Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 1 | /* |
Michael Clark | f6a6e48 | 2007-03-13 08:26:23 +0000 | [diff] [blame] | 2 | * $Id: linkhash.c,v 1.4 2006/01/26 02:16:28 mclark Exp $ |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 3 | * |
Michael Clark | f6a6e48 | 2007-03-13 08:26:23 +0000 | [diff] [blame] | 4 | * Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd. |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 5 | * Michael Clark <michael@metaparadigm.com> |
Keith Derrick | 4a2cd96 | 2012-04-12 11:43:34 -0700 | [diff] [blame] | 6 | * Copyright (c) 2009 Hewlett-Packard Development Company, L.P. |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 7 | * |
Michael Clark | f6a6e48 | 2007-03-13 08:26:23 +0000 | [diff] [blame] | 8 | * This library is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the MIT license. See COPYING for details. |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <stdio.h> |
| 14 | #include <string.h> |
| 15 | #include <stdlib.h> |
| 16 | #include <stdarg.h> |
Michael Clark | 4504df7 | 2007-03-13 08:26:20 +0000 | [diff] [blame] | 17 | #include <stddef.h> |
| 18 | #include <limits.h> |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 19 | |
Michael Clark | 64e3690 | 2014-04-09 13:48:21 +0800 | [diff] [blame] | 20 | #ifdef HAVE_ENDIAN_H |
| 21 | # include <endian.h> /* attempt to define endianness */ |
| 22 | #endif |
| 23 | |
| 24 | #include "random_seed.h" |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 25 | #include "linkhash.h" |
| 26 | |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 27 | void lh_abort(const char *msg, ...) |
| 28 | { |
| 29 | va_list ap; |
| 30 | va_start(ap, msg); |
| 31 | vprintf(msg, ap); |
Michael Clark | 8cdac64 | 2009-01-05 03:57:59 +0000 | [diff] [blame] | 32 | va_end(ap); |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 33 | exit(1); |
| 34 | } |
| 35 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 36 | unsigned long lh_ptr_hash(const void *k) |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 37 | { |
Michael Clark | 4504df7 | 2007-03-13 08:26:20 +0000 | [diff] [blame] | 38 | /* CAW: refactored to be 64bit nice */ |
| 39 | return (unsigned long)((((ptrdiff_t)k * LH_PRIME) >> 4) & ULONG_MAX); |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 40 | } |
| 41 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 42 | int lh_ptr_equal(const void *k1, const void *k2) |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 43 | { |
| 44 | return (k1 == k2); |
| 45 | } |
| 46 | |
Michael Clark | 64e3690 | 2014-04-09 13:48:21 +0800 | [diff] [blame] | 47 | /* |
| 48 | * hashlittle from lookup3.c, by Bob Jenkins, May 2006, Public Domain. |
| 49 | * http://burtleburtle.net/bob/c/lookup3.c |
| 50 | * minor modifications to make functions static so no symbols are exported |
| 51 | * minor mofifications to compile with -Werror |
| 52 | */ |
| 53 | |
| 54 | /* |
| 55 | ------------------------------------------------------------------------------- |
| 56 | lookup3.c, by Bob Jenkins, May 2006, Public Domain. |
| 57 | |
| 58 | These are functions for producing 32-bit hashes for hash table lookup. |
| 59 | hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() |
| 60 | are externally useful functions. Routines to test the hash are included |
| 61 | if SELF_TEST is defined. You can use this free for any purpose. It's in |
| 62 | the public domain. It has no warranty. |
