallelism. Read-after-writes are good at doubling
the number of bits affected, so the goal of mixing pulls in the opposite
direction as the goal of parallelism. I did what I could. Rotates
seem to cost as much as shifts on every machine I could lay my hands
on, and rotates are much kinder to the top and bottom bits, so I used
rotates.
-------------------------------------------------------------------------------
*/
#define mix(a,b,c) \
{ \
a -= c; a ^= rot(c, 4); c += b; \
b -= a; b ^= rot(a, 6); a += c; \
c -= b; c ^= rot(b, 8); b += a; \
a -= c; a ^= rot(c,16); c += b; \
b -= a; b ^= rot(a,19); a += c; \
c -= b; c ^= rot(b, 4); b += a; \
}
/*
-------------------------------------------------------------------------------
mix -- mix 3 32-bit values reversibly.
This is reversible, so any information in (a,b,c) before mix() is
still in (a,b,c) after mix().
If four pairs of (a,b,c) inputs are run through mix(), or through
mix() in reverse, there are at least 32 bits of the output that
are sometimes the same for one pair and different for another pair.
This was tested for:
* pairs that differed by one bit, by two bits, in any combination
of top bits of (a,b,c), or in any combination of bottom bits of
(a,b,c).
* "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
is commonly produced by subtraction) look like a single 1-bit
difference.
* the base values were pseudorandom, all zero but one bit set, or
all zero plus a counter that starts at zero.
Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that
satisfy this are
4 6 8 16 19 4
9 15 3 18 27 15
14 9 3 7 17 3
Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing
for "differ" defined as + with a one-bit base and a two-bit delta. I
used http://burtleburtle.net/bob/hash/avalanche.html to choose
the operations, constants, and arrangements of the variables.
This does not achieve avalanche. There are input bits of (a,b,c)
that fail to affect some output bits of (a,b,c), especially of a. The
most thoroughly mixed value is c, but it doesn't really even achieve
avalanche in c.
This allows some parallelism. Read-after-writes are good at doubling
the number of bits affected, so the goal of mixing pulls in the opposite
direction as the goal of parallelism. I did what I could. Rotates
seem to cost as much as shifts on every machine I could lay my hands
on, and rotates are much kinder to the top and bottom bits, so I used
rotates.
-------------------------------------------------------------------------------
*/
#define mix(a,b,c) \
{ \
a -= c; a ^= rot(c, 4); c += b; \
b -= a; b ^= rot(a, 6); a += c; \
c -= b; c ^= rot(b, 8); b += a; \
a -= c; a ^= rot(c,16); c += b; \
b -= a; b ^= rot(a,19); a += c; \
c -= b; c ^= rot(b, 4); b += a; \
}
/*
-------------------------------------------------------------------------------
final -- final mixing of 3 32-bit values (a,b,c) into c
Pairs of (a,b,c) values differing in only a few bits will usually
produce values of c that look totally different. This was tested for
* pairs that differed by one bit, by two bits, in any combination
of top bits of (a,b,c), or in any combination of bottom bits of
(a,b,c).
* "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
is commonly produced by subtraction) look like a single 1-bit
difference.
* the base values were pseudorandom, all zero but one bit set, or
all zero plus a counter that starts at zero.
These constants passed:
14 11 25 16 4 14 24
12 14 25 16 4 14 24
and these came close:
4 8 15 26 3 22 24
10 8 15 26 3 22 24
11 8 15 26 3 22 24
-------------------------------------------------------------------------------
*/
#define final(a,b,c) \
{ \
c ^= b; c -= rot(b,14); \
a ^= c; a -= rot(c,11); \
b ^= a; b -= rot(a,25); \
c ^= b; c -= rot(b,16); \
a ^= c; a -= rot(c,4); \
b ^= a; b -= rot(a,14); \
c ^= b; c -= rot(b,24); \
}
/*
-------------------------------------------------------------------------------
hashlittle() -- hash a variable-length key into a 32-bit value
k : the key (the unaligned variable-length array of bytes)
length : the length of the key, counting by bytes
initval : can be any 4-byte value
Returns a 32-bit value. Every bit of the key affects every bit of
the return value. Two keys differing by one or two bits will have
totally different hash values.
