Wed, 27 Apr 2016 01:25:04 +0800
Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17
aoqi@0 | 1 | /* |
aoqi@0 | 2 | * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. |
aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
aoqi@0 | 4 | * |
aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
aoqi@0 | 7 | * published by the Free Software Foundation. |
aoqi@0 | 8 | * |
aoqi@0 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
aoqi@0 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
aoqi@0 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
aoqi@0 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
aoqi@0 | 13 | * accompanied this code). |
aoqi@0 | 14 | * |
aoqi@0 | 15 | * You should have received a copy of the GNU General Public License version |
aoqi@0 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
aoqi@0 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
aoqi@0 | 18 | * |
aoqi@0 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
aoqi@0 | 20 | * or visit www.oracle.com if you need additional information or have any |
aoqi@0 | 21 | * questions. |
aoqi@0 | 22 | * |
aoqi@0 | 23 | */ |
aoqi@0 | 24 | |
aoqi@0 | 25 | #include "precompiled.hpp" |
aoqi@0 | 26 | #include "libadt/dict.hpp" |
aoqi@0 | 27 | #include "memory/allocation.inline.hpp" |
aoqi@0 | 28 | #include "memory/resourceArea.hpp" |
aoqi@0 | 29 | #include "runtime/thread.hpp" |
aoqi@0 | 30 | |
aoqi@0 | 31 | // Dictionaries - An Abstract Data Type |
aoqi@0 | 32 | |
aoqi@0 | 33 | // %%%%% includes not needed with AVM framework - Ungar |
aoqi@0 | 34 | |
aoqi@0 | 35 | // #include "port.hpp" |
aoqi@0 | 36 | //IMPLEMENTATION |
aoqi@0 | 37 | // #include "dict.hpp" |
aoqi@0 | 38 | |
aoqi@0 | 39 | #include <assert.h> |
aoqi@0 | 40 | |
aoqi@0 | 41 | PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
aoqi@0 | 42 | |
aoqi@0 | 43 | // The iostream is not needed and it gets confused for gcc by the |
aoqi@0 | 44 | // define of bool. |
aoqi@0 | 45 | // |
aoqi@0 | 46 | // #include <iostream.h> |
aoqi@0 | 47 | |
aoqi@0 | 48 | //------------------------------data----------------------------------------- |
aoqi@0 | 49 | // String hash tables |
aoqi@0 | 50 | #define MAXID 20 |
aoqi@0 | 51 | static byte initflag = 0; // True after 1st initialization |
aoqi@0 | 52 | static const char shft[MAXID] = {1,2,3,4,5,6,7,1,2,3,4,5,6,7,1,2,3,4,5,6}; |
aoqi@0 | 53 | static short xsum[MAXID]; |
aoqi@0 | 54 | |
aoqi@0 | 55 | //------------------------------bucket--------------------------------------- |
aoqi@0 | 56 | class bucket : public ResourceObj { |
aoqi@0 | 57 | public: |
aoqi@0 | 58 | uint _cnt, _max; // Size of bucket |
aoqi@0 | 59 | void **_keyvals; // Array of keys and values |
aoqi@0 | 60 | }; |
aoqi@0 | 61 | |
aoqi@0 | 62 | //------------------------------Dict----------------------------------------- |
aoqi@0 | 63 | // The dictionary is kept has a hash table. The hash table is a even power |