| 63 | |
| 64 | You probably want to use hashlittle(). hashlittle() and hashbig() |
| 65 | hash byte arrays. hashlittle() is is faster than hashbig() on |
| 66 | little-endian machines. Intel and AMD are little-endian machines. |
| 67 | On second thought, you probably want hashlittle2(), which is identical to |
| 68 | hashlittle() except it returns two 32-bit hashes for the price of one. |
| 69 | You could implement hashbig2() if you wanted but I haven't bothered here. |
| 70 | |
| 71 | If you want to find a hash of, say, exactly 7 integers, do |
| 72 | a = i1; b = i2; c = i3; |
| 73 | mix(a,b,c); |
| 74 | a += i4; b += i5; c += i6; |
| 75 | mix(a,b,c); |
| 76 | a += i7; |
| 77 | final(a,b,c); |
| 78 | then use c as the hash value. If you have a variable length array of |
| 79 | 4-byte integers to hash, use hashword(). If you have a byte array (like |
| 80 | a character string), use hashlittle(). If you have several byte arrays, or |
| 81 | a mix of things, see the comments above hashlittle(). |
| 82 | |
| 83 | Why is this so big? I read 12 bytes at a time into 3 4-byte integers, |
| 84 | then mix those integers. This is fast (you can do a lot more thorough |
| 85 | mixing with 12*3 instructions on 3 integers than you can with 3 instructions |
| 86 | on 1 byte), but shoehorning those bytes into integers efficiently is messy. |
| 87 | ------------------------------------------------------------------------------- |
| 88 | */ |
| 89 | |
| 90 | /* |
| 91 | * My best guess at if you are big-endian or little-endian. This may |
| 92 | * need adjustment. |
| 93 | */ |
| 94 | #if (defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && \ |
| 95 | __BYTE_ORDER == __LITTLE_ENDIAN) || \ |
| 96 | (defined(i386) || defined(__i386__) || defined(__i486__) || \ |
| 97 | defined(__i586__) || defined(__i686__) || defined(vax) || defined(MIPSEL)) |
| 98 | # define HASH_LITTLE_ENDIAN 1 |
| 99 | # define HASH_BIG_ENDIAN 0 |
| 100 | #elif (defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && \ |
| 101 | __BYTE_ORDER == __BIG_ENDIAN) || \ |
| 102 | (defined(sparc) || defined(POWERPC) || defined(mc68000) || defined(sel)) |
| 103 | # define HASH_LITTLE_ENDIAN 0 |
| 104 | # define HASH_BIG_ENDIAN 1 |
| 105 | #else |
| 106 | # define HASH_LITTLE_ENDIAN 0 |
| 107 | # define HASH_BIG_ENDIAN 0 |
| 108 | #endif |
| 109 | |
| 110 | #define hashsize(n) ((uint32_t)1<<(n)) |
| 111 | #define hashmask(n) (hashsize(n)-1) |
| 112 | #define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k)))) |
| 113 | |
| 114 | /* |
| 115 | ------------------------------------------------------------------------------- |
| 116 | mix -- mix 3 32-bit values reversibly. |
| 117 | |
| 118 | This is reversible, so any information in (a,b,c) before mix() is |
| 119 | still in (a,b,c) after mix(). |
| 120 | |
| 121 | If four pairs of (a,b,c) inputs are run through mix(), or through |
| 122 | mix() in reverse, there are at least 32 bits of the output that |
| 123 | are sometimes the same for one pair and different for another pair. |
| 124 | This was tested for: |
| 125 | * pairs that differed by one bit, by two bits, in any combination |
| 126 | of top bits of (a,b,c), or in any combination of bottom bits of |
| 127 | (a,b,c). |
| 128 | * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed |
| 129 | the output delta to a Gray code (a^(a>>1)) so a string of 1's (as |
| 130 | is commonly produced by subtraction) look like a single 1-bit |
