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

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

rdf/base/src/nsRDFContainer.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/. */
 /*
   Implementation for the RDF container.
   Notes
   -----
 . RDF containers are one-indexed. This means that a lot of the loops
      that you'd normally think you'd write like this:
        for (i = 0; i < count; ++i) {}
      You've gotta write like this:
        for (i = 1; i <= count; ++i) {}
      "Sure, right, yeah, of course.", you say. Well maybe I'm just
      thick, but it's easy to slip up.
 . The RDF:nextVal property on the container is an
      implementation-level hack that is used to quickly compute the
      next value for appending to the container. It will no doubt
      become royally screwed up in the case of aggregation.
 . The RDF:nextVal property is also used to retrieve the count of
      elements in the container.
  */
 #include "nsCOMPtr.h"
 #include "nsIRDFContainer.h"
 #include "nsIRDFContainerUtils.h"
 #include "nsIRDFInMemoryDataSource.h"
 #include "nsIRDFPropagatableDataSource.h"
 #include "nsIRDFService.h"
 #include "nsIServiceManager.h"
 #include "nsRDFCID.h"
 #include "nsString.h"
 #include "nsXPIDLString.h"
 #include "rdf.h"
 #define RDF_SEQ_LIST_LIMIT   8
 class RDFContainerImpl : public nsIRDFContainer
 {
 public:
     // nsISupports interface
     NS_DECL_ISUPPORTS
     // nsIRDFContainer interface
     NS_DECL_NSIRDFCONTAINER
 private:
     friend nsresult NS_NewRDFContainer(nsIRDFContainer** aResult);
     RDFContainerImpl();
     virtual ~RDFContainerImpl();
     nsresult Init();
     nsresult Renumber(int32_t aStartIndex, int32_t aIncrement);
     nsresult SetNextValue(int32_t aIndex);
     nsresult GetNextValue(nsIRDFResource** aResult);
     nsIRDFDataSource* mDataSource;
     nsIRDFResource*   mContainer;
     // pseudo constants
     static int32_t gRefCnt;
     static nsIRDFService*        gRDFService;
     static nsIRDFContainerUtils* gRDFContainerUtils;
     static nsIRDFResource*       kRDF_nextVal;
 };
 int32_t               RDFContainerImpl::gRefCnt = 0;
 nsIRDFService*        RDFContainerImpl::gRDFService;
 nsIRDFContainerUtils* RDFContainerImpl::gRDFContainerUtils;
 nsIRDFResource*       RDFContainerImpl::kRDF_nextVal;
 ////////////////////////////////////////////////////////////////////////
 // nsISupports interface
 NS_IMPL_ISUPPORTS(RDFContainerImpl, nsIRDFContainer)
 ////////////////////////////////////////////////////////////////////////
 // nsIRDFContainer interface
 NS_IMETHODIMP
 RDFContainerImpl::GetDataSource(nsIRDFDataSource** _retval)
 {
     *_retval = mDataSource;
     NS_IF_ADDREF(*_retval);
     return NS_OK;
 }
 NS_IMETHODIMP
 RDFContainerImpl::GetResource(nsIRDFResource** _retval)
 {
     *_retval = mContainer;
     NS_IF_ADDREF(*_retval);
     return NS_OK;
 }
 NS_IMETHODIMP
 RDFContainerImpl::Init(nsIRDFDataSource *aDataSource, nsIRDFResource *aContainer)
 {
     NS_PRECONDITION(aDataSource != nullptr, "null ptr");
     if (! aDataSource)
         return NS_ERROR_NULL_POINTER;
     NS_PRECONDITION(aContainer != nullptr, "null ptr");
     if (! aContainer)
         return NS_ERROR_NULL_POINTER;
     nsresult rv;
     bool isContainer;
     rv = gRDFContainerUtils->IsContainer(aDataSource, aContainer, &isContainer);
     if (NS_FAILED(rv)) return rv;
     // ``throw'' if we can't create a container on the specified
     // datasource/resource combination.
     if (! isContainer)
         return NS_ERROR_FAILURE;
     NS_IF_RELEASE(mDataSource);
     mDataSource = aDataSource;
     NS_ADDREF(mDataSource);
     NS_IF_RELEASE(mContainer);
     mContainer = aContainer;
     NS_ADDREF(mContainer);
     return NS_OK;
 }
 NS_IMETHODIMP
 RDFContainerImpl::GetCount(int32_t *aCount)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     nsresult rv;
     // Get the next value, which hangs off of the bag via the
     // RDF:nextVal property. This is the _next value_ that will get
     // assigned in a one-indexed array. So, it's actually _one more_
     // than the actual count of elements in the container.
