Mercurial > hg > graal-compiler
diff src/share/vm/libadt/dict.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 1580954e694c |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/libadt/dict.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,383 @@ +/* + * Copyright 1997-2003 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +// Dictionaries - An Abstract Data Type + +#include "incls/_precompiled.incl" +#include "incls/_dict.cpp.incl" + +// %%%%% includes not needed with AVM framework - Ungar + +// #include "port.hpp" +//IMPLEMENTATION +// #include "dict.hpp" + +#include <assert.h> + +// The iostream is not needed and it gets confused for gcc by the +// define of bool. +// +// #include <iostream.h> + +//------------------------------data----------------------------------------- +// String hash tables +#define MAXID 20 +static byte initflag = 0; // True after 1st initialization +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}; +static short xsum[MAXID]; + +//------------------------------bucket--------------------------------------- +class bucket : public ResourceObj { +public: + uint _cnt, _max; // Size of bucket + void **_keyvals; // Array of keys and values +}; + +//------------------------------Dict----------------------------------------- +// The dictionary is kept has a hash table. The hash table is a even power +// of two, for nice modulo operations. Each bucket in the hash table points +// to a linear list of key-value pairs; each key & value is just a (void *). +// The list starts with a count. A hash lookup finds the list head, then a +// simple linear scan finds the key. If the table gets too full, it's +// doubled in size; the total amount of EXTRA times all hash functions are +// computed for the doubling is no more than the current size - thus the +// doubling in size costs no more than a constant factor in speed. +Dict::Dict(CmpKey initcmp, Hash inithash) : _hash(inithash), _cmp(initcmp), + _arena(Thread::current()->resource_area()) { + int i; + + // Precompute table of null character hashes + if( !initflag ) { // Not initializated yet? + xsum[0] = (1<<shft[0])+1; // Initialize + for(i=1; i<MAXID; i++) { + xsum[i] = (1<<shft[i])+1+xsum[i-1]; + } + initflag = 1; // Never again + } + + _size = 16; // Size is a power of 2 + _cnt = 0; // Dictionary is empty + _bin = (bucket*)_arena->Amalloc_4(sizeof(bucket)*_size); + memset(_bin,0,sizeof(bucket)*_size); +} + +Dict::Dict(CmpKey initcmp, Hash inithash, Arena *arena, int size) +: _hash(inithash), _cmp(initcmp), _arena(arena) { + int i; + + // Precompute table of null character hashes + if( !initflag ) { // Not initializated yet? + xsum[0] = (1<<shft[0])+1; // Initialize + for(i=1; i<MAXID; i++) { + xsum[i] = (1<<shft[i])+1+xsum[i-1]; + } + initflag = 1; // Never again + } + + i=16; + while( i < size ) i <<= 1; + _size = i; // Size is a power of 2 + _cnt = 0; // Dictionary is empty + _bin = (bucket*)_arena->Amalloc_4(sizeof(bucket)*_size); + memset(_bin,0,sizeof(bucket)*_size); +} + +//------------------------------~Dict------------------------------------------ +// Delete an existing dictionary. +Dict::~Dict() { + /* + tty->print("~Dict %d/%d: ",_cnt,_size); + for( uint i=0; i < _size; i++) // For complete new table do + tty->print("%d ",_bin[i]._cnt); + tty->print("\n");*/ + /*for( uint i=0; i<_size; i++ ) { + FREE_FAST( _bin[i]._keyvals ); + } */ +} + +//------------------------------Clear---------------------------------------- +// Zap to empty; ready for re-use +void Dict::Clear() { + _cnt = 0; // Empty contents + for( uint i=0; i<_size; i++ ) + _bin[i]._cnt = 0; // Empty buckets, but leave allocated + // Leave _size & _bin alone, under the assumption that dictionary will + // grow to this size again. +} + +//------------------------------doubhash--------------------------------------- +// Double hash table size. If can't do so, just suffer. If can, then run +// thru old hash table, moving things to new table. Note that since hash +// table doubled, exactly 1 new bit is exposed in the mask - so everything +// in the old table ends up on 1 of two lists in the new table; a hi and a +// lo list depending on the value of the bit. +void Dict::doubhash(void) { + uint oldsize = _size; + _size <<= 1; // Double in size + _bin = (bucket*)_arena->Arealloc( _bin, sizeof(bucket)*oldsize, sizeof(bucket)*_size ); + memset( &_bin[oldsize], 0, oldsize*sizeof(bucket) ); + // Rehash things to spread into new table + for( uint i=0; i < oldsize; i++) { // For complete OLD table do + bucket *b = &_bin[i]; // Handy shortcut for _bin[i] + if( !b->_keyvals ) continue; // Skip empties fast + + bucket *nb = &_bin[i+oldsize]; // New bucket shortcut + uint j = b->_max; // Trim new bucket to nearest power of 2 + while( j > b->_cnt ) j >>= 1; // above old bucket _cnt + if( !j ) j = 1; // Handle zero-sized buckets + nb->_max = j<<1; + // Allocate worst case space for key-value pairs + nb->_keyvals = (void**)_arena->Amalloc_4( sizeof(void *)*nb->_max*2 ); + uint nbcnt = 0; + + for( j=0; j<b->_cnt; j++ ) { // Rehash all keys in this bucket + void *key = b->_keyvals[j+j]; + if( (_hash( key ) & (_size-1)) != i ) { // Moving to hi bucket? + nb->_keyvals[nbcnt+nbcnt] = key; + nb->_keyvals[nbcnt+nbcnt+1] = b->_keyvals[j+j+1]; + nb->_cnt = nbcnt = nbcnt+1; + b->_cnt--; // Remove key/value from lo bucket + b->_keyvals[j+j ] = b->_keyvals[b->_cnt+b->_cnt ]; + b->_keyvals[j+j+1] = b->_keyvals[b->_cnt+b->_cnt+1]; + j--; // Hash compacted element also + } + } // End of for all key-value pairs in bucket + } // End of for all buckets + + +} + +//------------------------------Dict----------------------------------------- +// Deep copy a dictionary. +Dict::Dict( const Dict &d ) : _size(d._size), _cnt(d._cnt), _hash(d._hash),_cmp(d._cmp), _arena(d._arena) { + _bin = (bucket*)_arena->Amalloc_4(sizeof(bucket)*_size); + memcpy( _bin, d._bin, sizeof(bucket)*_size ); + for( uint i=0; i<_size; i++ ) { + if( !_bin[i]._keyvals ) continue; + _bin[i]._keyvals=(void**)_arena->Amalloc_4( sizeof(void *)*_bin[i]._max*2); + memcpy( _bin[i]._keyvals, d._bin[i]._keyvals,_bin[i]._cnt*2*sizeof(void*)); + } +} + +//------------------------------Dict----------------------------------------- +// Deep copy a dictionary. +Dict &Dict::operator =( const Dict &d ) { + if( _size < d._size ) { // If must have more buckets + _arena = d._arena; + _bin = (bucket*)_arena->Arealloc( _bin, sizeof(bucket)*_size, sizeof(bucket)*d._size ); + memset( &_bin[_size], 0, (d._size-_size)*sizeof(bucket) ); + _size = d._size; + } + uint i; + for( i=0; i<_size; i++ ) // All buckets are empty + _bin[i]._cnt = 0; // But leave bucket allocations alone + _cnt = d._cnt; + *(Hash*)(&_hash) = d._hash; + *(CmpKey*)(&_cmp) = d._cmp; + for( i=0; i<_size; i++ ) { + bucket *b = &d._bin[i]; // Shortcut to source bucket + for( uint j=0; j<b->_cnt; j++ ) + Insert( b->_keyvals[j+j], b->_keyvals[j+j+1] ); + } + return *this; +} + +//------------------------------Insert---------------------------------------- +// Insert or replace a key/value pair in the given dictionary. If the +// dictionary is too full, it's size is doubled. The prior value being +// replaced is returned (NULL if this is a 1st insertion of that key). If +// an old value is found, it's swapped with the prior key-value pair on the +// list. This moves a commonly searched-for value towards the list head. +void *Dict::Insert(void *key, void *val, bool replace) { + uint hash = _hash( key ); // Get hash key + uint i = hash & (_size-1); // Get hash key, corrected for size + bucket *b = &_bin[i]; // Handy shortcut + for( uint j=0; j<b->_cnt; j++ ) { + if( !_cmp(key,b->_keyvals[j+j]) ) { + if (!replace) { + return b->_keyvals[j+j+1]; + } else { + void *prior = b->_keyvals[j+j+1]; + b->_keyvals[j+j ] = key; // Insert current key-value + b->_keyvals[j+j+1] = val; + return prior; // Return prior + } + } + } + if( ++_cnt > _size ) { // Hash table is full + doubhash(); // Grow whole table if too full + i = hash & (_size-1); // Rehash + b = &_bin[i]; // Handy shortcut + } + if( b->_cnt == b->_max ) { // Must grow bucket? + if( !b->_keyvals ) { + b->_max = 2; // Initial bucket size + b->_keyvals = (void**)_arena->Amalloc_4(sizeof(void*) * b->_max * 2); + } else { + b->_keyvals = (void**)_arena->Arealloc(b->_keyvals, sizeof(void*) * b->_max * 2, sizeof(void*) * b->_max * 4); + b->_max <<= 1; // Double bucket + } + } + b->_keyvals[b->_cnt+b->_cnt ] = key; + b->_keyvals[b->_cnt+b->_cnt+1] = val; + b->_cnt++; + return NULL; // Nothing found prior +} + +//------------------------------Delete--------------------------------------- +// Find & remove a value from dictionary. Return old value. +void *Dict::Delete(void *key) { + uint i = _hash( key ) & (_size-1); // Get hash key, corrected for size + bucket *b = &_bin[i]; // Handy shortcut + for( uint j=0; j<b->_cnt; j++ ) + if( !