diff -r 000000000000 -r 6474c204b198 rdf/tests/rdfcat/rdfcat.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rdf/tests/rdfcat/rdfcat.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,154 @@
+/* -*- 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 test program that reads in RDF/XML into an in-memory data
+  source, then uses the RDF/XML serialization API to write an
+  equivalent (but not identical) RDF/XML file back to stdout.
+
+  The program takes a single parameter: the URL from which to read.
+
+ */
+
+#include <stdio.h>
+#include "nsXPCOM.h"
+#include "nsCOMPtr.h"
+#include "nsIComponentManager.h"
+#include "nsComponentManagerUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsIIOService.h"
+#include "nsIInputStream.h"
+#include "nsIOutputStream.h"
+#include "nsIRDFCompositeDataSource.h"
+#include "nsIRDFNode.h"
+#include "nsIRDFRemoteDataSource.h"
+#include "nsIRDFService.h"
+#include "nsIRDFXMLSource.h"
+#include "nsIServiceManager.h"
+#include "nsIStreamListener.h"
+#include "nsIURL.h"
+#include "nsRDFCID.h"
+#include "nsThreadUtils.h"
+#include "plstr.h"
+#include "prio.h"
+#include "prthread.h"
+
+////////////////////////////////////////////////////////////////////////
+// CIDs
+
+// rdf
+static NS_DEFINE_CID(kRDFXMLDataSourceCID,  NS_RDFXMLDATASOURCE_CID);
+
+////////////////////////////////////////////////////////////////////////
+// Blatantly stolen from netwerk/test/
+#define RETURN_IF_FAILED(rv, step) \
+    PR_BEGIN_MACRO \
+    if (NS_FAILED(rv)) { \
+        printf(">>> %s failed: rv=%x\n", step, static_cast<uint32_t>(rv)); \
+        return 1;\
+    } \
+    PR_END_MACRO
+
+////////////////////////////////////////////////////////////////////////
+
+class ConsoleOutputStreamImpl : public nsIOutputStream
+{
+public:
+    ConsoleOutputStreamImpl(void) {}
+    virtual ~ConsoleOutputStreamImpl(void) {}
+
+    // nsISupports interface
+    NS_DECL_ISUPPORTS
+
+    // nsIOutputStream interface
+    NS_IMETHOD Close(void) {
+        return NS_OK;
+    }
+
+    NS_IMETHOD Write(const char* aBuf, uint32_t aCount, uint32_t *aWriteCount) {
+        PR_Write(PR_GetSpecialFD(PR_StandardOutput), aBuf, aCount);
+        *aWriteCount = aCount;
+        return NS_OK;
+    }
+
+    NS_IMETHOD
+    WriteFrom(nsIInputStream *inStr, uint32_t count, uint32_t *_retval) {
+        NS_NOTREACHED("WriteFrom");
+        return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    NS_IMETHOD
+    WriteSegments(nsReadSegmentFun reader, void * closure, uint32_t count, uint32_t *_retval) {
+        NS_NOTREACHED("WriteSegments");
+        return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    NS_IMETHOD
+    IsNonBlocking(bool *aNonBlocking) {
+        NS_NOTREACHED("IsNonBlocking");
+        return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    NS_IMETHOD Flush(void) {
+        PR_Sync(PR_GetSpecialFD(PR_StandardOutput));
+        return NS_OK;
+    }
+};
+
+NS_IMPL_ISUPPORTS(ConsoleOutputStreamImpl, nsIOutputStream)
+
+////////////////////////////////////////////////////////////////////////
+
+int
+main(int argc, char** argv)
+{
+    nsresult rv;
+
+    if (argc < 2) {
+        fprintf(stderr, "usage: %s <url>\n", argv[0]);
+        return 1;
+    }
+
+    NS_InitXPCOM2(nullptr, nullptr, nullptr);
+
+    // Create a stream data source and initialize it on argv[1], which
+    // is hopefully a "file:" URL.
+    nsCOMPtr<nsIRDFDataSource> ds = do_CreateInstance(kRDFXMLDataSourceCID,
+                                                      &rv);
+    RETURN_IF_FAILED(rv, "RDF/XML datasource creation");
+
+    nsCOMPtr<nsIRDFRemoteDataSource> remote = do_QueryInterface(ds, &rv);
+    RETURN_IF_FAILED(rv, "QI to nsIRDFRemoteDataSource");
+
+    rv = remote->Init(argv[1]);
+    RETURN_IF_FAILED(rv, "datasource initialization");
+
+    // Okay, this should load the XML file...
+    rv = remote->Refresh(false);
+    RETURN_IF_FAILED(rv, "datasource refresh");
+
+    // Pump events until the load is finished
+    nsCOMPtr<nsIThread> thread = do_GetCurrentThread();
+    bool done = false;
+    while (!done) {
+        NS_ENSURE_TRUE(NS_ProcessNextEvent(thread), 1);
+        remote->GetLoaded(&done);
+    }
+
+    // And this should write it back out. The do_QI() on the pointer
+    // is a hack to make sure that the new object gets AddRef()-ed.
+    nsCOMPtr<nsIOutputStream> out =
+        do_QueryInterface(new ConsoleOutputStreamImpl, &rv);
+    RETURN_IF_FAILED(rv, "creation of console output stream");
+
+    nsCOMPtr<nsIRDFXMLSource> source = do_QueryInterface(ds);
+    RETURN_IF_FAILED(rv, "QI to nsIRDFXMLSource");
+
+    rv = source->Serialize(out);
+    RETURN_IF_FAILED(rv, "datasoure serialization");
+
+    return 0;
+}