gecko-dev/xpcom/ds/nsSupportsArray.cpp

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C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <string.h>
#include "mozilla/MathAlgorithms.h"
#include "nsSupportsArray.h"
#include "nsSupportsArrayEnumerator.h"
#include "nsIObjectInputStream.h"
#include "nsIObjectOutputStream.h"
#if DEBUG_SUPPORTSARRAY
#define MAXSUPPORTS 20
class SupportsStats
{
public:
SupportsStats();
~SupportsStats();
};
static int sizesUsed; // number of the elements of the arrays used
static int sizesAlloced[MAXSUPPORTS]; // sizes of the allocations. sorted
static int NumberOfSize[MAXSUPPORTS]; // number of this allocation size (1 per array)
static int AllocedOfSize[MAXSUPPORTS]; // number of this allocation size (each size for array used)
static int GrowInPlace[MAXSUPPORTS];
// these are per-allocation
static int MaxElements[3000];
// very evil
#define ADD_TO_STATS(x,size) do {int i; for (i = 0; i < sizesUsed; i++) \
{ \
if (sizesAlloced[i] == (int)(size)) \
{ ((x)[i])++; break; } \
} \
if (i >= sizesUsed && sizesUsed < MAXSUPPORTS) \
{ sizesAlloced[sizesUsed] = (size); \
((x)[sizesUsed++])++; break; \
} \
} while (0);
#define SUB_FROM_STATS(x,size) do {int i; for (i = 0; i < sizesUsed; i++) \
{ \
if (sizesAlloced[i] == (int)(size)) \
{ ((x)[i])--; break; } \
} \
} while (0);
SupportsStats::SupportsStats()
{
sizesUsed = 1;
sizesAlloced[0] = 0;
}
SupportsStats::~SupportsStats()
{
int i;
for (i = 0; i < sizesUsed; ++i) {
printf("Size %d:\n", sizesAlloced[i]);
printf("\tNumber of SupportsArrays this size (max): %d\n", NumberOfSize[i]);
printf("\tNumber of allocations this size (total): %d\n", AllocedOfSize[i]);
printf("\tNumber of GrowsInPlace this size (total): %d\n", GrowInPlace[i]);
}
printf("Max Size of SupportsArray:\n");
for (i = 0; i < (int)(sizeof(MaxElements) / sizeof(MaxElements[0])); ++i) {
if (MaxElements[i]) {
printf("\t%d: %d\n", i, MaxElements[i]);
}
}
}
// Just so constructor/destructor get called
SupportsStats gSupportsStats;
#endif
nsresult
nsQueryElementAt::operator()(const nsIID& aIID, void** aResult) const
{
nsresult status =
mCollection ? mCollection->QueryElementAt(mIndex, aIID, aResult) :
NS_ERROR_NULL_POINTER;
if (mErrorPtr) {
*mErrorPtr = status;
}
return status;
}
static const int32_t kGrowArrayBy = 8;
static const int32_t kLinearThreshold = 16 * sizeof(nsISupports*);
nsSupportsArray::nsSupportsArray()
{
mArray = mAutoArray;
mArraySize = kAutoArraySize;
mCount = 0;
#if DEBUG_SUPPORTSARRAY
mMaxCount = 0;
mMaxSize = 0;
ADD_TO_STATS(NumberOfSize, kAutoArraySize * sizeof(mArray[0]));
MaxElements[0]++;
#endif
}
nsSupportsArray::~nsSupportsArray()
{
DeleteArray();
}
void
nsSupportsArray::GrowArrayBy(int32_t aGrowBy)
{
// We have to grow the array. Grow by kGrowArrayBy slots if we're smaller
// than kLinearThreshold bytes, or a power of two if we're larger.
// This is much more efficient with most memory allocators, especially
// if it's very large, or of the allocator is binned.
if (aGrowBy < kGrowArrayBy) {
aGrowBy = kGrowArrayBy;
}
uint32_t newCount = mArraySize + aGrowBy; // Minimum increase
uint32_t newSize = sizeof(mArray[0]) * newCount;
if (newSize >= (uint32_t)kLinearThreshold) {
// newCount includes enough space for at least kGrowArrayBy new slots.