| 131 | difference. |
| 132 | * the base values were pseudorandom, all zero but one bit set, or |
| 133 | all zero plus a counter that starts at zero. |
| 134 | |
| 135 | Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that |
| 136 | satisfy this are |
| 137 | 4 6 8 16 19 4 |
| 138 | 9 15 3 18 27 15 |
| 139 | 14 9 3 7 17 3 |
| 140 | Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing |
| 141 | for "differ" defined as + with a one-bit base and a two-bit delta. I |
| 142 | used http://burtleburtle.net/bob/hash/avalanche.html to choose |
| 143 | the operations, constants, and arrangements of the variables. |
| 144 | |
| 145 | This does not achieve avalanche. There are input bits of (a,b,c) |
| 146 | that fail to affect some output bits of (a,b,c), especially of a. The |
| 147 | most thoroughly mixed value is c, but it doesn't really even achieve |
| 148 | avalanche in c. |
| 149 | |
| 150 | This allows some parallelism. Read-after-writes are good at doubling |
| 151 | the number of bits affected, so the goal of mixing pulls in the opposite |
| 152 | direction as the goal of parallelism. I did what I could. Rotates |
| 153 | seem to cost as much as shifts on every machine I could lay my hands |
| 154 | on, and rotates are much kinder to the top and bottom bits, so I used |
| 155 | rotates. |
| 156 | ------------------------------------------------------------------------------- |
| 157 | */ |
| 158 | #define mix(a,b,c) \ |
| 159 | { \ |
| 160 | a -= c; a ^= rot(c, 4); c += b; \ |
| 161 | b -= a; b ^= rot(a, 6); a += c; \ |
| 162 | c -= b; c ^= rot(b, 8); b += a; \ |
| 163 | a -= c; a ^= rot(c,16); c += b; \ |
| 164 | b -= a; b ^= rot(a,19); a += c; \ |
| 165 | c -= b; c ^= rot(b, 4); b += a; \ |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | ------------------------------------------------------------------------------- |
| 170 | final -- final mixing of 3 32-bit values (a,b,c) into c |
| 171 | |
| 172 | Pairs of (a,b,c) values differing in only a few bits will usually |
| 173 | produce values of c that look totally different. This was tested for |
| 174 | * pairs that differed by one bit, by two bits, in any combination |
| 175 | of top bits of (a,b,c), or in any combination of bottom bits of |
| 176 | (a,b,c). |
| 177 | * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed |
| 178 | the output delta to a Gray code (a^(a>>1)) so a string of 1's (as |
| 179 | is commonly produced by subtraction) look like a single 1-bit |
| 180 | difference. |
| 181 | * the base values were pseudorandom, all zero but one bit set, or |
| 182 | all zero plus a counter that starts at zero. |
| 183 | |
| 184 | These constants passed: |
| 185 | 14 11 25 16 4 14 24 |
| 186 | 12 14 25 16 4 14 24 |
| 187 | and these came close: |
| 188 | 4 8 15 26 3 22 24 |
| 189 | 10 8 15 26 3 22 24 |
| 190 | 11 8 15 26 3 22 24 |
| 191 | ------------------------------------------------------------------------------- |
| 192 | */ |
| 193 | #define final(a,b,c) \ |
| 194 | { \ |
| 195 | c ^= b; c -= rot(b,14); \ |
| 196 | a ^= c; a -= rot(c,11); \ |
| 197 | b ^= a; b -= rot(a,25); \ |
| 198 | c ^= b; c -= rot(b,16); \ |
| 199 | a ^= c; a -= rot(c,4); \ |
| 200 | b ^= a; b -= rot(a,14); \ |
| 201 | c ^= b; c -= rot(b,24); \ |
| 202 | } |
| 203 | |
| 204 | |
| 205 | /* |
| 206 | ------------------------------------------------------------------------------- |