     //
     // XXX To handle aggregation, this should probably be a
     // GetTargets() that enumerates all of the values and picks the
     // largest one.
     nsCOMPtr<nsIRDFNode> nextValNode;
     rv = mDataSource->GetTarget(mContainer, kRDF_nextVal, true, getter_AddRefs(nextValNode));
     if (NS_FAILED(rv)) return rv;
     if (rv == NS_RDF_NO_VALUE)
         return NS_ERROR_UNEXPECTED;
     nsCOMPtr<nsIRDFLiteral> nextValLiteral;
     rv = nextValNode->QueryInterface(NS_GET_IID(nsIRDFLiteral), getter_AddRefs(nextValLiteral));
     if (NS_FAILED(rv)) return rv;
     const char16_t *s;
     rv = nextValLiteral->GetValueConst( &s );
     if (NS_FAILED(rv)) return rv;
     nsAutoString nextValStr(s);
     int32_t nextVal;
     nsresult err;
     nextVal = nextValStr.ToInteger(&err);
     if (NS_FAILED(err))
         return NS_ERROR_UNEXPECTED;
     *aCount = nextVal - 1;
     return NS_OK;
 }
 NS_IMETHODIMP
 RDFContainerImpl::GetElements(nsISimpleEnumerator **_retval)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     return NS_NewContainerEnumerator(mDataSource, mContainer, _retval);
 }
 NS_IMETHODIMP
 RDFContainerImpl::AppendElement(nsIRDFNode *aElement)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     NS_PRECONDITION(aElement != nullptr, "null ptr");
     if (! aElement)
         return NS_ERROR_NULL_POINTER;
     nsresult rv;
     nsCOMPtr<nsIRDFResource> nextVal;
     rv = GetNextValue(getter_AddRefs(nextVal));
     if (NS_FAILED(rv)) return rv;
     rv = mDataSource->Assert(mContainer, nextVal, aElement, true);
     if (NS_FAILED(rv)) return rv;
     return NS_OK;
 }
 NS_IMETHODIMP
 RDFContainerImpl::RemoveElement(nsIRDFNode *aElement, bool aRenumber)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     NS_PRECONDITION(aElement != nullptr, "null ptr");
     if (! aElement)
         return NS_ERROR_NULL_POINTER;
     nsresult rv;
     int32_t idx;
     rv = IndexOf(aElement, &idx);
     if (NS_FAILED(rv)) return rv;
     if (idx < 0)
         return NS_OK;
     // Remove the element.
     nsCOMPtr<nsIRDFResource> ordinal;
     rv = gRDFContainerUtils->IndexToOrdinalResource(idx,
                                                     getter_AddRefs(ordinal));
     if (NS_FAILED(rv)) return rv;
     rv = mDataSource->Unassert(mContainer, ordinal, aElement);
     if (NS_FAILED(rv)) return rv;
     if (aRenumber) {
         // Now slide the rest of the collection backwards to fill in
         // the gap. This will have the side effect of completely
         // renumber the container from index to the end.
         rv = Renumber(idx + 1, -1);
         if (NS_FAILED(rv)) return rv;
     }
     return NS_OK;
 }
 NS_IMETHODIMP
 RDFContainerImpl::InsertElementAt(nsIRDFNode *aElement, int32_t aIndex, bool aRenumber)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     NS_PRECONDITION(aElement != nullptr, "null ptr");
     if (! aElement)
         return NS_ERROR_NULL_POINTER;
     NS_PRECONDITION(aIndex >= 1, "illegal value");
     if (aIndex < 1)
         return NS_ERROR_ILLEGAL_VALUE;
     nsresult rv;
     int32_t count;
     rv = GetCount(&count);
     if (NS_FAILED(rv)) return rv;
     NS_ASSERTION(aIndex <= count + 1, "illegal value");
     if (aIndex > count + 1)
         return NS_ERROR_ILLEGAL_VALUE;
     if (aRenumber) {
         // Make a hole for the element. This will have the side effect of
         // completely renumbering the container from 'aIndex' to 'count',
         // and will spew assertions.
