UT/UT_PtrArrayRaw.h

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * Produced by:
 *      Cristin Barghiel
 *      Side Effects Software Inc.
 *      123 Front Street West, Suite 1401
 *      Toronto, Ontario
 *      Canada   M5J 2M2
 *      416-504-9876
 *
 * NAME:        Utility Library (C++)
 *
 * COMMENTS:
 *      This is a class that is used by UT_PtrArray to do all the work...
 *
 */

#ifndef __UT_PtrArrayRaw_h__
#define __UT_PtrArrayRaw_h__

#include "UT_API.h"
#include <string.h>
#include <malloc.h>
#include <SYS/SYS_Types.h>
#include "UT_ArrayHelp.h"
#include "UT_Assert.h"

UT_API extern int UTcomparePointers(void *const* a, void *const* b);

class UT_API UT_PtrArrayRaw {
public:
    typedef int (*Comparator)(const void *, const void *);

    // Trivial constructor and destructor. WARNING: this is really meant to
    // be a private class. You should normally instantiate it through its
    // friend(s). We made these 2 methods public to avoid compiler warnings.
    explicit UT_PtrArrayRaw(unsigned int sz = 0) : arrSize(sz), nbrEntries(0)
    {
        arr = (sz) ? (void **)calloc(sizeof(void *), sz) : 0;
    }
    ~UT_PtrArrayRaw(void);

    // Copy constructor that uses operator '=' to assign each of a's Things
    // to this array.
    UT_PtrArrayRaw(const UT_PtrArrayRaw &a);

    void swap( UT_PtrArrayRaw &other );

    // Append an element to the current entries and return its index in the
    // array, or insert the element at a specified position; if necessary,
    // insert() grows the array to accommodate the element. The insert
    // methods use the assignment operator '=' to place the Thing into the
    // right spot; be aware that '=' works differently on objects and pointers.
    // The test for duplicates uses the logical equal operator '=='; as with
    // '=', the behaviour of the equality operator on pointers versus objects
    // is not the same.
    // Use the subscript operators instead of insert() if you are appending
    // to the array, or if  you don't mind overwriting the element already 
    // inserted at the given index.
    unsigned int        append(void)            { return insert(nbrEntries); }
    unsigned int        append(const void *t);
    unsigned int        append(const void *t, int checkForDup);
    unsigned int        insert(unsigned index);
    unsigned int        insert(const void *t, unsigned index);

    // Assuming the array is sorted, it inserts item t maintaining the sorted
    // state of the array. It returns the index of the inserted item.
    unsigned int        sortedInsert(const void *t, Comparator compare);
    unsigned int        uniqueSortedInsert(const void *t, Comparator compare);

    bool                hasSortedSubset( UT_PtrArrayRaw const& other,
                                         Comparator compare) const;

    void                sortedIntersection( UT_PtrArrayRaw const& other,
                                            Comparator compare);
    void                sortedIntersection( UT_PtrArrayRaw const& other,
                                            UT_PtrArrayRaw &result,
                                            Comparator compare) const;
    void                sortedUnion( UT_PtrArrayRaw const& other,
                                     Comparator compare );
    void                sortedUnion( UT_PtrArrayRaw const& other,
                                     UT_PtrArrayRaw &result,
                                     Comparator compare ) const;

    // Assuming that the array is sorted without duplicates, it inserts item t
    // provided that it does not already exist in the array.
    // Returns the index of the inserted item, or the index of the existing
    // item if found.
    unsigned int        uniqueSortedInsert(const void *t);

    // Assuming the array is already a heap, it inserts item t maintaining
    // the heap. It returns the index of the inserted item.
    unsigned int        heapPush(const void *t, Comparator compare );
    // Assuming the array is already a heap, extracts the top (maximum)
    // element from the heap and returns it.
    void                *heapPop(Comparator compare);
    // Assuming the array is already a heap, return the top (maximum)
    // element.
    void                *heapMax() const
                        {
                             UT_ASSERT_P(nbrEntries > 0);
                             return arr[0];
                        }

    // Takes another pointer array and concatenate it onto my end
    unsigned int        concat(const UT_PtrArrayRaw &a);

    // Insert an element "count" times at the given index. Return the index.
    unsigned  int       multipleInsert(unsigned int index, unsigned int count);

    // An alias for unique element insertion at a certain index. Also used by
    // the other insertion methods.
    unsigned int         insertAt(const void *t, unsigned int index);

    // Remove one element from the array given the element itself or its 
    // position in the list, and fill the gap by shifting the elements down
    // by one position. Both methods return the index if successful, 
    // If dupliCheck is 1, both methods search for all objects that match t or 
    // arr[index] respectively.
    int         remove(const void *t);
    int         remove(unsigned int index)
                {
                    return (index < nbrEntries) ? removeAt(index) : -1;
                }

    int         removeZeros();

