[tracker/wip/sam/resource-rebase-6: 4/7] libtracker-sparql: Add TrackerNamespaceManager
- From: Sam Thursfield <sthursfield src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [tracker/wip/sam/resource-rebase-6: 4/7] libtracker-sparql: Add TrackerNamespaceManager
- Date: Thu, 14 Jul 2016 12:20:48 +0000 (UTC)
commit 167b06ae395fa3f94aea110d2139ee849e03551b
Author: Sam Thursfield <sam afuera me uk>
Date: Fri Apr 8 17:57:46 2016 +0100
libtracker-sparql: Add TrackerNamespaceManager
This will keep track of a set of namespaces and their prefixes. Then,
when we are serializing a resource, we can use it.
This is separate from the Namespace and Ontologies classes in
libtracker-data. They may be able to make use of it though.
https://bugzilla.gnome.org/show_bug.cgi?id=767472
src/libtracker-sparql/Makefile.am | 3 +
src/libtracker-sparql/tracker-namespace-manager.c | 332 +++++++++++++++++++++
src/libtracker-sparql/tracker-namespace-manager.h | 49 +++
3 files changed, 384 insertions(+), 0 deletions(-)
---
diff --git a/src/libtracker-sparql/Makefile.am b/src/libtracker-sparql/Makefile.am
index b63e4ef..d12190d 100644
--- a/src/libtracker-sparql/Makefile.am
+++ b/src/libtracker-sparql/Makefile.am
@@ -22,6 +22,8 @@ libtracker_sparql_la_SOURCES = \
tracker-builder.vala \
tracker-connection.vala \
tracker-cursor.vala \
+ tracker-namespace-manager.c \
+ tracker-namespace-manager.h \
tracker-utils.vala \
tracker-uri.c \
tracker-uri.h \
@@ -49,6 +51,7 @@ tracker-sparql-$(TRACKER_API_VERSION).vapi: tracker-sparql.vapi
libtracker_sparqlinclude_HEADERS = \
$(vala_header) \
+ tracker-namespace-manager.h \
tracker-ontologies.h \
tracker-sparql.h \
tracker-uri.h \
diff --git a/src/libtracker-sparql/tracker-namespace-manager.c
b/src/libtracker-sparql/tracker-namespace-manager.c
new file mode 100644
index 0000000..a96284e
--- /dev/null
+++ b/src/libtracker-sparql/tracker-namespace-manager.c
@@ -0,0 +1,332 @@
+/*
+ * Copyright (C) 2016, Sam Thursfield <sam afuera me uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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 "config.h"
+
+#include <string.h>
+#include <stdlib.h>
+
+#include <glib.h>
+
+#include "tracker-namespace-manager.h"
+#include "tracker-ontologies.h"
+
+#define MAX_PREFIX_LENGTH 100
+
+struct _TrackerNamespaceManager {
+ GObject parent;
+};
+
+typedef struct {
+ GHashTable *prefix_to_namespace;
+ GHashTable *namespace_to_prefix;
+} TrackerNamespaceManagerPrivate;
+
+G_DEFINE_TYPE_WITH_PRIVATE (TrackerNamespaceManager, tracker_namespace_manager, G_TYPE_OBJECT);
+#define GET_PRIVATE(object) (tracker_namespace_manager_get_instance_private (object))
+
+/**
+ * SECTION: tracker-namespace-manager
+ * @short_description: A set of well-known namespaces, and known abbreviations for them
+ * @title: TrackerNamespaceManager
+ * @stability: Stable
+ * @include: tracker-namespace-manager.h
+ *
+ * <para>
+ * #TrackerNamespaceManager keeps track of namespaces. It allows you to assign
+ * short prefixes for them to avoid typing full URLs all the time.
+ *
+ * The syntax used is that of Compact URIs (CURIEs) as defined here:
+ * <https://www.w3.org/TR/2010/NOTE-curie-20101216/>
+ *
+ * Usually you'll want to use the default namespace manager, as returned by
+ * tracker_namespace_manager_get_default(). This has a set of well-known
+ * prefixes predefined.