aoqi@0 | 64 | // of two, for nice modulo operations. Each bucket in the hash table points |
aoqi@0 | 65 | // to a linear list of key-value pairs; each key & value is just a (void *). |
aoqi@0 | 66 | // The list starts with a count. A hash lookup finds the list head, then a |
aoqi@0 | 67 | // simple linear scan finds the key. If the table gets too full, it's |
aoqi@0 | 68 | // doubled in size; the total amount of EXTRA times all hash functions are |
aoqi@0 | 69 | // computed for the doubling is no more than the current size - thus the |
aoqi@0 | 70 | // doubling in size costs no more than a constant factor in speed. |
aoqi@0 | 71 | Dict::Dict(CmpKey initcmp, Hash inithash) : _hash(inithash), _cmp(initcmp), |
aoqi@0 | 72 | _arena(Thread::current()->resource_area()) { |
aoqi@0 | 73 | int i; |
aoqi@0 | 74 | |
aoqi@0 | 75 | // Precompute table of null character hashes |
aoqi@0 | 76 | if( !initflag ) { // Not initializated yet? |
aoqi@0 | 77 | xsum[0] = (1<<shft[0])+1; // Initialize |
aoqi@0 | 78 | for(i=1; i<MAXID; i++) { |
aoqi@0 | 79 | xsum[i] = (1<<shft[i])+1+xsum[i-1]; |
aoqi@0 | 80 | } |
aoqi@0 | 81 | initflag = 1; // Never again |
aoqi@0 | 82 | } |
aoqi@0 | 83 | |
aoqi@0 | 84 | _size = 16; // Size is a power of 2 |
aoqi@0 | 85 | _cnt = 0; // Dictionary is empty |
aoqi@0 | 86 | _bin = (bucket*)_arena->Amalloc_4(sizeof(bucket)*_size); |
aoqi@0 | 87 | memset(_bin,0,sizeof(bucket)*_size); |
aoqi@0 | 88 | } |
aoqi@0 | 89 | |
aoqi@0 | 90 | Dict::Dict(CmpKey initcmp, Hash inithash, Arena *arena, int size) |
aoqi@0 | 91 | : _hash(inithash), _cmp(initcmp), _arena(arena) { |
aoqi@0 | 92 | int i; |
aoqi@0 | 93 | |
aoqi@0 | 94 | // Precompute table of null character hashes |
aoqi@0 | 95 | if( !initflag ) { // Not initializated yet? |
aoqi@0 | 96 | xsum[0] = (1<<shft[0])+1; // Initialize |
aoqi@0 | 97 | for(i=1; i<MAXID; i++) { |
aoqi@0 | 98 | xsum[i] = (1<<shft[i])+1+xsum[i-1]; |
aoqi@0 | 99 | } |
aoqi@0 | 100 | initflag = 1; // Never again |
aoqi@0 | 101 | } |
aoqi@0 | 102 | |
aoqi@0 | 103 | i=16; |
aoqi@0 | 104 | while( i < size ) i <<= 1; |
aoqi@0 | 105 | _size = i; // Size is a power of 2 |
aoqi@0 | 106 | _cnt = 0; // Dictionary is empty |
aoqi@0 | 107 | _bin = (bucket*)_arena->Amalloc_4(sizeof(bucket)*_size); |
aoqi@0 | 108 | memset(_bin,0,sizeof(bucket)*_size); |
aoqi@0 | 109 | } |
aoqi@0 | 110 | |
aoqi@0 | 111 | //------------------------------~Dict------------------------------------------ |
aoqi@0 | 112 | // Delete an existing dictionary. |
aoqi@0 | 113 | Dict::~Dict() { |
aoqi@0 | 114 | /* |
aoqi@0 | 115 | tty->print("~Dict %d/%d: ",_cnt,_size); |
aoqi@0 | 116 | for( uint i=0; i < _size; i++) // For complete new table do |
aoqi@0 | 117 | tty->print("%d ",_bin[i]._cnt); |
aoqi@0 | 118 | tty->print("\n");*/ |
aoqi@0 | 119 | /*for( uint i=0; i<_size; i++ ) { |
aoqi@0 | 120 | FREE_FAST( _bin[i]._keyvals ); |
aoqi@0 | 121 | } */ |
aoqi@0 | 122 | } |
aoqi@0 | 123 | |
