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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 17:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 17:47:29 +0000 |
commit | 4f5791ebd03eaec1c7da0865a383175b05102712 (patch) | |
tree | 8ce7b00f7a76baa386372422adebbe64510812d4 /third_party/popt/lookup3.c | |
parent | Initial commit. (diff) | |
download | samba-4f5791ebd03eaec1c7da0865a383175b05102712.tar.xz samba-4f5791ebd03eaec1c7da0865a383175b05102712.zip |
Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/popt/lookup3.c')
-rw-r--r-- | third_party/popt/lookup3.c | 969 |
1 files changed, 969 insertions, 0 deletions
diff --git a/third_party/popt/lookup3.c b/third_party/popt/lookup3.c new file mode 100644 index 0000000..eb4e5ce --- /dev/null +++ b/third_party/popt/lookup3.c @@ -0,0 +1,969 @@ +/* -------------------------------------------------------------------- */ +/* + * lookup3.c, by Bob Jenkins, May 2006, Public Domain. + * + * These are functions for producing 32-bit hashes for hash table lookup. + * jlu32w(), jlu32l(), jlu32lpair(), jlu32b(), _JLU3_MIX(), and _JLU3_FINAL() + * are externally useful functions. Routines to test the hash are included + * if SELF_TEST is defined. You can use this free for any purpose. It's in + * the public domain. It has no warranty. + * + * You probably want to use jlu32l(). jlu32l() and jlu32b() + * hash byte arrays. jlu32l() is is faster than jlu32b() on + * little-endian machines. Intel and AMD are little-endian machines. + * On second thought, you probably want jlu32lpair(), which is identical to + * jlu32l() except it returns two 32-bit hashes for the price of one. + * You could implement jlu32bpair() if you wanted but I haven't bothered here. + * + * If you want to find a hash of, say, exactly 7 integers, do + * a = i1; b = i2; c = i3; + * _JLU3_MIX(a,b,c); + * a += i4; b += i5; c += i6; + * _JLU3_MIX(a,b,c); + * a += i7; + * _JLU3_FINAL(a,b,c); + * then use c as the hash value. If you have a variable size array of + * 4-byte integers to hash, use jlu32w(). If you have a byte array (like + * a character string), use jlu32l(). If you have several byte arrays, or + * a mix of things, see the comments above jlu32l(). + * + * Why is this so big? I read 12 bytes at a time into 3 4-byte integers, + * then mix those integers. This is fast (you can do a lot more thorough + * mixing with 12*3 instructions on 3 integers than you can with 3 instructions + * on 1 byte), but shoehorning those bytes into integers efficiently is messy. +*/ +/* -------------------------------------------------------------------- */ + +#include <stdint.h> + +#if defined(_JLU3_SELFTEST) +# define _JLU3_jlu32w 1 +# define _JLU3_jlu32l 1 +# define _JLU3_jlu32lpair 1 +# define _JLU3_jlu32b 1 +#endif + +/*@-redef@*/ +/*@unchecked@*/ +static const union _dbswap { + const uint32_t ui; + const unsigned char uc[4]; +} endian = { .ui = 0x11223344 }; +# define HASH_LITTLE_ENDIAN (endian.uc[0] == (unsigned char) 0x44) +# define HASH_BIG_ENDIAN (endian.uc[0] == (unsigned char) 0x11) +/*@=redef@*/ + +#ifndef ROTL32 +# define ROTL32(x, s) (((x) << (s)) | ((x) >> (32 - (s)))) +#endif + +/* NOTE: The _size parameter should be in bytes. */ +#define _JLU3_INIT(_h, _size) (0xdeadbeef + ((uint32_t)(_size)) + (_h)) + +/* -------------------------------------------------------------------- */ +/* + * _JLU3_MIX -- mix 3 32-bit values reversibly. + * + * This is reversible, so any information in (a,b,c) before _JLU3_MIX() is + * still in (a,b,c) after _JLU3_MIX(). + * + * If four pairs of (a,b,c) inputs are run through _JLU3_MIX(), or through + * _JLU3_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^=ROTL32(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 _JLU3_MIX(a,b,c) \ +{ \ + a -= c; a ^= ROTL32(c, 4); c += b; \ + b -= a; b ^= ROTL32(a, 6); a += c; \ + c -= b; c ^= ROTL32(b, 8); b += a; \ + a -= c; a ^= ROTL32(c,16); c += b; \ + b -= a; b ^= ROTL32(a,19); a += c; \ + c -= b; c ^= ROTL32(b, 4); b += a; \ +} + +/* -------------------------------------------------------------------- */ +/** + * _JLU3_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 _JLU3_FINAL(a,b,c) \ +{ \ + c ^= b; c -= ROTL32(b,14); \ + a ^= c; a -= ROTL32(c,11); \ + b ^= a; b -= ROTL32(a,25); \ + c ^= b; c -= ROTL32(b,16); \ + a ^= c; a -= ROTL32(c,4); \ + b ^= a; b -= ROTL32(a,14); \ + c ^= b; c -= ROTL32(b,24); \ +} + +#if defined(_JLU3_jlu32w) +uint32_t jlu32w(uint32_t h, /*@null@*/ const uint32_t *k, size_t size) + /*@*/; +/* -------------------------------------------------------------------- */ +/** + * This works on all machines. To be useful, it requires + * -- that the key be an array of uint32_t's, and + * -- that the size be the number of uint32_t's in the key + * + * The function jlu32w() is identical to jlu32l() on little-endian + * machines, and identical to jlu32b() on big-endian machines, + * except that the size has to be measured in uint32_ts rather than in + * bytes. jlu32l() is more complicated than jlu32w() only because + * jlu32l() has to dance around fitting the key bytes into registers. + * + * @param h the previous hash, or an arbitrary value + * @param *k the key, an array of uint32_t values + * @param size the size of the key, in uint32_ts + * @return the lookup3 hash + */ +/* -------------------------------------------------------------------- */ +uint32_t jlu32w(uint32_t h, const uint32_t *k, size_t size) +{ + uint32_t a = _JLU3_INIT(h, (size * sizeof(*k))); + uint32_t b = a; + uint32_t c = a; + + if (k == NULL) + goto exit; + + /*----------------------------------------------- handle most of the key */ + while (size > 3) { + a += k[0]; + b += k[1]; + c += k[2]; + _JLU3_MIX(a,b,c); + size -= 3; + k += 3; + } + + /*----------------------------------------- handle the last 3 uint32_t's */ + switch (size) { + case 3 : c+=k[2]; + case 2 : b+=k[1]; + case 1 : a+=k[0]; + _JLU3_FINAL(a,b,c); + /*@fallthrough@*/ + case 0: + break; + } + /*---------------------------------------------------- report the result */ +exit: + return c; +} +#endif /* defined(_JLU3_jlu32w) */ + +#if defined(_JLU3_jlu32l) +uint32_t jlu32l(uint32_t h, const void *key, size_t