added sorted arrays: they automatically sort items on insertion (using user

provided compare function) and binary search in Index(). Using them in
situations where Index() performance is important brings 30%-40% performance
boost.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@280 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Vadim Zeitlin
1998-07-16 17:29:46 +00:00
parent 400735a8fa
commit 3bfa440288
2 changed files with 149 additions and 35 deletions

View File

@@ -17,7 +17,7 @@
#endif
#include "wx/defs.h"
#include "wx/utils.h"
#include "wx/debug.h"
/** @name Dynamic arrays and lists
@memo Arrays which grow on demand and do range checking (only in debug)
@@ -41,7 +41,7 @@
/**
callback compare function for quick sort
must return -1, 0 or +1 if pItem1 <, = or > pItem2
must return negative value, 0 or positive value if pItem1 <, = or > pItem2
*/
#ifdef __VISUALC__
@@ -123,10 +123,14 @@ protected:
@return index of the first item matched or NOT_FOUND
@see NOT_FOUND
*/
int Index (long lItem, bool bFromEnd = FALSE) const;
int Index(long lItem, bool bFromEnd = FALSE) const;
/// search for an item using binary search in a sorted array
int Index(long lItem, CMPFUNC fnCompare);
/// add new element at the end
void Add (long lItem);
/// add new element at given position
void Add(long lItem);
/// add item assuming the array is sorted with fnCompare function
void Add(long lItem, CMPFUNC fnCompare);
/// add new element at given position (it becomes Item[uiIndex])
void Insert(long lItem, uint uiIndex);
/// remove first item matching this value
void Remove(long lItem);
@@ -135,7 +139,7 @@ protected:
//@}
/// sort array elements using given compare function
void Sort(CMPFUNC fCmp);
void Sort(CMPFUNC fnCompare);
private:
void Grow(); // makes array bigger if needed
@@ -193,6 +197,60 @@ public: \
void Sort(CMPFUNC##T fCmp) { wxBaseArray::Sort((CMPFUNC)fCmp); } \
}
// ----------------------------------------------------------------------------
// This is the same as the previous macro, but it defines a sorted array.
// Differences:
// 1) it must be given a COMPARE function in ctor which takes 2 items of type
// T* and should return -1, 0 or +1 if the first one is less/greater
// than/equal to the second one.
// 2) the Add() method inserts the item in such was that the array is always
// sorted (it uses the COMPARE function)
// 3) it has no Sort() method because it's always sorted
// 4) Index() method is much faster (the sorted arrays use binary search
// instead of linear one), but Add() is slower.
//
// Summary: use this class when the speed of Index() function is important, use
// the normal arrays otherwise.
//
// NB: it has only inline functions => takes no space at all
// ----------------------------------------------------------------------------
#define _WX_DEFINE_SORTED_ARRAY(T, name) \
typedef int (CMPFUNC_CONV *SCMPFUNC##T)(T pItem1, T pItem2); \
class name : public wxBaseArray \
{ \
public: \
name(SCMPFUNC##T fn) \
{ wxASSERT( sizeof(T) <= sizeof(long) ); m_fnCompare = fn; } \
\
name& operator=(const name& src) \
{ ((wxBaseArray *)this)->operator=((const wxBaseArray&)src); \
m_fnCompare = src.m_fnCompare; \
return *this; } \
\
T& operator[](uint uiIndex) const \
{ return (T&)(wxBaseArray::Item(uiIndex)); } \
T& Item(uint uiIndex) const \
{ return (T&)(wxBaseArray::Item(uiIndex)); } \
T& Last() const \
{ return (T&)(wxBaseArray::Item(Count() - 1)); } \
\
int Index(T Item) const \
{ return wxBaseArray::Index((long)Item, (CMPFUNC)m_fnCompare); }\
\
void Add(T Item) \
{ wxBaseArray::Add((long)Item, (CMPFUNC)m_fnCompare); } \
\
void Remove(uint uiIndex) { wxBaseArray::Remove(uiIndex); } \
void Remove(T Item) \
{ int iIndex = Index(Item); \
wxCHECK2_MSG( iIndex != NOT_FOUND, return, \
"removing inexisting element in wxArray::Remove" ); \
wxBaseArray::Remove((uint)iIndex); } \
\
private: \
SCMPFUNC##T m_fnCompare; \
}
// ----------------------------------------------------------------------------
// see WX_DECLARE_LIST and WX_DEFINE_LIST
// ----------------------------------------------------------------------------
@@ -264,6 +322,14 @@ private: \
*/
#define WX_DEFINE_ARRAY(T, name) typedef T _A##name; \
_WX_DEFINE_ARRAY(_A##name, name)
/**
This macro does the same as WX_DEFINE_ARRAY except that the array will be
sorted with the specified compare function.
*/
#define WX_DEFINE_SORTED_ARRAY(T, name) typedef T _A##name; \
_WX_DEFINE_SORTED_ARRAY(_A##name, name)
/**
This macro generates a new list class which owns the objects it contains,
i.e. it will delete them when it is destroyed. An element is of type T*,