The best hash table sizes are powers of 2. There is no need to do
mod a prime (mod is sooo slow!). If you need less than 32 bits,
use a bitmask. For example, if you need only 10 bits, do
h = (h & hashmask(10));
In which case, the hash table should have hashsize(10) elements.
If you are hashing n strings (uint8_t **)k, do it like this:
for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h);
By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this
code any way you wish, private, educational, or commercial. It's free.
Use for hash table lookup, or anything where one collision in 2^^32 is
acceptable. Do NOT use for cryptographic purposes.
-------------------------------------------------------------------------------
*/
static __inline uint32_t ks_hash_default_arbitrary( const void *key, ks_size_t length, uint32_t initval)
{
uint32_t a,b,c; /* internal state */
union { const void *ptr; ks_size_t i; } u; /* needed for Mac Powerbook G4 */
/* Set up the internal state */
a = b = c = 0xdeadbeef + ((uint32_t)length) + initval;
u.ptr = key;
if (KS_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) {
const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */
/*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
while (length > 12)
{
a += k[0];
b += k[1];
c += k[2];
mix(a,b,c);
length -= 12;
k += 3;
}
/*----------------------------- handle the last (probably partial) block */
/*
* "k[2]&0xffffff" actually reads beyond the end of the string, but
* then masks off the part it's not allowed to read. Because the
* string is aligned, the masked-off tail is in the same word as the
* rest of the string. Every machine with memory protection I've seen
* does it on word boundaries, so is OK with this. But VALGRIND will
* still catch it and complain. The masking trick does make the hash
* noticably faster for short strings (like English words).
*/
#ifndef VALGRIND
switch(length)
{
case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break;
case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break;
case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break;
case 8 : b+=k[1]; a+=k[0]; break;
case 7 : b+=k[1]&0xffffff; a+=k[0]; break;
case 6 : b+=k[1]&0xffff; a+=k[0]; break;
case 5 : b+=k[1]&0xff; a+=k[0]; break;
case 4 : a+=k[0]; break;
case 3 : a+=k[0]&0xffffff; break;
case 2 : a+=k[0]&0xffff; break;
case 1 : a+=k[0]&0xff; break;
case 0 : return c; /* zero length strings require no mixing */
}
#else /* make valgrind happy */
k8 = (const uint8_t *)k;
switch(length)
{
case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
case 11: c+=((uint32_t)k8[10])<<16; /* fall through */
case 10: c+=((uint32_t)k8[9])<<8; /* fall through */
case 9 : c+=k8[8]; /* fall through */
case 8 : b+=k[1]; a+=k[0]; break;
case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */
case 6 : b+=((uint32_t)k8[5])<<8; /* fall through */
case 5 : b+=k8[4]; /* fall through */
case 4 : a+=k[0]; break;
case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */
case 2 : a+=((uint32_t)k8[1])<<8; /* fall through */
case 1 : a+=k8[0]; break;
case 0 : return c;
}
#endif /* !valgrind */
} else if (KS_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) {