| 207 | hashlittle() -- hash a variable-length key into a 32-bit value |
| 208 | k : the key (the unaligned variable-length array of bytes) |
| 209 | length : the length of the key, counting by bytes |
| 210 | initval : can be any 4-byte value |
| 211 | Returns a 32-bit value. Every bit of the key affects every bit of |
| 212 | the return value. Two keys differing by one or two bits will have |
| 213 | totally different hash values. |
| 214 | |
| 215 | The best hash table sizes are powers of 2. There is no need to do |
| 216 | mod a prime (mod is sooo slow!). If you need less than 32 bits, |
| 217 | use a bitmask. For example, if you need only 10 bits, do |
| 218 | h = (h & hashmask(10)); |
| 219 | In which case, the hash table should have hashsize(10) elements. |
| 220 | |
| 221 | If you are hashing n strings (uint8_t **)k, do it like this: |
| 222 | for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h); |
| 223 | |
| 224 | By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this |
| 225 | code any way you wish, private, educational, or commercial. It's free. |
| 226 | |
| 227 | Use for hash table lookup, or anything where one collision in 2^^32 is |
| 228 | acceptable. Do NOT use for cryptographic purposes. |
| 229 | ------------------------------------------------------------------------------- |
| 230 | */ |
| 231 | |
| 232 | static uint32_t hashlittle( const void *key, size_t length, uint32_t initval) |
| 233 | { |
| 234 | uint32_t a,b,c; /* internal state */ |
| 235 | union { const void *ptr; size_t i; } u; /* needed for Mac Powerbook G4 */ |
| 236 | |
| 237 | /* Set up the internal state */ |
| 238 | a = b = c = 0xdeadbeef + ((uint32_t)length) + initval; |
| 239 | |
| 240 | u.ptr = key; |
| 241 | if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) { |
| 242 | const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */ |
| 243 | |
| 244 | /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ |
| 245 | while (length > 12) |
| 246 | { |
| 247 | a += k[0]; |
| 248 | b += k[1]; |
| 249 | c += k[2]; |
| 250 | mix(a,b,c); |
| 251 | length -= 12; |
| 252 | k += 3; |
| 253 | } |
| 254 | |
| 255 | /*----------------------------- handle the last (probably partial) block */ |
| 256 | /* |
| 257 | * "k[2]&0xffffff" actually reads beyond the end of the string, but |
| 258 | * then masks off the part it's not allowed to read. Because the |
| 259 | * string is aligned, the masked-off tail is in the same word as the |
| 260 | * rest of the string. Every machine with memory protection I've seen |
| 261 | * does it on word boundaries, so is OK with this. But VALGRIND will |
| 262 | * still catch it and complain. The masking trick does make the hash |
| 263 | * noticably faster for short strings (like English words). |
| 264 | */ |
| 265 | #ifndef VALGRIND |
| 266 | |
| 267 | switch(length) |
| 268 | { |
| 269 | case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; |
| 270 | case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break; |
| 271 | case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break; |
| 272 | case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break; |
| 273 | case 8 : b+=k[1]; a+=k[0]; break; |
| 274 | case 7 : b+=k[1]&0xffffff; a+=k[0]; break; |
| 275 | case 6 : b+=k[1]&0xffff; a+=k[0]; break; |
| 276 | case 5 : b+=k[1]&0xff; a+=k[0]; break; |
| 277 | case 4 : a+=k[0]; break; |
| 278 | case 3 : a+=k[0]&0xffffff; break; |
