/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* 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/. */ /* A simple composite data source implementation. A composit data source is just a strategy for combining individual data sources into a collective graph. 1) A composite data source holds a sequence of data sources. The set of data sources can be specified during creation of the database. Data sources can also be added/deleted from a database later. 2) The aggregation mechanism is based on simple super-positioning of the graphs from the datasources. If there is a conflict (i.e., data source A has a true arc from foo to bar while data source B has a false arc from foo to bar), the data source that it earlier in the sequence wins. The implementation below doesn't really do this and needs to be fixed. */ #include "xpcom-config.h" #include "nsCOMPtr.h" #include "nsIComponentManager.h" #include "nsIRDFCompositeDataSource.h" #include "nsIRDFNode.h" #include "nsIRDFObserver.h" #include "nsIRDFRemoteDataSource.h" #include "nsTArray.h" #include "nsCOMArray.h" #include "nsArrayEnumerator.h" #include "nsXPIDLString.h" #include "rdf.h" #include "nsCycleCollectionParticipant.h" #include "nsEnumeratorUtils.h" #include "mozilla/Logging.h" #include "prprf.h" #include <stdio.h> mozilla::LazyLogModule nsRDFLog("RDF"); //---------------------------------------------------------------------- // // CompositeDataSourceImpl // class CompositeEnumeratorImpl; class CompositeArcsInOutEnumeratorImpl; class CompositeAssertionEnumeratorImpl; class CompositeDataSourceImpl : public nsIRDFCompositeDataSource, public nsIRDFObserver { public: CompositeDataSourceImpl(void); explicit CompositeDataSourceImpl(char** dataSources); // nsISupports interface NS_DECL_CYCLE_COLLECTING_ISUPPORTS NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(CompositeDataSourceImpl, nsIRDFCompositeDataSource) // nsIRDFDataSource interface NS_DECL_NSIRDFDATASOURCE // nsIRDFCompositeDataSource interface NS_DECL_NSIRDFCOMPOSITEDATASOURCE // nsIRDFObserver interface NS_DECL_NSIRDFOBSERVER bool HasAssertionN(int n, nsIRDFResource* source, nsIRDFResource* property, nsIRDFNode* target, bool tv); protected: nsCOMArray<nsIRDFObserver> mObservers; nsCOMArray<nsIRDFDataSource> mDataSources; bool mAllowNegativeAssertions; bool mCoalesceDuplicateArcs; int32_t mUpdateBatchNest; virtual ~CompositeDataSourceImpl() {} friend class CompositeEnumeratorImpl; friend class CompositeArcsInOutEnumeratorImpl; friend class CompositeAssertionEnumeratorImpl; }; //---------------------------------------------------------------------- // // CompositeEnumeratorImpl // class CompositeEnumeratorImpl : public nsISimpleEnumerator { // nsISupports NS_DECL_ISUPPORTS // nsISimpleEnumerator interface NS_DECL_NSISIMPLEENUMERATOR // pure abstract methods to be overridden virtual nsresult GetEnumerator(nsIRDFDataSource* aDataSource, nsISimpleEnumerator** aResult) = 0; virtual nsresult HasNegation(nsIRDFDataSource* aDataSource, nsIRDFNode* aNode, bool* aResult) = 0; protected: CompositeEnumeratorImpl(CompositeDataSourceImpl* aCompositeDataSource, bool aAllowNegativeAssertions, bool aCoalesceDuplicateArcs); virtual ~CompositeEnumeratorImpl(); CompositeDataSourceImpl* mCompositeDataSource; nsISimpleEnumerator* mCurrent; nsIRDFNode* mResult; int32_t mNext; AutoTArray<nsCOMPtr<nsIRDFNode>, 8> mAlreadyReturned; bool mAllowNegativeAssertions; bool mCoalesceDuplicateArcs; }; CompositeEnumeratorImpl::CompositeEnumeratorImpl(CompositeDataSourceImpl* aCompositeDataSource, bool aAllowNegativeAssertions, bool aCoalesceDuplicateArcs) : mCompositeDataSource(aCompositeDataSource), mCurrent(nullptr), mResult(nullptr), mNext(0), mAllowNegativeAssertions(aAllowNegativeAssertions), mCoalesceDuplicateArcs(aCoalesceDuplicateArcs) { NS_ADDREF(mCompositeDataSource); } CompositeEnumeratorImpl::~CompositeEnumeratorImpl(void) { NS_IF_RELEASE(mCurrent); NS_IF_RELEASE(mResult); NS_RELEASE(mCompositeDataSource); } NS_IMPL_ADDREF(CompositeEnumeratorImpl) NS_IMPL_RELEASE(CompositeEnumeratorImpl) NS_IMPL_QUERY_INTERFACE(CompositeEnumeratorImpl, nsISimpleEnumerator) NS_IMETHODIMP