// Select the next power-of-two size in bytes above that if newSize is
// not a power of two.
if (newSize & (newSize - 1)) {
newSize = 1u << mozilla::CeilingLog2(newSize);
}
newCount = newSize / sizeof(mArray[0]);
}
// XXX This would be far more efficient in many allocators if we used
// XXX PR_Realloc(), etc
nsISupports** oldArray = mArray;
mArray = new nsISupports*[newCount];
mArraySize = newCount;
#if DEBUG_SUPPORTSARRAY
if (oldArray == mArray) { // can't happen without use of realloc
ADD_TO_STATS(GrowInPlace, mCount);
}
ADD_TO_STATS(AllocedOfSize, mArraySize * sizeof(mArray[0]));
if (mArraySize > mMaxSize) {
ADD_TO_STATS(NumberOfSize, mArraySize * sizeof(mArray[0]));
if (oldArray != &(mAutoArray[0])) {
SUB_FROM_STATS(NumberOfSize, mCount * sizeof(mArray[0]));
}
mMaxSize = mArraySize;
}
#endif
if (oldArray) { // need to move old data
if (0 < mCount) {
::memcpy(mArray, oldArray, mCount * sizeof(nsISupports*));
}
if (oldArray != &(mAutoArray[0])) {
delete[] oldArray;
}
}
}
nsresult
nsSupportsArray::Create(nsISupports* aOuter, REFNSIID aIID, void** aResult)
{
if (aOuter) {
return NS_ERROR_NO_AGGREGATION;
}
nsCOMPtr<nsISupportsArray> it = new nsSupportsArray();
return it->QueryInterface(aIID, aResult);
}
NS_IMPL_ISUPPORTS(nsSupportsArray, nsISupportsArray, nsICollection,
nsISerializable)
NS_IMETHODIMP
nsSupportsArray::Read(nsIObjectInputStream* aStream)
{
nsresult rv;
uint32_t newArraySize;
rv = aStream->Read32(&newArraySize);
if (newArraySize <= kAutoArraySize) {
if (mArray != mAutoArray) {
delete[] mArray;
mArray = mAutoArray;
}
newArraySize = kAutoArraySize;
} else {
if (newArraySize <= mArraySize) {
// Keep non-default-size mArray, it's more than big enough.
newArraySize = mArraySize;
} else {
nsISupports** array = new nsISupports*[newArraySize];
if (mArray != mAutoArray) {
delete[] mArray;
}
mArray = array;
}
}
mArraySize = newArraySize;
rv = aStream->Read32(&mCount);
if (NS_FAILED(rv)) {
return rv;
}
NS_ASSERTION(mCount <= mArraySize, "overlarge mCount!");
if (mCount > mArraySize) {
mCount = mArraySize;
}
for (uint32_t i = 0; i < mCount; i++) {
rv = aStream->ReadObject(true, &mArray[i]);
if (NS_FAILED(rv)) {
return rv;
}
}
return NS_OK;
}
NS_IMETHODIMP
nsSupportsArray::Write(nsIObjectOutputStream* aStream)
{
nsresult rv;
rv = aStream->Write32(mArraySize);
if (NS_FAILED(rv)) {
return rv;
}
rv = aStream->Write32(mCount);
if (NS_FAILED(rv)) {
return rv;
}
for (uint32_t i = 0; i < mCount; i++) {
rv = aStream->WriteObject(mArray[i], true);
if (NS_FAILED(rv)) {
return rv;
}
}
return NS_OK;
}
void
nsSupportsArray::DeleteArray(void)
{
Clear();
if (mArray != &(mAutoArray[0])) {
delete[] mArray;
mArray = mAutoArray;
mArraySize = kAutoArraySize;
}
}
NS_IMETHODIMP_(bool)
nsSupportsArray::Equals(const nsISupportsArray* aOther)
{
if (aOther) {
uint32_t countOther;
nsISupportsArray* other = const_cast<nsISupportsArray*>(aOther);
nsresult rv = other->Count(&countOther);
if (NS_FAILED(rv)) {
return false;
}
if (mCount == countOther) {
uint32_t index = mCount;
nsCOMPtr<nsISupports> otherElem;
while (index--) {
if (NS_FAILED(other->GetElementAt(index, getter_AddRefs(otherElem)))) {
return false;
}
if (mArray[index] != otherElem) {
return false;
}
}
return true;
}
}
return false;
}
NS_IMETHODIMP
nsSupportsArray::GetElementAt(uint32_t aIndex, nsISupports** aOutPtr)
{
*aOutPtr = nullptr;
if (aIndex < mCount) {
NS_IF_ADDREF(*aOutPtr = mArray[aIndex]);
}
return NS_OK;
}
NS_IMETHODIMP_(int32_t)
nsSupportsArray::IndexOf(const nsISupports* aPossibleElement)
{
return IndexOfStartingAt(aPossibleElement, 0);
}
NS_IMETHODIMP_(int32_t)
nsSupportsArray::IndexOfStartingAt(const nsISupports* aPossibleElement,
uint32_t aStartIndex)
{
if (aStartIndex < mCount) {
const nsISupports** start = (const nsISupports**)mArray; // work around goofy compiler behavior
const nsISupports** ep = (start + aStartIndex);
const nsISupports** end = (start + mCount);
while (ep < end) {
if (aPossibleElement == *ep) {
return (ep - start);
}
ep++;
}
}
return -1;
}
NS_IMETHODIMP_(int32_t)
nsSupportsArray::LastIndexOf(const nsISupports* aPossibleElement)
{
if (0 < mCount) {
const nsISupports** start = (const nsISupports**)mArray; // work around goofy compiler behavior
const nsISupports** ep = (start + mCount);
while (start <= --ep) {
if (aPossibleElement == *ep) {
return (ep - start);
}
}
}
return -1;
}
NS_IMETHODIMP_(bool)
nsSupportsArray::InsertElementAt(nsISupports* aElement, uint32_t aIndex)
{
if (aIndex <= mCount) {
if (mArraySize < (mCount + 1)) {
// need to grow the array
GrowArrayBy(1);
}
// Could be slightly more efficient if GrowArrayBy knew about the
// split, but the difference is trivial.