size) + /*@*/; +/* -------------------------------------------------------------------- */ +/* + * jlu32l() -- hash a variable-length key into a 32-bit value + * h : can be any 4-byte value + * k : the key (the unaligned variable-length array of bytes) + * size : the size of the key, counting by bytes + * 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 = jlu32l(h, k[i], len[i]); + * + * 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. + * + * @param h the previous hash, or an arbitrary value + * @param *k the key, an array of uint8_t values + * @param size the size of the key + * @return the lookup3 hash + */ +/* -------------------------------------------------------------------- */ +uint32_t jlu32l(uint32_t h, const void *key, size_t size) +{ + union { const void *ptr; size_t i; } u; + uint32_t a = _JLU3_INIT(h, size); + uint32_t b = a; + uint32_t c = a; + + if (key == NULL) + goto exit; + + u.ptr = key; + if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) { + const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */ +#ifdef VALGRIND + const uint8_t *k8; +#endif + + /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ + while (size > 12) { + a += k[0]; + b += k[1]; + c += k[2]; + _JLU3_MIX(a,b,c); + size -= 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 (size) { + 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: goto exit; + } + +#else /* make valgrind happy */ + + k8 = (const uint8_t *)k; + switch (size) { + case 12: c += k[2]; b+=k[1]; a+=k[0] break; + case 11: c += ((uint32_t)k8[10])<<16; /*@fallthrough@*/ + case 10: c += ((uint32_t)k8[9])<<8; /*@fallthrough@*/ + case 9: c += k8[8]; /*@fallthrough@*/ + case 8: b += k[1]; a+=k[0]; break; + case 7: b += ((uint32_t)k8[6])<<16; /*@fallthrough@*/ + case 6: b += ((uint32_t)k8[5])<<8; /*@fallthrough@*/ + case 5: b += k8[4]; /*@fallthrough@*/ + case 4: a += k[0]; break; + case 3: a += ((uint32_t)k8[2])<<16; /*@fallthrough@*/ + case 2: a += ((uint32_t)k8[1])<<8; /*@fallthrough@*/ + case 1: a += k8[0]; break; + case 0: goto exit; + } + +#endif /* !valgrind */ + + } else if (HASH_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 (size > 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); + _JLU3_MIX(a,b,c); + size -= 12; + k += 6; + } + + /*------------------------- handle the last (probably partial) block */ + k8 = (const uint8_t *)k; + switch (size) { + 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; + /*@fallthrough@*/ + case 10: + c += (uint32_t)k[4]; + b += k[2]+(((uint32_t)k[3])<<16); + a += k[0]+(((uint32_t)k[1])<<16); + break; + case 9: + c += (uint32_t)k8[8]; + /*@fallthrough@*/ + 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; + /*@fallthrough@*/ + case 6: + b += (uint32_t)k[2]; + a += k[0]+(((uint32_t)k[1])<<16); + break; + case 5: + b += (uint32_t)k8[4]; + /*@fallthrough@*/ + case 4: + a += k[0]+(((uint32_t)k[1])<<16); + break; + case 3: + a += ((uint32_t)k8[2])<<16; + /*@fallthrough@*/ + case 2: + a += (uint32_t)k[0]; + break; + case 1: + a += (uint32_t)k8[0]; + break; + case 0: + goto exit; + } + + } 