+ * </para>
+ */
+
+static void finalize (GObject *object);
+
+static void
+tracker_namespace_manager_class_init (TrackerNamespaceManagerClass *klass)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+ object_class->finalize = finalize;
+}
+
+static void
+tracker_namespace_manager_init (TrackerNamespaceManager *self)
+{
+ TrackerNamespaceManagerPrivate *priv = GET_PRIVATE (self);
+
+ priv->prefix_to_namespace = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
+ priv->namespace_to_prefix = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
+}
+
+static void
+finalize (GObject *object)
+{
+ TrackerNamespaceManagerPrivate *priv;
+
+ priv = GET_PRIVATE (TRACKER_NAMESPACE_MANAGER (object));
+
+ g_hash_table_unref (priv->prefix_to_namespace);
+ g_hash_table_unref (priv->namespace_to_prefix);
+
+ (G_OBJECT_CLASS (tracker_namespace_manager_parent_class)->finalize)(object);
+}
+
+/**
+ * tracker_namespace_manager_new:
+ *
+ * Creates a new #TrackerNamespaceManager instance.
+ *
+ * Returns: a new #TrackerNamespaceManager instance
+ *
+ * Since: 1.10
+ */
+TrackerNamespaceManager *
+tracker_namespace_manager_new ()
+{
+ TrackerNamespaceManager *namespace_manager;
+
+ namespace_manager = g_object_new (TRACKER_TYPE_NAMESPACE_MANAGER, NULL);
+
+ return namespace_manager;
+}
+
+/**
+ * tracker_namespace_manager_get_default:
+ *
+ * Returns the global #TrackerNamespaceManager that contains a set of well-known
+ * namespaces and prefixes, such as rdf:, rdfs:, nie:, tracker:, etc.
+ *
+ * Note that the list of prefixes and namespaces is hardcoded in
+ * libtracker-sparql. It may not correspond with the installed set of
+ * ontologies, if they have been modified since they were installed.
+ *
+ * Returns: a global, shared #TrackerNamespaceManager instance
+ *
+ * Since: 1.10
+ */
+TrackerNamespaceManager *
+tracker_namespace_manager_get_default ()
+{
+ static TrackerNamespaceManager * volatile default_namespace_manager__volatile = NULL;
+
+ if (g_once_init_enter (&default_namespace_manager__volatile)) {
+ TrackerNamespaceManager *manager = tracker_namespace_manager_new();
+
+ tracker_namespace_manager_add_prefix (manager, "rdf", TRACKER_PREFIX_RDF);
+ tracker_namespace_manager_add_prefix (manager, "rdfs", TRACKER_PREFIX_RDFS);
+ tracker_namespace_manager_add_prefix (manager, "xsd", TRACKER_PREFIX_XSD);
+ tracker_namespace_manager_add_prefix (manager, "tracker", TRACKER_PREFIX_TRACKER);
+ tracker_namespace_manager_add_prefix (manager, "dc", TRACKER_PREFIX_DC);
+
+ tracker_namespace_manager_add_prefix (manager, "nrl", TRACKER_PREFIX_NRL);
+ tracker_namespace_manager_add_prefix (manager, "nmo", TRACKER_PREFIX_NMO);
+ tracker_namespace_manager_add_prefix (manager, "nie", TRACKER_PREFIX_NIE);
+ tracker_namespace_manager_add_prefix (manager, "nco", TRACKER_PREFIX_NCO);
+ tracker_namespace_manager_add_prefix (manager, "nao", TRACKER_PREFIX_NAO);
+ tracker_namespace_manager_add_prefix (manager, "nid3", TRACKER_PREFIX_NID3);
+ tracker_namespace_manager_add_prefix (manager, "nfo", TRACKER_PREFIX_NFO);
+
+ tracker_namespace_manager_add_prefix (manager, "slo", TRACKER_PREFIX_SLO);
+ tracker_namespace_manager_add_prefix (manager, "nmm", TRACKER_PREFIX_NMM);
+ tracker_namespace_manager_add_prefix (manager, "mlo", TRACKER_PREFIX_MLO);
+ tracker_namespace_manager_add_prefix (manager, "mfo", TRACKER_PREFIX_MFO);
+
+ g_once_init_leave (&default_namespace_manager__volatile, manager);
+ }
+
+ return default_namespace_manager__volatile;
+}
+
+/**
+ * tracker_namespace_manager_has_prefix:
+ * @self: a #TrackerNamespaceManager
+ * @prefix: a string
+ *
+ * Returns: %TRUE if the #TrackerNamespaceManager knows about @prefix, %FALSE otherwise
+ *
+ * Since: 1.10
+ */
+gboolean
+tracker_namespace_manager_has_prefix (TrackerNamespaceManager *self,
+ const char *prefix)
+{
+ TrackerNamespaceManagerPrivate *priv;
+
+ g_return_val_if_fail (TRACKER_IS_NAMESPACE_MANAGER (self), FALSE);
+
+ priv = GET_PRIVATE (self);
+
+ return g_hash_table_contains (priv->prefix_to_namespace, prefix);
+}
+
+/**
+ * tracker_namespace_manager_lookup_prefix:
+ * @self: a #TrackerNamespaceManager
+ * @prefix: a string
+ *
+ * Looks up the namespace URI corresponding to @prefix, or %NULL if the prefix
+ * is not known.