uint32_t slide = (mCount - aIndex);
if (0 < slide) {
::memmove(mArray + aIndex + 1, mArray + aIndex,
slide * sizeof(nsISupports*));
}
mArray[aIndex] = aElement;
NS_IF_ADDREF(aElement);
mCount++;
#if DEBUG_SUPPORTSARRAY
if (mCount > mMaxCount &&
mCount < (int32_t)(sizeof(MaxElements) / sizeof(MaxElements[0]))) {
MaxElements[mCount]++;
MaxElements[mMaxCount]--;
mMaxCount = mCount;
}
#endif
return true;
}
return false;
}
NS_IMETHODIMP_(bool)
nsSupportsArray::InsertElementsAt(nsISupportsArray* aElements, uint32_t aIndex)
{
if (!aElements) {
return false;
}
uint32_t countElements;
if (NS_FAILED(aElements->Count(&countElements))) {
return false;
}
if (aIndex <= mCount) {
if (mArraySize < (mCount + countElements)) {
// need to grow the array
GrowArrayBy(countElements);
}
// Could be slightly more efficient if GrowArrayBy knew about the
// split, but the difference is trivial.
uint32_t slide = (mCount - aIndex);
if (0 < slide) {
::memmove(mArray + aIndex + countElements, mArray + aIndex,
slide * sizeof(nsISupports*));
}
for (uint32_t i = 0; i < countElements; ++i, ++mCount) {
// use GetElementAt to copy and do AddRef for us
if (NS_FAILED(aElements->GetElementAt(i, mArray + aIndex + i))) {
return false;
}
}
#if DEBUG_SUPPORTSARRAY
if (mCount > mMaxCount &&
mCount < (int32_t)(sizeof(MaxElements) / sizeof(MaxElements[0]))) {
MaxElements[mCount]++;
MaxElements[mMaxCount]--;
mMaxCount = mCount;
}
#endif
return true;
}
return false;
}
NS_IMETHODIMP_(bool)
nsSupportsArray::ReplaceElementAt(nsISupports* aElement, uint32_t aIndex)
{
if (aIndex < mCount) {
NS_IF_ADDREF(aElement); // addref first in case it's the same object!
NS_IF_RELEASE(mArray[aIndex]);
mArray[aIndex] = aElement;
return true;
}
return false;
}
NS_IMETHODIMP_(bool)
nsSupportsArray::RemoveElementsAt(uint32_t aIndex, uint32_t aCount)
{
if (aIndex + aCount <= mCount) {
for (uint32_t i = 0; i < aCount; i++) {
NS_IF_RELEASE(mArray[aIndex + i]);
}
mCount -= aCount;
int32_t slide = (mCount - aIndex);
if (0 < slide) {
::memmove(mArray + aIndex, mArray + aIndex + aCount,
slide * sizeof(nsISupports*));
}
return true;
}
return false;
}
NS_IMETHODIMP
nsSupportsArray::RemoveElement(nsISupports* aElement)
{
int32_t theIndex = IndexOfStartingAt(aElement, 0);
if (theIndex >= 0) {
return RemoveElementAt(theIndex) ? NS_OK : NS_ERROR_FAILURE;
}
return NS_ERROR_FAILURE;
}
NS_IMETHODIMP_(bool)
nsSupportsArray::RemoveLastElement(const nsISupports* aElement)
{
int32_t theIndex = LastIndexOf(aElement);
if (theIndex >= 0) {
return RemoveElementAt(theIndex);
}
return false;
}
NS_IMETHODIMP_(bool)
nsSupportsArray::MoveElement(int32_t aFrom, int32_t aTo)
{
nsISupports* tempElement;
if (aTo == aFrom) {
return true;
}
if (aTo < 0 || aFrom < 0 ||
(uint32_t)aTo >= mCount || (uint32_t)aFrom >= mCount) {
// can't extend the array when moving an element. Also catches mImpl = null
return false;
}
tempElement = mArray[aFrom];
if (aTo < aFrom) {
// Moving one element closer to the head; the elements inbetween move down
::memmove(mArray + aTo + 1, mArray + aTo,
(aFrom - aTo) * sizeof(mArray[0]));
