The Tor Browser: rdf/base/src/nsCompositeDataSource.cpp@6474c204b198 (annotated)

rdf/base/src/nsCompositeDataSource.cpp@6474c204b198 (annotated)

rdf/base/src/nsCompositeDataSource.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- 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.
 ) 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.
 ) 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"
 #ifdef PR_LOGGING
 #include "prlog.h"
 #include "prprf.h"
 #include <stdio.h>
 PRLogModuleInfo* nsRDFLog = nullptr;
 #endif
 //----------------------------------------------------------------------
 //
 // CompositeDataSourceImpl
 //
 class CompositeEnumeratorImpl;
 class CompositeArcsInOutEnumeratorImpl;
 class CompositeAssertionEnumeratorImpl;
 class CompositeDataSourceImpl : public nsIRDFCompositeDataSource,
                                 public nsIRDFObserver
 {
 public:
     CompositeDataSourceImpl(void);
     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;
     nsAutoTArray<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)
 {
 #ifdef PR_LOGGING
     if (nsRDFLog == nullptr)
         nsRDFLog = PR_NewLogModule("RDF");
 #endif
 }
 //----------------------------------------------------------------------
 //
 // 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(nsISupportsArray/*<nsIRDFResource>*/* aSources,
                                           nsIRDFResource*   aCommand,
                                           nsISupportsArray/*<nsIRDFResource>*/* 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(nsISupportsArray/*<nsIRDFResource>*/* aSources,
                                    nsIRDFResource*   aCommand,
                                    nsISupportsArray/*<nsIRDFResource>*/* 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;
 }

The Tor Browser / annotate

rdf/base/src/nsCompositeDataSource.cpp@6474c204b198 (annotated)

rdf/base/src/nsCompositeDataSource.cpp