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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /xpcom/glue/nsArrayEnumerator.cpp
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'xpcom/glue/nsArrayEnumerator.cpp')
-rw-r--r--xpcom/glue/nsArrayEnumerator.cpp213
1 files changed, 213 insertions, 0 deletions
diff --git a/xpcom/glue/nsArrayEnumerator.cpp b/xpcom/glue/nsArrayEnumerator.cpp
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+++ b/xpcom/glue/nsArrayEnumerator.cpp
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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 "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;
+}