diff options
Diffstat (limited to 'src/libs/xpcom18a4/xpcom/ds/nsArrayEnumerator.cpp')
-rw-r--r-- | src/libs/xpcom18a4/xpcom/ds/nsArrayEnumerator.cpp | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/src/libs/xpcom18a4/xpcom/ds/nsArrayEnumerator.cpp b/src/libs/xpcom18a4/xpcom/ds/nsArrayEnumerator.cpp new file mode 100644 index 00000000..c105622a --- /dev/null +++ b/src/libs/xpcom18a4/xpcom/ds/nsArrayEnumerator.cpp @@ -0,0 +1,210 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* ***** BEGIN LICENSE BLOCK ***** + * Version: MPL 1.1/GPL 2.0/LGPL 2.1 + * + * The contents of this file are subject to the Mozilla Public License Version + * 1.1 (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * Software distributed under the License is distributed on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License + * for the specific language governing rights and limitations under the + * License. + * + * The Original Code is XPCOM Array implementation. + * + * The Initial Developer of the Original Code + * Netscape Communications Corp. + * Portions created by the Initial Developer are Copyright (C) 2002 + * the Initial Developer. All Rights Reserved. + * + * Contributor(s): + * Alec Flett <alecf@netscape.com> + * + * Alternatively, the contents of this file may be used under the terms of + * either the GNU General Public License Version 2 or later (the "GPL"), or + * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), + * in which case the provisions of the GPL or the LGPL are applicable instead + * of those above. If you wish to allow use of your version of this file only + * under the terms of either the GPL or the LGPL, and not to allow others to + * use your version of this file under the terms of the MPL, indicate your + * decision by deleting the provisions above and replace them with the notice + * and other provisions required by the GPL or the LGPL. If you do not delete + * the provisions above, a recipient may use your version of this file under + * the terms of any one of the MPL, the GPL or the LGPL. + * + * ***** END LICENSE BLOCK ***** */ + +#include "nsArrayEnumerator.h" + +NS_IMPL_ISUPPORTS1(nsSimpleArrayEnumerator, nsISimpleEnumerator) + +NS_IMETHODIMP +nsSimpleArrayEnumerator::HasMoreElements(PRBool* aResult) +{ + NS_PRECONDITION(aResult != 0, "null ptr"); + if (! aResult) + return NS_ERROR_NULL_POINTER; + + if (!mValueArray) { + *aResult = PR_FALSE; + return NS_OK; + } + + PRUint32 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 = nsnull; + return NS_OK; + } + + PRUint32 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); +} + +extern NS_COM nsresult +NS_NewArrayEnumerator(nsISimpleEnumerator* *result, + nsIArray* array) +{ + nsSimpleArrayEnumerator* enumer = new nsSimpleArrayEnumerator(array); + if (enumer == nsnull) + return NS_ERROR_OUT_OF_MEMORY; + + NS_ADDREF(*result = enumer); + 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 : 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 size, const nsCOMArray_base& aArray) CPP_THROW_NEW; + void operator delete(void* ptr) { + ::operator delete(ptr); + } + +private: + ~nsCOMArrayEnumerator(void); + +protected: + PRUint32 mIndex; // current position + PRUint32 mArraySize; // size of the array + + // this is actually bigger + nsISupports* mValueArray[1]; +}; + +NS_IMPL_ISUPPORTS1(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(PRBool* 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)] = nsnull; + + return NS_OK; +} + +void* +nsCOMArrayEnumerator::operator new (size_t size, 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 size gives us + // space for mValueArray[0], so we must subtract + size += (aArray.Count() - 1) * sizeof(aArray[0]); + + // do the actual allocation + nsCOMArrayEnumerator * result = + NS_STATIC_CAST(nsCOMArrayEnumerator*, ::operator new(size)); + + // now need to copy over the values, and addref each one + // now this might seem like alot 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 + PRUint32 i; + PRUint32 max = result->mArraySize = aArray.Count(); + for (i = 0; i<max; i++) { + result->mValueArray[i] = aArray[i]; + NS_IF_ADDREF(result->mValueArray[i]); + } + + return result; +} + +extern NS_COM nsresult +NS_NewArrayEnumerator(nsISimpleEnumerator* *aResult, + const nsCOMArray_base& aArray) +{ + nsCOMArrayEnumerator *enumerator = new (aArray) nsCOMArrayEnumerator(); + if (!enumerator) return NS_ERROR_OUT_OF_MEMORY; + + NS_ADDREF(*aResult = enumerator); + return NS_OK; +} |