+ *
+ * Returns: a string owned by the #TrackerNamespaceManager, or %NULL
+ *
+ * Since: 1.10
+ */
+const char *
+tracker_namespace_manager_lookup_prefix (TrackerNamespaceManager *self,
+ const char *prefix)
+{
+ TrackerNamespaceManagerPrivate *priv;
+
+ g_return_val_if_fail (TRACKER_IS_NAMESPACE_MANAGER (self), NULL);
+
+ priv = GET_PRIVATE (self);
+
+ return g_hash_table_lookup (priv->prefix_to_namespace, prefix);
+}
+
+/**
+ * tracker_namespace_manager_add_prefix:
+ * @self: a #TrackerNamespaceManager
+ * @prefix: a short, unique prefix to identify @namespace
+ * @namespace: the URL of the given namespace
+ *
+ * Adds @prefix as the recognised abbreviaton of @namespace.
+ *
+ * Only one prefix is allowed for a given namespace, and all prefixes must
+ * be unique.
+ *
+ * Since: 1.10
+ */
+void
+tracker_namespace_manager_add_prefix (TrackerNamespaceManager *self,
+ const char *prefix,
+ const char *namespace)
+{
+ TrackerNamespaceManagerPrivate *priv;
+ const char *str;
+
+ g_return_if_fail (TRACKER_IS_NAMESPACE_MANAGER (self));
+ g_return_if_fail (prefix != NULL);
+ g_return_if_fail (namespace != NULL);
+
+ priv = GET_PRIVATE (TRACKER_NAMESPACE_MANAGER (self));
+
+ if (strlen (prefix) > MAX_PREFIX_LENGTH) {
+ g_error ("Prefix is too long: max %i characters.", MAX_PREFIX_LENGTH);
+ return;
+ }
+
+ str = g_hash_table_lookup (priv->prefix_to_namespace, prefix);
+ if (str) {
+ g_error ("Prefix %s already points to %s", prefix, str);
+ return;
+ }
+
+ str = g_hash_table_lookup (priv->namespace_to_prefix, namespace);
+ if (str) {
+ g_error ("Namespace %s already has prefix %s", namespace, str);
+ return;
+ }
+
+ g_hash_table_insert (priv->prefix_to_namespace, g_strdup (prefix), g_strdup (namespace));
+ g_hash_table_insert (priv->namespace_to_prefix, g_strdup (namespace), g_strdup (prefix));
+}
+
+/**
+ * tracker_namespace_manager_expand_uri:
+ * @self: a #TrackerNamespaceManager
+ * @compact_uri: a URI or compact URI
+ *
+ * If @compact_uri begins with one of the prefixes known to this
+ * #TrackerNamespaceManager, then the return value will be the
+ * expanded URI. Otherwise, a copy of @compact_uri will be returned.