CompositeEnumeratorImpl::HasMoreElements(bool* aResult) { NS_PRECONDITION(aResult != nullptr, "null ptr"); if (! aResult) return NS_ERROR_NULL_POINTER; nsresult rv; // If we've already queued up a next target, then yep, there are // more elements. if (mResult) { *aResult = true; return NS_OK; } // Otherwise, we'll need to find a next target, switching cursors // if necessary. for ( ; mNext < mCompositeDataSource->mDataSources.Count(); ++mNext) { if (! mCurrent) { // We don't have a current enumerator, so create a new one on // the next data source. nsIRDFDataSource* datasource = mCompositeDataSource->mDataSources[mNext]; rv = GetEnumerator(datasource, &mCurrent); if (NS_FAILED(rv)) return rv; if (rv == NS_RDF_NO_VALUE) continue; NS_ASSERTION(mCurrent != nullptr, "you're always supposed to return an enumerator from GetEnumerator, punk."); if (! mCurrent) continue; } do { int32_t i; bool hasMore; rv = mCurrent->HasMoreElements(&hasMore); if (NS_FAILED(rv)) return rv; // Is the current enumerator depleted? if (! hasMore) { NS_RELEASE(mCurrent); break; } // Even if the current enumerator has more elements, we still // need to check that the current element isn't masked by // a negation in an earlier data source. // "Peek" ahead and pull out the next target. nsCOMPtr<nsISupports> result; rv = mCurrent->GetNext(getter_AddRefs(result)); if (NS_FAILED(rv)) return rv; rv = result->QueryInterface(NS_GET_IID(nsIRDFNode), (void**) &mResult); if (NS_FAILED(rv)) return rv; if (mAllowNegativeAssertions) { // See if any previous data source negates this bool hasNegation = false; for (i = mNext - 1; i >= 0; --i) { nsIRDFDataSource* datasource = mCompositeDataSource->mDataSources[i]; rv = HasNegation(datasource, mResult, &hasNegation); if (NS_FAILED(rv)) return rv; if (hasNegation) break; } // if so, we've gotta keep looking if (hasNegation) { NS_RELEASE(mResult); continue; } } if (mCoalesceDuplicateArcs) { // Now see if we've returned it once already. // XXX N.B. performance here...may want to hash if things get large? bool alreadyReturned = false; for (i = mAlreadyReturned.Length() - 1; i >= 0; --i) { if (mAlreadyReturned[i] == mResult) { alreadyReturned = true; break; } } if (alreadyReturned) { NS_RELEASE(mResult); continue; } } // If we get here, then we've really found one. It'll // remain cached in mResult until GetNext() sucks it out. *aResult = true; // Remember that we returned it, so we don't return duplicates. // XXX I wonder if we should make unique-checking be // optional. This could get to be pretty expensive (this // implementation turns iteration into O(n^2)). if (mCoalesceDuplicateArcs) { mAlreadyReturned.AppendElement(mResult); } return NS_OK; } while (1); } // if we get here, there aren't any elements left. *aResult = false; return NS_OK; } NS_IMETHODIMP CompositeEnumeratorImpl::GetNext(nsISupports** aResult) { nsresult rv; bool hasMore; rv = HasMoreElements(&hasMore); if (NS_FAILED(rv)) return rv; if (! hasMore) return NS_ERROR_UNEXPECTED; // Don't AddRef: we "transfer" ownership to the caller *aResult = mResult; mResult = nullptr; return NS_OK; } //---------------------------------------------------------------------- // // CompositeArcsInOutEnumeratorImpl // // class CompositeArcsInOutEnumeratorImpl : public CompositeEnumeratorImpl { public: enum Type { eArcsIn, eArcsOut }; virtual ~CompositeArcsInOutEnumeratorImpl(); virtual nsresult GetEnumerator(nsIRDFDataSource* aDataSource, nsISimpleEnumerator** aResult); virtual nsresult HasNegation(nsIRDFDataSource* aDataSource, nsIRDFNode* aNode, bool* aResult); CompositeArcsInOutEnumeratorImpl(CompositeDataSourceImpl* aCompositeDataSource, nsIRDFNode* aNode, Type aType, bool aAllowNegativeAssertions, bool aCoalesceDuplicateArcs); private: nsIRDFNode* mNode; Type mType; }; CompositeArcsInOutEnumeratorImpl::CompositeArcsInOutEnumeratorImpl( CompositeDataSourceImpl* aCompositeDataSource, nsIRDFNode* aNode, Type aType, bool