| /* SPDX-License-Identifier: LicenseRef-lookup3-public-domain */ |
| /* Slightly modified by Lennart Poettering, to avoid name clashes, and |
| * unexport a few functions. */ |
| |
| #include "lookup3.h" |
| |
| /* |
| ------------------------------------------------------------------------------- |
| lookup3.c, by Bob Jenkins, May 2006, Public Domain. |
| |
| These are functions for producing 32-bit hashes for hash table lookup. |
| hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and 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 hashlittle(). hashlittle() and hashbig() |
| hash byte arrays. hashlittle() is faster than hashbig() on |
| little-endian machines. Intel and AMD are little-endian machines. |
| On second thought, you probably want hashlittle2(), which is identical to |
| hashlittle() except it returns two 32-bit hashes for the price of one. |
| You could implement hashbig2() 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; |
| mix(a,b,c); |
| a += i4; b += i5; c += i6; |
| mix(a,b,c); |
| a += i7; |
| final(a,b,c); |
| then use c as the hash value. If you have a variable length array of |
| 4-byte integers to hash, use hashword(). If you have a byte array (like |
| a character string), use hashlittle(). If you have several byte arrays, or |
| a mix of things, see the comments above hashlittle(). |
| |
| 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. |
| ------------------------------------------------------------------------------- |
| */ |
| /* #define SELF_TEST 1 */ |
| |
| #include <stdint.h> /* defines uint32_t etc */ |
| #include <stdio.h> /* defines printf for tests */ |
| #include <sys/param.h> /* attempt to define endianness */ |
| #include <time.h> /* defines time_t for timings in the test */ |
| #ifdef linux |
| # include <endian.h> /* attempt to define endianness */ |
| #endif |
| |
| #if __GNUC__ >= 7 |
| _Pragma("GCC diagnostic ignored \"-Wimplicit-fallthrough\"") |
| #endif |
| |
| /* |
| * My best guess at if you are big-endian or little-endian. This may |
| * need adjustment. |
| */ |
| #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 HASH_LITTLE_ENDIAN 1 |
| # define HASH_BIG_ENDIAN 0 |
| #elif (defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && \ |
| __BYTE_ORDER == __BIG_ENDIAN) || \ |
| (defined(sparc) || defined(POWERPC) || defined(mc68000) || defined(sel)) |
| # define HASH_LITTLE_ENDIAN 0 |
| # define HASH_BIG_ENDIAN 1 |
| #else |
| # define HASH_LITTLE_ENDIAN 0 |
| # define HASH_BIG_ENDIAN 0 |
| #endif |
| |
| #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; \ |
| } |
| |
| /* |
| ------------------------------------------------------------------------------- |
| 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); \ |
| } |
| |
| /* |
| -------------------------------------------------------------------- |
| This works on all machines. To be useful, it requires |
| -- that the key be an array of uint32_t's, and |
| -- that the length be the number of uint32_t's in the key |
| |
| The function hashword() is identical to hashlittle() on little-endian |
| machines, and identical to hashbig() on big-endian machines, |
| except that the length has to be measured in uint32_ts rather than in |
| bytes. hashlittle() is more complicated than hashword() only because |
| hashlittle() has to dance around fitting the key bytes into registers. |
| -------------------------------------------------------------------- |
| */ |
| uint32_t jenkins_hashword( |
| const uint32_t *k, /* the key, an array of uint32_t values */ |
| size_t length, /* the length of the key, in uint32_ts */ |
| uint32_t initval) /* the previous hash, or an arbitrary value */ |
| { |
| uint32_t a,b,c; |
| |
| /* Set up the internal state */ |
| a = b = c = 0xdeadbeef + (((uint32_t)length)<<2) + initval; |
| |
| /*------------------------------------------------- handle most of the key */ |
| while (length > 3) |
| { |
| a += k[0]; |
| b += k[1]; |
| c += k[2]; |
| mix(a,b,c); |
| length -= 3; |
| k += 3; |
| } |
| |