| 279 | case 2 : a+=k[0]&0xffff; break; |
| 280 | case 1 : a+=k[0]&0xff; break; |
| 281 | case 0 : return c; /* zero length strings require no mixing */ |
| 282 | } |
| 283 | |
| 284 | #else /* make valgrind happy */ |
| 285 | |
| 286 | const uint8_t *k8 = (const uint8_t *)k; |
| 287 | switch(length) |
| 288 | { |
| 289 | case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; |
| 290 | case 11: c+=((uint32_t)k8[10])<<16; /* fall through */ |
| 291 | case 10: c+=((uint32_t)k8[9])<<8; /* fall through */ |
| 292 | case 9 : c+=k8[8]; /* fall through */ |
| 293 | case 8 : b+=k[1]; a+=k[0]; break; |
| 294 | case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */ |
| 295 | case 6 : b+=((uint32_t)k8[5])<<8; /* fall through */ |
| 296 | case 5 : b+=k8[4]; /* fall through */ |
| 297 | case 4 : a+=k[0]; break; |
| 298 | case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */ |
| 299 | case 2 : a+=((uint32_t)k8[1])<<8; /* fall through */ |
| 300 | case 1 : a+=k8[0]; break; |
| 301 | case 0 : return c; |
| 302 | } |
| 303 | |
| 304 | #endif /* !valgrind */ |
| 305 | |
| 306 | } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) { |
| 307 | const uint16_t *k = (const uint16_t *)key; /* read 16-bit chunks */ |
| 308 | const uint8_t *k8; |
| 309 | |
| 310 | /*--------------- all but last block: aligned reads and different mixing */ |
| 311 | while (length > 12) |
| 312 | { |
| 313 | a += k[0] + (((uint32_t)k[1])<<16); |
| 314 | b += k[2] + (((uint32_t)k[3])<<16); |
| 315 | c += k[4] + (((uint32_t)k[5])<<16); |
| 316 | mix(a,b,c); |
| 317 | length -= 12; |
| 318 | k += 6; |
| 319 | } |
| 320 | |
| 321 | /*----------------------------- handle the last (probably partial) block */ |
| 322 | k8 = (const uint8_t *)k; |
| 323 | switch(length) |
| 324 | { |
| 325 | case 12: c+=k[4]+(((uint32_t)k[5])<<16); |
| 326 | b+=k[2]+(((uint32_t)k[3])<<16); |
| 327 | a+=k[0]+(((uint32_t)k[1])<<16); |
| 328 | break; |
| 329 | case 11: c+=((uint32_t)k8[10])<<16; /* fall through */ |
| 330 | case 10: c+=k[4]; |
| 331 | b+=k[2]+(((uint32_t)k[3])<<16); |
| 332 | a+=k[0]+(((uint32_t)k[1])<<16); |
| 333 | break; |
| 334 | case 9 : c+=k8[8]; /* fall through */ |
| 335 | case 8 : b+=k[2]+(((uint32_t)k[3])<<16); |
| 336 | a+=k[0]+(((uint32_t)k[1])<<16); |
| 337 | break; |
| 338 | case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */ |
| 339 | case 6 : b+=k[2]; |
| 340 | a+=k[0]+(((uint32_t)k[1])<<16); |
| 341 | break; |
| 342 | case 5 : b+=k8[4]; /* fall through */ |
| 343 | case 4 : a+=k[0]+(((uint32_t)k[1])<<16); |
| 344 | break; |
| 345 | case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */ |
| 346 | case 2 : a+=k[0]; |
| 347 | break; |
| 348 | case 1 : a+=k8[0]; |
| 349 | break; |
| 350 | case 0 : return c; /* zero length requires no mixing */ |
| 351 | } |
| 352 | |
| 353 | } else { /* need to read the key one byte at a time */ |
| 354 | const uint8_t *k = (const uint8_t *)key; |
| 355 | |
| 356 | /*--------------- all but the last block: affect some 32 bits of (a,b,c) */ |
| 357 | while (length > 12) |
| 358 | { |
| 359 | a += k[0]; |
| 360 | a += ((uint32_t)k[1])<<8; |
| 361 | a += ((uint32_t)k[2])<<16; |
| 362 | a += ((uint32_t)k[3])<<24; |
| 363 | b += k[4]; |
| 364 | b += ((uint32_t)k[5])<<8; |
| 365 | b += ((uint32_t)k[6])<<16; |
| 366 | b += ((uint32_t)k[7])<<24; |
| 367 | c += k[8]; |
| 368 | c += ((uint32_t)k[9])<<8; |
| 369 | c += ((uint32_t)k[10])<<16; |
| 370 | c += ((uint32_t)k[11])<<24; |