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 (size > 12) { + a += (uint32_t)k[0]; + a += ((uint32_t)k[1])<<8; + a += ((uint32_t)k[2])<<16; + a += ((uint32_t)k[3])<<24; + b += (uint32_t)k[4]; + b += ((uint32_t)k[5])<<8; + b += ((uint32_t)k[6])<<16; + b += ((uint32_t)k[7])<<24; + c += (uint32_t)k[8]; + c += ((uint32_t)k[9])<<8; + c += ((uint32_t)k[10])<<16; + c += ((uint32_t)k[11])<<24; + _JLU3_MIX(a,b,c); + size -= 12; + k += 12; + } + + /*---------------------------- last block: affect all 32 bits of (c) */ + switch (size) { + case 12: c += ((uint32_t)k[11])<<24; /*@fallthrough@*/ + case 11: c += ((uint32_t)k[10])<<16; /*@fallthrough@*/ + case 10: c += ((uint32_t)k[9])<<8; /*@fallthrough@*/ + case 9: c += (uint32_t)k[8]; /*@fallthrough@*/ + case 8: b += ((uint32_t)k[7])<<24; /*@fallthrough@*/ + case 7: b += ((uint32_t)k[6])<<16; /*@fallthrough@*/ + case 6: b += ((uint32_t)k[5])<<8; /*@fallthrough@*/ + case 5: b += (uint32_t)k[4]; /*@fallthrough@*/ + case 4: a += ((uint32_t)k[3])<<24; /*@fallthrough@*/ + case 3: a += ((uint32_t)k[2])<<16; /*@fallthrough@*/ + case 2: a += ((uint32_t)k[1])<<8; /*@fallthrough@*/ + case 1: a += (uint32_t)k[0]; + break; + case 0: + goto exit; + } + } + + _JLU3_FINAL(a,b,c); + +exit: + return c; +} +#endif /* defined(_JLU3_jlu32l) */ + +#if defined(_JLU3_jlu32lpair) +/** + * jlu32lpair: return 2 32-bit hash values. + * + * This is identical to jlu32l(), except it returns two 32-bit hash + * values instead of just one. This is good enough for hash table + * lookup with 2^^64 buckets, or if you want a second hash if you're not + * happy with the first, or if you want a probably-unique 64-bit ID for + * the key. *pc is better mixed than *pb, so use *pc first. If you want + * a 64-bit value do something like "*pc + (((uint64_t)*pb)<<32)". + * + * @param h the previous hash, or an arbitrary value + * @param *key the key, an array of uint8_t values + * @param size the size of the key in bytes + * @retval *pc, IN: primary initval, OUT: primary hash + * *retval *pb IN: secondary initval, OUT: secondary hash + */ +void jlu32lpair(const void *key, size_t size, uint32_t *pc, uint32_t *pb) +{ + union { const void *ptr; size_t i; } u; + uint32_t a = _JLU3_INIT(*pc, size); + uint32_t b = a; + uint32_t c = a; + + if (key == NULL) + goto exit; + + c += *pb; /* Add the secondary hash. */ + + u.ptr = key; + if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) { + const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */ +#ifdef VALGRIND + const uint8_t *k8; +#endif + + /*-- all but last block: aligned reads and affect 32 bits of (a,b,c) */ + while (size > (size_t)12) { + a += k[0]; + b += k[1]; + c += k[2]; + _JLU3_MIX(a,b,c); + size -= 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 (size) { + 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: goto exit; + } + +#else /* make valgrind happy */ + + k8 = (const uint8_t *)k; + switch (size) { + case 12: c += k[2]; b+=k[1]; a+=k[0]; break; + case 11: c += ((uint32_t)k8[10])<<16; /*@fallthrough@*/ + case 10: c += ((uint32_t)k8[9])<<8; /*@fallthrough@*/ + case 9: c += k8[8]; /*@fallthrough@*/ + case 8: b += k[1]; a+=k[0]; break; + case 7: b += ((uint32_t)k8[6])<<16; /*@fallthrough@*/ + case 6: b += ((uint32_t)k8[5])<<8; /*@fallthrough@*/ + case 5: b += k8[4]; /*@fallthrough@*/ + case 4: a += k[0]; break; + case 3: a += ((uint32_t)k8[2])<<16; /*@fallthrough@*/ + case 2: a += ((uint32_t)k8[1])<<8; /*@fallthrough@*/ + case 1: a += k8[0]; break; + case 0: goto exit; + } + +#endif /* !valgrind */ + + } else if (HASH_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 (size > (size_t)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); + _JLU3_MIX(a,b,c); + size -= 12; + k += 6; + } + + /*------------------------- handle the last (probably partial) block */ + k8 = (const uint8_t *)k; + switch (size) { + 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; + /*@fallthrough@*/ + 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]; + /*@fallthrough@*/ + 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; + /*@fallthrough@*/ + case 6: + b += k[2]; + a += k[0]+(((uint32_t)k[1])<<16); + break; + case 5: + b += k8[4]; + /*@fallthrough@*/ + case 4: + a += k[0]+(((uint32_t)k[1])<<16); + break; + case 3: + a += ((uint32_t)k8[2])<<16; + /*@fallthrough@*/ + case 2: + a += k[0]; + break; + case 1: + a += k8[0]; + break; + case 0: + goto exit; + } + + } 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 (size > (size_t)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; + _JLU3_MIX(a,b,c); + size -= 12; + k += 12; + } + + /*---------------------------- last block: affect all 32 bits of (c) */ + switch (size) { + case 12: c += ((uint32_t)k[11])<<24; /*@fallthrough@*/ + case 11: c += ((uint32_t)k[10])<<16; /*@fallthrough@*/ + case 10: c += ((uint32_t)k[9])<<8; /*@fallthrough@*/ + case 9: c += k[8]; /*@fallthrough@*/ + case 8: b += ((uint32_t)k[7])<<24; /*@fallthrough@*/ + case 7: b += ((uint32_t)k[6])<<16; /*@fallthrough@*/ + case 6: b += ((uint32_t)k[5])<<8; /*@fallthrough@*/ + case 5: b += k[4]; /*@fallthrough@*/ + case 4: a += ((uint32_t)k[3])<<24; /*@fallthrough@*/ + case 3: a += ((uint32_t)k[2])<<16; /*@fallthrough@*/ + case 2: a += ((uint32_t)k[1])<<8; /*@fallthrough@*/ + case 1: a += k[0]; + break; + case 0: + goto exit; + } + } + + _JLU3_FINAL(a,b,c); + +exit: + *pc = c; + *pb = b; + return; +} +#endif /* defined(_JLU3_jlu32lpair) */ + +#if defined(_JLU3_jlu32b) +uint32_t jlu32b(uint32_t h, /*@null@*/ const void *key, size_t size) + /*@*/; +/* + * jlu32b(): + * This is the same as jlu32w() on big-endian machines. It is different + * from jlu32l() on all machines. jlu32b() takes advantage of + * big-endian byte ordering. + * + * @param h the previous hash, or an arbitrary value + * @param *k the key, an array of uint8_t values + * @param size the size of the key + * @return the lookup3 hash + */ +uint32_t jlu32b(uint32_t h, const void *key, size_t size) +{ + union { const void *ptr; size_t i; } u; + uint32_t a = _JLU3_INIT(h, size); + uint32_t b = a; + uint32_t c = a; + + if (key == NULL) + return h; + + u.ptr = key; + if (HASH_BIG_ENDIAN && ((u.i & 0x3) == 0)) { + const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */ +#ifdef VALGRIND + const uint8_t *k8; +#endif + + /*-- all but last block: aligned reads and affect 32 bits of (a,b,c) */ + while (size > 12) { + a += k[0]; + b += k[1]; + c += k[2]; + _JLU3_MIX(a,b,c); + size -= 12; + k += 3; + } + + /*------------------------- handle the last (probably partial) block */ + /* + * "k[2]<<8" actually reads beyond the end of the string, but + * then shifts out the part it's not allowed to read. Because the + * string is aligned, the illegal read 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 (size) { + case 12: c += k[2]; b+=k[1]; a+=k[0]; break; + case 11: c += k[2]&0xffffff00; b+=k[1]; a+=k[0]; break; + case 10: c += k[2]&0xffff0000; b+=k[1]; a+=k[0]; break; + case 9: c += k[2]&0xff000000; b+=k[1]; a+=k[0]; break; + case 8: b += k[1]; a+=k[0]; break; + case 7: b += k[1]&0xffffff00; a+=k[0]; break; + case 6: b += k[1]&0xffff0000; a+=k[0]; break; + case 5: b += k[1]&0xff000000; a+=k[0]; break; + case 4: a += k[0]; break; + case 3: a += k[0]&0xffffff00; break; + case 2: a += k[0]&0xffff0000; break; + case 1: a += k[0]&0xff000000; break; + case 0: goto exit; + } + +#else /* make valgrind happy */ + + k8 = (const uint8_t *)k; + switch (size) { /* all the case statements fall through */ + case 12: c += k[2]; b+=k[1]; a+=k[0]; break; + case 11: c += ((uint32_t)k8[10])<<8; /*@fallthrough@*/ + case 10: c += ((uint32_t)k8[9])<<16; /*@fallthrough@*/ + case 9: c += ((uint32_t)k8[8])<<24; /*@fallthrough@*/ + case 8: b += k[1]; a+=k[0]; break; + case 7: b += ((uint32_t)k8[6])<<8; /*@fallthrough@*/ + case 6: b += ((uint32_t)k8[5])<<16; /*@fallthrough@*/ + case 5: b += ((uint32_t)k8[4])<<24; /*@fallthrough@*/ + case 4: a += k[0]; break; + case 3: a += ((uint32_t)k8[2])<<8; /*@fallthrough@*/ + case 2: a += ((uint32_t)k8[1])<<16; /*@fallthrough@*/ + case 1: a += ((uint32_t)k8[0])<<24; break; + case 0: goto exit; + } + +#endif /* !VALGRIND */ + + } 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 (size > 12) { + a += ((uint32_t)k[0])<<24; + a += ((uint32_t)k[1])<<16; + a += ((uint32_t)k[2])<<8; + a += ((uint32_t)k[3]); + b += ((uint32_t)k[4])<<24; + b += ((uint32_t)k[5])<<16; + b += ((uint32_t)k[6])<<8; + b += ((uint32_t)k[7]); + c += ((uint32_t)k[8])<<24; + c += ((uint32_t)k[9])<<16; + c += ((uint32_t)k[10])<<8; + c += ((uint32_t)k[11]); + _JLU3_MIX(a,b,c); + size -= 12; + k += 12; + } + + /*---------------------------- last block: affect all 32 bits of (c) */ + switch (size) { /* all the case statements fall through */ + case 12: c += k[11]; /*@fallthrough@*/ + case 11: c += ((uint32_t)k[10])<<8; /*@fallthrough@*/ + case 10: c += ((uint32_t)k[9])<<16; /*@fallthrough@*/ + case 9: c += ((uint32_t)k[8])<<24; /*@fallthrough@*/ + case 8: b += k[7]; /*@fallthrough@*/ + case 7: b += ((uint32_t)k[6])<<8; /*@fallthrough@*/ + case 6: b += ((uint32_t)k[5])<<16; /*@fallthrough@*/ + case 5: b += ((uint32_t)k[4])<<24; /*@fallthrough@*/ + case 4: a += k[3]; /*@fallthrough@*/ + case 3: a += ((uint32_t)k[2])<<8; /*@fallthrough@*/ + case 2: a += ((uint32_t)k[1])<<16; /*@fallthrough@*/ + case 