const uint16_t *k = (const uint16_t *)key; /* read 16-bit chunks */
const uint8_t *k8;
/*--------------- all but last block: aligned reads and different mixing */
while (length > 12)
{
a += k[0] + (((uint32_t)k[1])<<16);
b += k[2] + (((uint32_t)k[3])<<16);
c += k[4] + (((uint32_t)k[5])<<16);
mix(a,b,c);
length -= 12;
k += 6;
}
/*----------------------------- handle the last (probably partial) block */
k8 = (const uint8_t *)k;
switch(length)
{
case 12: c+=k[4]+(((uint32_t)k[5])<<16);
b+=k[2]+(((uint32_t)k[3])<<16);
a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 11: c+=((uint32_t)k8[10])<<16; /* fall through */
case 10: c+=k[4];
b+=k[2]+(((uint32_t)k[3])<<16);
a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 9 : c+=k8[8]; /* fall through */
case 8 : b+=k[2]+(((uint32_t)k[3])<<16);
a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */
case 6 : b+=k[2];
a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 5 : b+=k8[4]; /* fall through */
case 4 : a+=k[0]+(((uint32_t)k[1])<<16);
break;
case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */
case 2 : a+=k[0];
break;
case 1 : a+=k8[0];
break;
case 0 : return c; /* zero length requires no mixing */
}
} else { /* need to read the key one byte at a time */
const uint8_t *k = (const uint8_t *)key;
/*--------------- all but the last block: affect some 32 bits of (a,b,c) */
while (length > 12)
{
a += k[0];
a += ((uint32_t)k[1])<<8;
a += ((uint32_t)k[2])<<16;
a += ((uint32_t)k[3])<<24;
b += k[4];
b += ((uint32_t)k[5])<<8;
b += ((uint32_t)k[6])<<16;
b += ((uint32_t)k[7])<<24;
c += k[8];
c += ((uint32_t)k[9])<<8;
c += ((uint32_t)k[10])<<16;
c += ((uint32_t)k[11])<<24;
mix(a,b,c);
length -= 12;
k += 12;
}
/*-------------------------------- last block: affect all 32 bits of (c) */
switch(length) /* all the case statements fall through */
{
case 12: c+=((uint32_t)k[11])<<24;
case 11: c+=((uint32_t)k[10])<<16;
case 10: c+=((uint32_t)k[9])<<8;
case 9 : c+=k[8];
case 8 : b+=((uint32_t)k[7])<<24;
case 7 : b+=((uint32_t)k[6])<<16;
case 6 : b+=((uint32_t)k[5])<<8;
case 5 : b+=k[4];
case 4 : a+=((uint32_t)k[3])<<24;
case 3 : a+=((uint32_t)k[2])<<16;
case 2 : a+=((uint32_t)k[1])<<8;
case 1 : a+=k[0];
break;
case 0 : return c;
}
}
final(a,b,c);
return c;
}

16
libs/libks/src/include/ks_platform.h
View File

@ -56,6 +56,22 @@ KS_BEGIN_EXTERN_C
#define KS_64BIT 1 #define KS_64BIT 1
#endif #endif
#if (defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && \
__BYTE_ORDER == __LITTLE_ENDIAN) || \
(defined(i386) || defined(__i386__) || defined(__i486__) || \
defined(__i586__) || defined(__i686__) || defined(vax) || defined(MIPSEL))
# define KS_LITTLE_ENDIAN 1
# define KS_BIG_ENDIAN 0
#elif (defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && \
__BYTE_ORDER == __BIG_ENDIAN) || \
(defined(sparc) || defined(POWERPC) || defined(mc68000) || defined(sel))
# define KS_LITTLE_ENDIAN 0
# define KS_BIG_ENDIAN 1
#else
# define KS_LITTLE_ENDIAN 0
# define KS_BIG_ENDIAN 0
#endif
#include <stdarg.h> #include <stdarg.h>
#include <time.h> #include <time.h>
#include <stdarg.h> #include <stdarg.h>

2
libs/libks/src/include/ks_types.h
View File

@ -75,7 +75,7 @@ KS_BEGIN_EXTERN_C