         rv = Renumber(aIndex, +1);
         if (NS_FAILED(rv)) return rv;
     }
     nsCOMPtr<nsIRDFResource> ordinal;
     rv = gRDFContainerUtils->IndexToOrdinalResource(aIndex, getter_AddRefs(ordinal));
     if (NS_FAILED(rv)) return rv;
     rv = mDataSource->Assert(mContainer, ordinal, aElement, true);
     if (NS_FAILED(rv)) return rv;
     return NS_OK;
 }
 NS_IMETHODIMP
 RDFContainerImpl::RemoveElementAt(int32_t aIndex, bool aRenumber, nsIRDFNode** _retval)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     *_retval = nullptr;
     if (aIndex< 1)
         return NS_ERROR_ILLEGAL_VALUE;
     nsresult rv;
     int32_t count;
     rv = GetCount(&count);
     if (NS_FAILED(rv)) return rv;
     if (aIndex > count)
         return NS_ERROR_ILLEGAL_VALUE;
     nsCOMPtr<nsIRDFResource> ordinal;
     rv = gRDFContainerUtils->IndexToOrdinalResource(aIndex, getter_AddRefs(ordinal));
     if (NS_FAILED(rv)) return rv;
     nsCOMPtr<nsIRDFNode> old;
     rv = mDataSource->GetTarget(mContainer, ordinal, true, getter_AddRefs(old));
     if (NS_FAILED(rv)) return rv;
     if (rv == NS_OK) {
         rv = mDataSource->Unassert(mContainer, ordinal, old);
         if (NS_FAILED(rv)) return rv;
         if (aRenumber) {
             // Now slide the rest of the collection backwards to fill in
             // the gap. This will have the side effect of completely
             // renumber the container from index to the end.
             rv = Renumber(aIndex + 1, -1);
             if (NS_FAILED(rv)) return rv;
         }
     }
     old.swap(*_retval);
     return NS_OK;
 }
 NS_IMETHODIMP
 RDFContainerImpl::IndexOf(nsIRDFNode *aElement, int32_t *aIndex)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     return gRDFContainerUtils->IndexOf(mDataSource, mContainer,
                                        aElement, aIndex);
 }
 ////////////////////////////////////////////////////////////////////////
 RDFContainerImpl::RDFContainerImpl()
     : mDataSource(nullptr), mContainer(nullptr)
 {
 }
 nsresult
 RDFContainerImpl::Init()
 {
     if (gRefCnt++ == 0) {
         nsresult rv;
         NS_DEFINE_CID(kRDFServiceCID, NS_RDFSERVICE_CID);
         rv = CallGetService(kRDFServiceCID, &gRDFService);
         if (NS_FAILED(rv)) {
             NS_ERROR("unable to get RDF service");
             return rv;
         }
         rv = gRDFService->GetResource(NS_LITERAL_CSTRING(RDF_NAMESPACE_URI "nextVal"),
                                       &kRDF_nextVal);
         if (NS_FAILED(rv)) return rv;
         NS_DEFINE_CID(kRDFContainerUtilsCID, NS_RDFCONTAINERUTILS_CID);
         rv = CallGetService(kRDFContainerUtilsCID, &gRDFContainerUtils);
         if (NS_FAILED(rv)) {
             NS_ERROR("unable to get RDF container utils service");
             return rv;
         }
     }
     return NS_OK;
 }
 RDFContainerImpl::~RDFContainerImpl()
 {
 #ifdef DEBUG_REFS
     --gInstanceCount;
     fprintf(stdout, "%d - RDF: RDFContainerImpl\n", gInstanceCount);
 #endif
     NS_IF_RELEASE(mContainer);
     NS_IF_RELEASE(mDataSource);
     if (--gRefCnt == 0) {
         NS_IF_RELEASE(gRDFContainerUtils);
         NS_IF_RELEASE(gRDFService);
         NS_IF_RELEASE(kRDF_nextVal);
     }
 }
 nsresult
 NS_NewRDFContainer(nsIRDFContainer** aResult)
 {
     RDFContainerImpl* result = new RDFContainerImpl();
     if (! result)
         return NS_ERROR_OUT_OF_MEMORY;
     nsresult rv;
     rv = result->Init();
     if (NS_FAILED(rv)) {
         delete result;
         return rv;
     }
     NS_ADDREF(result);
     *aResult = result;
     return NS_OK;
 }
 nsresult
 NS_NewRDFContainer(nsIRDFDataSource* aDataSource,
                    nsIRDFResource* aResource,
                    nsIRDFContainer** aResult)
 {
     nsresult rv;
     rv = NS_NewRDFContainer(aResult);
     if (NS_FAILED(rv)) return rv;
     rv = (*aResult)->Init(aDataSource, aResource);
     if (NS_FAILED(rv)) {
         NS_RELEASE(*aResult);
     }
     return rv;
 }
 nsresult
 RDFContainerImpl::Renumber(int32_t aStartIndex, int32_t aIncrement)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     // Renumber the elements in the container starting with
     // aStartIndex, updating each element's index by aIncrement. For
     // example,
     //
     //   (1:a 2:b 3:c)
     //   Renumber(2, +1);
     //   (1:a 3:b 4:c)
     //   Renumber(3, -1);
     //   (1:a 2:b 3:c)
     //
     nsresult rv;
     if (! aIncrement)
         return NS_OK;
     int32_t count;
     rv = GetCount(&count);
     if (NS_FAILED(rv)) return rv;
     if (aIncrement > 0) {
         // Update the container's nextVal to reflect the
         // renumbering. We do this now if aIncrement > 0 because we'll
         // want to be able to acknowledge that new elements are in the
         // container.
