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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /xpcom/glue/nsArrayEnumerator.cpp | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
download | UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.gz UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.lz UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.xz UXP-5f8de423f190bbb79a62f804151bc24824fa32d8.zip |
Add m-esr52 at 52.6.0
Diffstat (limited to 'xpcom/glue/nsArrayEnumerator.cpp')
-rw-r--r-- | xpcom/glue/nsArrayEnumerator.cpp | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/xpcom/glue/nsArrayEnumerator.cpp b/xpcom/glue/nsArrayEnumerator.cpp new file mode 100644 index 000000000..2d2ef6da7 --- /dev/null +++ b/xpcom/glue/nsArrayEnumerator.cpp @@ -0,0 +1,213 @@ +/* -*- 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 "nsArrayEnumerator.h" + +#include "nsIArray.h" +#include "nsISimpleEnumerator.h" + +#include "nsCOMArray.h" +#include "nsCOMPtr.h" +#include "mozilla/RefPtr.h" + +class nsSimpleArrayEnumerator final : public nsISimpleEnumerator +{ +public: + // nsISupports interface + NS_DECL_ISUPPORTS + + // nsISimpleEnumerator interface + NS_DECL_NSISIMPLEENUMERATOR + + // nsSimpleArrayEnumerator methods + explicit nsSimpleArrayEnumerator(nsIArray* aValueArray) + : mValueArray(aValueArray) + , mIndex(0) + { + } + +private: + ~nsSimpleArrayEnumerator() {} + +protected: + nsCOMPtr<nsIArray> mValueArray; + uint32_t mIndex; +}; + +NS_IMPL_ISUPPORTS(nsSimpleArrayEnumerator, nsISimpleEnumerator) + +NS_IMETHODIMP +nsSimpleArrayEnumerator::HasMoreElements(bool* aResult) +{ + NS_PRECONDITION(aResult != 0, "null ptr"); + if (!aResult) { + return NS_ERROR_NULL_POINTER; + } + + if (!mValueArray) { + *aResult = false; + return NS_OK; + } + + uint32_t cnt; + nsresult rv = mValueArray->GetLength(&cnt); + if (NS_FAILED(rv)) { + return rv; + } + *aResult = (mIndex < cnt); + return NS_OK; +} + +NS_IMETHODIMP +nsSimpleArrayEnumerator::GetNext(nsISupports** aResult) +{ + NS_PRECONDITION(aResult != 0, "null ptr"); + if (!aResult) { + return NS_ERROR_NULL_POINTER; + } + + if (!mValueArray) { + *aResult = nullptr; + return NS_OK; + } + + uint32_t cnt; + nsresult rv = mValueArray->GetLength(&cnt); + if (NS_FAILED(rv)) { + return rv; + } + if (mIndex >= cnt) { + return NS_ERROR_UNEXPECTED; + } + + return mValueArray->QueryElementAt(mIndex++, NS_GET_IID(nsISupports), + (void**)aResult); +} + +nsresult +NS_NewArrayEnumerator(nsISimpleEnumerator** aResult, nsIArray* aArray) +{ + RefPtr<nsSimpleArrayEnumerator> enumer = new nsSimpleArrayEnumerator(aArray); + enumer.forget(aResult); + return NS_OK; +} + +//////////////////////////////////////////////////////////////////////////////// + +// enumerator implementation for nsCOMArray +// creates a snapshot of the array in question +// you MUST use NS_NewArrayEnumerator to create this, so that +// allocation is done correctly +class nsCOMArrayEnumerator final : public nsISimpleEnumerator +{ +public: + // nsISupports interface + NS_DECL_ISUPPORTS + + // nsISimpleEnumerator interface + NS_DECL_NSISIMPLEENUMERATOR + + // nsSimpleArrayEnumerator methods + nsCOMArrayEnumerator() : mIndex(0) {} + + // specialized operator to make sure we make room for mValues + void* operator new(size_t aSize, const nsCOMArray_base& aArray) CPP_THROW_NEW; + void operator delete(void* aPtr) { ::operator delete(aPtr); } + +private: + ~nsCOMArrayEnumerator(void); + +protected: + uint32_t mIndex; // current position + uint32_t mArraySize; // size of the array + + // this is actually bigger + nsISupports* mValueArray[1]; +}; + +NS_IMPL_ISUPPORTS(nsCOMArrayEnumerator, nsISimpleEnumerator) + +nsCOMArrayEnumerator::~nsCOMArrayEnumerator() +{ + // only release the entries that we haven't visited yet + for (; mIndex < mArraySize; ++mIndex) { + NS_IF_RELEASE(mValueArray[mIndex]); + } +} + +NS_IMETHODIMP +nsCOMArrayEnumerator::HasMoreElements(bool* aResult) +{ + NS_PRECONDITION(aResult != 0, "null ptr"); + if (!aResult) { + return NS_ERROR_NULL_POINTER; + } + + *aResult = (mIndex < mArraySize); + return NS_OK; +} + +NS_IMETHODIMP +nsCOMArrayEnumerator::GetNext(nsISupports** aResult) +{ + NS_PRECONDITION(aResult != 0, "null ptr"); + if (!aResult) { + return NS_ERROR_NULL_POINTER; + } + + if (mIndex >= mArraySize) { + return NS_ERROR_UNEXPECTED; + } + + // pass the ownership of the reference to the caller. Since + // we AddRef'ed during creation of |this|, there is no need + // to AddRef here + *aResult = mValueArray[mIndex++]; + + // this really isn't necessary. just pretend this happens, since + // we'll never visit this value again! + // mValueArray[(mIndex-1)] = nullptr; + + return NS_OK; +} + +void* +nsCOMArrayEnumerator::operator new(size_t aSize, + const nsCOMArray_base& aArray) CPP_THROW_NEW +{ + // create enough space such that mValueArray points to a large + // enough value. Note that the initial value of aSize gives us + // space for mValueArray[0], so we must subtract + aSize += (aArray.Count() - 1) * sizeof(aArray[0]); + + // do the actual allocation + nsCOMArrayEnumerator* result = + static_cast<nsCOMArrayEnumerator*>(::operator new(aSize)); + + // now need to copy over the values, and addref each one + // now this might seem like a lot of work, but we're actually just + // doing all our AddRef's ahead of time since GetNext() doesn't + // need to AddRef() on the way out + uint32_t i; + uint32_t max = result->mArraySize = aArray.Count(); + for (i = 0; i < max; ++i) { + result->mValueArray[i] = aArray[i]; + NS_IF_ADDREF(result->mValueArray[i]); + } + + return result; +} + +nsresult +NS_NewArrayEnumerator(nsISimpleEnumerator** aResult, + const nsCOMArray_base& aArray) +{ + RefPtr<nsCOMArrayEnumerator> enumerator = new (aArray) nsCOMArrayEnumerator(); + enumerator.forget(aResult); + return NS_OK; +} |