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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.
+hashword(), hashlittle(), 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 has no warranty.
+
+You probably want to use hashlittle(). hashlittle() and hashbig()
+hash byte arrays. hashlittle() is is faster than hashbig() on
+little-endian machines. Intel and AMD are little-endian machines.
+
+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().
+-------------------------------------------------------------------------------
+*/
+//#define SELF_TEST 1
+
+#include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <time.h>
+
+typedef unsigned long int uint32; /* unsigned 4-byte quantities */
+typedef unsigned short int uint16; /* unsigned 2-byte quantities */
+typedef unsigned char uint8; /* unsigned 1-byte quantities */
+
+/*
+ * My best guess at if you are big-endian or little-endian. This may
+ * need adjustment.
+ */
+#if defined(i386) || defined(__i486__) || defined(__i586__) || defined(__i686__) || defined(vax) || defined(MIPSEL)
+# define HASH_LITTLE_ENDIAN 1
+# define HASH_BIG_ENDIAN 0
+#elif defined(sparc)
+# 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)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's, and
+ -- that all your machines have the same endianness, and
+ -- that the length be the number of uint32'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 uint32s rather than in
+ bytes. hashlittle() is more complicated than hashword() only because
+ hashlittle() has to dance around fitting the key bytes into registers.
+--------------------------------------------------------------------
+*/
+uint32 hashword( uint32 *k, size_t length, uint32 initval)
+{
+ uint32 a,b,c;
+
+ /* Set up the internal state */
+ a = b = c = 0xdeadbeef + (((uint32)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'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;
+}
+
+
+/*
+-------------------------------------------------------------------------------
+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 **)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 hashlittle( void *key, size_t length, uint32 initval)
+{
+ uint32 a,b,c;
+
+ /* Set up the internal state */
+ a = b = c = 0xdeadbeef + ((uint32)length) + initval;
+
+ if (HASH_LITTLE_ENDIAN && !((((uint8 *)key)-(uint8 *)0) & 0x3)) {
+ uint32 *k = ( uint32 *)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 */
+ 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 if (HASH_LITTLE_ENDIAN && !((((uint8 *)key)-(uint8 *)0) & 0x1)) {
+ uint16 *k = (uint16 *)key; /* read 16-bit chunks */
+
+ /*--------------- all but last block: aligned reads and different mixing */
+ while (length > 12)
+ {
+ a += k[0] + (((uint32)k[1])<<16);
+ b += k[2] + (((uint32)k[3])<<16);
+ c += k[4] + (((uint32)k[5])<<16);
+ mix(a,b,c);
+ length -= 12;
+ k += 6;
+ }
+
+ /*----------------------------- handle the last (probably partial) block */
+ switch(length)
+ {
+ case 12: c+=k[4]+(((uint32)k[5])<<16);
+ b+=k[2]+(((uint32)k[3])<<16);
+ a+=k[0]+(((uint32)k[1])<<16);
+ break;
+ case 11: c+=((uint32)(k[5]&0xff))<<16;/* fall through */
+ case 10: c+=k[4];
+ b+=k[2]+(((uint32)k[3])<<16);
+ a+=k[0]+(((uint32)k[1])<<16);
+ break;
+ case 9 : c+=k[4]&0xff; /* fall through */
+ case 8 : b+=k[2]+(((uint32)k[3])<<16);
+ a+=k[0]+(((uint32)k[1])<<16);
+ break;
+ case 7 : b+=((uint32)(k[3]&0xff))<<16;/* fall through */
+ case 6 : b+=k[2];
+ a+=k[0]+(((uint32)k[1])<<16);
+ break;
+ case 5 : b+=k[2]&0xff; /* fall through */
+ case 4 : a+=k[0]+(((uint32)k[1])<<16);
+ break;
+ case 3 : a+=((uint32)(k[1]&0xff))<<16;/* fall through */
+ case 2 : a+=k[0];
+ break;
+ case 1 : a+=k[0]&0xff;
+ break;
+ case 0 : return c; /* zero length requires no mixing */
+ }
+
+ } else { /* need to read the key one byte at a time */
+ uint8 *k = (uint8 *)key;
+
+ /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
+ while (length > 12)
+ {
+ a += k[0];
+ a += ((uint32)k[1])<<8;
+ a += ((uint32)k[2])<<16;
+ a += ((uint32)k[3])<<24;
+ b += k[4];
+ b += ((uint32)k[5])<<8;
+ b += ((uint32)k[6])<<16;
+ b += ((uint32)k[7])<<24;
+ c += k[8];
+ c += ((uint32)k[9])<<8;
+ c += ((uint32)k[10])<<16;
+ c += ((uint32)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)k[11])<<24;
+ case 11: c+=((uint32)k[10])<<16;
+ case 10: c+=((uint32)k[9])<<8;
+ case 9 : c+=k[8];
+ case 8 : b+=((uint32)k[7])<<24;
+ case 7 : b+=((uint32)k[6])<<16;
+ case 6 : b+=((uint32)k[5])<<8;
+ case 5 : b+=k[4];
+ case 4 : a+=((uint32)k[3])<<24;
+ case 3 : a+=((uint32)k[2])<<16;
+ case 2 : a+=((uint32)k[1])<<8;
+ case 1 : a+=k[0];
+ break;
+ case 0 : return c;
+ }
+ }
+
+ final(a,b,c);
+ return c;
+}
+
+
+
+/*
+ * 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 hashbig( void *key, size_t length, uint32 initval)
+{
+ uint32 a,b,c;