| 371 | mix(a,b,c); |
| 372 | length -= 12; |
| 373 | k += 12; |
| 374 | } |
| 375 | |
| 376 | /*-------------------------------- last block: affect all 32 bits of (c) */ |
| 377 | switch(length) /* all the case statements fall through */ |
| 378 | { |
| 379 | case 12: c+=((uint32_t)k[11])<<24; |
| 380 | case 11: c+=((uint32_t)k[10])<<16; |
| 381 | case 10: c+=((uint32_t)k[9])<<8; |
| 382 | case 9 : c+=k[8]; |
| 383 | case 8 : b+=((uint32_t)k[7])<<24; |
| 384 | case 7 : b+=((uint32_t)k[6])<<16; |
| 385 | case 6 : b+=((uint32_t)k[5])<<8; |
| 386 | case 5 : b+=k[4]; |
| 387 | case 4 : a+=((uint32_t)k[3])<<24; |
| 388 | case 3 : a+=((uint32_t)k[2])<<16; |
| 389 | case 2 : a+=((uint32_t)k[1])<<8; |
| 390 | case 1 : a+=k[0]; |
| 391 | break; |
| 392 | case 0 : return c; |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | final(a,b,c); |
| 397 | return c; |
| 398 | } |
| 399 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 400 | unsigned long lh_char_hash(const void *k) |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 401 | { |
Michael Clark | 64e3690 | 2014-04-09 13:48:21 +0800 | [diff] [blame] | 402 | static volatile int random_seed = -1; |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 403 | |
Michael Clark | 64e3690 | 2014-04-09 13:48:21 +0800 | [diff] [blame] | 404 | if (random_seed == -1) { |
| 405 | int seed; |
| 406 | /* we can't use -1 as it is the unitialized sentinel */ |
| 407 | while ((seed = json_c_get_random_seed()) == -1); |
| 408 | #if defined __GNUC__ |
| 409 | __sync_val_compare_and_swap(&random_seed, -1, seed); |
| 410 | #elif defined _MSC_VER |
| 411 | InterlockedCompareExchange(&random_seed, seed, -1); |
| 412 | #else |
| 413 | #warning "racy random seed initializtion if used by multiple threads" |
| 414 | random_seed = seed; /* potentially racy */ |
| 415 | #endif |
| 416 | } |
| 417 | |
| 418 | return hashlittle((const char*)k, strlen((const char*)k), random_seed); |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 419 | } |
| 420 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 421 | int lh_char_equal(const void *k1, const void *k2) |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 422 | { |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 423 | return (strcmp((const char*)k1, (const char*)k2) == 0); |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 424 | } |
| 425 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 426 | struct lh_table* lh_table_new(int size, const char *name, |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 427 | lh_entry_free_fn *free_fn, |
| 428 | lh_hash_fn *hash_fn, |
| 429 | lh_equal_fn *equal_fn) |
| 430 | { |
| 431 | int i; |
| 432 | struct lh_table *t; |
| 433 | |
Michael Clark | aaec1ef | 2009-02-25 02:31:32 +0000 | [diff] [blame] | 434 | t = (struct lh_table*)calloc(1, sizeof(struct lh_table)); |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 435 | if(!t) lh_abort("lh_table_new: calloc failed\n"); |
| 436 | t->count = 0; |
| 437 | t->size = size; |
| 438 | t->name = name; |
Michael Clark | aaec1ef | 2009-02-25 02:31:32 +0000 | [diff] [blame] | 439 | t->table = (struct lh_entry*)calloc(size, sizeof(struct lh_entry)); |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 440 | if(!t->table) lh_abort("lh_table_new: calloc failed\n"); |
| 441 | t->free_fn = free_fn; |
| 442 | t->hash_fn = hash_fn; |
| 443 | t->equal_fn = equal_fn; |