aoqi@0 | 124 | //------------------------------Clear---------------------------------------- |
aoqi@0 | 125 | // Zap to empty; ready for re-use |
aoqi@0 | 126 | void Dict::Clear() { |
aoqi@0 | 127 | _cnt = 0; // Empty contents |
aoqi@0 | 128 | for( uint i=0; i<_size; i++ ) |
aoqi@0 | 129 | _bin[i]._cnt = 0; // Empty buckets, but leave allocated |
aoqi@0 | 130 | // Leave _size & _bin alone, under the assumption that dictionary will |
aoqi@0 | 131 | // grow to this size again. |
aoqi@0 | 132 | } |
aoqi@0 | 133 | |
aoqi@0 | 134 | //------------------------------doubhash--------------------------------------- |
aoqi@0 | 135 | // Double hash table size. If can't do so, just suffer. If can, then run |
aoqi@0 | 136 | // thru old hash table, moving things to new table. Note that since hash |
aoqi@0 | 137 | // table doubled, exactly 1 new bit is exposed in the mask - so everything |
aoqi@0 | 138 | // in the old table ends up on 1 of two lists in the new table; a hi and a |
aoqi@0 | 139 | // lo list depending on the value of the bit. |
aoqi@0 | 140 | void Dict::doubhash(void) { |
aoqi@0 | 141 | uint oldsize = _size; |
aoqi@0 | 142 | _size <<= 1; // Double in size |
aoqi@0 | 143 | _bin = (bucket*)_arena->Arealloc( _bin, sizeof(bucket)*oldsize, sizeof(bucket)*_size ); |
aoqi@0 | 144 | memset( &_bin[oldsize], 0, oldsize*sizeof(bucket) ); |
aoqi@0 | 145 | // Rehash things to spread into new table |
aoqi@0 | 146 | for( uint i=0; i < oldsize; i++) { // For complete OLD table do |
aoqi@0 | 147 | bucket *b = &_bin[i]; // Handy shortcut for _bin[i] |
aoqi@0 | 148 | if( !b->_keyvals ) continue; // Skip empties fast |
aoqi@0 | 149 | |
aoqi@0 | 150 | bucket *nb = &_bin[i+oldsize]; // New bucket shortcut |
aoqi@0 | 151 | uint j = b->_max; // Trim new bucket to nearest power of 2 |
aoqi@0 | 152 | while( j > b->_cnt ) j >>= 1; // above old bucket _cnt |
aoqi@0 | 153 | if( !j ) j = 1; // Handle zero-sized buckets |
aoqi@0 | 154 | nb->_max = j<<1; |
aoqi@0 | 155 | // Allocate worst case space for key-value pairs |
aoqi@0 | 156 | nb->_keyvals = (void**)_arena->Amalloc_4( sizeof(void *)*nb->_max*2 ); |
aoqi@0 | 157 | uint nbcnt = 0; |
aoqi@0 | 158 | |
aoqi@0 | 159 | for( j=0; j<b->_cnt; j++ ) { // Rehash all keys in this bucket |
aoqi@0 | 160 | void *key = b->_keyvals[j+j]; |
aoqi@0 | 161 | if( (_hash( key ) & (_size-1)) != i ) { // Moving to hi bucket? |
aoqi@0 | 162 | nb->_keyvals[nbcnt+nbcnt] = key; |
aoqi@0 | 163 | nb->_keyvals[nbcnt+nbcnt+1] = b->_keyvals[j+j+1]; |
aoqi@0 | 164 | nb->_cnt = nbcnt = nbcnt+1; |
aoqi@0 | 165 | b->_cnt--; // Remove key/value from lo bucket |
aoqi@0 | 166 | b->_keyvals[j+j ] = b->_keyvals[b->_cnt+b->_cnt ]; |
aoqi@0 | 167 | b->_keyvals[j+j+1] = b->_keyvals[b->_cnt+b->_cnt+1]; |
aoqi@0 | 168 | j--; // Hash compacted element also |
aoqi@0 | 169 | } |
aoqi@0 | 170 | } // End of for all key-value pairs in bucket |
aoqi@0 | 171 | } // End of for all buckets |
aoqi@0 | 172 | |