typedef uint16_t ks_port_t; typedef uint16_t ks_port_t;
typedef size_t ks_size_t; typedef size_t ks_size_t;
typedef unsigned char ks_byte_t;
typedef enum { typedef enum {
KS_STATUS_SUCCESS, KS_STATUS_SUCCESS,
KS_STATUS_FAIL, KS_STATUS_FAIL,

52
libs/libks/src/ks_hash.c
View File

@ -64,6 +64,8 @@ struct ks_hash {
ks_rwl_t *rwl; ks_rwl_t *rwl;
ks_mutex_t *mutex; ks_mutex_t *mutex;
uint32_t readers; uint32_t readers;
ks_size_t keysize;
ks_hash_mode_t mode;
}; };
/*****************************************************************************/ /*****************************************************************************/
@ -72,13 +74,22 @@ struct ks_hash {
static inline unsigned int static inline unsigned int
hash(ks_hash_t *h, void *k) hash(ks_hash_t *h, void *k)
{ {
/* Aim to protect against poor hash functions by adding logic here unsigned int i;
* - logic taken from java 1.4 ks_hash source */
unsigned int i = h->hashfn(k); if (h->mode == KS_HASH_MODE_ARBITRARY) {
i += ~(i << 9); i = ks_hash_default_arbitrary(k, h->keysize, 13);
i ^= ((i >> 14) | (i << 18)); /* >>> */ } else {
i += (i << 4); i = h->hashfn(k);
i ^= ((i >> 10) | (i << 22)); /* >>> */ }
/* Aim to protect against poor hash functions by adding logic here
* - logic taken from java 1.4 hash source */
i += ~(i << 9);
i ^= ((i >> 14) | (i << 18)); /* >>> */
i += (i << 4);
i ^= ((i >> 10) | (i << 22)); /* >>> */
return i; return i;
} }
@ -146,6 +157,11 @@ KS_DECLARE(void) ks_hash_set_flags(ks_hash_t *h, ks_hash_flag_t flags)
h->flags = flags; h->flags = flags;
} }
KS_DECLARE(void) ks_hash_set_keysize(ks_hash_t *h, ks_size_t keysize)
{
h->keysize = keysize;
}
KS_DECLARE(void) ks_hash_set_destructor(ks_hash_t *h, ks_hash_destructor_t destructor) KS_DECLARE(void) ks_hash_set_destructor(ks_hash_t *h, ks_hash_destructor_t destructor)
{ {
h->destructor = destructor; h->destructor = destructor;
@ -159,6 +175,7 @@ ks_hash_create_ex(ks_hash_t **hp, unsigned int minsize,
{ {
ks_hash_t *h; ks_hash_t *h;
unsigned int pindex, size = primes[0]; unsigned int pindex, size = primes[0];
ks_size_t keysize = 0;
switch(mode) { switch(mode) {
case KS_HASH_MODE_CASE_INSENSITIVE: case KS_HASH_MODE_CASE_INSENSITIVE:
@ -170,18 +187,24 @@ ks_hash_create_ex(ks_hash_t **hp, unsigned int minsize,
ks_assert(eqf == NULL); ks_assert(eqf == NULL);
hashf = ks_hash_default_int; hashf = ks_hash_default_int;
eqf = ks_hash_equalkeys_int; eqf = ks_hash_equalkeys_int;
keysize = 4;
break; break;
case KS_HASH_MODE_INT64: case KS_HASH_MODE_INT64:
ks_assert(hashf == NULL); ks_assert(hashf == NULL);
ks_assert(eqf == NULL); ks_assert(eqf == NULL);
hashf = ks_hash_default_int64; hashf = ks_hash_default_int64;
eqf = ks_hash_equalkeys_int64; eqf = ks_hash_equalkeys_int64;
keysize = 8;
break; break;
case KS_HASH_MODE_PTR: case KS_HASH_MODE_PTR:
ks_assert(hashf == NULL); ks_assert(hashf == NULL);
ks_assert(eqf == NULL); ks_assert(eqf == NULL);
hashf = ks_hash_default_ptr; hashf = ks_hash_default_ptr;
eqf = ks_hash_equalkeys_ptr; eqf = ks_hash_equalkeys_ptr;
keysize = sizeof(void *);
break;
case KS_HASH_MODE_ARBITRARY:
keysize = sizeof(void *);
break; break;
default: default:
break; break;
@ -210,6 +233,8 @@ ks_hash_create_ex(ks_hash_t **hp, unsigned int minsize,