aAllowNegativeAssertions, bool aCoalesceDuplicateArcs) : CompositeEnumeratorImpl(aCompositeDataSource, aAllowNegativeAssertions, aCoalesceDuplicateArcs), mNode(aNode), mType(aType) { NS_ADDREF(mNode); } CompositeArcsInOutEnumeratorImpl::~CompositeArcsInOutEnumeratorImpl() { NS_RELEASE(mNode); } nsresult CompositeArcsInOutEnumeratorImpl::GetEnumerator( nsIRDFDataSource* aDataSource, nsISimpleEnumerator** aResult) { if (mType == eArcsIn) { return aDataSource->ArcLabelsIn(mNode, aResult); } else { nsCOMPtr<nsIRDFResource> resource( do_QueryInterface(mNode) ); return aDataSource->ArcLabelsOut(resource, aResult); } } nsresult CompositeArcsInOutEnumeratorImpl::HasNegation( nsIRDFDataSource* aDataSource, nsIRDFNode* aNode, bool* aResult) { *aResult = false; return NS_OK; } //---------------------------------------------------------------------- // // CompositeAssertionEnumeratorImpl // class CompositeAssertionEnumeratorImpl : public CompositeEnumeratorImpl { public: virtual nsresult GetEnumerator(nsIRDFDataSource* aDataSource, nsISimpleEnumerator** aResult); virtual nsresult HasNegation(nsIRDFDataSource* aDataSource, nsIRDFNode* aNode, bool* aResult); CompositeAssertionEnumeratorImpl(CompositeDataSourceImpl* aCompositeDataSource, nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget, bool aTruthValue, bool aAllowNegativeAssertions, bool aCoalesceDuplicateArcs); virtual ~CompositeAssertionEnumeratorImpl(); private: nsIRDFResource* mSource; nsIRDFResource* mProperty; nsIRDFNode* mTarget; bool mTruthValue; }; CompositeAssertionEnumeratorImpl::CompositeAssertionEnumeratorImpl( CompositeDataSourceImpl* aCompositeDataSource, nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget, bool aTruthValue, bool aAllowNegativeAssertions, bool aCoalesceDuplicateArcs) : CompositeEnumeratorImpl(aCompositeDataSource, aAllowNegativeAssertions, aCoalesceDuplicateArcs), mSource(aSource), mProperty(aProperty), mTarget(aTarget), mTruthValue(aTruthValue) { NS_IF_ADDREF(mSource); NS_ADDREF(mProperty); // always must be specified NS_IF_ADDREF(mTarget); } CompositeAssertionEnumeratorImpl::~CompositeAssertionEnumeratorImpl() { NS_IF_RELEASE(mSource); NS_RELEASE(mProperty); NS_IF_RELEASE(mTarget); } nsresult CompositeAssertionEnumeratorImpl::GetEnumerator( nsIRDFDataSource* aDataSource, nsISimpleEnumerator** aResult) { if (mSource) { return aDataSource->GetTargets(mSource, mProperty, mTruthValue, aResult); } else { return aDataSource->GetSources(mProperty, mTarget, mTruthValue, aResult); } } nsresult CompositeAssertionEnumeratorImpl::HasNegation( nsIRDFDataSource* aDataSource, nsIRDFNode* aNode, bool* aResult) { if (mSource) { return aDataSource->HasAssertion(mSource, mProperty, aNode, !mTruthValue, aResult); } else { nsCOMPtr<nsIRDFResource> source( do_QueryInterface(aNode) ); return aDataSource->HasAssertion(source, mProperty, mTarget, !mTruthValue, aResult); } } //////////////////////////////////////////////////////////////////////// nsresult NS_NewRDFCompositeDataSource(nsIRDFCompositeDataSource** result) { CompositeDataSourceImpl* db = new CompositeDataSourceImpl(); if (! db) return NS_ERROR_OUT_OF_MEMORY; *result = db; NS_ADDREF(*result); return NS_OK; } CompositeDataSourceImpl::CompositeDataSourceImpl(void) : mAllowNegativeAssertions(true), mCoalesceDuplicateArcs(true), mUpdateBatchNest(0) { } //---------------------------------------------------------------------- // // nsISupports interface // NS_IMPL_CYCLE_COLLECTION_CLASS(CompositeDataSourceImpl) NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(CompositeDataSourceImpl) uint32_t i, count = tmp->mDataSources.Count(); for (i = count; i > 0; --i) { tmp->mDataSources[i - 1]->RemoveObserver(tmp); tmp->mDataSources.RemoveObjectAt(i - 1); } NS_IMPL_CYCLE_COLLECTION_UNLINK(mObservers); NS_IMPL_CYCLE_COLLECTION_UNLINK_END NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(CompositeDataSourceImpl) NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mObservers) NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDataSources) NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END