    // A little quicker version of remove which avoids the
    // unneccessary shift
    void        *removeLast()
                 { return nbrEntries ? arr[--nbrEntries] : 0; }

    // Sort and remove all duplicate entries
    void        sortAndRemoveDuplicates();

    // Move howMany objects starting at index srcIndex to destIndex;
    // Method returns 0 if OK, -1 if overflow.
    int                 shift(unsigned int srcIdx,
                              unsigned int destIdx,
                              unsigned int howMany);
    // Move howMany objects starting at index srcIndex to destIndex;
    // Unlike shift, this method moves entries instead of overwriting them.
    void                move(int srcIdx, int destIdx, int howMany);
    // Collapse the array to remove all the null pointer entries.
    // Note: Indices to elements may change due to shifting 
    void                collapse();

    // Cyclically shifts the entire array by howMany
    void                cycle(int howMany);

    // Reverse the entries in the array
    void                reverse();

    // Search for t in one of two ways: linearly using the '==' operator, or
    // binary using the function specified in the parameter list respectively.
    // find() returns the index of the matching element or (int)-1.
    // Parameter s indicates the index the search should start at.
    int          find(const void *t, unsigned int s = 0) const;
    int          find(const void *t, int (*compare)(const void *, const void *)) const;

    // Searches for the given string assuming that our array points to
    // strings.
    // The advantage is that we avoid all callbacks, can inline code,
    // so should be super fast.
    int          findString(const char *str) const;

    // Sort the array using a comparison function that you must provide. t1 and
    // t2 are pointers to Thing.
    void                sort(Comparator compare);

    // Resize the array, ie. grow it or shrink it. If copyFlag is 1, the 
    // function copies the data after reallocating space for the array.
    void                resize(unsigned int sz, unsigned short copyFlag=1);

    // Query the allocated length of the array or the number of elements
    // in the array: capacity() >= entries().
    uint        capacity(void) const    { return arrSize;       }
    int64       getMemoryUsage() const  { return capacity()*sizeof(void *); }
    uint        entries(void) const     { return nbrEntries;    }
    bool        isEmpty(void) const     { return nbrEntries==0; }

    // Set the number of entries. Normally, you should not have to use it.
    void         entries(unsigned int ne)       { nbrEntries = ne; }

    // Assign array a to this array by copying each of a's Things with the
    // '=' operator. The size of this array must be greater or equal to the 
    // entry count of array a.
    // WARNING: Will *NOT* reduce nbrEntries, will only increase if necessary
    UT_PtrArrayRaw      &assignSubset(const UT_PtrArrayRaw &a);

    // Assign array a to this array by copying each of a's Things with the
    // '=' operator.
    UT_PtrArrayRaw      &operator=(const UT_PtrArrayRaw &a);

    // Compare two array and return 1 if they are equal and 0 otherwise.
    // Two Things are checked against each other using operator '==' or
    // compare() respectively. Arrays of different size but equal number of
    // entries are checked for member-wise equality.
    // t1 and t2 must point to Things.
    int                 operator==(const UT_PtrArrayRaw &a) const;
    int                 isEqual(const UT_PtrArrayRaw &a,
                                int (*compare)(const void *t1, const void *t2)
                               ) const;
     
    // Subscript operators. operator() does NOT do any bound checking, while
    // the non-const operator[] grows the array to accommodate the given index.
    void                *&operator()(unsigned int i)       
                        { 
                            UT_ASSERT_P( i < nbrEntries );
                            return arr[i]; 
                        }
    void                *operator()(unsigned int i) const  
                        { 
                            UT_ASSERT_P( i < nbrEntries );
                            return arr[i]; 
                        }
    void                *&operator[](unsigned int i)
                         {
                            if (i >= arrSize   ) resize(bumpAlloc(i+1));
                            if (i >= nbrEntries) nbrEntries = i+1;
                            return arr[i];
                         }
    void                *operator[](unsigned int i) const
                         {
                            UT_ASSERT_P( i < nbrEntries );
                            return (i < nbrEntries) ? arr[i] : (void *)0; 
                         }

    // Apply a user-defined function to each element of the array 
    // as int as the function returns zero. If applyFct returns
    // 1, apply() stops traversing the list and returns the current
    // index; otherwise, apply() returns the number of entries.
    unsigned int        apply(int (*applyFct)(void *t, void *d), void *d);


    // Derived class should use these three methods to get a handle to the
    // internal data, and set the array size.
    void        *array(void) const              { return arr;      }
    void         setCapacity(unsigned int sz)   { arrSize    = sz; }
    
    // Pointer to a list of elements of type Thing:
    void                **arr;

    // The number of elements we have allocated space for versus the actual
    // number of entries in the array:
    unsigned int         arrSize;
    unsigned int         nbrEntries;

    // The guts of the remove() methods.
    int                 removeAt(unsigned int index);
    // The guts of the popHeap() method.
    void                heapify(unsigned int index, Comparator compare);
};

#endif

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