gecko-dev/xpcom/ds/nsStringEnumerator.cpp

263 lines
6.1 KiB
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 "nsStringEnumerator.h"
#include "nsISimpleEnumerator.h"
#include "nsSupportsPrimitives.h"
#include "mozilla/Attributes.h"
#include "nsTArray.h"
//
// nsStringEnumerator
//
class nsStringEnumerator 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) override;
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);
}