gecko-dev/xpcom/ds/nsVoidArray.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; c-file-offsets: ((substatement-open . 0)) -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
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* ***** END LICENSE BLOCK ***** */
#ifndef nsVoidArray_h___
#define nsVoidArray_h___
//#define DEBUG_VOIDARRAY 1
#include "nscore.h"
#include "nsAString.h"
// Comparator callback function for sorting array values.
typedef int (* PR_CALLBACK nsVoidArrayComparatorFunc)
(const void* aElement1, const void* aElement2, void* aData);
// Enumerator callback function. Return PR_FALSE to stop
typedef PRBool (* PR_CALLBACK nsVoidArrayEnumFunc)(void* aElement, void *aData);
/// A basic zero-based array of void*'s that manages its own memory
class NS_COM nsVoidArray {
public:
nsVoidArray();
nsVoidArray(PRInt32 aCount); // initial count of aCount elements set to nsnull
virtual ~nsVoidArray();
nsVoidArray& operator=(const nsVoidArray& other);
inline PRInt32 Count() const {
return mImpl ? mImpl->mCount : 0;
}
// returns the max number that can be held without allocating
inline PRInt32 GetArraySize() const {
return mImpl ? (PRInt32(mImpl->mBits) & kArraySizeMask) : 0;
}
void* ElementAt(PRInt32 aIndex) const
{
NS_ASSERTION(aIndex >= 0,"nsVoidArray::ElementAt(negative index) - note on bug 96108");
NS_ASSERTION(aIndex < Count(),"nsVoidArray::ElementAt(index past end array) - note on bug 96108");
// This will go away once all assertions are handled and we feel
// comfortable that there aren't any more out there. Negative values
// are all handled I think.
if (aIndex >= Count())
{
return nsnull;
}
return mImpl ? mImpl->mArray[aIndex] : nsnull;
}
// bounds-checked version
void* SafeElementAt(PRInt32 aIndex) const
{
if (aIndex < 0 || aIndex >= Count())
{
return nsnull;
}
return mImpl ? mImpl->mArray[aIndex] : nsnull;
}
void* operator[](PRInt32 aIndex) const { return ElementAt(aIndex); }
PRInt32 IndexOf(void* aPossibleElement) const;
PRBool InsertElementAt(void* aElement, PRInt32 aIndex);
PRBool InsertElementsAt(const nsVoidArray &other, PRInt32 aIndex);
PRBool ReplaceElementAt(void* aElement, PRInt32 aIndex);
// useful for doing LRU arrays, sorting, etc
PRBool MoveElement(PRInt32 aFrom, PRInt32 aTo);
PRBool AppendElement(void* aElement) {
return InsertElementAt(aElement, Count());
}
PRBool AppendElements(nsVoidArray& aElements) {
return InsertElementsAt(aElements, Count());
}
PRBool RemoveElement(void* aElement);
PRBool RemoveElementsAt(PRInt32 aIndex, PRInt32 aCount);
PRBool RemoveElementAt(PRInt32 aIndex) { return RemoveElementsAt(aIndex,1); }
virtual void Clear();
virtual PRBool SizeTo(PRInt32 aMin);
// Subtly different - Compact() tries to be smart about whether we
// should reallocate the array; SizeTo() just does it.
virtual void Compact();
void Sort(nsVoidArrayComparatorFunc aFunc, void* aData);
PRBool EnumerateForwards(nsVoidArrayEnumFunc aFunc, void* aData);
PRBool EnumerateBackwards(nsVoidArrayEnumFunc aFunc, void* aData);
protected:
virtual PRBool GrowArrayBy(PRInt32 aGrowBy);
struct Impl {
/**
* Packed bits. The low 31 bits are the array's size.
* The highest bit is a flag that indicates
* whether or not we "own" mArray, and must free() it when
* destroyed.
*/
PRUint32 mBits;
/**
* The number of elements in the array
*/
PRInt32 mCount;
/**
* Array data, padded out to the actual size of the array.