| /*------------------------------------------- handle the last 3 uint32_t's */ |
| switch(length) /* all the case statements fall through */ |
| { |
| case 3 : c+=k[2]; |
| case 2 : b+=k[1]; |
| case 1 : a+=k[0]; |
| final(a,b,c); |
| case 0: /* case 0: nothing left to add */ |
| break; |
| } |
| /*------------------------------------------------------ report the result */ |
| return c; |
| } |
| |
| /* |
| -------------------------------------------------------------------- |
| hashword2() -- same as hashword(), but take two seeds and return two |
| 32-bit values. pc and pb must both be nonnull, and *pc and *pb must |
| both be initialized with seeds. If you pass in (*pb)==0, the output |
| (*pc) will be the same as the return value from hashword(). |
| -------------------------------------------------------------------- |
| */ |
| void jenkins_hashword2 ( |
| const uint32_t *k, /* the key, an array of uint32_t values */ |
| size_t length, /* the length of the key, in uint32_ts */ |
| uint32_t *pc, /* IN: seed OUT: primary hash value */ |
| uint32_t *pb) /* IN: more seed OUT: secondary hash value */ |
| { |
| uint32_t a,b,c; |
| |
| /* Set up the internal state */ |
| a = b = c = 0xdeadbeef + ((uint32_t)(length<<2)) + *pc; |
| c += *pb; |
| |
| /*------------------------------------------------- handle most of the key */ |
| while (length > 3) |
| { |
| a += k[0]; |
| b += k[1]; |
| c += k[2]; |
| mix(a,b,c); |
| length -= 3; |
| k += 3; |
| } |
| |
| /*------------------------------------------- handle the last 3 uint32_t's */ |
| switch(length) /* all the case statements fall through */ |
| { |
| case 3 : c+=k[2]; |
| case 2 : b+=k[1]; |
| case 1 : a+=k[0]; |
| final(a,b,c); |
| case 0: /* case 0: nothing left to add */ |
| break; |
| } |
| /*------------------------------------------------------ report the result */ |
| *pc=c; *pb=b; |
| } |
| |
| /* |
| ------------------------------------------------------------------------------- |
| 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. |
| ------------------------------------------------------------------------------- |
| */ |
| |
| uint32_t jenkins_hashlittle( const void *key, size_t length, uint32_t initval) |
| { |
| uint32_t a,b,c; /* internal state */ |
| union { const void *ptr; 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 (HASH_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 |
| * noticeably faster for short strings (like English words). |
| */ |
| #if !VALGRIND && !HAS_FEATURE_ADDRESS_SANITIZER && !HAS_FEATURE_MEMORY_SANITIZER |
| |
| 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 */ |
| { |
| const uint8_t *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 (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 (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; |
| } |
| |
| /* |
| * hashlittle2: return 2 32-bit hash values |
| * |
| * This is identical to hashlittle(), 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)". |
| */ |
| void jenkins_hashlittle2( |
| const void *key, /* the key to hash */ |
| size_t length, /* length of the key */ |
| uint32_t *pc, /* IN: primary initval, OUT: primary hash */ |
| uint32_t *pb) /* IN: secondary initval, OUT: secondary hash */ |
| { |
| uint32_t a,b,c; /* internal state */ |
| union { const void *ptr; size_t i; } u; /* needed for Mac Powerbook G4 */ |
| |
| /* Set up the internal state */ |
| a = b = c = 0xdeadbeef + ((uint32_t)length) + *pc; |
| c += *pb; |
| |
| u.ptr = key; |
| if (HASH_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 |
| * noticeably faster for short strings (like English words). |
| */ |
| #if !VALGRIND && !HAS_FEATURE_ADDRESS_SANITIZER && !HAS_FEATURE_MEMORY_SANITIZER |
| |
| 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 : *pc=c; *pb=b; return; /* zero length strings require no mixing */ |
| } |
| |
| #else /* make valgrind happy */ |
| |
| { |
| const uint8_t *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 : *pc=c; *pb=b; return; /* zero length strings require no mixing */ |