+ *
+ * Returns: a newly-allocated string
+ *
+ * Since: 1.10
+ */
+char *
+tracker_namespace_manager_expand_uri (TrackerNamespaceManager *self,
+ const char *compact_uri)
+{
+ TrackerNamespaceManagerPrivate *priv;
+
+ char prefix[MAX_PREFIX_LENGTH + 1] = { 0 };
+ char *colon;
+ char *namespace = NULL;
+
+ g_return_val_if_fail (TRACKER_IS_NAMESPACE_MANAGER (self), NULL);
+ g_return_val_if_fail (compact_uri != NULL, NULL);
+
+ priv = GET_PRIVATE (self);
+
+ colon = strchr (compact_uri, ':');
+ if (colon != NULL) {
+ int colon_pos = colon - compact_uri;
+ if (colon_pos < MAX_PREFIX_LENGTH) {
+ strncpy (prefix, compact_uri, colon_pos - 1);
+ prefix[colon_pos] = 0;
+
+ namespace = g_hash_table_lookup (priv->prefix_to_namespace, prefix);
+ }
+ }
+
+ if (namespace) {
+ return g_strconcat (namespace, colon, NULL);
+ } else {
+ return g_strdup (compact_uri);
+ }
+}
+
+/**
+ * tracker_namespace_manager_print_turtle:
+ * @self: a #TrackerNamespaceManager
+ *
+ * Writes out all namespaces as Turtle @prefix statements.
+ *
+ * Returns: a newly-allocated string
+ *
+ * Since: 1.10
+ */
+char *
+tracker_namespace_manager_print_turtle (TrackerNamespaceManager *self)
+{
+ TrackerNamespaceManagerPrivate *priv;
+ GString *result = g_string_new ("");
+ GHashTableIter iter;
+ const char *prefix;
+ const char *namespace;
+
+ g_return_val_if_fail (TRACKER_IS_NAMESPACE_MANAGER (self), NULL);
+
+ priv = GET_PRIVATE (self);
+
+ g_hash_table_iter_init (&iter, priv->prefix_to_namespace);
+ while (g_hash_table_iter_next (&iter, (gpointer *)&prefix, (gpointer *)&namespace)) {
+ g_string_append_printf (result, "@prefix %s: <%s> .\n", prefix, namespace);
+ }
+
+ return g_string_free (result, FALSE);
+}
diff --git a/src/libtracker-sparql/tracker-namespace-manager.h
b/src/libtracker-sparql/tracker-namespace-manager.h
new file mode 100644
index 0000000..2a6e45e
--- /dev/null
+++ b/src/libtracker-sparql/tracker-namespace-manager.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2016, Sam Thursfield <sam afuera me uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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 __LIBTRACKER_SPARQL_NAMESPACE_MANAGER_H__
+#define __LIBTRACKER_SPARQL_NAMESPACE_MANAGER_H__
+
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+#if !defined (__LIBTRACKER_SPARQL_INSIDE__) && !defined (TRACKER_COMPILATION)
+#error "only <libtracker-sparql/tracker-sparql.h> must be included directly."
+#endif
+
+#define TRACKER_TYPE_NAMESPACE_MANAGER (tracker_namespace_manager_get_type())
+G_DECLARE_FINAL_TYPE (TrackerNamespaceManager, tracker_namespace_manager, TRACKER, NAMESPACE_MANAGER,
GObject)
+
+TrackerNamespaceManager *tracker_namespace_manager_new (void);
+TrackerNamespaceManager *tracker_namespace_manager_get_default (void);
+
+char *tracker_namespace_manager_expand_uri (TrackerNamespaceManager *self, const char *compact_uri);
+
+gboolean tracker_namespace_manager_has_prefix (TrackerNamespaceManager *self, const char *prefix);
+const char *tracker_namespace_manager_lookup_prefix (TrackerNamespaceManager *self, const char *prefix);
+
+void tracker_namespace_manager_add_prefix (TrackerNamespaceManager *self, const char *prefix, const char
*namespace);
+
+char *tracker_namespace_manager_print_turtle (TrackerNamespaceManager *self);
+
+G_END_DECLS
+
+#endif /* __LIBTRACKER_SPARQL_NAMESPACE_MANAGER_H__ */
+
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