mArray[aTo] = tempElement;
} else { // already handled aFrom == aTo
// Moving one element closer to the tail; the elements inbetween move up
::memmove(mArray + aFrom, mArray + aFrom + 1,
(aTo - aFrom) * sizeof(mArray[0]));
mArray[aTo] = tempElement;
}
return true;
}
NS_IMETHODIMP
nsSupportsArray::Clear(void)
{
if (0 < mCount) {
do {
--mCount;
NS_IF_RELEASE(mArray[mCount]);
} while (0 != mCount);
}
return NS_OK;
}
NS_IMETHODIMP
nsSupportsArray::Compact(void)
{
#if DEBUG_SUPPORTSARRAY
uint32_t oldArraySize = mArraySize;
#endif
if ((mArraySize != mCount) && (kAutoArraySize < mArraySize)) {
nsISupports** oldArray = mArray;
if (mCount <= kAutoArraySize) {
mArray = mAutoArray;
mArraySize = kAutoArraySize;
} else {
mArray = new nsISupports*[mCount];
if (!mArray) {
mArray = oldArray;
return NS_OK;
}
mArraySize = mCount;
}
#if DEBUG_SUPPORTSARRAY
if (oldArray == mArray &&
oldArray != &(mAutoArray[0])) { // can't happen without use of realloc
ADD_TO_STATS(GrowInPlace, oldArraySize);
}
if (oldArray != &(mAutoArray[0])) {
ADD_TO_STATS(AllocedOfSize, mArraySize * sizeof(mArray[0]));
}
#endif
::memcpy(mArray, oldArray, mCount * sizeof(nsISupports*));
delete[] oldArray;
}
return NS_OK;
}
NS_IMETHODIMP_(bool)
nsSupportsArray::SizeTo(int32_t aSize)
{
#if DEBUG_SUPPORTSARRAY
uint32_t oldArraySize = mArraySize;
#endif
NS_ASSERTION(aSize >= 0, "negative aSize!");
// XXX for aSize < mCount we could resize to mCount
if (mArraySize == (uint32_t)aSize || (uint32_t)aSize < mCount) {
return true; // nothing to do
}
// switch back to autoarray if possible
nsISupports** oldArray = mArray;
if ((uint32_t)aSize <= kAutoArraySize) {
mArray = mAutoArray;
mArraySize = kAutoArraySize;
} else {
mArray = new nsISupports*[aSize];
if (!mArray) {
mArray = oldArray;
return false;
}
mArraySize = aSize;
}
#if DEBUG_SUPPORTSARRAY
if (oldArray == mArray &&
oldArray != &(mAutoArray[0])) { // can't happen without use of realloc
ADD_TO_STATS(GrowInPlace, oldArraySize);
}
if (oldArray != &(mAutoArray[0])) {
ADD_TO_STATS(AllocedOfSize, mArraySize * sizeof(mArray[0]));
}
#endif
::memcpy(mArray, oldArray, mCount * sizeof(nsISupports*));
if (oldArray != mAutoArray) {
delete[] oldArray;
}
return true;
}
NS_IMETHODIMP
nsSupportsArray::Enumerate(nsIEnumerator** aResult)
{
nsSupportsArrayEnumerator* e = new nsSupportsArrayEnumerator(this);
if (!e) {
return NS_ERROR_OUT_OF_MEMORY;
}
*aResult = e;
NS_ADDREF(e);
return NS_OK;
}
NS_IMETHODIMP
nsSupportsArray::Clone(nsISupportsArray** aResult)
{
nsCOMPtr<nsISupportsArray> newArray;
nsresult rv = NS_NewISupportsArray(getter_AddRefs(newArray));
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
uint32_t count = 0;
Count(&count);
for (uint32_t i = 0; i < count; i++) {
if (!newArray->InsertElementAt(mArray[i], i)) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
newArray.forget(aResult);
return NS_OK;
}
nsresult
NS_NewISupportsArray(nsISupportsArray** aInstancePtrResult)
{
nsresult rv;
rv = nsSupportsArray::Create(nullptr, NS_GET_IID(nsISupportsArray),
(void**)aInstancePtrResult);
return rv;
}