_cmp(key,b->_keyvals[j+j]) ) { + void *prior = b->_keyvals[j+j+1]; + b->_cnt--; // Remove key/value from lo bucket + b->_keyvals[j+j ] = b->_keyvals[b->_cnt+b->_cnt ]; + b->_keyvals[j+j+1] = b->_keyvals[b->_cnt+b->_cnt+1]; + _cnt--; // One less thing in table + return prior; + } + return NULL; +} + +//------------------------------FindDict------------------------------------- +// Find a key-value pair in the given dictionary. If not found, return NULL. +// If found, move key-value pair towards head of list. +void *Dict::operator [](const void *key) const { + uint i = _hash( key ) & (_size-1); // Get hash key, corrected for size + bucket *b = &_bin[i]; // Handy shortcut + for( uint j=0; j<b->_cnt; j++ ) + if( !_cmp(key,b->_keyvals[j+j]) ) + return b->_keyvals[j+j+1]; + return NULL; +} + +//------------------------------CmpDict-------------------------------------- +// CmpDict compares two dictionaries; they must have the same keys (their +// keys must match using CmpKey) and they must have the same values (pointer +// comparison). If so 1 is returned, if not 0 is returned. +int32 Dict::operator ==(const Dict &d2) const { + if( _cnt != d2._cnt ) return 0; + if( _hash != d2._hash ) return 0; + if( _cmp != d2._cmp ) return 0; + for( uint i=0; i < _size; i++) { // For complete hash table do + bucket *b = &_bin[i]; // Handy shortcut + if( b->_cnt != d2._bin[i]._cnt ) return 0; + if( memcmp(b->_keyvals, d2._bin[i]._keyvals, b->_cnt*2*sizeof(void*) ) ) + return 0; // Key-value pairs must match + } + return 1; // All match, is OK +} + +//------------------------------print------------------------------------------ +// Handier print routine +void Dict::print() { + DictI i(this); // Moved definition in iterator here because of g++. + tty->print("Dict@0x%lx[%d] = {", this, _cnt); + for( ; i.test(); ++i ) { + tty->print("(0x%lx,0x%lx),", i._key, i._value); + } + tty->print_cr("}"); +} + +//------------------------------Hashing Functions---------------------------- +// Convert string to hash key. This algorithm implements a universal hash +// function with the multipliers frozen (ok, so it's not universal). The +// multipliers (and allowable characters) are all odd, so the resultant sum +// is odd - guarenteed not divisible by any power of two, so the hash tables +// can be any power of two with good results. Also, I choose multipliers +// that have only 2 bits set (the low is always set to be odd) so +// multiplication requires only shifts and adds. Characters are required to +// be in the range 0-127 (I double & add 1 to force oddness). Keys are +// limited to MAXID characters in length. Experimental evidence on 150K of +// C text shows excellent spreading of values for any size hash table. +int hashstr(const void *t) { + register char c, k = 0; + register int32 sum = 0; + register const char *s = (const char *)t; + + while( ((c = *s++) != '\0') && (k < MAXID-1) ) { // Get characters till null or MAXID-1 + c = (c<<1)+1; // Characters are always odd! + sum += c + (c<<shft[k++]); // Universal hash function + } + return (int)((sum+xsum[k]) >> 1); // Hash key, un-modulo'd table size +} + +//------------------------------hashptr-------------------------------------- +// Slimey cheap hash function; no guarenteed performance. Better than the +// default for pointers, especially on MS-DOS machines. +int hashptr(const void *key) { +#ifdef __TURBOC__ + return ((intptr_t)key >> 16); +#else // __TURBOC__ + return ((intptr_t)key >> 2); +#endif +} + +// Slimey cheap hash function; no guarenteed performance. +int hashkey(const void *key) { + return (intptr_t)key; +} + +//------------------------------Key Comparator Functions--------------------- +int32 cmpstr(const void *k1, const void *k2) { + return strcmp((const char *)k1,(const char *)k2); +} + +// Slimey cheap key comparator. +int32 cmpkey(const void *key1, const void *key2) { + return (int32)((intptr_t)key1 - (intptr_t)key2); +} + +//============================================================================= +//------------------------------reset------------------------------------------ +// Create an iterator and initialize the first variables. +void DictI::reset( const Dict *dict ) { + _d = dict; // The dictionary + _i = (uint)-1; // Before the first bin + _j = 0; // Nothing left in the current bin + ++(*this); // Step to first real value +} + +//------------------------------next------------------------------------------- +// Find the next key-value pair in the dictionary, or return a NULL key and +// value. +void DictI::operator ++(void) { + if( _j-- ) { // Still working in current bin? + _key = _d->_bin[_i]._keyvals[_j+_j]; + _value = _d->_bin[_i]._keyvals[_j+_j+1]; + return; + } + + while( ++_i < _d->_size ) { // Else scan for non-zero bucket + _j = _d->_bin[_i]._cnt; + if( !_j ) continue; + _j--; + _key = _d->_bin[_i]._keyvals[_j+_j]; + _value = _d->_bin[_i]._keyvals[_j+_j+1]; + return; + } + _key = _value = NULL; +}