         rv = SetNextValue(count + aIncrement + 1);
         if (NS_FAILED(rv)) return rv;
     }
     int32_t i;
     if (aIncrement < 0) {
         i = aStartIndex;
     }
     else {
         i = count; // we're one-indexed.
     }
     // Note: once we disable notifications, don't exit this method until
     // enabling notifications
     nsCOMPtr<nsIRDFPropagatableDataSource> propagatable =
         do_QueryInterface(mDataSource);
     if (propagatable) {
         propagatable->SetPropagateChanges(false);
     }
     bool    err = false;
     while (!err && ((aIncrement < 0) ? (i <= count) : (i >= aStartIndex)))
     {
         nsCOMPtr<nsIRDFResource> oldOrdinal;
         rv = gRDFContainerUtils->IndexToOrdinalResource(i, getter_AddRefs(oldOrdinal));
         if (NS_FAILED(rv))
         {
             err = true;
             continue;
         }
         nsCOMPtr<nsIRDFResource> newOrdinal;
         rv = gRDFContainerUtils->IndexToOrdinalResource(i + aIncrement, getter_AddRefs(newOrdinal));
         if (NS_FAILED(rv))
         {
             err = true;
             continue;
         }
         // Because of aggregation, we need to be paranoid about the
         // possibility that >1 element may be present per ordinal. If
         // there _is_ in fact more than one element, they'll all get
         // assigned to the same new ordinal; i.e., we don't make any
         // attempt to "clean up" the duplicate numbering. (Doing so
         // would require two passes.)
         nsCOMPtr<nsISimpleEnumerator> targets;
         rv = mDataSource->GetTargets(mContainer, oldOrdinal, true, getter_AddRefs(targets));
         if (NS_FAILED(rv))
         {
             err = true;
             continue;
         }
         while (1) {
             bool hasMore;
             rv = targets->HasMoreElements(&hasMore);
             if (NS_FAILED(rv))
             {
                 err = true;
                 break;
             }
             if (! hasMore)
                 break;
             nsCOMPtr<nsISupports> isupports;
             rv = targets->GetNext(getter_AddRefs(isupports));
             if (NS_FAILED(rv))
             {
                 err = true;
                 break;
             }
             nsCOMPtr<nsIRDFNode> element( do_QueryInterface(isupports) );
             NS_ASSERTION(element != nullptr, "something funky in the enumerator");
             if (! element)
             {
                 err = true;
                 rv = NS_ERROR_UNEXPECTED;
                 break;
             }
             rv = mDataSource->Unassert(mContainer, oldOrdinal, element);
             if (NS_FAILED(rv))
             {
                 err = true;
                 break;
             }
             rv = mDataSource->Assert(mContainer, newOrdinal, element, true);
             if (NS_FAILED(rv))
             {
                 err = true;
                 break;
             }
         }
         i -= aIncrement;
     }
     if (!err && (aIncrement < 0))
     {
         // Update the container's nextVal to reflect the
         // renumbering. We do this now if aIncrement < 0 because, up
         // until this point, we'll want people to be able to find
         // things that are still "at the end".
