winamp/Src/Wasabi/bfc/ptrlist.cpp

331 lines
7.1 KiB
C++

#include "ptrlist.h"
#include <bfc/bfc_assert.h>
// if this symbol is enabled, do sanity checking in a bunch of methods
//#define DO_VERIFY_PTRLIST
#if defined(ASSERTS_ENABLED) && defined(DO_VERIFY_PTRLIST)
#define VERIFY_PTRLIST verify()
#else
#define VERIFY_PTRLIST
#endif
#ifdef _DEBUG
int ptrlist_totalnitems = 0;
#endif
PtrListRoot::PtrListRoot( int initial_size )
{
nitems = nslots = 0;
items = NULL;
//FG>why? we might as well save initial_size*4 bytes if nobody inserts anything in the list, no?
//BU No. initial_size defaults to 0 and therefore no memory is actually
//allocated in a typical construction. But, sometimes you want to start with
//a specific size, generally when you know the exact size you want,
//so that you can avoid REALLOCs when you initially populate the list.
//FG>Ah, makes sense.
setMinimumSize( initial_size );
}
PtrListRoot::PtrListRoot( const PtrListRoot *from )
{
nitems = nslots = 0;
items = NULL;
copyFrom( from );
}
PtrListRoot::~PtrListRoot()
{
removeAll();
}
void PtrListRoot::copyFrom( const PtrListRoot *from )
{
ASSERT( from != NULL );
removeAll();
appendFrom( from );
VERIFY_PTRLIST;
}
void PtrListRoot::appendFrom( const PtrListRoot *from )
{
ASSERT( from != NULL );
int n = from->getNumItems();
if ( n <= 0 )
return;
void **mem = from->getItemList();
ASSERT( mem != NULL ); // can't be NULL if getNumItems() >= 1
setMinimumSize( getNumItems() + n );
MEMCPY( items + getNumItems(), from->getItemList(), sizeof( void * ) * n );
nitems += n;
#ifdef _DEBUG
ptrlist_totalnitems += n;
#endif
VERIFY_PTRLIST;
}
void PtrListRoot::setMinimumSize( int _nslots )
{
ASSERT( _nslots >= 0 );
#ifdef DECREASE_PTRLISTS_SIZE
if ( _nslots + 2 * DEF_PTRLIST_INCREMENT < nslots )
{
nslots = ( ( _nslots / DEF_PTRLIST_INCREMENT ) + 2 ) * DEF_PTRLIST_INCREMENT;
items = (void **) REALLOC( items, sizeof( void * ) * nslots );
}
#endif
if ( _nslots == 0 || _nslots <= nslots )
return;
nslots = _nslots;
if ( items )
items = (void **) REALLOC( items, sizeof( void * ) * nslots );
else
items = (void **) MALLOC( sizeof( void * ) * nslots );
VERIFY_PTRLIST;
}
int PtrListRoot::getNumItems() const
{
return nitems;
}
void *PtrListRoot::enumItem( int n ) const
{
if ( items == NULL || n < 0 || n >= nitems )
return NULL;
return items[ n ];
}
void *PtrListRoot::addItem( void *item, int pos, int increment )
{
ASSERT( increment > 0 );
ASSERTPR( item != NULL, "can't put NULLs into ptrlists" );
ASSERT( nitems <= nslots );
#ifdef DECREASE_PTRLISTS_SIZE
// expand or shrink as necessary
if ( items == NULL || nslots == nitems )
setMinimumSize( nslots + increment );
else
setMinimumSize( nitems );
#else
// expand if necessary
if ( items == NULL || nslots == nitems )
setMinimumSize( nslots + increment );
#endif
items[ nitems++ ] = item;
if ( pos != PTRLIST_POS_LAST )
moveItem( nitems - 1, pos );
VERIFY_PTRLIST;
#ifdef _DEBUG
ptrlist_totalnitems++;
#endif
return item;
}
// replace what's in the slot with the new value
void *PtrListRoot::setItem( void *item, int pos )
{
ASSERT( nitems >= pos );
items[ pos ] = item;
VERIFY_PTRLIST;
return item;
}
void PtrListRoot::reverse()
{
if ( nitems <= 1 )
return;
MemBlock<void *> block( nitems, items );
void **blockmem = block.getMemory();
for ( int i = 0, j = nitems - 1; j >= 0; i++, j-- )
{
items[ i ] = blockmem[ j ];
}
}
void PtrListRoot::moveItem( int from, int to )
{
if ( from == to )
return;
void *ptr = items[ from ];
if ( nitems > from + 1 ) // if moving from the end, there is nothing to shift behind our src position
{
//IMPORTANT note for future ports: This assumes MEMCPY accepts overlapping segments.