| 444 | for(i = 0; i < size; i++) t->table[i].k = LH_EMPTY; |
| 445 | return t; |
| 446 | } |
| 447 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 448 | struct lh_table* lh_kchar_table_new(int size, const char *name, |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 449 | lh_entry_free_fn *free_fn) |
| 450 | { |
| 451 | return lh_table_new(size, name, free_fn, lh_char_hash, lh_char_equal); |
| 452 | } |
| 453 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 454 | struct lh_table* lh_kptr_table_new(int size, const char *name, |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 455 | lh_entry_free_fn *free_fn) |
| 456 | { |
| 457 | return lh_table_new(size, name, free_fn, lh_ptr_hash, lh_ptr_equal); |
| 458 | } |
| 459 | |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 460 | void lh_table_resize(struct lh_table *t, int new_size) |
| 461 | { |
| 462 | struct lh_table *new_t; |
| 463 | struct lh_entry *ent; |
| 464 | |
| 465 | new_t = lh_table_new(new_size, t->name, NULL, t->hash_fn, t->equal_fn); |
| 466 | ent = t->head; |
| 467 | while(ent) { |
| 468 | lh_table_insert(new_t, ent->k, ent->v); |
| 469 | ent = ent->next; |
| 470 | } |
| 471 | free(t->table); |
| 472 | t->table = new_t->table; |
| 473 | t->size = new_size; |
| 474 | t->head = new_t->head; |
| 475 | t->tail = new_t->tail; |
| 476 | t->resizes++; |
| 477 | free(new_t); |
| 478 | } |
| 479 | |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 480 | void lh_table_free(struct lh_table *t) |
| 481 | { |
| 482 | struct lh_entry *c; |
| 483 | for(c = t->head; c != NULL; c = c->next) { |
| 484 | if(t->free_fn) { |
| 485 | t->free_fn(c); |
| 486 | } |
| 487 | } |
| 488 | free(t->table); |
| 489 | free(t); |
| 490 | } |
| 491 | |
| 492 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 493 | int lh_table_insert(struct lh_table *t, void *k, const void *v) |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 494 | { |
| 495 | unsigned long h, n; |
| 496 | |
| 497 | t->inserts++; |
Eric Haszlakiewicz | 64c0ca3 | 2012-03-31 17:33:58 -0500 | [diff] [blame] | 498 | if(t->count >= t->size * LH_LOAD_FACTOR) lh_table_resize(t, t->size * 2); |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 499 | |
| 500 | h = t->hash_fn(k); |
| 501 | n = h % t->size; |
| 502 | |
| 503 | while( 1 ) { |
| 504 | if(t->table[n].k == LH_EMPTY || t->table[n].k == LH_FREED) break; |
| 505 | t->collisions++; |
Eric Haszlakiewicz | ca8b27d | 2013-02-09 16:35:24 -0600 | [diff] [blame] | 506 | if ((int)++n == t->size) n = 0; |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 507 | } |
| 508 | |
| 509 | t->table[n].k = k; |
| 510 | t->table[n].v = v; |
| 511 | t->count++; |
| 512 | |
| 513 | if(t->head == NULL) { |
| 514 | t->head = t->tail = &t->table[n]; |
| 515 | t->table[n].next = t->table[n].prev = NULL; |
| 516 | } else { |
| 517 | t->tail->next = &t->table[n]; |
| 518 | t->table[n].prev = t->tail; |
| 519 | t->table[n].next = NULL; |
| 520 | t->tail = &t->table[n]; |
| 521 | } |
| 522 | |
| 523 | return 0; |
| 524 | } |
| 525 | |
| 526 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 527 | struct lh_entry* lh_table_lookup_entry(struct lh_table *t, const void *k) |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 528 | { |
| 529 | unsigned long h = t->hash_fn(k); |
| 530 | unsigned long n = h % t->size; |
Michael Clark | f5dd43a | 2009-08-27 06:40:00 +0000 | [diff] [blame] | 531 | int count = 0; |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 532 | |
