[gupnp-av/wip/didl-lite-fragments: 11/20] Add XSDData structure for document validation.

[Krzesimir Nowak <krnowak src gnome org>]

commit 94fbec73e41f347e4e746a38bb594d4a6b795d06
Author: Krzesimir Nowak <krnowak openismus com>
Date:   Thu Oct 25 11:23:46 2012 +0200

    Add XSDData structure for document validation.
    
    Will be used by fragments code.

 libgupnp-av/Makefile.am |    2 +
 libgupnp-av/xsd-data.c  |  146 +++++++++++++++++++++++++++++++++++++++++++++++
 libgupnp-av/xsd-data.h  |   44 ++++++++++++++
 3 files changed, 192 insertions(+), 0 deletions(-)
---
diff --git a/libgupnp-av/Makefile.am b/libgupnp-av/Makefile.am
index 3fbb02a..c7e9438 100644
--- a/libgupnp-av/Makefile.am
+++ b/libgupnp-av/Makefile.am
@@ -71,6 +71,8 @@ libgupnp_av_1_0_la_SOURCES = gupnp-didl-lite-object.c \
 			     xml-util.h \
 			     gvalue-util.c \
 			     gvalue-util.h \
+			     xsd-data.c \
+			     xsd-data.h \
 			     $(BUILT_SOURCES)
 
 libgupnp_av_1_0_la_LIBADD = $(LIBGUPNP_LIBS)
diff --git a/libgupnp-av/xsd-data.c b/libgupnp-av/xsd-data.c
new file mode 100644
index 0000000..3f985a4
--- /dev/null
+++ b/libgupnp-av/xsd-data.c
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2012 Intel Corporation
+ *
+ * Authors: Krzesimir Nowak <krnowak openismus com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <libxml/parser.h>
+#include <libxml/xmlschemas.h>
+
+#include "xsd-data.h"
+
+struct _XSDData {
+        xmlSchemaPtr schema;
+        xmlSchemaValidCtxtPtr valid_context;
+};
+
+XSDData *
+xsd_data_new (const gchar *xsd_file)
+{
+        XSDData *xsd_data = g_slice_new0 (XSDData);
+        gboolean failed = TRUE;
+        xmlSchemaParserCtxtPtr context = xmlSchemaNewParserCtxt (xsd_file);
+
+        if (context == NULL)
+                /* unable to create a parser context for the schema */
+                goto out;
+        xsd_data->schema = xmlSchemaParse (context);
+        if (xsd_data->schema == NULL)
+                /* the schema itself is not valid */
+                goto out;
+        xsd_data->valid_context = xmlSchemaNewValidCtxt (xsd_data->schema);
+        if (xsd_data->valid_context == NULL)
+                /* unable to create a validation context for the schema */
+                goto out;
+        failed = FALSE;
+ out:
+        if (context != NULL)
+                xmlSchemaFreeParserCtxt (context);
+        if (failed) {
+                xsd_data_free (xsd_data);
+                xsd_data = NULL;
+        }
+
+        return xsd_data;
+}
+
+void
+xsd_data_free (XSDData *xsd_data)
+{
+        if (xsd_data == NULL)
+                return;
+        if (xsd_data->valid_context != NULL)
+                xmlSchemaFreeValidCtxt (xsd_data->valid_context);
+        if (xsd_data->schema != NULL)
+                xmlSchemaFree (xsd_data->schema);
+        g_slice_free (XSDData, xsd_data);
+}
+
+gboolean
+xsd_data_validate_doc (XSDData *xsd_data,
+                       xmlDoc  *doc)
+{
+        static xmlSAXHandler empty_handler = {
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                NULL,
+                XML_SAX2_MAGIC,
+                NULL,
+                NULL,
+                NULL,
+                NULL
+        };
+        xmlChar *dump = NULL;
+        int size = 0;
+        xmlParserInputBufferPtr buffer = NULL;
+        gboolean result = FALSE;
+
+        if (xsd_data == NULL)
+                return TRUE;
+
+        xmlDocDumpMemory (doc, &dump, &size);
+        if (dump == NULL)
+                goto out;
+        g_debug ("Doc dump:\n%s", dump);
+        buffer = xmlParserInputBufferCreateMem ((char *) dump,
+                                                   size,
+                                                   XML_CHAR_ENCODING_NONE);
+        if (buffer == NULL)
+                goto out;
+        if (!xmlSchemaValidateStream (xsd_data->valid_context,
+                                      buffer,
+                                      XML_CHAR_ENCODING_NONE,
+                                      &empty_handler,
+                                      NULL))
+                result = TRUE;
+ out:
+        /* Commented out, because it crashes because of double free. I
+         * suppose that it is freed by xmlSchemaValidateStream.
+         */
+        /*
+        if (buffer)
+                xmlFreeParserInputBuffer (buffer);
+        */
+        if (dump != NULL)
+                xmlFree (dump);
+        return result;
+}
diff --git a/libgupnp-av/xsd-data.h b/libgupnp-av/xsd-data.h
new file mode 100644
index 0000000..b89dcd6
--- /dev/null
+++ b/libgupnp-av/xsd-data.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2012 Intel Corporation
+ *
+ * Authors: Krzesimir Nowak <krnowak openismus com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __XSD_DATA_H__
+#define __XSD_DATA_H__
+
+#include <glib.h>
+#include <libxml/tree.h>
+
+G_BEGIN_DECLS
+
+typedef struct _XSDData XSDData;
+
+G_GNUC_INTERNAL XSDData *
+xsd_data_new                            (const gchar *xsd_file);
+
+G_GNUC_INTERNAL void
+xsd_data_free                           (XSDData *data);
+
+G_GNUC_INTERNAL gboolean
+xsd_data_validate_doc                   (XSDData *data,
+                                         xmlDoc  *doc);
+
+G_END_DECLS
+
+#endif /* __XSD_DATA_H__ */