gecko-dev/rdf/base/rdfTriplesSerializer.cpp

152 строки
4.3 KiB
C++

/* -*- 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/. */
#include "nsIOutputStream.h"
#include "nsReadableUtils.h"
#include "nsCRT.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsPrintfCString.h"
#include "nsIBufferedStreams.h"
#include "nsNetCID.h"
#include "nsComponentManagerUtils.h"
#include "rdfISerializer.h"
#include "rdfIDataSource.h"
#include "rdfITripleVisitor.h"
#include "nsIRDFResource.h"
#include "nsIRDFLiteral.h"
#include "mozilla/Attributes.h"
class TriplesVisitor final : public rdfITripleVisitor
{
public:
explicit TriplesVisitor(nsIOutputStream* aOut) : mOut(aOut) {}
NS_DECL_RDFITRIPLEVISITOR
NS_DECL_ISUPPORTS
protected:
~TriplesVisitor() {}
nsresult writeResource(nsIRDFResource* aResource);
nsIOutputStream* mOut;
};
NS_IMPL_ISUPPORTS(TriplesVisitor, rdfITripleVisitor)
nsresult
TriplesVisitor::writeResource(nsIRDFResource *aResource)
{
nsCString res;
uint32_t writeCount, wroteCount;
mOut->Write("<", 1, &wroteCount);
NS_ENSURE_TRUE(wroteCount == 1, NS_ERROR_FAILURE);
nsresult rv = aResource->GetValueUTF8(res);
NS_ENSURE_SUCCESS(rv, rv);
writeCount = res.Length();
mOut->Write(res.get(), writeCount, &wroteCount);
NS_ENSURE_TRUE(writeCount == wroteCount, NS_ERROR_FAILURE);
mOut->Write("> ", 2, &wroteCount);
NS_ENSURE_TRUE(wroteCount == 2, NS_ERROR_FAILURE);
return NS_OK;
}
NS_IMETHODIMP
TriplesVisitor::Visit(nsIRDFNode *aSubject, nsIRDFResource *aPredicate,
nsIRDFNode *aObject, bool aTruthValue)
{
nsCOMPtr<nsIRDFResource> subjectRes = do_QueryInterface(aSubject);
nsresult rv = NS_OK;
if (subjectRes) {
rv = writeResource(subjectRes);
}
if (NS_FAILED(rv)) {
return rv;
}
rv = writeResource(aPredicate);
if (NS_FAILED(rv)) {
return rv;
}
nsCOMPtr<nsIRDFResource> res = do_QueryInterface(aObject);
nsCOMPtr<nsIRDFLiteral> lit;
nsCOMPtr<nsIRDFInt> intLit;
uint32_t wroteCount;
if (res) {
rv = writeResource(res);
} else if ((lit = do_QueryInterface(aObject)) != nullptr) {
const char16_t *value;
lit->GetValueConst(&value);
nsAutoCString object;
object.Append('"');
AppendUTF16toUTF8(value, object);
object.AppendLiteral("\" ");
uint32_t writeCount = object.Length();
rv = mOut->Write(object.get(), writeCount, &wroteCount);
NS_ENSURE_TRUE(writeCount == wroteCount, NS_ERROR_FAILURE);
} else if ((intLit = do_QueryInterface(aObject)) != nullptr) {
int32_t value;
intLit->GetValue(&value);
nsPrintfCString
object("\"%i\"^^<http://www.w3.org/2001/XMLSchema#integer> ",
value);
uint32_t writeCount = object.Length();
rv = mOut->Write(object.get(), writeCount, &wroteCount);
NS_ENSURE_TRUE(writeCount == wroteCount, NS_ERROR_FAILURE);
}
NS_ENSURE_SUCCESS(rv, rv);
return mOut->Write(".\n", 2, &wroteCount);
}
class rdfTriplesSerializer final : public rdfISerializer
{
public:
NS_DECL_ISUPPORTS
NS_DECL_RDFISERIALIZER
rdfTriplesSerializer();
private:
~rdfTriplesSerializer();
};
nsresult
NS_NewTriplesSerializer(rdfISerializer** aResult)
{
NS_PRECONDITION(aResult != nullptr, "null ptr");
if (! aResult)
return NS_ERROR_NULL_POINTER;
*aResult = new rdfTriplesSerializer();
if (! *aResult)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*aResult);
return NS_OK;
}
NS_IMPL_ISUPPORTS(rdfTriplesSerializer, rdfISerializer)
rdfTriplesSerializer::rdfTriplesSerializer()
{
}
rdfTriplesSerializer::~rdfTriplesSerializer()
{
}
NS_IMETHODIMP
rdfTriplesSerializer::Serialize(rdfIDataSource *aDataSource,
nsIOutputStream *aOut)
{
nsresult rv;
nsCOMPtr<nsIBufferedOutputStream> bufout =
do_CreateInstance(NS_BUFFEREDOUTPUTSTREAM_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
rv = bufout->Init(aOut, 1024);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<rdfITripleVisitor> tv = new TriplesVisitor(bufout);
NS_ENSURE_TRUE(tv, NS_ERROR_OUT_OF_MEMORY);
return aDataSource->VisitAllTriples(tv);
}