View File

@@ -26,6 +26,7 @@
#include "wx/dynarray.h"
#include <stdlib.h>
#include <string.h> // for memmove
#ifndef max
#define max(a, b) (((a) > (b)) ? (a) : (b))
@@ -57,34 +58,32 @@ wxBaseArray::wxBaseArray()
// copy ctor
wxBaseArray::wxBaseArray(const wxBaseArray& src)
{
m_uiSize = src.m_uiSize;
m_uiSize = // not src.m_uiSize to save memory
m_uiCount = src.m_uiCount;
if ( m_uiSize != 0 )
if ( m_uiSize != 0 ) {
m_pItems = new long[m_uiSize];
memcpy(m_pItems, src.m_pItems, m_uiCount*sizeof(long));
}
else
m_pItems = NULL;
if ( m_uiCount != 0 )
memcpy(m_pItems, src.m_pItems, m_uiCount*sizeof(long));
}
// copy operator
// assignment operator
wxBaseArray& wxBaseArray::operator=(const wxBaseArray& src)
{
DELETEA(m_pItems);
m_uiSize = src.m_uiSize;
m_uiSize = // not src.m_uiSize to save memory
m_uiCount = src.m_uiCount;
if ( m_uiSize != 0 )
if ( m_uiSize != 0 ) {
m_pItems = new long[m_uiSize];
memcpy(m_pItems, src.m_pItems, m_uiCount*sizeof(long));
}
else
m_pItems = NULL;
if ( m_uiCount != 0 )
memcpy(m_pItems, src.m_pItems, m_uiCount*sizeof(long));
return *this;
}
@@ -169,6 +168,28 @@ int wxBaseArray::Index(long lItem, bool bFromEnd) const
return NOT_FOUND;
}
// search for an item in a sorted array (binary search)
int wxBaseArray::Index(long lItem, CMPFUNC fnCompare)
{
uint i,
lo = 0,
hi = m_uiCount;
int res;
while ( lo < hi ) {
i = (lo + hi)/2;
res = (*fnCompare)((const void *)lItem, (const void *)m_pItems[i]);
if ( res < 0 )
hi = i;
else if ( res > 0 )
lo = i + 1;
else
return i;
}
return NOT_FOUND;
}
// add item at the end
void wxBaseArray::Add(long lItem)
{
@@ -176,6 +197,33 @@ void wxBaseArray::Add(long lItem)
m_pItems[m_uiCount++] = lItem;
}
// add item assuming the array is sorted with fnCompare function
void wxBaseArray::Add(long lItem, CMPFUNC fnCompare)
{
uint i,
lo = 0,
hi = m_uiCount;
int res;
while ( lo < hi ) {
i = (lo + hi)/2;
res = (*fnCompare)((const void *)lItem, (const void *)m_pItems[i]);
if ( res < 0 )
hi = i;
else if ( res > 0 )
lo = i + 1;
else {
lo = hi = i;
break;
}
}
wxASSERT( lo == hi ); // I hope I got binary search right :-)
Insert(lItem, lo);
}
// add item at the given position
void wxBaseArray::Insert(long lItem, uint uiIndex)
{