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gecko-dev/rdf/base/nsCompositeDataSource.cpp

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/* -*- 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>
PRLogModuleInfo* nsRDFLog = nullptr;
//----------------------------------------------------------------------
//
// 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;
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)
{
if (nsRDFLog == nullptr)
nsRDFLog = PR_NewLogModule("RDF");
}
//----------------------------------------------------------------------
//
// 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;
}
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