*/
void* mArray[1];
};
Impl* mImpl;
#if DEBUG_VOIDARRAY
PRInt32 mMaxCount;
PRInt32 mMaxSize;
PRBool mIsAuto;
#endif
enum {
kArrayOwnerMask = 1 << 31,
kArraySizeMask = ~kArrayOwnerMask
};
// bit twiddlers
void SetArray(Impl *newImpl, PRInt32 aSize, PRInt32 aCount, PRBool owner);
inline PRBool IsArrayOwner() const {
return mImpl ? (PRBool(mImpl->mBits) & kArrayOwnerMask) : PR_FALSE;
}
private:
/// Copy constructors are not allowed
nsVoidArray(const nsVoidArray& other);
};
// A zero-based array with a bit of automatic internal storage
class NS_COM nsAutoVoidArray : public nsVoidArray {
public:
nsAutoVoidArray();
void Clear();
virtual PRBool SizeTo(PRInt32 aMin);
virtual void Compact();
protected:
// The internal storage
enum { kAutoBufSize = 8 };
char mAutoBuf[sizeof(Impl) + (kAutoBufSize - 1) * sizeof(void*)];
};
class nsString;
typedef int (* PR_CALLBACK nsStringArrayComparatorFunc)
(const nsString* aElement1, const nsString* aElement2, void* aData);
typedef PRBool (*nsStringArrayEnumFunc)(nsString& aElement, void *aData);
class NS_COM nsStringArray: protected nsVoidArray
{
public:
nsStringArray(void);
nsStringArray(PRInt32 aCount); // Storage for aCount elements will be pre-allocated
virtual ~nsStringArray(void);
nsStringArray& operator=(const nsStringArray& other);
PRInt32 Count(void) const {
return nsVoidArray::Count();
}
void StringAt(PRInt32 aIndex, nsAString& aString) const;
nsString* StringAt(PRInt32 aIndex) const;
nsString* operator[](PRInt32 aIndex) const { return StringAt(aIndex); }
PRInt32 IndexOf(const nsAString& aPossibleString) const;
PRBool InsertStringAt(const nsAString& aString, PRInt32 aIndex);
PRBool ReplaceStringAt(const nsAString& aString, PRInt32 aIndex);
PRBool AppendString(const nsAString& aString) {
return InsertStringAt(aString, Count());
}
PRBool RemoveString(const nsAString& aString);
PRBool RemoveStringAt(PRInt32 aIndex);
void Clear(void);
void Compact(void) {
nsVoidArray::Compact();
}
void Sort(void);
void Sort(nsStringArrayComparatorFunc aFunc, void* aData);
PRBool EnumerateForwards(nsStringArrayEnumFunc aFunc, void* aData);
PRBool EnumerateBackwards(nsStringArrayEnumFunc aFunc, void* aData);
private:
/// Copy constructors are not allowed
nsStringArray(const nsStringArray& other);
};
class nsCString;
typedef int (* PR_CALLBACK nsCStringArrayComparatorFunc)
(const nsCString* aElement1, const nsCString* aElement2, void* aData);
typedef PRBool (*nsCStringArrayEnumFunc)(nsCString& aElement, void *aData);
class NS_COM nsCStringArray: protected nsVoidArray
{
public:
nsCStringArray(void);
nsCStringArray(PRInt32 aCount); // Storage for aCount elements will be pre-allocated
virtual ~nsCStringArray(void);
nsCStringArray& operator=(const nsCStringArray& other);
// Parses a given string using the delimiter passed in. If the array
// already has some elements, items parsed from string will be appended
// to array. For example, array.ParseString("a,b,c", ","); will add strings
// "a", "b" and "c" to the array. Parsing process has the same tokenizing
// behavior as strtok().
