The Tor Browser: xpcom/ds/nsSupportsArray.cpp@6474c204b198 (annotated)

xpcom/ds/nsSupportsArray.cpp@6474c204b198 (annotated)

xpcom/ds/nsSupportsArray.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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_(bool)
 nsSupportsArray::RemoveElement(const nsISupports* aElement, uint32_t aStartIndex)
 {
   int32_t theIndex = IndexOfStartingAt(aElement,aStartIndex);
   if (theIndex >= 0)
     return RemoveElementAt(theIndex);
   return false;
 }
 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* *result)
 {
   nsSupportsArrayEnumerator* e = new nsSupportsArrayEnumerator(this);
   if (!e)
     return NS_ERROR_OUT_OF_MEMORY;
   *result = 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;
 }

The Tor Browser / annotate

xpcom/ds/nsSupportsArray.cpp@6474c204b198 (annotated)

xpcom/ds/nsSupportsArray.cpp