NS_IMPL_CYCLE_COLLECTING_ADDREF(CompositeDataSourceImpl) NS_IMPL_CYCLE_COLLECTING_RELEASE(CompositeDataSourceImpl) NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CompositeDataSourceImpl) NS_INTERFACE_MAP_ENTRY(nsIRDFCompositeDataSource) NS_INTERFACE_MAP_ENTRY(nsIRDFDataSource) NS_INTERFACE_MAP_ENTRY(nsIRDFObserver) NS_INTERFACE_MAP_ENTRY(nsIRDFCompositeDataSource) NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIRDFCompositeDataSource) NS_INTERFACE_MAP_END //---------------------------------------------------------------------- // // nsIRDFDataSource interface // NS_IMETHODIMP CompositeDataSourceImpl::GetURI(char* *uri) { *uri = nullptr; return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::GetSource(nsIRDFResource* property, nsIRDFNode* target, bool tv, nsIRDFResource** source) { if (!mAllowNegativeAssertions && !tv) return(NS_RDF_NO_VALUE); int32_t count = mDataSources.Count(); for (int32_t i = 0; i < count; ++i) { nsresult rv; rv = mDataSources[i]->GetSource(property, target, tv, source); if (NS_FAILED(rv)) return rv; if (rv == NS_RDF_NO_VALUE) continue; if (!mAllowNegativeAssertions) return(NS_OK); // okay, found it. make sure we don't have the opposite // asserted in a more local data source if (!HasAssertionN(count-1, *source, property, target, !tv)) return NS_OK; NS_RELEASE(*source); return NS_RDF_NO_VALUE; } return NS_RDF_NO_VALUE; } NS_IMETHODIMP CompositeDataSourceImpl::GetSources(nsIRDFResource* aProperty, nsIRDFNode* aTarget, bool aTruthValue, nsISimpleEnumerator** aResult) { NS_PRECONDITION(aProperty != nullptr, "null ptr"); if (! aProperty) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aTarget != nullptr, "null ptr"); if (! aTarget) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aResult != nullptr, "null ptr"); if (! aResult) return NS_ERROR_NULL_POINTER; if (! mAllowNegativeAssertions && ! aTruthValue) return(NS_RDF_NO_VALUE); *aResult = new CompositeAssertionEnumeratorImpl(this, nullptr, aProperty, aTarget, aTruthValue, mAllowNegativeAssertions, mCoalesceDuplicateArcs); if (! *aResult) return NS_ERROR_OUT_OF_MEMORY; NS_ADDREF(*aResult); return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::GetTarget(nsIRDFResource* aSource, nsIRDFResource* aProperty, bool aTruthValue, nsIRDFNode** aResult) { NS_PRECONDITION(aSource != nullptr, "null ptr"); if (! aSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aProperty != nullptr, "null ptr"); if (! aProperty) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aResult != nullptr, "null ptr"); if (! aResult) return NS_ERROR_NULL_POINTER; if (! mAllowNegativeAssertions && ! aTruthValue) return(NS_RDF_NO_VALUE); int32_t count = mDataSources.Count(); for (int32_t i = 0; i < count; ++i) { nsresult rv; rv = mDataSources[i]->GetTarget(aSource, aProperty, aTruthValue, aResult); if (NS_FAILED(rv)) return rv; if (rv == NS_OK) { // okay, found it. make sure we don't have the opposite // asserted in an earlier data source if (mAllowNegativeAssertions) { if (HasAssertionN(count-1, aSource, aProperty, *aResult, !aTruthValue)) { // whoops, it's been negated. NS_RELEASE(*aResult); return NS_RDF_NO_VALUE; } } return NS_OK; } } // Otherwise, we couldn't find it at all. return NS_RDF_NO_VALUE; } bool CompositeDataSourceImpl::HasAssertionN(int n, nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget, bool aTruthValue) { nsresult rv; for (int32_t m = 0; m < n; ++m) { bool result; rv = mDataSources[m]->HasAssertion(aSource, aProperty, aTarget, aTruthValue, &result); if (NS_FAILED(rv)) return false; // found it! if (result) return true; } return false; } NS_IMETHODIMP CompositeDataSourceImpl::GetTargets(nsIRDFResource* aSource, nsIRDFResource* aProperty, bool aTruthValue, nsISimpleEnumerator** aResult) { NS_PRECONDITION(aSource != nullptr, "null ptr"); if (! aSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aProperty != nullptr, "null ptr"); if (! aProperty) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aResult != nullptr, "null