void ParseString(const char* string, const char* delimiter);
PRInt32 Count(void) const {
return nsVoidArray::Count();
}
void CStringAt(PRInt32 aIndex, nsACString& aCString) const;
nsCString* CStringAt(PRInt32 aIndex) const;
nsCString* operator[](PRInt32 aIndex) const { return CStringAt(aIndex); }
PRInt32 IndexOf(const nsACString& aPossibleString) const;
PRInt32 IndexOfIgnoreCase(const nsACString& aPossibleString) const;
PRBool InsertCStringAt(const nsACString& aCString, PRInt32 aIndex);
PRBool ReplaceCStringAt(const nsACString& aCString, PRInt32 aIndex);
PRBool AppendCString(const nsACString& aCString) {
return InsertCStringAt(aCString, Count());
}
PRBool RemoveCString(const nsACString& aCString);
PRBool RemoveCStringIgnoreCase(const nsACString& aCString);
PRBool RemoveCStringAt(PRInt32 aIndex);
void Clear(void);
void Compact(void) {
nsVoidArray::Compact();
}
void Sort(void);
void SortIgnoreCase(void);
void Sort(nsCStringArrayComparatorFunc aFunc, void* aData);
PRBool EnumerateForwards(nsCStringArrayEnumFunc aFunc, void* aData);
PRBool EnumerateBackwards(nsCStringArrayEnumFunc aFunc, void* aData);
private:
/// Copy constructors are not allowed
nsCStringArray(const nsCStringArray& other);
};
//===================================================================
// nsSmallVoidArray is not a general-purpose replacement for
// ns(Auto)VoidArray because there is (some) extra CPU overhead for arrays
// larger than 1 element, though not a lot. It is appropriate for
// space-sensitive uses where sizes of 0 or 1 are moderately common or
// more, and where we're NOT storing arbitrary integers or arbitrary
// pointers.
// NOTE: nsSmallVoidArray can ONLY be used for holding items that always
// have the low bit as a 0 - i.e. element & 1 == 0. This happens to be
// true for allocated and object pointers for all the architectures we run
// on, but conceivably there might be some architectures/compilers for
// which it is NOT true. We know this works for all existing architectures
// because if it didn't then nsCheapVoidArray would have failed. Also note
// that we will ASSERT if this assumption is violated in DEBUG builds.
// XXX we're really re-implementing the whole nsVoidArray interface here -
// some form of abstract class would be useful
// I disagree on the abstraction here. If the point of this class is to be
// as small as possible, and no one will ever derive from it, as I found
// today, there should not be any virtualness to it to avoid the vtable
// ptr overhead.
class NS_COM nsSmallVoidArray
{
public:
nsSmallVoidArray();
~nsSmallVoidArray();
nsSmallVoidArray& operator=(nsSmallVoidArray& other);
void* operator[](PRInt32 aIndex) const { return ElementAt(aIndex); }
PRInt32 GetArraySize() const;
PRInt32 Count() const;
void* ElementAt(PRInt32 aIndex) const;
void* SafeElementAt(PRInt32 aIndex) const {
// let compiler inline; it may be able to remove these checks
if (aIndex < 0 || aIndex >= Count())
return nsnull;
return ElementAt(aIndex);
}
PRInt32 IndexOf(void* aPossibleElement) const;
PRBool InsertElementAt(void* aElement, PRInt32 aIndex);
PRBool InsertElementsAt(const nsVoidArray &other, PRInt32 aIndex);
PRBool ReplaceElementAt(void* aElement, PRInt32 aIndex);
PRBool MoveElement(PRInt32 aFrom, PRInt32 aTo);
PRBool AppendElement(void* aElement);
PRBool AppendElements(nsVoidArray& aElements) {
return InsertElementsAt(aElements, Count());
}
PRBool RemoveElement(void* aElement);
PRBool RemoveElementsAt(PRInt32 aIndex, PRInt32 aCount);
PRBool RemoveElementAt(PRInt32 aIndex);
void Clear();
PRBool SizeTo(PRInt32 aMin);
void Compact();
void Sort(nsVoidArrayComparatorFunc aFunc, void* aData);
PRBool EnumerateForwards(nsVoidArrayEnumFunc aFunc, void* aData);
PRBool EnumerateBackwards(nsVoidArrayEnumFunc aFunc, void* aData);
private:
typedef unsigned long PtrBits;
PRBool HasSingleChild() const
{
return (mChildren && (PtrBits(mChildren) & 0x1));
}
PRBool HasVector() const
{
return (mChildren && !(PtrBits(mChildren) & 0x1));
}
void* GetSingleChild() const
{
return (mChildren ? ((void*)(PtrBits(mChildren) & ~0x1)) : nsnull);
}
void SetSingleChild(void *aChild);
nsVoidArray* GetChildVector() const
{
return (nsVoidArray*)mChildren;
}
nsVoidArray* SwitchToVector();
// A tagged pointer that's either a pointer to a single child
// or a pointer to a vector of multiple children. This is a space
// optimization since a large number of containers have only a
// single child.
void *mChildren;
};
#endif /* nsVoidArray_h___ */