gecko-dev/xpcom/ds/nsDeque.cpp
1999-04-07 21:05:19 +00:00

570 lines
13 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#include "nsDeque.h"
#include "nsCRT.h"
//#define _SELFTEST_DEQUE 1
#undef _SELFTEST_DEQUE
/**
* Standard constructor
* @update gess4/18/98
* @return new deque
*/
nsDeque::nsDeque(nsDequeFunctor* aDeallocator) {
mDeallocator=aDeallocator;
mCapacity=eGrowthDelta;
mOrigin=mSize=0;
mData=new void*[mCapacity];
}
/**
* Destructor
* @update gess4/18/98
*/
nsDeque::~nsDeque() {
Erase();
delete [] mData;
mData=0;
if(mDeallocator) {
delete mDeallocator;
}
mDeallocator=0;
}
/**
* Returns the number of elements currently stored in
* this deque.
*
* @update gess4/18/98
* @param
* @return int contains element count
*/
PRInt32 nsDeque::GetSize(void) const {
return mSize;
}
void nsDeque::SetDeallocator(nsDequeFunctor* aDeallocator){
if(mDeallocator) {
delete mDeallocator;
}
mDeallocator=aDeallocator;
}
/**
* Remove all items from container without destroying them.
*
* @update gess4/18/98
* @param
* @return
*/
nsDeque& nsDeque::Empty() {
if((0<mCapacity) && (mData)) {
nsCRT::zero(mData,mCapacity*sizeof(mData));
}
mSize=0;
mOrigin=0;
return *this;
}
/**
* Remove and delete all items from container
*
* @update gess4/18/98
* @return this
*/
nsDeque& nsDeque::Erase() {
if(mDeallocator) {
ForEach(*mDeallocator);
}
return Empty();
}
/**
* This method adds an item to the end of the deque.
* This operation has the potential to cause the
* underlying buffer to resize.
*
* @update gess4/18/98
* @param anItem: new item to be added to deque
* @return nada
*/
nsDeque& nsDeque::GrowCapacity(void) {
void** temp=new void*[mCapacity+eGrowthDelta];
//Here's the interesting part: You can't just move the elements
//directy (in situ) from the old buffer to the new one.
//Since capacity has changed, the old origin doesn't make
//sense anymore. It's better to resequence the elements now.
int tempi=0;
int i=0;
int j=0;
for(i=mOrigin;i<mCapacity;i++) temp[tempi++]=mData[i]; //copy the leading elements...
for(j=0;j<mOrigin;j++) temp[tempi++]=mData[j]; //copy the trailing elements...
mCapacity+=eGrowthDelta;
mOrigin=0; //now realign the origin...
delete[]mData;
mData=temp;
return *this;
}
/**
* This method adds an item to the end of the deque.
* This operation has the potential to cause the
* underlying buffer to resize.
*
* @update gess4/18/98
* @param anItem: new item to be added to deque
* @return nada
*/
nsDeque& nsDeque::Push(void* anItem) {
if(mSize==mCapacity) {
GrowCapacity();
}
int offset=mOrigin+mSize;
if(offset<mCapacity)
mData[offset]=anItem;
else mData[offset-mCapacity]=anItem;
mSize++;
return *this;
}
/**
* This method adds an item to the front of the deque.
* This operation has the potential to cause the
* underlying buffer to resize.
*
* @update gess4/18/98
* @param anItem: new item to be added to deque
* @return nada
*/
nsDeque& nsDeque::PushFront(void* anItem) {
if(mSize==mCapacity) {
GrowCapacity();
}
if(0==mOrigin){ //case1: [xxx..]
//mOrigin=mCapacity-1-mSize++;
mOrigin=mCapacity-1;
mData[mOrigin]=anItem;
}
else {// if(mCapacity==(mOrigin+mSize-1)){ //case2: [..xxx] and case3: [.xxx.]
mData[--mOrigin]=anItem;
}
mSize++;
return *this;
}
/**
* Remove and return the last item in the container.
*
* @update gess4/18/98
* @param none
* @return ptr to last item in container
*/
void* nsDeque::Pop(void) {
void* result=0;
if(mSize>0) {
int offset=mOrigin+mSize-1;
if(offset>=mCapacity)
offset-=mCapacity;
result=mData[offset];
mData[offset]=0;
mSize--;
if(0==mSize)
mOrigin=0;
}
return result;
}
/**
* This method gets called you want to remove and return
* the first member in the container.