aoqi@0 | 173 | |
aoqi@0 | 174 | } |
aoqi@0 | 175 | |
aoqi@0 | 176 | //------------------------------Dict----------------------------------------- |
aoqi@0 | 177 | // Deep copy a dictionary. |
aoqi@0 | 178 | Dict::Dict( const Dict &d ) : _size(d._size), _cnt(d._cnt), _hash(d._hash),_cmp(d._cmp), _arena(d._arena) { |
aoqi@0 | 179 | _bin = (bucket*)_arena->Amalloc_4(sizeof(bucket)*_size); |
aoqi@0 | 180 | memcpy( _bin, d._bin, sizeof(bucket)*_size ); |
aoqi@0 | 181 | for( uint i=0; i<_size; i++ ) { |
aoqi@0 | 182 | if( !_bin[i]._keyvals ) continue; |
aoqi@0 | 183 | _bin[i]._keyvals=(void**)_arena->Amalloc_4( sizeof(void *)*_bin[i]._max*2); |
aoqi@0 | 184 | memcpy( _bin[i]._keyvals, d._bin[i]._keyvals,_bin[i]._cnt*2*sizeof(void*)); |
aoqi@0 | 185 | } |
aoqi@0 | 186 | } |
aoqi@0 | 187 | |
aoqi@0 | 188 | //------------------------------Dict----------------------------------------- |
aoqi@0 | 189 | // Deep copy a dictionary. |
aoqi@0 | 190 | Dict &Dict::operator =( const Dict &d ) { |
aoqi@0 | 191 | if( _size < d._size ) { // If must have more buckets |
aoqi@0 | 192 | _arena = d._arena; |
aoqi@0 | 193 | _bin = (bucket*)_arena->Arealloc( _bin, sizeof(bucket)*_size, sizeof(bucket)*d._size ); |
aoqi@0 | 194 | memset( &_bin[_size], 0, (d._size-_size)*sizeof(bucket) ); |
aoqi@0 | 195 | _size = d._size; |
aoqi@0 | 196 | } |
aoqi@0 | 197 | uint i; |
aoqi@0 | 198 | for( i=0; i<_size; i++ ) // All buckets are empty |
aoqi@0 | 199 | _bin[i]._cnt = 0; // But leave bucket allocations alone |
aoqi@0 | 200 | _cnt = d._cnt; |
aoqi@0 | 201 | *(Hash*)(&_hash) = d._hash; |
aoqi@0 | 202 | *(CmpKey*)(&_cmp) = d._cmp; |
aoqi@0 | 203 | for( i=0; i<_size; i++ ) { |
aoqi@0 | 204 | bucket *b = &d._bin[i]; // Shortcut to source bucket |
aoqi@0 | 205 | for( uint j=0; j<b->_cnt; j++ ) |
aoqi@0 | 206 | Insert( b->_keyvals[j+j], b->_keyvals[j+j+1] ); |
aoqi@0 | 207 | } |
aoqi@0 | 208 | return *this; |
aoqi@0 | 209 | } |
aoqi@0 | 210 | |
aoqi@0 | 211 | //------------------------------Insert---------------------------------------- |
aoqi@0 | 212 | // Insert or replace a key/value pair in the given dictionary. If the |
aoqi@0 | 213 | // dictionary is too full, it's size is doubled. The prior value being |
aoqi@0 | 214 | // replaced is returned (NULL if this is a 1st insertion of that key). If |
aoqi@0 | 215 | // an old value is found, it's swapped with the prior key-value pair on the |
aoqi@0 | 216 | // list. This moves a commonly searched-for value towards the list head. |
aoqi@0 | 217 | void *Dict::Insert(void *key, void *val, bool replace) { |
aoqi@0 | 218 | uint hash = _hash( key ); // Get hash key |
aoqi@0 | 219 | uint i = hash & (_size-1); // Get hash key, corrected for size |
aoqi@0 | 220 | bucket *b = &_bin[i]; // Handy shortcut |
aoqi@0 | 221 | for( uint j=0; j<b->_cnt; j++ ) { |
aoqi@0 | 222 | if( !_cmp(key,b->_keyvals[j+j]) ) { |
aoqi@0 | 223 | if (!replace) { |
aoqi@0 | 224 | return b->_keyvals[j+j+1]; |
