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-rw-r--r--third_party/popt/lookup3.c969
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+/* -------------------------------------------------------------------- */
+/*
+ * 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 */
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-20 14:03:35 +0000