*
* @update gess4/18/98
* @param nada
* @return last item in container
*/
void* nsDeque::PopFront() {
void* result=0;
if(mSize>0) {
result=mData[mOrigin];
mData[mOrigin++]=0; //zero it out for debugging purposes.
mSize--;
if(mCapacity==mOrigin) //you popped off the end, so cycle back around...
mOrigin=0;
if(0==mSize)
mOrigin=0;
}
NS_ASSERTION(mOrigin<mCapacity,"Error: Bad origin");
return result;
}
/**
* This method gets called you want to peek at the topmost
* member without removing it.
*
* @update gess4/18/98
* @param nada
* @return last item in container
*/
void* nsDeque::Peek() {
void* result=0;
if(mSize>0) {
result=mData[mOrigin];
}
return result;
}
/**
* Call this to retrieve the ith element from this container.
* Keep in mind that accessing the underlying elements is
* done in a relative fashion. Object 0 is not necessarily
* the first element (the first element is at mOrigin).
*
* @update gess4/18/98
* @param anIndex : 0 relative offset of item you want
* @return void* or null
*/
void* nsDeque::ObjectAt(PRInt32 anIndex) const {
void* result=0;
if((anIndex>=0) && (anIndex<mSize))
{
if(anIndex<(mCapacity-mOrigin)) {
result=mData[mOrigin+anIndex];
}
else {
result=mData[anIndex-(mCapacity-mOrigin)];
}
}
return result;
}
/**
* Create and return an iterator pointing to
* the beginning of the queue. Note that this
* takes the circular buffer semantics into account.
*
* @update gess4/18/98
* @return new deque iterator, init'ed to 1st item
*/
nsDequeIterator nsDeque::Begin(void) const{
return nsDequeIterator(*this,0);
}
/**
* Create and return an iterator pointing to
* the last of the queue. Note that this
* takes the circular buffer semantics into account.
*
* @update gess4/18/98
* @return new deque iterator, init'ed to last item
*/
nsDequeIterator nsDeque::End(void) const{
return nsDequeIterator(*this,mSize);
}
/**
* Call this method when you wanto to iterate all the
* members of the container, passing a functor along
* to call your code.
*
* @update gess4/20/98
* @param aFunctor object to call for each member
* @return *this
*/
void nsDeque::ForEach(nsDequeFunctor& aFunctor) const{
int i=0;
for(i=0;i<mSize;i++){
void* obj=ObjectAt(i);
obj=aFunctor(obj);
}
}
/**
* Call this method when you wanto to iterate all the
* members of the container, passing a functor along
* to call your code. Iteration continues until your
* functor returns a non-null.
*
* @update gess4/20/98
* @param aFunctor object to call for each member
* @return *this
*/
const void* nsDeque::FirstThat(nsDequeFunctor& aFunctor) const{
int i=0;
for(i=0;i<mSize;i++){
void* obj=ObjectAt(i);
obj=aFunctor(obj);
if(obj)
return obj;
}
return 0;
}
/******************************************************
* Here comes the nsDequeIterator class...
******************************************************/
/**
* DequeIterator is an object that knows how to iterate (forward and backward)
* a Deque. Normally, you don't need to do this, but there are some special
* cases where it is pretty handy, so here you go.
*
* This is a standard dequeiterator constructor
*
* @update gess4/18/98
* @param aQueue is the deque object to be iterated
* @param anIndex is the starting position for your iteration
*/
nsDequeIterator::nsDequeIterator(const nsDeque& aQueue,int anIndex): mIndex(anIndex), mDeque(aQueue) {
}
/**
* Copy construct a new iterator beginning with given
*
* @update gess4/20/98
* @param aCopy is another iterator to copy from
* @return
*/
nsDequeIterator::nsDequeIterator(const nsDequeIterator& aCopy) : mIndex(aCopy.mIndex), mDeque(aCopy.mDeque) {
}
/**
* Moves iterator to first element in deque
* @update gess4/18/98
* @return this
*/
nsDequeIterator& nsDequeIterator::First(void){
mIndex=0;
return *this;
}
/**
* Standard assignment operator for dequeiterator
*
* @update gess4/18/98
* @param aCopy is an iterator to be copied from
* @return *this
*/
nsDequeIterator& nsDequeIterator::operator=(const nsDequeIterator& aCopy) {
//queue's are already equal.
mIndex=aCopy.mIndex;
return *this;
}
/**
* preform ! operation against to iterators to test for equivalence
* (or lack thereof)!