aoqi@0 | 225 | } else { |
aoqi@0 | 226 | void *prior = b->_keyvals[j+j+1]; |
aoqi@0 | 227 | b->_keyvals[j+j ] = key; // Insert current key-value |
aoqi@0 | 228 | b->_keyvals[j+j+1] = val; |
aoqi@0 | 229 | return prior; // Return prior |
aoqi@0 | 230 | } |
aoqi@0 | 231 | } |
aoqi@0 | 232 | } |
aoqi@0 | 233 | if( ++_cnt > _size ) { // Hash table is full |
aoqi@0 | 234 | doubhash(); // Grow whole table if too full |
aoqi@0 | 235 | i = hash & (_size-1); // Rehash |
aoqi@0 | 236 | b = &_bin[i]; // Handy shortcut |
aoqi@0 | 237 | } |
aoqi@0 | 238 | if( b->_cnt == b->_max ) { // Must grow bucket? |
aoqi@0 | 239 | if( !b->_keyvals ) { |
aoqi@0 | 240 | b->_max = 2; // Initial bucket size |
aoqi@0 | 241 | b->_keyvals = (void**)_arena->Amalloc_4(sizeof(void*) * b->_max * 2); |
aoqi@0 | 242 | } else { |
aoqi@0 | 243 | b->_keyvals = (void**)_arena->Arealloc(b->_keyvals, sizeof(void*) * b->_max * 2, sizeof(void*) * b->_max * 4); |
aoqi@0 | 244 | b->_max <<= 1; // Double bucket |
aoqi@0 | 245 | } |
aoqi@0 | 246 | } |
aoqi@0 | 247 | b->_keyvals[b->_cnt+b->_cnt ] = key; |
aoqi@0 | 248 | b->_keyvals[b->_cnt+b->_cnt+1] = val; |
aoqi@0 | 249 | b->_cnt++; |
aoqi@0 | 250 | return NULL; // Nothing found prior |
aoqi@0 | 251 | } |
aoqi@0 | 252 | |
aoqi@0 | 253 | //------------------------------Delete--------------------------------------- |
aoqi@0 | 254 | // Find & remove a value from dictionary. Return old value. |
aoqi@0 | 255 | void *Dict::Delete(void *key) { |
aoqi@0 | 256 | uint i = _hash( key ) & (_size-1); // Get hash key, corrected for size |
aoqi@0 | 257 | bucket *b = &_bin[i]; // Handy shortcut |
aoqi@0 | 258 | for( uint j=0; j<b->_cnt; j++ ) |
aoqi@0 | 259 | if( !_cmp(key,b->_keyvals[j+j]) ) { |
aoqi@0 | 260 | void *prior = b->_keyvals[j+j+1]; |
aoqi@0 | 261 | b->_cnt--; // Remove key/value from lo bucket |
aoqi@0 | 262 | b->_keyvals[j+j ] = b->_keyvals[b->_cnt+b->_cnt ]; |
aoqi@0 | 263 | b->_keyvals[j+j+1] = b->_keyvals[b->_cnt+b->_cnt+1]; |
aoqi@0 | 264 | _cnt--; // One less thing in table |
aoqi@0 | 265 | return prior; |
aoqi@0 | 266 | } |
aoqi@0 | 267 | return NULL; |
aoqi@0 | 268 | } |
aoqi@0 | 269 | |
aoqi@0 | 270 | //------------------------------FindDict------------------------------------- |
aoqi@0 | 271 | // Find a key-value pair in the given dictionary. If not found, return NULL. |
aoqi@0 | 272 | // If found, move key-value pair towards head of list. |
aoqi@0 | 273 | void *Dict::operator [](const void *key) const { |
aoqi@0 | 274 | uint i = _hash( key ) & (_size-1); // Get hash key, corrected for size |
aoqi@0 | 275 | bucket *b = &_bin[i]; // Handy shortcut |
aoqi@0 | 276 | for( uint j=0; j<b->_cnt; j++ ) |
aoqi@0 | 277 | if( !_cmp(key,b->_keyvals[j+j]) ) |
aoqi@0 | 278 | return b->_keyvals[j+j+1]; |
aoqi@0 | 279 | return NULL; |
aoqi@0 | 280 | } |
aoqi@0 | 281 | |
aoqi@0 | 282 | //------------------------------CmpDict-------------------------------------- |