1: a += ((uint32_t)k[0])<<24; /*@fallthrough@*/ + break; + case 0: + goto exit; + } + } + + _JLU3_FINAL(a,b,c); + +exit: + return c; +} +#endif /* defined(_JLU3_jlu32b) */ + +#if defined(_JLU3_SELFTEST) + +/* used for timings */ +static void driver1(void) + /*@*/ +{ + uint8_t buf[256]; + uint32_t i; + uint32_t h=0; + time_t a,z; + + time(&a); + for (i=0; i<256; ++i) buf[i] = 'x'; + for (i=0; i<1; ++i) { + h = jlu32l(h, &buf[0], sizeof(buf[0])); + } + time(&z); + if (z-a > 0) printf("time %d %.8x\n", (int)(z-a), h); +} + +/* check that every input bit changes every output bit half the time */ +#define HASHSTATE 1 +#define HASHLEN 1 +#define MAXPAIR 60 +#define MAXLEN 70 +static void driver2(void) + /*@*/ +{ + uint8_t qa[MAXLEN+1], qb[MAXLEN+2], *a = &qa[0], *b = &qb[1]; + uint32_t c[HASHSTATE], d[HASHSTATE], i=0, j=0, k, l, m=0, z; + uint32_t e[HASHSTATE],f[HASHSTATE],g[HASHSTATE],h[HASHSTATE]; + uint32_t x[HASHSTATE],y[HASHSTATE]; + uint32_t hlen; + + printf("No more than %d trials should ever be needed \n",MAXPAIR/2); + for (hlen=0; hlen < MAXLEN; ++hlen) { + z=0; + for (i=0; i<hlen; ++i) { /*-------------- for each input byte, */ + for (j=0; j<8; ++j) { /*--------------- for each input bit, */ + for (m=1; m<8; ++m) { /*--- for serveral possible initvals, */ + for (l=0; l<HASHSTATE; ++l) + e[l]=f[l]=g[l]=h[l]=x[l]=y[l]=~((uint32_t)0); + + /* check that every output bit is affected by that input bit */ + for (k=0; k<MAXPAIR; k+=2) { + uint32_t finished=1; + /* keys have one bit different */ + for (l=0; l<hlen+1; ++l) {a[l] = b[l] = (uint8_t)0;} + /* have a and b be two keys differing in only one bit */ + a[i] ^= (k<<j); + a[i] ^= (k>>(8-j)); + c[0] = jlu32l(m, a, hlen); + b[i] ^= ((k+1)<<j); + b[i] ^= ((k+1)>>(8-j)); + d[0] = jlu32l(m, b, hlen); + /* check every bit is 1, 0, set, and not set at least once */ + for (l=0; l<HASHSTATE; ++l) { + e[l] &= (c[l]^d[l]); + f[l] &= ~(c[l]^d[l]); + g[l] &= c[l]; + h[l] &= ~c[l]; + x[l] &= d[l]; + y[l] &= ~d[l]; + if (e[l]|f[l]|g[l]|h[l]|x[l]|y[l]) finished=0; + } + if (finished) break; + } + if (k>z) z=k; + if (k == MAXPAIR) { + printf("Some bit didn't change: "); + printf("%.8x %.8x %.8x %.8x %.8x %.8x ", + e[0],f[0],g[0],h[0],x[0],y[0]); + printf("i %d j %d m %d len %d\n", i, j, m, hlen); + } + if (z == MAXPAIR) goto done; + } + } + } + done: + if (z < MAXPAIR) { + printf("Mix success %2d bytes %2d initvals ",i,m); + printf("required %d trials\n", z/2); + } + } + printf("\n"); +} + +/* Check for reading beyond the end of the buffer and alignment problems */ +static void driver3(void) + /*@*/ +{ + uint8_t buf[MAXLEN+20], *b; + uint32_t len; + uint8_t q[] = "This is the time for all good men to come to the aid of their country..."; + uint32_t h; + uint8_t qq[] = "xThis is the time for all good men to come to the aid of their country..."; + uint32_t i; + uint8_t qqq[] = "xxThis is the time for all good men to come to the aid of their country..."; + uint32_t j; + uint8_t qqqq[] = "xxxThis is the time for all good men to come to the aid of their country..."; + uint32_t ref,x,y; + uint8_t *p; + uint32_t m = 13; + + printf("Endianness. These lines should all be the same (for values filled in):\n"); + printf("%.8x %.8x %.8x\n", + jlu32w(m, (const uint32_t *)q, (sizeof(q)-1)/4), + jlu32w(m, (const uint32_t *)q, (sizeof(q)-5)/4), + jlu32w(m, (const uint32_t *)q, (sizeof(q)-9)/4)); + p = q; + printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", + jlu32l(m, p, sizeof(q)-1), jlu32l(m, p, sizeof(q)-2), + jlu32l(m, p, sizeof(q)-3), jlu32l(m, p, sizeof(q)-4), + jlu32l(m, p, sizeof(q)-5), jlu32l(m, p, sizeof(q)-6), + jlu32l(m, p, sizeof(q)-7), jlu32l(m, p, sizeof(q)-8), + jlu32l(m, p, sizeof(q)-9), jlu32l(m, p, sizeof(q)-10), + jlu32l(m, p, sizeof(q)-11), jlu32l(m, p, sizeof(q)-12)); + p = &qq[1]; + printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", + jlu32l(m, p, sizeof(q)-1), jlu32l(m, p, sizeof(q)-2), + jlu32l(m, p, sizeof(q)-3), jlu32l(m, p, sizeof(q)-4), + jlu32l(m, p, sizeof(q)-5), jlu32l(m, p, sizeof(q)-6), + jlu32l(m, p, sizeof(q)-7), jlu32l(m, p, sizeof(q)-8), + jlu32l(m, p, sizeof(q)-9), jlu32l(m, p, sizeof(q)-10), + jlu32l(m, p, sizeof(q)-11), jlu32l(m, p, sizeof(q)-12)); + p = &qqq[2]; + printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", + jlu32l(m, p, sizeof(q)-1), jlu32l(m, p, sizeof(q)-2), + jlu32l(m, p, sizeof(q)-3), jlu32l(m, p, sizeof(q)-4), + jlu32l(m, p, sizeof(q)-5), jlu32l(m, p, sizeof(q)-6), + jlu32l(m, p, sizeof(q)-7), jlu32l(m, p, sizeof(q)-8), + jlu32l(m, p, sizeof(q)-9), jlu32l(m, p, sizeof(q)-10), + jlu32l(m, p, sizeof(q)-11), jlu32l(m, p, sizeof(q)-12)); + p = &qqqq[3]; + printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", + jlu32l(m, p, sizeof(q)-1), jlu32l(m, p, sizeof(q)-2), + jlu32l(m, p, sizeof(q)-3), jlu32l(m, p, sizeof(q)-4), + jlu32l(m, p, sizeof(q)-5), jlu32l(m, p, sizeof(q)-6), + jlu32l(m, p, sizeof(q)-7), jlu32l(m, p, sizeof(q)-8), + jlu32l(m, p, sizeof(q)-9), jlu32l(m, p, sizeof(q)-10), + jlu32l(m, p, sizeof(q)-11), jlu32l(m, p, sizeof(q)-12)); + printf("\n"); + for (h=0, b=buf+1; h<8; ++h, ++b) { + for (i=0; i<MAXLEN; ++i) { + len = i; + for (j=0; j<i; ++j) + *(b+j)=0; + + /* these should all be equal */ + m = 1; + ref = jlu32l(m, b, len); + *(b+i)=(uint8_t)~0; + *(b-1)=(uint8_t)~0; + x = jlu32l(m, b, len); + y = jlu32l(m, b, len); + if ((ref != x) || (ref != y)) + printf("alignment error: %.8x %.8x %.8x %d %d\n",ref,x,y, h, i); + } + } +} + +/* check for problems with nulls */ +static void driver4(void) + /*@*/ +{ + uint8_t buf[1]; + uint32_t h; + uint32_t i; + uint32_t state[HASHSTATE]; + + buf[0] = ~0; + for (i=0; i<HASHSTATE; ++i) + state[i] = 1; + printf("These should all be different\n"); + h = 0; + for (i=0; i<8; ++i) { + h = jlu32l(h, buf, 0); + printf("%2ld 0-byte strings, hash is %.8x\n", (long)i, h); + } +} + + +int main(int argc, char ** argv) +{ + driver1(); /* test that the key is hashed: used for timings */ + driver2(); /* test that whole key is hashed thoroughly */ + driver3(); /* test that nothing but the key is hashed */ + driver4(); /* test hashing multiple buffers (all buffers are null) */ + return 1; +} + +#endif /* _JLU3_SELFTEST */ |