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Diffstat (limited to 'xpcom/ds/nsStringEnumerator.cpp')
| -rw-r--r-- | xpcom/ds/nsStringEnumerator.cpp | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/xpcom/ds/nsStringEnumerator.cpp b/xpcom/ds/nsStringEnumerator.cpp new file mode 100644 index 0000000000..7b8cf72d00 --- /dev/null +++ b/xpcom/ds/nsStringEnumerator.cpp @@ -0,0 +1,311 @@ +/* -*- 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 "nsSimpleEnumerator.h" +#include "nsSupportsPrimitives.h" +#include "mozilla/Attributes.h" +#include "mozilla/ResultExtensions.h" +#include "mozilla/dom/IteratorResultBinding.h" +#include "mozilla/dom/RootedDictionary.h" +#include "mozilla/dom/ToJSValue.h" +#include "nsTArray.h" + +using namespace mozilla; +using namespace mozilla::dom; + +namespace { + +class JSStringEnumerator final : public nsIJSEnumerator { + NS_DECL_ISUPPORTS + NS_DECL_NSIJSENUMERATOR + + explicit JSStringEnumerator(nsIStringEnumerator* aEnumerator) + : mEnumerator(aEnumerator) { + MOZ_ASSERT(mEnumerator); + } + + private: + ~JSStringEnumerator() = default; + + nsCOMPtr<nsIStringEnumerator> mEnumerator; +}; + +} // anonymous namespace + +nsresult JSStringEnumerator::Iterator(nsIJSEnumerator** aResult) { + RefPtr<JSStringEnumerator> result(this); + result.forget(aResult); + return NS_OK; +} + +nsresult JSStringEnumerator::Next(JSContext* aCx, + JS::MutableHandleValue aResult) { + RootedDictionary<IteratorResult> result(aCx); + + nsAutoString elem; + if (NS_FAILED(mEnumerator->GetNext(elem))) { + result.mDone = true; + } else { + result.mDone = false; + + if (!ToJSValue( + aCx, elem, + JS::MutableHandleValue::fromMarkedLocation(&result.mValue))) { + return NS_ERROR_OUT_OF_MEMORY; + } + } + + if (!ToJSValue(aCx, result, aResult)) { + return NS_ERROR_OUT_OF_MEMORY; + } + return NS_OK; +} + +NS_IMPL_ISUPPORTS(JSStringEnumerator, nsIJSEnumerator) + +// +// nsStringEnumeratorBase +// + +nsresult nsStringEnumeratorBase::GetNext(nsAString& aResult) { + nsAutoCString str; + MOZ_TRY(GetNext(str)); + + CopyUTF8toUTF16(str, aResult); + return NS_OK; +} + +NS_IMETHODIMP +nsStringEnumeratorBase::StringIterator(nsIJSEnumerator** aRetVal) { + auto result = MakeRefPtr<JSStringEnumerator>(this); + result.forget(aRetVal); + return NS_OK; +} + +// +// nsStringEnumerator +// + +class nsStringEnumerator final : public nsSimpleEnumerator, + public nsIStringEnumerator, + public nsIUTF8StringEnumerator { + 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_INHERITED + NS_DECL_NSIUTF8STRINGENUMERATOR + NS_DECL_NSISTRINGENUMERATORBASE + + // have to declare nsIStringEnumerator manually, because of + // overlapping method names + NS_IMETHOD GetNext(nsAString& aResult) override; + NS_DECL_NSISIMPLEENUMERATOR + + const nsID& DefaultInterface() override { + if (mIsUnicode) { + return NS_GET_IID(nsISupportsString); + } + return NS_GET_IID(nsISupportsCString); + } + + 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_INHERITED(nsStringEnumerator, nsSimpleEnumerator, + nsIStringEnumerator, nsIUTF8StringEnumerator) + +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 (mIndex >= mArray->Length()) { + return NS_ERROR_FAILURE; + } + + if (mIsUnicode) { + nsSupportsString* stringImpl = new nsSupportsString(); + + stringImpl->SetData(mArray->ElementAt(mIndex++)); + *aResult = stringImpl; + } else { + nsSupportsCString* cstringImpl = new nsSupportsCString(); + + 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; +} + +NS_IMETHODIMP +nsStringEnumerator::StringIterator(nsIJSEnumerator** aRetVal) { + auto result = MakeRefPtr<JSStringEnumerator>(this); + result.forget(aRetVal); + 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); +} |