aoqi@0 | 283 | // CmpDict compares two dictionaries; they must have the same keys (their |
aoqi@0 | 284 | // keys must match using CmpKey) and they must have the same values (pointer |
aoqi@0 | 285 | // comparison). If so 1 is returned, if not 0 is returned. |
aoqi@0 | 286 | int32 Dict::operator ==(const Dict &d2) const { |
aoqi@0 | 287 | if( _cnt != d2._cnt ) return 0; |
aoqi@0 | 288 | if( _hash != d2._hash ) return 0; |
aoqi@0 | 289 | if( _cmp != d2._cmp ) return 0; |
aoqi@0 | 290 | for( uint i=0; i < _size; i++) { // For complete hash table do |
aoqi@0 | 291 | bucket *b = &_bin[i]; // Handy shortcut |
aoqi@0 | 292 | if( b->_cnt != d2._bin[i]._cnt ) return 0; |
aoqi@0 | 293 | if( memcmp(b->_keyvals, d2._bin[i]._keyvals, b->_cnt*2*sizeof(void*) ) ) |
aoqi@0 | 294 | return 0; // Key-value pairs must match |
aoqi@0 | 295 | } |
aoqi@0 | 296 | return 1; // All match, is OK |
aoqi@0 | 297 | } |
aoqi@0 | 298 | |
aoqi@0 | 299 | //------------------------------print------------------------------------------ |
aoqi@0 | 300 | // Handier print routine |
aoqi@0 | 301 | void Dict::print() { |
aoqi@0 | 302 | DictI i(this); // Moved definition in iterator here because of g++. |
aoqi@0 | 303 | tty->print("Dict@0x%lx[%d] = {", this, _cnt); |
aoqi@0 | 304 | for( ; i.test(); ++i ) { |
aoqi@0 | 305 | tty->print("(0x%lx,0x%lx),", i._key, i._value); |
aoqi@0 | 306 | } |
aoqi@0 | 307 | tty->print_cr("}"); |
aoqi@0 | 308 | } |
aoqi@0 | 309 | |
aoqi@0 | 310 | //------------------------------Hashing Functions---------------------------- |
aoqi@0 | 311 | // Convert string to hash key. This algorithm implements a universal hash |
aoqi@0 | 312 | // function with the multipliers frozen (ok, so it's not universal). The |
aoqi@0 | 313 | // multipliers (and allowable characters) are all odd, so the resultant sum |
aoqi@0 | 314 | // is odd - guaranteed not divisible by any power of two, so the hash tables |
aoqi@0 | 315 | // can be any power of two with good results. Also, I choose multipliers |
aoqi@0 | 316 | // that have only 2 bits set (the low is always set to be odd) so |
aoqi@0 | 317 | // multiplication requires only shifts and adds. Characters are required to |
aoqi@0 | 318 | // be in the range 0-127 (I double & add 1 to force oddness). Keys are |
aoqi@0 | 319 | // limited to MAXID characters in length. Experimental evidence on 150K of |
aoqi@0 | 320 | // C text shows excellent spreading of values for any size hash table. |
aoqi@0 | 321 | int hashstr(const void *t) { |
aoqi@0 | 322 | register char c, k = 0; |
aoqi@0 | 323 | register int32 sum = 0; |
aoqi@0 | 324 | register const char *s = (const char *)t; |
aoqi@0 | 325 | |
aoqi@0 | 326 | while( ((c = *s++) != '\0') && (k < MAXID-1) ) { // Get characters till null or MAXID-1 |
aoqi@0 | 327 | c = (c<<1)+1; // Characters are always odd! |
aoqi@0 | 328 | sum += c + (c<<shft[k++]); // Universal hash function |
aoqi@0 | 329 | } |