*
* @update gess4/18/98
* @param anIter is the object to be compared to
* @return TRUE if NOT equal.
*/
PRBool nsDequeIterator::operator!=(nsDequeIterator& anIter) {
return PRBool(!this->operator==(anIter));
}
/**
* Compare 2 iterators for equivalence.
*
* @update gess4/18/98
* @param anIter is the other iterator to be compared to
* @return TRUE if EQUAL
*/
PRBool nsDequeIterator::operator<(nsDequeIterator& anIter) {
return PRBool(((mIndex<anIter.mIndex) && (&mDeque==&anIter.mDeque)));
}
/**
* Compare 2 iterators for equivalence.
*
* @update gess4/18/98
* @param anIter is the other iterator to be compared to
* @return TRUE if EQUAL
*/
PRBool nsDequeIterator::operator==(nsDequeIterator& anIter) {
return PRBool(((mIndex==anIter.mIndex) && (&mDeque==&anIter.mDeque)));
}
/**
* Compare 2 iterators for equivalence.
*
* @update gess4/18/98
* @param anIter is the other iterator to be compared to
* @return TRUE if EQUAL
*/
PRBool nsDequeIterator::operator>=(nsDequeIterator& anIter) {
return PRBool(((mIndex>=anIter.mIndex) && (&mDeque==&anIter.mDeque)));
}
/**
* Pre-increment operator
*
* @update gess4/18/98
* @return object at preincremented index
*/
void* nsDequeIterator::operator++() {
return mDeque.ObjectAt(++mIndex);
}
/**
* Post-increment operator
*
* @update gess4/18/98
* @param param is ignored
* @return object at post-incremented index
*/
void* nsDequeIterator::operator++(int) {
return mDeque.ObjectAt(mIndex++);
}
/**
* Pre-decrement operator
*
* @update gess4/18/98
* @return object at pre-decremented index
*/
void* nsDequeIterator::operator--() {
return mDeque.ObjectAt(--mIndex);
}
/**
* Post-decrement operator
*
* @update gess4/18/98
* @param param is ignored
* @return object at post-decremented index
*/
void* nsDequeIterator::operator--(int) {
return mDeque.ObjectAt(mIndex--);
}
/**
* Dereference operator
*
* @update gess4/18/98
* @return object at ith index
*/
void* nsDequeIterator::GetCurrent(void) {
return mDeque.ObjectAt(mIndex);
}
/**
* Call this method when you wanto to iterate all the
* members of the container, passing a functor along
* to call your code.
*
* @update gess4/20/98
* @param aFunctor object to call for each member
* @return *this
*/
void nsDequeIterator::ForEach(nsDequeFunctor& aFunctor) const{
mDeque.ForEach(aFunctor);
}
/**
* Call this method when you wanto to iterate all the
* members of the container, passing a functor along
* to call your code.
*
* @update gess4/20/98
* @param aFunctor object to call for each member
* @return *this
*/
const void* nsDequeIterator::FirstThat(nsDequeFunctor& aFunctor) const{
return mDeque.FirstThat(aFunctor);
}
#ifdef _SELFTEST_DEQUE
/**************************************************************
Now define the token deallocator class...
**************************************************************/
class _SelfTestDeallocator: public nsDequeFunctor{
public:
_SelfTestDeallocator::_SelfTestDeallocator() {
nsDeque::SelfTest();
}
virtual void* operator()(void* anObject) {
return 0;
}
};
static _SelfTestDeallocator gDeallocator;
#endif
/**
* conduct automated self test for this class
*
* @update gess4/18/98
* @param
* @return
*/
void nsDeque::SelfTest(void) {
#ifdef _SELFTEST_DEQUE
{
nsDeque theDeque(gDeallocator); //construct a simple one...
int ints[200];
int count=sizeof(ints)/sizeof(int);
int i=0;
for(i=0;i<count;i++){ //initialize'em
ints[i]=10*(1+i);
}
for(i=0;i<70;i++){
theDeque.Push(&ints[i]);
}
for(i=0;i<56;i++){
int* temp=(int*)theDeque.Pop();
}
for(i=0;i<55;i++){
theDeque.Push(&ints[i]);
}
for(i=0;i<35;i++){
int* temp=(int*)theDeque.Pop();
}
for(i=0;i<35;i++){
theDeque.Push(&ints[i]);
}
for(i=0;i<38;i++){
int* temp=(int*)theDeque.Pop();
}
}
int x;
x=10;
#endif
}