| 533 | t->lookups++; |
Michael Clark | f5dd43a | 2009-08-27 06:40:00 +0000 | [diff] [blame] | 534 | while( count < t->size ) { |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 535 | if(t->table[n].k == LH_EMPTY) return NULL; |
| 536 | if(t->table[n].k != LH_FREED && |
| 537 | t->equal_fn(t->table[n].k, k)) return &t->table[n]; |
Eric Haszlakiewicz | ca8b27d | 2013-02-09 16:35:24 -0600 | [diff] [blame] | 538 | if ((int)++n == t->size) n = 0; |
Michael Clark | f5dd43a | 2009-08-27 06:40:00 +0000 | [diff] [blame] | 539 | count++; |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 540 | } |
| 541 | return NULL; |
| 542 | } |
| 543 | |
| 544 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 545 | const void* lh_table_lookup(struct lh_table *t, const void *k) |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 546 | { |
Keith Derrick | 4a2cd96 | 2012-04-12 11:43:34 -0700 | [diff] [blame] | 547 | void *result; |
| 548 | lh_table_lookup_ex(t, k, &result); |
| 549 | return result; |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 550 | } |
| 551 | |
Keith Derrick | 4a2cd96 | 2012-04-12 11:43:34 -0700 | [diff] [blame] | 552 | json_bool lh_table_lookup_ex(struct lh_table* t, const void* k, void **v) |
| 553 | { |
| 554 | struct lh_entry *e = lh_table_lookup_entry(t, k); |
| 555 | if (e != NULL) { |
| 556 | if (v != NULL) *v = (void *)e->v; |
| 557 | return TRUE; /* key found */ |
| 558 | } |
| 559 | if (v != NULL) *v = NULL; |
| 560 | return FALSE; /* key not found */ |
| 561 | } |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 562 | |
| 563 | int lh_table_delete_entry(struct lh_table *t, struct lh_entry *e) |
| 564 | { |
Michael Clark | 4504df7 | 2007-03-13 08:26:20 +0000 | [diff] [blame] | 565 | ptrdiff_t n = (ptrdiff_t)(e - t->table); /* CAW: fixed to be 64bit nice, still need the crazy negative case... */ |
| 566 | |
| 567 | /* CAW: this is bad, really bad, maybe stack goes other direction on this machine... */ |
| 568 | if(n < 0) { return -2; } |
| 569 | |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 570 | if(t->table[n].k == LH_EMPTY || t->table[n].k == LH_FREED) return -1; |
| 571 | t->count--; |
| 572 | if(t->free_fn) t->free_fn(e); |
| 573 | t->table[n].v = NULL; |
| 574 | t->table[n].k = LH_FREED; |
| 575 | if(t->tail == &t->table[n] && t->head == &t->table[n]) { |
| 576 | t->head = t->tail = NULL; |
| 577 | } else if (t->head == &t->table[n]) { |
| 578 | t->head->next->prev = NULL; |
| 579 | t->head = t->head->next; |
| 580 | } else if (t->tail == &t->table[n]) { |
| 581 | t->tail->prev->next = NULL; |
| 582 | t->tail = t->tail->prev; |
| 583 | } else { |
| 584 | t->table[n].prev->next = t->table[n].next; |
| 585 | t->table[n].next->prev = t->table[n].prev; |
| 586 | } |
| 587 | t->table[n].next = t->table[n].prev = NULL; |
| 588 | return 0; |
| 589 | } |
| 590 | |
| 591 | |
Michael Clark | 68cafad | 2009-01-06 22:56:57 +0000 | [diff] [blame] | 592 | int lh_table_delete(struct lh_table *t, const void *k) |
Michael Clark | f0d0888 | 2007-03-13 08:26:18 +0000 | [diff] [blame] | 593 | { |
| 594 | struct lh_entry *e = lh_table_lookup_entry(t, k); |
| 595 | if(!e) return -1; |
| 596 | return lh_table_delete_entry(t, e); |
| 597 | } |
| 598 | |
Greg Hazel | cca74c6 | 2013-01-11 01:36:55 -0800 | [diff] [blame] | 599 | int lh_table_length(struct lh_table *t) |
| 600 | { |
| 601 | return t->count; |
| 602 | } |