         rv = SetNextValue(count + aIncrement + 1);
         if (NS_FAILED(rv))
         {
             err = true;
         }
     }
     // Note: MUST enable notifications before exiting this method
     if (propagatable) {
         propagatable->SetPropagateChanges(true);
     }
     if (err) return(rv);
     return NS_OK;
 }
 nsresult
 RDFContainerImpl::SetNextValue(int32_t aIndex)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     nsresult rv;
     // Remove the current value of nextVal, if there is one.
     nsCOMPtr<nsIRDFNode> nextValNode;
     if (NS_SUCCEEDED(rv = mDataSource->GetTarget(mContainer,
                                                  kRDF_nextVal,
                                                  true,
                                                  getter_AddRefs(nextValNode)))) {
         if (NS_FAILED(rv = mDataSource->Unassert(mContainer, kRDF_nextVal, nextValNode))) {
             NS_ERROR("unable to update nextVal");
             return rv;
         }
     }
     nsAutoString s;
     s.AppendInt(aIndex, 10);
     nsCOMPtr<nsIRDFLiteral> nextVal;
     if (NS_FAILED(rv = gRDFService->GetLiteral(s.get(), getter_AddRefs(nextVal)))) {
         NS_ERROR("unable to get nextVal literal");
         return rv;
     }
     rv = mDataSource->Assert(mContainer, kRDF_nextVal, nextVal, true);
     if (rv != NS_RDF_ASSERTION_ACCEPTED) {
         NS_ERROR("unable to update nextVal");
         return NS_ERROR_FAILURE;
     }
     return NS_OK;
 }
 nsresult
 RDFContainerImpl::GetNextValue(nsIRDFResource** aResult)
 {
     if (!mDataSource || !mContainer)
         return NS_ERROR_NOT_INITIALIZED;
     nsresult rv;
     // Get the next value, which hangs off of the bag via the
     // RDF:nextVal property.
     nsCOMPtr<nsIRDFNode> nextValNode;
     rv = mDataSource->GetTarget(mContainer, kRDF_nextVal, true, getter_AddRefs(nextValNode));
     if (NS_FAILED(rv)) return rv;
     if (rv == NS_RDF_NO_VALUE)
         return NS_ERROR_UNEXPECTED;
     nsCOMPtr<nsIRDFLiteral> nextValLiteral;
     rv = nextValNode->QueryInterface(NS_GET_IID(nsIRDFLiteral), getter_AddRefs(nextValLiteral));
     if (NS_FAILED(rv)) return rv;
     const char16_t* s;
     rv = nextValLiteral->GetValueConst(&s);
     if (NS_FAILED(rv)) return rv;
     int32_t nextVal = 0;
     {
         for (const char16_t* p = s; *p != 0; ++p) {
             NS_ASSERTION(*p >= '0' && *p <= '9', "not a digit");
             if (*p < '0' || *p > '9')
                 break;
             nextVal *= 10;
             nextVal += *p - '0';
         }
     }
     static const char kRDFNameSpaceURI[] = RDF_NAMESPACE_URI;
     char buf[sizeof(kRDFNameSpaceURI) + 16];
     nsFixedCString nextValStr(buf, sizeof(buf), 0);
     nextValStr = kRDFNameSpaceURI;
     nextValStr.Append("_");
     nextValStr.AppendInt(nextVal, 10);
     rv = gRDFService->GetResource(nextValStr, aResult);
     if (NS_FAILED(rv)) return rv;
     // Now increment the RDF:nextVal property.
     rv = mDataSource->Unassert(mContainer, kRDF_nextVal, nextValLiteral);
     if (NS_FAILED(rv)) return rv;
     ++nextVal;
     nextValStr.Truncate();
     nextValStr.AppendInt(nextVal, 10);
     rv = gRDFService->GetLiteral(NS_ConvertASCIItoUTF16(nextValStr).get(), getter_AddRefs(nextValLiteral));
     if (NS_FAILED(rv)) return rv;
     rv = mDataSource->Assert(mContainer, kRDF_nextVal, nextValLiteral, true);
     if (NS_FAILED(rv)) return rv;
     if (RDF_SEQ_LIST_LIMIT == nextVal)
     {
         // focal point for RDF container mutation;
         // basically, provide a hint to allow for fast access
         nsCOMPtr<nsIRDFInMemoryDataSource> inMem = do_QueryInterface(mDataSource);
         if (inMem)
         {
             // ignore error; failure just means slower access
             (void)inMem->EnsureFastContainment(mContainer);
         }
     }
     return NS_OK;
 }

The Tor Browser / annotate

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

rdf/base/src/nsRDFContainer.cpp