text: /*
   * Copyright (c) 1998, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   *
   */
  
  // Dictionaries - An Abstract Data Type
  
  #include "adlc.hpp"
  
  // #include "dict.hpp"
  
  
  //------------------------------data-----------------------------------------
  // String hash tables
  #define MAXID 20
  static char initflag = 0;       // True after 1st initialization
  static char shft[MAXID + 1] = {1,2,3,4,5,6,7,1,2,3,4,5,6,7,1,2,3,4,5,6,7};
  static short xsum[MAXID];
  
  //------------------------------bucket---------------------------------------
  class bucket {
  public:
    int          _cnt, _max;      // Size of bucket
    const 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(NULL) {
    init();
  }
  
  Dict::Dict(CmpKey initcmp, Hash inithash, Arena *arena) : _hash(inithash), _cmp(initcmp), _arena(arena) {
    init();
  }
  
  void Dict::init() {
    int i;
  
    // Precompute table of null character hashes
    if (!initflag) {              // Not initializated yet?
      xsum[0] = (short) ((1 << shft[0]) + 1);  // Initialize
      for( i = 1; i < MAXID; i++) {
        xsum[i] = (short) ((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------------------------------------------
  // Delete an existing dictionary.
  Dict::~Dict() {
  }
  
  //------------------------------Clear----------------------------------------
  // Zap to empty; ready for re-use
  void Dict::Clear() {
    _cnt = 0;                     // Empty contents
    for( int 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) {
    int 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( int 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
      int 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 = (const void**)_arena->Amalloc_4( sizeof(void *)*nb->_max*2 );
      int nbcnt = 0;
  
      for( j=0; j<b->_cnt; j++ ) {  // Rehash all keys in this bucket
        const 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( int i=0; i<_size; i++ ) {
      if( !_bin[i]._keyvals ) continue;
      _bin[i]._keyvals=(const 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;
    }
    for( int 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(int k=0; k<_size; k++ ) {
      bucket *b = &d._bin[k];     // Shortcut to source bucket
      for( int 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.
  const void *Dict::Insert(const void *key, const void *val) {
    int hash = _hash( key );      // Get hash key
    int i = hash & (_size-1);     // Get hash key, corrected for size
    bucket *b = &_bin[i];         // Handy shortcut
    for( int j=0; j<b->_cnt; j++ )
      if( !_cmp(key,b->_keyvals[j+j]) ) {
        const 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 = (const void**)_arena->Amalloc_4( sizeof(void *)*b->_max*2 );
      } else {
        b->_keyvals = (const 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.
  const void *Dict::Delete(void *key) {
    int i = _hash( key ) & (_size-1);     // Get hash key, corrected for size
    bucket *b = &_bin[i];         // Handy shortcut
    for( int j=0; j<b->_cnt; j++ )
      if( !_cmp(key,b->_keyvals[j+j]) ) {
        const 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.
  const void *Dict::operator [](const void *key) const {
    int i = _hash( key ) & (_size-1);     // Get hash key, corrected for size
    bucket *b = &_bin[i];         // Handy shortcut
    for( int 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.
  int 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( int 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----------------------------------------
  static void printvoid(const void* x) { printf("%p", x);  }
  void Dict::print() {
    print(printvoid, printvoid);
  }
  void Dict::print(PrintKeyOrValue print_key, PrintKeyOrValue print_value) {
    for( int i=0; i < _size; i++) {       // For complete hash table do
      bucket *b = &_bin[i];       // Handy shortcut
      for( int j=0; j<b->_cnt; j++ ) {
        print_key(  b->_keyvals[j+j  ]);
        printf(" -> ");
        print_value(b->_keyvals[j+j+1]);
        printf("\n");
      }
    }
  }
  
  //------------------------------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 - guaranteed 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) {
    char c, k = 0;
    int sum = 0;
    const char *s = (const char *)t;
  
    while (((c = s[k]) != '\0') && (k < MAXID-1)) { // Get characters till nul
      c = (char) ((c << 1) + 1);    // Characters are always odd!
      sum += c + (c << shft[k++]);  // Universal hash function
    }
    assert(k < (MAXID), "Exceeded maximum name length");
    return (int)((sum+xsum[k]) >> 1); // Hash key, un-modulo'd table size
  }
  
  //------------------------------hashptr--------------------------------------
  // Slimey cheap hash function; no guaranteed performance.  Better than the
  // default for pointers, especially on MS-DOS machines.
  int hashptr(const void *key) {
  #ifdef __TURBOC__
      return (int)((intptr_t)key >> 16);
  #else  // __TURBOC__
      return (int)((intptr_t)key >> 2);
  #endif
  }
  
  // Slimey cheap hash function; no guaranteed performance.
  int hashkey(const void *key) {
    return (int)((intptr_t)key);
  }
  
  //------------------------------Key Comparator Functions---------------------
  int cmpstr(const void *k1, const void *k2) {
    return strcmp((const char *)k1,(const char *)k2);
  }
  
  // Cheap key comparator.
  int cmpkey(const void *key1, const void *key2) {
    if (key1 == key2) return 0;
    intptr_t delta = (intptr_t)key1 - (intptr_t)key2;
    if (delta > 0) return 1;
    return -1;
  }
  
  //=============================================================================
  //------------------------------reset------------------------------------------
  // Create an iterator and initialize the first variables.
  void DictI::reset( const Dict *dict ) {
    _d = dict;                    // The dictionary
    _i = (int)-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;
  }
  