aoqi@0 | 330 | return (int)((sum+xsum[k]) >> 1); // Hash key, un-modulo'd table size |
aoqi@0 | 331 | } |
aoqi@0 | 332 | |
aoqi@0 | 333 | //------------------------------hashptr-------------------------------------- |
aoqi@0 | 334 | // Slimey cheap hash function; no guaranteed performance. Better than the |
aoqi@0 | 335 | // default for pointers, especially on MS-DOS machines. |
aoqi@0 | 336 | int hashptr(const void *key) { |
aoqi@0 | 337 | #ifdef __TURBOC__ |
aoqi@0 | 338 | return ((intptr_t)key >> 16); |
aoqi@0 | 339 | #else // __TURBOC__ |
aoqi@0 | 340 | return ((intptr_t)key >> 2); |
aoqi@0 | 341 | #endif |
aoqi@0 | 342 | } |
aoqi@0 | 343 | |
aoqi@0 | 344 | // Slimey cheap hash function; no guaranteed performance. |
aoqi@0 | 345 | int hashkey(const void *key) { |
aoqi@0 | 346 | return (intptr_t)key; |
aoqi@0 | 347 | } |
aoqi@0 | 348 | |
aoqi@0 | 349 | //------------------------------Key Comparator Functions--------------------- |
aoqi@0 | 350 | int32 cmpstr(const void *k1, const void *k2) { |
aoqi@0 | 351 | return strcmp((const char *)k1,(const char *)k2); |
aoqi@0 | 352 | } |
aoqi@0 | 353 | |
aoqi@0 | 354 | // Cheap key comparator. |
aoqi@0 | 355 | int32 cmpkey(const void *key1, const void *key2) { |
aoqi@0 | 356 | if (key1 == key2) return 0; |
aoqi@0 | 357 | intptr_t delta = (intptr_t)key1 - (intptr_t)key2; |
aoqi@0 | 358 | if (delta > 0) return 1; |
aoqi@0 | 359 | return -1; |
aoqi@0 | 360 | } |
aoqi@0 | 361 | |
aoqi@0 | 362 | //============================================================================= |
aoqi@0 | 363 | //------------------------------reset------------------------------------------ |
aoqi@0 | 364 | // Create an iterator and initialize the first variables. |
aoqi@0 | 365 | void DictI::reset( const Dict *dict ) { |
aoqi@0 | 366 | _d = dict; // The dictionary |
aoqi@0 | 367 | _i = (uint)-1; // Before the first bin |
aoqi@0 | 368 | _j = 0; // Nothing left in the current bin |
aoqi@0 | 369 | ++(*this); // Step to first real value |
aoqi@0 | 370 | } |
aoqi@0 | 371 | |
aoqi@0 | 372 | //------------------------------next------------------------------------------- |
aoqi@0 | 373 | // Find the next key-value pair in the dictionary, or return a NULL key and |
aoqi@0 | 374 | // value. |
aoqi@0 | 375 | void DictI::operator ++(void) { |
aoqi@0 | 376 | if( _j-- ) { // Still working in current bin? |
aoqi@0 | 377 | _key = _d->_bin[_i]._keyvals[_j+_j]; |
aoqi@0 | 378 | _value = _d->_bin[_i]._keyvals[_j+_j+1]; |
aoqi@0 | 379 | return; |
aoqi@0 | 380 | } |
aoqi@0 | 381 | |
aoqi@0 | 382 | while( ++_i < _d->_size ) { // Else scan for non-zero bucket |
aoqi@0 | 383 | _j = _d->_bin[_i]._cnt; |
aoqi@0 | 384 | if( !_j ) continue; |
aoqi@0 | 385 | _j--; |
aoqi@0 | 386 | _key = _d->_bin[_i]._keyvals[_j+_j]; |
aoqi@0 | 387 | _value = _d->_bin[_i]._keyvals[_j+_j+1]; |
aoqi@0 | 388 | return; |
aoqi@0 | 389 | } |
aoqi@0 | 390 | _key = _value = NULL; |
aoqi@0 | 391 | } |