+
+ /* Set up the internal state */
+ a = b = c = 0xdeadbeef + ((uint32)length) + initval;
+
+ if (HASH_BIG_ENDIAN && !((((uint8 *)key)-(uint8 *)0) & 0x3)) {
+ uint32 *k = (uint32 *)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 */
+ switch(length)
+ {
+ case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+ case 11: c+=k[2]<<8; b+=k[1]; a+=k[0]; break;
+ case 10: c+=k[2]<<16; b+=k[1]; a+=k[0]; break;
+ case 9 : c+=k[2]<<24; b+=k[1]; a+=k[0]; break;
+ case 8 : b+=k[1]; a+=k[0]; break;
+ case 7 : b+=k[1]<<8; a+=k[0]; break;
+ case 6 : b+=k[1]<<16; a+=k[0]; break;
+ case 5 : b+=k[1]<<24; a+=k[0]; break;
+ case 4 : a+=k[0]; break;
+ case 3 : a+=k[0]<<8; break;
+ case 2 : a+=k[0]<<16; break;
+ case 1 : a+=k[0]<<24; break;
+ case 0 : return c; /* zero length strings require no mixing */
+ }
+
+ } else { /* need to read the key one byte at a time */
+ uint8 *k = (uint8 *)key;
+
+ /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
+ while (length > 12)
+ {
+ a += ((uint32)k[0])<<24;
+ a += ((uint32)k[1])<<16;
+ a += ((uint32)k[2])<<8;
+ a += ((uint32)k[3]);
+ b += ((uint32)k[4])<<24;
+ b += ((uint32)k[5])<<16;
+ b += ((uint32)k[6])<<8;
+ b += ((uint32)k[7]);
+ c += ((uint32)k[8])<<24;
+ c += ((uint32)k[9])<<16;
+ c += ((uint32)k[10])<<8;
+ c += ((uint32)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+=((uint32)k[11])<<24;
+ case 11: c+=((uint32)k[10])<<16;
+ case 10: c+=((uint32)k[9])<<8;
+ case 9 : c+=k[8];
+ case 8 : b+=((uint32)k[7])<<24;
+ case 7 : b+=((uint32)k[6])<<16;
+ case 6 : b+=((uint32)k[5])<<8;
+ case 5 : b+=k[4];
+ case 4 : a+=((uint32)k[3])<<24;
+ case 3 : a+=((uint32)k[2])<<16;
+ case 2 : a+=((uint32)k[1])<<8;
+ case 1 : a+=k[0];
+ break;
+ case 0 : return c;
+ }
+ }
+
+ final(a,b,c);
+ return c;
+}
+
+
+#ifdef SELF_TEST
+
+/* used for timings */
+void driver1()
+{
+ uint8 buf[256];
+ uint32 i;
+ uint32 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 %ld %.8lx\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 qa[MAXLEN+1], qb[MAXLEN+2], *a = &qa[0], *b = &qb[1];
+ uint32 c[HASHSTATE], d[HASHSTATE], i, j=0, k, l, m, z;
+ uint32 e[HASHSTATE],f[HASHSTATE],g[HASHSTATE],h[HASHSTATE];
+ uint32 x[HASHSTATE],y[HASHSTATE];
+ uint32 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)0);
+
+ /*---- check that every output bit is affected by that input bit */
+ for (k=0; k<MAXPAIR; k+=2)
+ {
+ uint32 finished=1;
+ /* keys have one bit different */
+ for (l=0; l<hlen+1; ++l) {a[l] = b[l] = (uint8)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("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx ",
+ e[0],f[0],g[0],h[0],x[0],y[0]);
+ printf("i %ld j %ld m %ld len %ld\n",i,j,m,hlen);
+ }
+ if (z==MAXPAIR) goto done;
+ }
+ }
+ }
+ done:
+ if (z < MAXPAIR)
+ {
+ printf("Mix success %2ld bytes %2ld initvals ",i,m);
+ printf("required %ld trials\n",z/2);
+ }
+ }
+ printf("\n");
+}
+
+/* Check for reading beyond the end of the buffer and alignment problems */
+void driver3()
+{
+ uint8 buf[MAXLEN+20], *b;
+ uint32 len;
+ uint8 q[] = "This is the time for all good men to come to the aid of their country...";
+ //uint32 dummy1;
+ uint8 qq[] = "xThis is the time for all good men to come to the aid of their country...";
+ //uint32 dummy2;
+ uint8 qqq[] = "xxThis is the time for all good men to come to the aid of their country...";
+ //uint32 dummy3;
+ uint8 qqqq[] = "xxxThis is the time for all good men to come to the aid of their country...";
+ uint32 h,i,j,ref,x,y;
+ uint8 *p;
+
+ printf("Endianness. These lines should all be the same (for values filled in):\n");
+ printf("%.8lx %.8lx %.8lx\n",
+ hashword((uint32 *)q, (sizeof(q)-1)/4, 13),
+ hashword((uint32 *)q, (sizeof(q)-5)/4, 13),
+ hashword((uint32 *)q, (sizeof(q)-9)/4, 13));
+ p = q;
+ printf("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx\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("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx\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("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx\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("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx\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");
+ 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)1);
+ *(b+i)=(uint8)~0;
+ *(b-1)=(uint8)~0;
+ x = hashlittle(b, len, (uint32)1);
+ y = hashlittle(b, len, (uint32)1);
+ if ((ref != x) || (ref != y))
+ {
+ printf("alignment error: %.8lx %.8lx %.8lx %ld %ld\n",ref,x,y,h,i);
+ }
+ }
+ }
+}
+
+/* check for problems with nulls */
+ void driver4()
+{
+ uint8 buf[1];
+ uint32 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, (uint32)0, h);
+ printf("%2ld 0-byte strings, hash is %.8lx\n", i, h);
+ }
+}
+
+
+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) */
+ return 1;
+}
+
+#endif /* SELF_TEST */