| } |
| } |
| |
| #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 (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 : *pc=c; *pb=b; return; /* zero length strings require 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 : *pc=c; *pb=b; return; /* zero length strings require no mixing */ |
| } |
| } |
| |
| final(a,b,c); |
| *pc=c; *pb=b; |
| } |
| |
| /* |
| * hashbig(): |
| * This is the same as hashword() on big-endian machines. It is different |
| * from hashlittle() on all machines. hashbig() takes advantage of |
| * big-endian byte ordering. |
| */ |
| uint32_t jenkins_hashbig( const void *key, size_t length, uint32_t initval) |
| { |
| uint32_t a,b,c; |
| union { const void *ptr; size_t i; } u; /* to cast key to (size_t) happily */ |
| |
| /* Set up the internal state */ |
| a = b = c = 0xdeadbeef + ((uint32_t)length) + initval; |
| |
| u.ptr = key; |
| if (HASH_BIG_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]<<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 |
| * noticeably faster for short strings (like English words). |
| */ |
| #if !VALGRIND && !HAS_FEATURE_ADDRESS_SANITIZER && !HAS_FEATURE_MEMORY_SANITIZER |
| |
| switch(length) |
| { |
| 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 : return c; /* zero length strings require no mixing */ |
| } |
| |
| #else /* make valgrind happy */ |
| |
| { |
| const uint8_t *k8 = (const uint8_t *)k; |
| switch(length) /* 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; /* fall through */ |
| case 10: c+=((uint32_t)k8[9])<<16; /* fall through */ |
| case 9 : c+=((uint32_t)k8[8])<<24; /* fall through */ |
| case 8 : b+=k[1]; a+=k[0]; break; |
| case 7 : b+=((uint32_t)k8[6])<<8; /* fall through */ |
| case 6 : b+=((uint32_t)k8[5])<<16; /* fall through */ |
| case 5 : b+=((uint32_t)k8[4])<<24; /* fall through */ |
| case 4 : a+=k[0]; break; |
| case 3 : a+=((uint32_t)k8[2])<<8; /* fall through */ |
| case 2 : a+=((uint32_t)k8[1])<<16; /* fall through */ |
| case 1 : a+=((uint32_t)k8[0])<<24; break; |
| case 0 : return c; |
| } |
| } |
| |
| #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 (length > 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]); |
| 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+=k[11]; |
| case 11: c+=((uint32_t)k[10])<<8; |
| case 10: c+=((uint32_t)k[9])<<16; |
| case 9 : c+=((uint32_t)k[8])<<24; |
| case 8 : b+=k[7]; |
| case 7 : b+=((uint32_t)k[6])<<8; |
| case 6 : b+=((uint32_t)k[5])<<16; |
| case 5 : b+=((uint32_t)k[4])<<24; |
| case 4 : a+=k[3]; |
| case 3 : a+=((uint32_t)k[2])<<8; |
| case 2 : a+=((uint32_t)k[1])<<16; |
| case 1 : a+=((uint32_t)k[0])<<24; |
| break; |
| case 0 : return c; |
| } |
| } |
| |
| final(a,b,c); |
| return c; |
| } |
| |
| #ifdef SELF_TEST |
| |
| /* used for timings */ |
| void driver1() |
| { |
| 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 = hashlittle(&buf[0],1,h); |
| } |
| time(&z); |
| if (z-a > 0) printf("time %d %.8x\n", 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 |
| void driver2() |
| { |
| 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 several 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] = hashlittle(a, hlen, m); |
| b[i] ^= ((k+1)<<j); |
| b[i] ^= ((k+1)>>(8-j)); |
| d[0] = hashlittle(b, hlen, m); |
| /* 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 */ |
| void driver3() |
| { |
| 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; |
| |
| printf("Endianness. These lines should all be the same (for values filled in):\n"); |
| printf("%.8x %.8x %.8x\n", |
| hashword((const uint32_t *)q, (sizeof(q)-1)/4, 13), |
| hashword((const uint32_t *)q, (sizeof(q)-5)/4, 13), |
| hashword((const uint32_t *)q, (sizeof(q)-9)/4, 13)); |
| p = q; |
| printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", |
| hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), |
| hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), |
| hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), |
| hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), |
| hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), |
| hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); |
| p = &qq[1]; |
| printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", |
| hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), |
| hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), |
| hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), |
| hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), |
| hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), |
| hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); |
| p = &qqq[2]; |
| printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", |
| hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), |
| hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), |
| hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), |
| hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), |
| hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), |
| hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); |
| p = &qqqq[3]; |
| printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", |
| hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), |
| hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), |
| hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), |
| hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), |
| hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), |
| hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); |
| printf("\n"); |
| |
| /* check that hashlittle2 and hashlittle produce the same results */ |
| i=47; j=0; |
| hashlittle2(q, sizeof(q), &i, &j); |
| if (hashlittle(q, sizeof(q), 47) != i) |
| printf("hashlittle2 and hashlittle mismatch\n"); |
| |
| /* check that hashword2 and hashword produce the same results */ |
| len = 0xdeadbeef; |
| i=47, j=0; |
| hashword2(&len, 1, &i, &j); |
| if (hashword(&len, 1, 47) != i) |
| printf("hashword2 and hashword mismatch %x %x\n", |
| i, hashword(&len, 1, 47)); |
| |
| /* check hashlittle doesn't read before or after the ends of the string */ |
| 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 */ |
| ref = hashlittle(b, len, (uint32_t)1); |
| *(b+i)=(uint8_t)~0; |
| *(b-1)=(uint8_t)~0; |
| x = hashlittle(b, len, (uint32_t)1); |
| y = hashlittle(b, len, (uint32_t)1); |
| if ((ref != x) || (ref != y)) |
| { |
| printf("alignment error: %.8x %.8x %.8x %d %d\n",ref,x,y, |
| h, i); |
| } |
| } |
| } |
| } |
| |
| /* check for problems with nulls */ |
| void driver4() |
| { |
| uint8_t buf[1]; |
| uint32_t h,i,state[HASHSTATE]; |
| |
| buf[0] = ~0; |
| for (i=0; i<HASHSTATE; ++i) state[i] = 1; |
| printf("These should all be different\n"); |
| for (i=0, h=0; i<8; ++i) |
| { |
| h = hashlittle(buf, 0, h); |
| printf("%2ld 0-byte strings, hash is %.8x\n", i, h); |
| } |
| } |
| |
| void driver5() |
| { |
| uint32_t b,c; |
| b=0, c=0, hashlittle2("", 0, &c, &b); |
| printf("hash is %.8lx %.8lx\n", c, b); /* deadbeef deadbeef */ |
| b=0xdeadbeef, c=0, hashlittle2("", 0, &c, &b); |
| printf("hash is %.8lx %.8lx\n", c, b); /* bd5b7dde deadbeef */ |
| b=0xdeadbeef, c=0xdeadbeef, hashlittle2("", 0, &c, &b); |
| printf("hash is %.8lx %.8lx\n", c, b); /* 9c093ccd bd5b7dde */ |
| b=0, c=0, hashlittle2("Four score and seven years ago", 30, &c, &b); |
| printf("hash is %.8lx %.8lx\n", c, b); /* 17770551 ce7226e6 */ |
| b=1, c=0, hashlittle2("Four score and seven years ago", 30, &c, &b); |
| printf("hash is %.8lx %.8lx\n", c, b); /* e3607cae bd371de4 */ |
| b=0, c=1, hashlittle2("Four score and seven years ago", 30, &c, &b); |
| printf("hash is %.8lx %.8lx\n", c, b); /* cd628161 6cbea4b3 */ |
| c = hashlittle("Four score and seven years ago", 30, 0); |
| printf("hash is %.8lx\n", c); /* 17770551 */ |
| c = hashlittle("Four score and seven years ago", 30, 1); |
| printf("hash is %.8lx\n", c); /* cd628161 */ |
| } |
| |
| int main() |
| { |
| 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) */ |
| driver5(); /* test the hash against known vectors */ |
| return 1; |
| } |
| |
| #endif /* SELF_TEST */ |