MEMCPY( &items[ from ], &items[ from + 1 ], ( nitems - from ) * sizeof( void * ) );
}
if ( to > from )
to--;
if ( nitems > to ) // if moving to the end, there is nothing to shift behind our target position
MEMCPY( &items[ to + 1 ], &items[ to ], ( nitems - to - 1 ) * sizeof( void * ) );
items[ to ] = ptr;
VERIFY_PTRLIST;
}
int PtrListRoot::removeItem( void *item )
{
int c = 0;
if ( item == NULL || items == NULL || nitems <= 0 )
return 0;
// count occurences of item in items, remember the first one
void **p = items;
int first = -1;
for ( int i = 0; i < nitems; i++, p++ )
{
if ( *p == item )
{
if ( c++ == 0 )
first = i;
}
}
// if we found one, remove it
if ( c > 0 )
{
removeByPos( first ); // delByPos is faaast
c--; // decrease count
}
VERIFY_PTRLIST;
return c; // returns how many occurences of this item left
}
void PtrListRoot::removeEveryItem( void *item )
{
while ( removeItem( item ) );
VERIFY_PTRLIST;
}
void PtrListRoot::removeByPos( int pos )
{
if ( pos < 0 || pos >= nitems )
return; //JC
--nitems;
#ifdef _DEBUG
ptrlist_totalnitems--;
#endif
if ( pos == nitems )
return; // last one? nothing to copy over
MEMCPY( items + pos, items + ( pos + 1 ), sizeof( void * ) * ( nitems - pos ) ); // CT:not (nitems-(pos+1)) as nitems has been decremented earlier
#ifdef DECREASE_PTRLISTS_SIZE
// shrink if necessary
setMinimumSize( nitems );
#endif
VERIFY_PTRLIST;
}
void PtrListRoot::removeLastItem()
{
if ( nitems == 0 || items == NULL ) return;
nitems--; // hee hee
#ifdef _DEBUG
ptrlist_totalnitems--;
#endif
#ifdef DECREASE_PTRLISTS_SIZE
// shrink if necessary
setMinimumSize( nitems );
#endif
VERIFY_PTRLIST;
}
void PtrListRoot::removeAll()
{
FREE( items ); items = NULL;
#ifdef _DEBUG
ptrlist_totalnitems -= nitems;
#endif
#ifdef DECREASE_PTRLISTS_SIZE
// shrink if necessary
setMinimumSize( nitems );
#endif
nitems = 0;
nslots = 0;
VERIFY_PTRLIST;
}
void PtrListRoot::freeAll()
{
for ( int i = 0; i < nitems; i++ ) //JC
if ( items ) FREE( items[ i ] );
removeAll();
VERIFY_PTRLIST;
}
int PtrListRoot::searchItem( void *item ) const
{
for ( int i = 0; i < nitems; i++ )
if ( items[ i ] == item )
return i;
return -1;
}
void PtrListRoot::verify()
{
#ifdef DO_VERIFY_PTRLIST
ASSERT( nitems >= 0 );
ASSERT( nslots >= 0 );
ASSERT( nitems <= nslots );
#endif
}
#if 0
int PtrListRoot::bsearchItem( void *item ) const
{
// do binary search
if ( nitems == 0 || items == NULL ) return -1;
int bot = 0, top = nitems - 1, mid;
for ( int c = 0; c < nitems + 16; c++ )
{
if ( bot > top ) return -1;
mid = ( bot + top ) / 2;
if ( item == items[ mid ] ) return mid;
if ( item < items[ mid ] ) top = mid - 1;
else bot = mid + 1;
}
ASSERTPR( 0, "binary search fucked up" );
return -1;
}
#endif
void PtrListRoot::purge()
{
ASSERT( nitems == 0 );
if ( items != NULL )
{
FREE( items );
items = NULL;
}
}