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/* -*- 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 "mozilla/Attributes.h"
#include "nsEnumeratorUtils.h"
#include "nsIStringEnumerator.h"
#include "nsSimpleEnumerator.h"
#include "nsCOMPtr.h"
#include "mozilla/RefPtr.h"
class EmptyEnumeratorImpl : public nsSimpleEnumerator,
public nsIUTF8StringEnumerator,
public nsIStringEnumerator {
public:
EmptyEnumeratorImpl() = default;
// nsISupports interface. Not really inherited, but no mRefCnt.
NS_DECL_ISUPPORTS_INHERITED
// nsISimpleEnumerator
NS_DECL_NSISIMPLEENUMERATOR
NS_DECL_NSIUTF8STRINGENUMERATOR
NS_DECL_NSISTRINGENUMERATORBASE
// can't use NS_DECL_NSISTRINGENUMERATOR because they share the
// HasMore() signature
NS_IMETHOD GetNext(nsAString& aResult) override;
static EmptyEnumeratorImpl* GetInstance() {
static const EmptyEnumeratorImpl kInstance;
return const_cast<EmptyEnumeratorImpl*>(&kInstance);
}
};
// nsISupports interface
NS_IMETHODIMP_(MozExternalRefCountType)
EmptyEnumeratorImpl::AddRef(void) { return 2; }
NS_IMETHODIMP_(MozExternalRefCountType)
EmptyEnumeratorImpl::Release(void) { return 1; }
NS_IMPL_QUERY_INTERFACE_INHERITED(EmptyEnumeratorImpl, nsSimpleEnumerator,
nsIUTF8StringEnumerator, nsIStringEnumerator)
// nsISimpleEnumerator interface
NS_IMETHODIMP
EmptyEnumeratorImpl::HasMoreElements(bool* aResult) {
*aResult = false;
return NS_OK;
}
NS_IMETHODIMP
EmptyEnumeratorImpl::HasMore(bool* aResult) {
*aResult = false;
return NS_OK;
}
NS_IMETHODIMP
EmptyEnumeratorImpl::GetNext(nsISupports** aResult) { return NS_ERROR_FAILURE; }
NS_IMETHODIMP
EmptyEnumeratorImpl::GetNext(nsACString& aResult) {
return NS_ERROR_UNEXPECTED;
}
NS_IMETHODIMP
EmptyEnumeratorImpl::GetNext(nsAString& aResult) { return NS_ERROR_UNEXPECTED; }
NS_IMETHODIMP
EmptyEnumeratorImpl::StringIterator(nsIJSEnumerator** aRetVal) {
return NS_ERROR_NOT_IMPLEMENTED;
}
nsresult NS_NewEmptyEnumerator(nsISimpleEnumerator** aResult) {
*aResult = EmptyEnumeratorImpl::GetInstance();
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
class nsSingletonEnumerator final : public nsSimpleEnumerator {
public:
// nsISimpleEnumerator methods
NS_IMETHOD HasMoreElements(bool* aResult) override;
NS_IMETHOD GetNext(nsISupports** aResult) override;
explicit nsSingletonEnumerator(nsISupports* aValue);
private:
~nsSingletonEnumerator() override;
protected:
nsCOMPtr<nsISupports> mValue;
bool mConsumed;
};
nsSingletonEnumerator::nsSingletonEnumerator(nsISupports* aValue)
: mValue(aValue) {
mConsumed = (mValue ? false : true);
}
nsSingletonEnumerator::~nsSingletonEnumerator() = default;
NS_IMETHODIMP
nsSingletonEnumerator::HasMoreElements(bool* aResult) {
MOZ_ASSERT(aResult != 0, "null ptr");
if (!aResult) {
return NS_ERROR_NULL_POINTER;
}
*aResult = !mConsumed;
return NS_OK;
}
NS_IMETHODIMP
nsSingletonEnumerator::GetNext(nsISupports** aResult) {
MOZ_ASSERT(aResult != 0, "null ptr");
if (!aResult) {
return NS_ERROR_NULL_POINTER;
}
if (mConsumed) {
return NS_ERROR_FAILURE;
}
mConsumed = true;
*aResult = mValue;
NS_ADDREF(*aResult);
return NS_OK;
}
nsresult NS_NewSingletonEnumerator(nsISimpleEnumerator** aResult,
nsISupports* aSingleton) {
RefPtr<nsSingletonEnumerator> enumer = new nsSingletonEnumerator(aSingleton);
enumer.forget(aResult);
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
class nsUnionEnumerator final : public nsSimpleEnumerator {
public:
// nsISimpleEnumerator methods
NS_IMETHOD HasMoreElements(bool* aResult) override;
NS_IMETHOD GetNext(nsISupports** aResult) override;
nsUnionEnumerator(nsISimpleEnumerator* aFirstEnumerator,
nsISimpleEnumerator* aSecondEnumerator);
private:
~nsUnionEnumerator() override;
protected:
nsCOMPtr<nsISimpleEnumerator> mFirstEnumerator, mSecondEnumerator;
bool mConsumed;
bool mAtSecond;
};
nsUnionEnumerator::nsUnionEnumerator(nsISimpleEnumerator* aFirstEnumerator,
nsISimpleEnumerator* aSecondEnumerator)
: mFirstEnumerator(aFirstEnumerator),
mSecondEnumerator(aSecondEnumerator),
mConsumed(false),
mAtSecond(false) {}
nsUnionEnumerator::~nsUnionEnumerator() = default;
NS_IMETHODIMP
nsUnionEnumerator::HasMoreElements(bool* aResult) {
MOZ_ASSERT(aResult != 0, "null ptr");
if (!aResult) {
return NS_ERROR_NULL_POINTER;
}
nsresult rv;
if (mConsumed) {
*aResult = false;
return NS_OK;
}
if (!mAtSecond) {
rv = mFirstEnumerator->HasMoreElements(aResult);
if (NS_FAILED(rv)) {
return rv;
}
if (*aResult) {
return NS_OK;
}
mAtSecond = true;
}
rv = mSecondEnumerator->HasMoreElements(aResult);
if (NS_FAILED(rv)) {
return rv;
}
if (*aResult) {
return NS_OK;
}
*aResult = false;
mConsumed = true;
return NS_OK;
}
NS_IMETHODIMP
nsUnionEnumerator::GetNext(nsISupports** aResult) {
MOZ_ASSERT(aResult != 0, "null ptr");
if (!aResult) {
return NS_ERROR_NULL_POINTER;
}
if (mConsumed) {
return NS_ERROR_FAILURE;
}
if (!mAtSecond) {
return mFirstEnumerator->GetNext(aResult);
}
return mSecondEnumerator->GetNext(aResult);
}
nsresult NS_NewUnionEnumerator(nsISimpleEnumerator** aResult,
nsISimpleEnumerator* aFirstEnumerator,
nsISimpleEnumerator* aSecondEnumerator) {
*aResult = nullptr;
if (!aFirstEnumerator) {
*aResult = aSecondEnumerator;
} else if (!aSecondEnumerator) {
*aResult = aFirstEnumerator;
} else {
auto* enumer = new nsUnionEnumerator(aFirstEnumerator, aSecondEnumerator);
*aResult = enumer;
}
NS_ADDREF(*aResult);
return NS_OK;
}
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