h->pool = pool; h->pool = pool;
h->flags = flags; h->flags = flags;
h->destructor = destructor; h->destructor = destructor;
h->keysize = keysize;
h->mode = mode;
if ((flags & KS_HASH_FLAG_RWLOCK)) { if ((flags & KS_HASH_FLAG_RWLOCK)) {
ks_rwl_create(&h->rwl, h->pool); ks_rwl_create(&h->rwl, h->pool);
@ -303,6 +328,15 @@ ks_hash_count(ks_hash_t *h)
return h->entrycount; return h->entrycount;
} }
static int key_equals(ks_hash_t *h, void *k1, void *k2)
{
if (h->mode == KS_HASH_MODE_ARBITRARY) {
return !memcmp(k1, k2, h->keysize);
} else {
return h->eqfn(k1, k2);
}
}
static void * _ks_hash_remove(ks_hash_t *h, void *k, unsigned int hashvalue, unsigned int index) { static void * _ks_hash_remove(ks_hash_t *h, void *k, unsigned int hashvalue, unsigned int index) {
/* TODO: consider compacting the table when the load factor drops enough, /* TODO: consider compacting the table when the load factor drops enough,
* or provide a 'compact' method. */ * or provide a 'compact' method. */
@ -316,7 +350,7 @@ static void * _ks_hash_remove(ks_hash_t *h, void *k, unsigned int hashvalue, uns
e = *pE; e = *pE;
while (NULL != e) { while (NULL != e) {
/* Check hash value to short circuit heavier comparison */ /* Check hash value to short circuit heavier comparison */
if ((hashvalue == e->h) && (h->eqfn(k, e->k))) { if ((hashvalue == e->h) && (key_equals(h, k, e->k))) {
*pE = e->next; *pE = e->next;
h->entrycount--; h->entrycount--;
v = e->v; v = e->v;
@ -457,7 +491,7 @@ ks_hash_search(ks_hash_t *h, void *k, ks_locked_t locked)
e = h->table[index]; e = h->table[index];
while (NULL != e) { while (NULL != e) {
/* Check hash value to short circuit heavier comparison */ /* Check hash value to short circuit heavier comparison */
if ((hashvalue == e->h) && (h->eqfn(k, e->k))) { if ((hashvalue == e->h) && (key_equals(h, k, e->k))) {
v = e->v; v = e->v;
break; break;
} }

42
libs/libks/test/testhash.c
View File

@ -120,16 +120,56 @@ int test2(void)
return 1; return 1;
} }
#include "sodium.h"
#define TEST3_SIZE 20
int test3(void)
{
ks_pool_t *pool;
ks_hash_t *hash;
ks_byte_t data[TEST3_SIZE];
ks_byte_t data2[TEST3_SIZE];
ks_byte_t data3[TEST3_SIZE];
char *A, *B, *C;
ks_pool_open(&pool);
ks_hash_create(&hash, KS_HASH_MODE_ARBITRARY, KS_HASH_FLAG_NONE, pool);
ks_hash_set_keysize(hash, TEST3_SIZE);
randombytes_buf(data, sizeof(data));
randombytes_buf(data2, sizeof(data2));
ks_hash_insert(hash, data, "FOO");
ks_hash_insert(hash, data2, "BAR");
ks_hash_insert(hash, data3, "BAZ");
A = (char *)ks_hash_search(hash, data, KS_UNLOCKED);
B = (char *)ks_hash_search(hash, data2, KS_UNLOCKED);
C = (char *)ks_hash_search(hash, data3, KS_UNLOCKED);
printf("RESULT [%s][%s][%s]\n", A, B, C);
ks_hash_destroy(&hash);
ks_pool_close(&pool);
return !strcmp(A, "FOO") && !strcmp(B, "BAR") && !strcmp(C, "BAZ");
}
int main(int argc, char **argv) int main(int argc, char **argv)
{ {
ks_init(); ks_init();
srand((unsigned)(time(NULL) - (unsigned)(intptr_t)ks_thread_self())); srand((unsigned)(time(NULL) - (unsigned)(intptr_t)ks_thread_self()));
plan(2); plan(3);
ok(test1()); ok(test1());
ok(test2()); ok(test2());
ok(test3());
ks_shutdown(); ks_shutdown();