ptr"); if (! aResult) return NS_ERROR_NULL_POINTER; if (! mAllowNegativeAssertions && ! aTruthValue) return(NS_RDF_NO_VALUE); *aResult = new CompositeAssertionEnumeratorImpl(this, aSource, aProperty, nullptr, aTruthValue, mAllowNegativeAssertions, mCoalesceDuplicateArcs); if (! *aResult) return NS_ERROR_OUT_OF_MEMORY; NS_ADDREF(*aResult); return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::Assert(nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget, bool aTruthValue) { NS_PRECONDITION(aSource != nullptr, "null ptr"); if (! aSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aProperty != nullptr, "null ptr"); if (! aProperty) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aTarget != nullptr, "null ptr"); if (! aTarget) return NS_ERROR_NULL_POINTER; if (! mAllowNegativeAssertions && ! aTruthValue) return(NS_RDF_ASSERTION_REJECTED); nsresult rv; // XXX Need to add back the stuff for unblocking ... // We iterate backwards from the last data source which was added // ("the most remote") to the first ("the most local"), trying to // apply the assertion in each. for (int32_t i = mDataSources.Count() - 1; i >= 0; --i) { rv = mDataSources[i]->Assert(aSource, aProperty, aTarget, aTruthValue); if (NS_RDF_ASSERTION_ACCEPTED == rv) return rv; if (NS_FAILED(rv)) return rv; } // nobody wanted to accept it return NS_RDF_ASSERTION_REJECTED; } NS_IMETHODIMP CompositeDataSourceImpl::Unassert(nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget) { NS_PRECONDITION(aSource != nullptr, "null ptr"); if (! aSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aProperty != nullptr, "null ptr"); if (! aProperty) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aTarget != nullptr, "null ptr"); if (! aTarget) return NS_ERROR_NULL_POINTER; nsresult rv; // Iterate through each of the datasources, starting with "the // most local" and moving to "the most remote". If _any_ of the // datasources have the assertion, attempt to unassert it. bool unasserted = true; int32_t i; int32_t count = mDataSources.Count(); for (i = 0; i < count; ++i) { nsIRDFDataSource* ds = mDataSources[i]; bool hasAssertion; rv = ds->HasAssertion(aSource, aProperty, aTarget, true, &hasAssertion); if (NS_FAILED(rv)) return rv; if (hasAssertion) { rv = ds->Unassert(aSource, aProperty, aTarget); if (NS_FAILED(rv)) return rv; if (rv != NS_RDF_ASSERTION_ACCEPTED) { unasserted = false; break; } } } // Either none of the datasources had it, or they were all willing // to let it be unasserted. if (unasserted) return NS_RDF_ASSERTION_ACCEPTED; // If we get here, one of the datasources already had the // assertion, and was adamant about not letting us remove // it. Iterate from the "most local" to the "most remote" // attempting to assert the negation... for (i = 0; i < count; ++i) { rv = mDataSources[i]->Assert(aSource, aProperty, aTarget, false); if (NS_FAILED(rv)) return rv; // Did it take? if (rv == NS_RDF_ASSERTION_ACCEPTED) return rv; } // Couln't get anyone to accept the negation, either. return NS_RDF_ASSERTION_REJECTED; } NS_IMETHODIMP CompositeDataSourceImpl::Change(nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aOldTarget, nsIRDFNode* aNewTarget) { NS_PRECONDITION(aSource != nullptr, "null ptr"); if (! aSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aProperty != nullptr, "null ptr"); if (! aProperty) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aOldTarget != nullptr, "null ptr"); if (! aOldTarget) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aNewTarget != nullptr, "null ptr"); if (! aNewTarget) return NS_ERROR_NULL_POINTER; nsresult rv; // XXX So we're assuming that a datasource _must_ accept the // atomic change; i.e., we can't split it up across two // datasources. That sucks. // We iterate backwards from the last data source which was added // ("the most remote") to the first ("the most local"), trying to // apply the change in each. for (int32_t i = mDataSources.Count() - 1; i >= 0; --i) { rv = mDataSources[i]->Change(aSource, aProperty, aOldTarget, aNewTarget); if (NS_RDF_ASSERTION_ACCEPTED == rv) return rv; if (NS_FAILED(rv)) return rv; } // nobody wanted to accept it return NS_RDF_ASSERTION_REJECTED; } NS_IMETHODIMP CompositeDataSourceImpl::Move(nsIRDFResource* aOldSource, nsIRDFResource* aNewSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget) { NS_PRECONDITION(aOldSource != nullptr, "null ptr"); if (! aOldSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aNewSource != nullptr, "null ptr"); if (! aNewSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aProperty != nullptr, "null ptr"); if (! aProperty) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aTarget != nullptr, "null ptr"); if (! aTarget) return NS_ERROR_NULL_POINTER; nsresult rv; // XXX So we're assuming that a datasource _must_ accept the // atomic move; i.e., we can't split it up across two // datasources. That sucks. // We iterate backwards from the last data source which was added // ("the most remote") to the first ("the most local"), trying to // apply the assertion in each. for (int32_t i = mDataSources.Count() - 1; i >= 0; --i) { rv = mDataSources[i]->Move(aOldSource, aNewSource, aProperty, aTarget); if (NS_RDF_ASSERTION_ACCEPTED == rv) return rv; if (NS_FAILED(rv)) return rv; } // nobody wanted to accept it return NS_RDF_ASSERTION_REJECTED; } NS_IMETHODIMP CompositeDataSourceImpl::HasAssertion(nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget, bool aTruthValue, bool* aResult) { NS_PRECONDITION(aSource != nullptr, "null ptr"); if (! aSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aProperty != nullptr, "null ptr"); if (! aProperty) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aResult != nullptr, "null ptr"); if (! aResult) return NS_ERROR_NULL_POINTER; if (! mAllowNegativeAssertions && ! aTruthValue) { *aResult = false; return(NS_OK); } nsresult rv; // Otherwise, look through all the data sources to see if anyone // has the positive... int32_t count = mDataSources.Count(); for (int32_t i = 0; i < count; ++i) { nsIRDFDataSource* datasource = mDataSources[i]; rv = datasource->HasAssertion(aSource, aProperty, aTarget, aTruthValue, aResult); if (NS_FAILED(rv)) return rv; if (*aResult) return NS_OK; if (mAllowNegativeAssertions) { bool hasNegation; rv = datasource->HasAssertion(aSource, aProperty, aTarget, !aTruthValue, &hasNegation); if (NS_FAILED(rv)) return rv; if (hasNegation) { *aResult = false; return NS_OK; } } } // If we get here, nobody had the assertion at all *aResult = false; return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::AddObserver(nsIRDFObserver* aObserver) { NS_PRECONDITION(aObserver != nullptr, "null ptr"); if (! aObserver) return NS_ERROR_NULL_POINTER; // XXX ensure uniqueness? mObservers.AppendObject(aObserver); return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::RemoveObserver(nsIRDFObserver* aObserver) { NS_PRECONDITION(aObserver != nullptr, "null ptr"); if (! aObserver) return NS_ERROR_NULL_POINTER; mObservers.RemoveObject(aObserver); return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::HasArcIn(nsIRDFNode *aNode, nsIRDFResource *aArc, bool *result) { nsresult rv; *result = false; int32_t count = mDataSources.Count(); for (int32_t i = 0; i < count; ++i) { rv = mDataSources[i]->HasArcIn(aNode, aArc, result); if (NS_FAILED(rv)) return rv; if (*result) return NS_OK; } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::HasArcOut(nsIRDFResource *aSource, nsIRDFResource *aArc, bool *result) { nsresult rv; *result = false; int32_t count = mDataSources.Count(); for (int32_t i = 0; i < count; ++i) { rv = mDataSources[i]->HasArcOut(aSource, aArc, result); if (NS_FAILED(rv)) return rv; if (*result) return NS_OK; } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::ArcLabelsIn(nsIRDFNode* aTarget, nsISimpleEnumerator** aResult) { NS_PRECONDITION(aTarget != nullptr, "null ptr"); if (! aTarget) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aResult != nullptr, "null ptr"); if (! aResult) return NS_ERROR_NULL_POINTER; nsISimpleEnumerator* result = new