gecko/xpcom/ds/nsStringEnumerator.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2012-05-21 04:12:37 -07:00
/* 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 "nsStringEnumerator.h"
#include "nsISimpleEnumerator.h"
#include "nsSupportsPrimitives.h"
#include "mozilla/Attributes.h"
#include "nsTArray.h"
//
// nsStringEnumerator
//
class nsStringEnumerator MOZ_FINAL : public nsIStringEnumerator,
public nsIUTF8StringEnumerator,
public nsISimpleEnumerator
{
public:
nsStringEnumerator(const nsTArray<nsString>* aArray, bool aOwnsArray) :
mArray(aArray), mIndex(0), mOwnsArray(aOwnsArray), mIsUnicode(true)
{}
nsStringEnumerator(const nsTArray<nsCString>* aArray, bool aOwnsArray) :
mCArray(aArray), mIndex(0), mOwnsArray(aOwnsArray), mIsUnicode(false)
{}
nsStringEnumerator(const nsTArray<nsString>* aArray, nsISupports* aOwner) :
mArray(aArray), mIndex(0), mOwner(aOwner), mOwnsArray(false), mIsUnicode(true)
{}
nsStringEnumerator(const nsTArray<nsCString>* aArray, nsISupports* aOwner) :
mCArray(aArray), mIndex(0), mOwner(aOwner), mOwnsArray(false), mIsUnicode(false)
{}
NS_DECL_ISUPPORTS
NS_DECL_NSIUTF8STRINGENUMERATOR
// have to declare nsIStringEnumerator manually, because of
// overlapping method names
NS_IMETHOD GetNext(nsAString& aResult);
NS_DECL_NSISIMPLEENUMERATOR
private:
~nsStringEnumerator() {
if (mOwnsArray) {
// const-casting is safe here, because the NS_New*
// constructors make sure mOwnsArray is consistent with
// the constness of the objects
if (mIsUnicode)
delete const_cast<nsTArray<nsString>*>(mArray);
else
delete const_cast<nsTArray<nsCString>*>(mCArray);
}
}
union {
const nsTArray<nsString>* mArray;
const nsTArray<nsCString>* mCArray;
};
inline uint32_t Count() {
return mIsUnicode ? mArray->Length() : mCArray->Length();
}
uint32_t mIndex;
// the owner allows us to hold a strong reference to the object
// that owns the array. Having a non-null value in mOwner implies
// that mOwnsArray is false, because we rely on the real owner
// to release the array
nsCOMPtr<nsISupports> mOwner;
bool mOwnsArray;
bool mIsUnicode;
};
NS_IMPL_ISUPPORTS(nsStringEnumerator,
nsIStringEnumerator,
nsIUTF8StringEnumerator,
nsISimpleEnumerator)
NS_IMETHODIMP
nsStringEnumerator::HasMore(bool* aResult)
{
*aResult = mIndex < Count();
return NS_OK;
}
NS_IMETHODIMP
nsStringEnumerator::HasMoreElements(bool* aResult)
{
return HasMore(aResult);
}
NS_IMETHODIMP
nsStringEnumerator::GetNext(nsISupports** aResult)
{
if (mIsUnicode) {
nsSupportsStringImpl* stringImpl = new nsSupportsStringImpl();
if (!stringImpl) return NS_ERROR_OUT_OF_MEMORY;
stringImpl->SetData(mArray->ElementAt(mIndex++));
*aResult = stringImpl;
}
else {
nsSupportsCStringImpl* cstringImpl = new nsSupportsCStringImpl();
if (!cstringImpl) return NS_ERROR_OUT_OF_MEMORY;
cstringImpl->SetData(mCArray->ElementAt(mIndex++));
*aResult = cstringImpl;
}
NS_ADDREF(*aResult);
return NS_OK;
}
NS_IMETHODIMP
nsStringEnumerator::GetNext(nsAString& aResult)
{
if (NS_WARN_IF(mIndex >= Count()))
return NS_ERROR_UNEXPECTED;
if (mIsUnicode)
aResult = mArray->ElementAt(mIndex++);
else
CopyUTF8toUTF16(mCArray->ElementAt(mIndex++), aResult);
return NS_OK;
}
NS_IMETHODIMP
nsStringEnumerator::GetNext(nsACString& aResult)
{
if (NS_WARN_IF(mIndex >= Count()))
return NS_ERROR_UNEXPECTED;
if (mIsUnicode)
CopyUTF16toUTF8(mArray->ElementAt(mIndex++), aResult);
else
aResult = mCArray->ElementAt(mIndex++);
return NS_OK;
}
template<class T>
static inline nsresult
StringEnumeratorTail(T** aResult)
{
if (!*aResult)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*aResult);
return NS_OK;
}
//
// constructors
//
nsresult
NS_NewStringEnumerator(nsIStringEnumerator** aResult,
const nsTArray<nsString>* aArray, nsISupports* aOwner)
{
if (NS_WARN_IF(!aResult) || NS_WARN_IF(!aArray))
return NS_ERROR_INVALID_ARG;
*aResult = new nsStringEnumerator(aArray, aOwner);
return StringEnumeratorTail(aResult);
}
nsresult
NS_NewUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
const nsTArray<nsCString>* aArray, nsISupports* aOwner)
{
if (NS_WARN_IF(!aResult) || NS_WARN_IF(!aArray))
return NS_ERROR_INVALID_ARG;
*aResult = new nsStringEnumerator(aArray, aOwner);
return StringEnumeratorTail(aResult);
}
nsresult
NS_NewAdoptingStringEnumerator(nsIStringEnumerator** aResult,
nsTArray<nsString>* aArray)
{
if (NS_WARN_IF(!aResult) || NS_WARN_IF(!aArray))
return NS_ERROR_INVALID_ARG;
*aResult = new nsStringEnumerator(aArray, true);
return StringEnumeratorTail(aResult);
}
nsresult
NS_NewAdoptingUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
nsTArray<nsCString>* aArray)
{
if (NS_WARN_IF(!aResult) || NS_WARN_IF(!aArray))
return NS_ERROR_INVALID_ARG;
*aResult = new nsStringEnumerator(aArray, true);
return StringEnumeratorTail(aResult);
}
// const ones internally just forward to the non-const equivalents
nsresult
NS_NewStringEnumerator(nsIStringEnumerator** aResult,
const nsTArray<nsString>* aArray)
{
if (NS_WARN_IF(!aResult) || NS_WARN_IF(!aArray))
return NS_ERROR_INVALID_ARG;
*aResult = new nsStringEnumerator(aArray, false);
return StringEnumeratorTail(aResult);
}
nsresult
NS_NewUTF8StringEnumerator(nsIUTF8StringEnumerator** aResult,
const nsTArray<nsCString>* aArray)
{
if (NS_WARN_IF(!aResult) || NS_WARN_IF(!aArray))
return NS_ERROR_INVALID_ARG;
*aResult = new nsStringEnumerator(aArray, false);
return StringEnumeratorTail(aResult);
}