CompositeArcsInOutEnumeratorImpl(this, aTarget, CompositeArcsInOutEnumeratorImpl::eArcsIn, mAllowNegativeAssertions, mCoalesceDuplicateArcs); if (! result) return NS_ERROR_OUT_OF_MEMORY; NS_ADDREF(result); *aResult = result; return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::ArcLabelsOut(nsIRDFResource* aSource, nsISimpleEnumerator** aResult) { NS_PRECONDITION(aSource != nullptr, "null ptr"); if (! aSource) return NS_ERROR_NULL_POINTER; NS_PRECONDITION(aResult != nullptr, "null ptr"); if (! aResult) return NS_ERROR_NULL_POINTER; nsISimpleEnumerator* result = new CompositeArcsInOutEnumeratorImpl(this, aSource, CompositeArcsInOutEnumeratorImpl::eArcsOut, mAllowNegativeAssertions, mCoalesceDuplicateArcs); if (! result) return NS_ERROR_OUT_OF_MEMORY; NS_ADDREF(result); *aResult = result; return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::GetAllResources(nsISimpleEnumerator** aResult) { NS_NOTYETIMPLEMENTED("CompositeDataSourceImpl::GetAllResources"); return NS_ERROR_NOT_IMPLEMENTED; } NS_IMETHODIMP CompositeDataSourceImpl::GetAllCmds(nsIRDFResource* source, nsISimpleEnumerator/*<nsIRDFResource>*/** result) { nsresult rv; nsCOMPtr<nsISimpleEnumerator> set; for (int32_t i = 0; i < mDataSources.Count(); i++) { nsCOMPtr<nsISimpleEnumerator> dsCmds; rv = mDataSources[i]->GetAllCmds(source, getter_AddRefs(dsCmds)); if (NS_SUCCEEDED(rv)) { nsCOMPtr<nsISimpleEnumerator> tmp; rv = NS_NewUnionEnumerator(getter_AddRefs(tmp), set, dsCmds); set.swap(tmp); if (NS_FAILED(rv)) return(rv); } } set.forget(result); return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::IsCommandEnabled(nsISupports/* nsIRDFResource container */* aSources, nsIRDFResource* aCommand, nsISupports/* nsIRDFResource container */* aArguments, bool* aResult) { nsresult rv; for (int32_t i = mDataSources.Count() - 1; i >= 0; --i) { bool enabled = true; rv = mDataSources[i]->IsCommandEnabled(aSources, aCommand, aArguments, &enabled); if (NS_FAILED(rv) && (rv != NS_ERROR_NOT_IMPLEMENTED)) { return(rv); } if (! enabled) { *aResult = false; return(NS_OK); } } *aResult = true; return(NS_OK); } NS_IMETHODIMP CompositeDataSourceImpl::DoCommand(nsISupports/* nsIRDFResource container */* aSources, nsIRDFResource* aCommand, nsISupports/* nsIRDFResource container */* aArguments) { for (int32_t i = mDataSources.Count() - 1; i >= 0; --i) { nsresult rv = mDataSources[i]->DoCommand(aSources, aCommand, aArguments); if (NS_FAILED(rv) && (rv != NS_ERROR_NOT_IMPLEMENTED)) { return(rv); // all datasources must succeed } } return(NS_OK); } NS_IMETHODIMP CompositeDataSourceImpl::BeginUpdateBatch() { for (int32_t i = mDataSources.Count() - 1; i >= 0; --i) { mDataSources[i]->BeginUpdateBatch(); } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::EndUpdateBatch() { for (int32_t i = mDataSources.Count() - 1; i >= 0; --i) { mDataSources[i]->EndUpdateBatch(); } return NS_OK; } //////////////////////////////////////////////////////////////////////// // nsIRDFCompositeDataSource methods // XXX rvg We should make this take an additional argument specifying where // in the sequence of data sources (of the db), the new data source should // fit in. Right now, the new datasource gets stuck at the end. // need to add the observers of the CompositeDataSourceImpl to the new data source. NS_IMETHODIMP CompositeDataSourceImpl::GetAllowNegativeAssertions(bool *aAllowNegativeAssertions) { *aAllowNegativeAssertions = mAllowNegativeAssertions; return(NS_OK); } NS_IMETHODIMP CompositeDataSourceImpl::SetAllowNegativeAssertions(bool aAllowNegativeAssertions) { mAllowNegativeAssertions = aAllowNegativeAssertions; return(NS_OK); } NS_IMETHODIMP CompositeDataSourceImpl::GetCoalesceDuplicateArcs(bool *aCoalesceDuplicateArcs) { *aCoalesceDuplicateArcs = mCoalesceDuplicateArcs; return(NS_OK); } NS_IMETHODIMP CompositeDataSourceImpl::SetCoalesceDuplicateArcs(bool aCoalesceDuplicateArcs) { mCoalesceDuplicateArcs = aCoalesceDuplicateArcs; return(NS_OK); } NS_IMETHODIMP CompositeDataSourceImpl::AddDataSource(nsIRDFDataSource* aDataSource) { NS_ASSERTION(aDataSource != nullptr, "null ptr"); if (! aDataSource) return NS_ERROR_NULL_POINTER; mDataSources.AppendObject(aDataSource); aDataSource->AddObserver(this); return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::RemoveDataSource(nsIRDFDataSource* aDataSource) { NS_ASSERTION(aDataSource != nullptr, "null ptr"); if (! aDataSource) return NS_ERROR_NULL_POINTER; if (mDataSources.IndexOf(aDataSource) >= 0) { aDataSource->RemoveObserver(this); mDataSources.RemoveObject(aDataSource); } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::GetDataSources(nsISimpleEnumerator** _result) { // NS_NewArrayEnumerator for an nsCOMArray takes a snapshot of the // current state. return NS_NewArrayEnumerator(_result, mDataSources); } NS_IMETHODIMP CompositeDataSourceImpl::OnAssert(nsIRDFDataSource* aDataSource, nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget) { // Make sure that the assertion isn't masked by another // datasource. // // XXX We could make this more efficient if we knew _which_ // datasource actually served up the OnAssert(): we could use // HasAssertionN() to only search datasources _before_ the // datasource that coughed up the assertion. nsresult rv = NS_OK; if (mAllowNegativeAssertions) { bool hasAssertion; rv = HasAssertion(aSource, aProperty, aTarget, true, &hasAssertion); if (NS_FAILED(rv)) return rv; if (! hasAssertion) return(NS_OK); } for (int32_t i = mObservers.Count() - 1; i >= 0; --i) { mObservers[i]->OnAssert(this, aSource, aProperty, aTarget); } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::OnUnassert(nsIRDFDataSource* aDataSource, nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget) { // Make sure that the un-assertion doesn't just unmask the // same assertion in a different datasource. // // XXX We could make this more efficient if we knew _which_ // datasource actually served up the OnAssert(): we could use // HasAssertionN() to only search datasources _before_ the // datasource that coughed up the assertion. nsresult rv; if (mAllowNegativeAssertions) { bool hasAssertion; rv = HasAssertion(aSource, aProperty, aTarget, true, &hasAssertion); if (NS_FAILED(rv)) return rv; if (hasAssertion) return NS_OK; } for (int32_t i = mObservers.Count() - 1; i >= 0; --i) { mObservers[i]->OnUnassert(this, aSource, aProperty, aTarget); } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::OnChange(nsIRDFDataSource* aDataSource, nsIRDFResource* aSource, nsIRDFResource* aProperty, nsIRDFNode* aOldTarget, nsIRDFNode* aNewTarget) { // Make sure that the change is actually visible, and not hidden // by an assertion in a different datasource. // // XXX Because of aggregation, this could actually mutate into a // variety of OnAssert or OnChange notifications, which we'll // ignore for now :-/. for (int32_t i = mObservers.Count() - 1; i >= 0; --i) { mObservers[i]->OnChange(this, aSource, aProperty, aOldTarget, aNewTarget); } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::OnMove(nsIRDFDataSource* aDataSource, nsIRDFResource* aOldSource, nsIRDFResource* aNewSource, nsIRDFResource* aProperty, nsIRDFNode* aTarget) { // Make sure that the move is actually visible, and not hidden // by an assertion in a different datasource. // // XXX Because of aggregation, this could actually mutate into a // variety of OnAssert or OnMove notifications, which we'll // ignore for now :-/. for (int32_t i = mObservers.Count() - 1; i >= 0; --i) { mObservers[i]->OnMove(this, aOldSource, aNewSource, aProperty, aTarget); } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::OnBeginUpdateBatch(nsIRDFDataSource* aDataSource) { if (mUpdateBatchNest++ == 0) { for (int32_t i = mObservers.Count() - 1; i >= 0; --i) { mObservers[i]->OnBeginUpdateBatch(this); } } return NS_OK; } NS_IMETHODIMP CompositeDataSourceImpl::OnEndUpdateBatch(nsIRDFDataSource* aDataSource) { NS_ASSERTION(mUpdateBatchNest > 0, "badly nested update batch"); if (--mUpdateBatchNest == 0) { for (int32_t i = mObservers.Count() - 1; i >= 0; --i) { mObservers[i]->OnEndUpdateBatch(this); } } return NS_OK; }