libtracker-extract: Added example to examples/libtracker-extract

Moved mockup from src/tracker-extract/ to here.
Used MP3 source and added comments to detail what is going on

3 files changed, 369 insertions, 0 deletions

diff --git a/examples/Makefile.am b/examples/Makefile.am
index 44c1e3fbd..41a8a6762 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -1,5 +1,6 @@
 include $(top_srcdir)/Makefile.decl
 
 SUBDIRS = 			\
+	libtracker-extract	\
 	libtracker-miner	\
 	rss-reader
diff --git a/examples/libtracker-extract/Makefile.am b/examples/libtracker-extract/Makefile.am
new file mode 100644
index 000000000..eb6987d94
--- /dev/null
+++ b/examples/libtracker-extract/Makefile.am
@@ -0,0 +1,23 @@
+include $(top_srcdir)/Makefile.decl
+
+module_flags = -module -avoid-version -no-undefined
+modulesdir = $(libdir)/tracker-$(TRACKER_API_VERSION)/extract-modules
+
+INCLUDES = 								\
+	-DLOCALEDIR=\""$(localedir)"\" 					\
+	-DMODULESDIR=\"$(modulesdir)\"					\
+	-I$(top_srcdir)/src 						\
+	$(WARN_CFLAGS)							\
+	$(GLIB2_CFLAGS)							\
+	$(GCOV_CFLAGS)
+
+modules_LTLIBRARIES = libextract-mockup.la
+
+libextract_mockup_la_SOURCES = tracker-extract-mockup.c
+libextract_mockup_la_LDFLAGS = $(module_flags)
+libextract_mockup_la_LIBADD = 						\
+	$(top_builddir)/src/libtracker-extract/libtracker-extract-@TRACKER_API_VERSION@.la \
+	$(top_builddir)/src/libtracker-common/libtracker-common.la	\
+	$(GLIB2_LIBS)  							\
+	$(GCOV_LIBS)
+
diff --git a/examples/libtracker-extract/tracker-extract-mockup.c b/examples/libtracker-extract/tracker-extract-mockup.c
new file mode 100644
index 000000000..03879cc22
--- /dev/null
+++ b/examples/libtracker-extract/tracker-extract-mockup.c
@@ -0,0 +1,345 @@
+/*
+ * Copyright (C) 2010, Your name <Your email address>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA  02110-1301, USA.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+
+/* TODO: Include any 3rd party libraries here. */
+
+/* #include <libtracker-common/tracker-file-utils.h> */
+/* #include <libtracker-common/tracker-utils.h> */
+
+#include <gio/gio.h>
+
+#include <libtracker-extract/tracker-extract.h>
+#include <libtracker-extract/tracker-utils.h>
+
+#include <libtracker-client/tracker.h>
+
+static void extract_mockup (const gchar          *uri,
+                            TrackerSparqlBuilder *preupdate,
+                            TrackerSparqlBuilder *metadata);
+
+static TrackerExtractData data[] = {
+	/* TODO: Insert mime types and functions here. */
+	{ "audio/mpeg",  extract_mockup },
+	{ "audio/x-mp3", extract_mockup },
+	{ NULL, NULL }
+};
+
+static void
+extract_mockup (const gchar          *uri,
+                TrackerSparqlBuilder *preupdate,
+                TrackerSparqlBuilder *metadata)
+{
+	/* File information */
+	FILE *f;
+	GFileInfo *info;
+	GFile *file;
+	GError *error = NULL;
+	gchar *filename;
+	goffset size;
+
+	/* Data input */
+	gchar *title_tagv1;
+	gchar *title_tagv2;
+	gchar *title_tagv3;
+	gchar *title_unknown;
+	gchar *lyricist_tagv2;
+	gchar *lyricist_unknown;
+
+	/* Coalesced input */
+	gchar *title;
+	gchar *performer;
+	gchar *performer_uri;
+	gchar *lyricist;
+	gchar *lyricist_uri;
+	gchar *album;
+	gchar *album_uri;
+	gchar *genre;
+	gchar *text;
+	gchar *recording_time;
+	gchar *copyright;
+	gchar *publisher;
+	gchar *comment;
+	gchar *composer;
+	gchar *composer_uri;
+	gint track_number;
+	gint track_count;
+	guint32 duration;
+
+	filename = g_filename_from_uri (uri, NULL, NULL);
+
+	file = g_file_new_for_path (filename);
+	info = g_file_query_info (file,
+	                          G_FILE_ATTRIBUTE_STANDARD_SIZE,
+	                          G_FILE_QUERY_INFO_NONE,
+	                          NULL,
+	                          &error);
+
+	if (G_UNLIKELY (error)) {
+		g_message ("Could not get size for '%s', %s",
+		           filename,
+		           error->message);
+		g_error_free (error);
+		size = 0;
+	} else {
+		size = g_file_info_get_size (info);
+		g_object_unref (info);
+	}
+
+	g_object_unref (file);
+
+	/* TODO: Do any pre-checks on the file
+	 * (i.e check file size so we don't handle files of 0 size)
+	 */
+	if (size < 64) {
+		g_free (filename);
+		return;
+	}
+
+	/* TODO: Open file */
+	f = fopen (filename, "r");
+
+	if (!f) {
+		g_free (filename);
+		return;
+	}
+	
+	/* TODO: Get data from file.
+	 *
+	 * (We will use dummy data for this example)
+	 */
+	title_tagv1 = NULL;
+	title_tagv2 = g_strdup ("Burn The Witch");
+	title_tagv3 = g_strdup ("");
+	title_unknown = g_strdup ("Unknown");
+
+	lyricist_tagv2 = g_strdup ("Someone");
+	lyricist_unknown = g_strdup ("Someone");
+
+	/* TODO: Close file */
+	fclose (f);
+
+	/* TODO: Make sure we coalesce duplicate values */
+	title = tracker_extract_coalesce (4, title_tagv1, title_tagv2, title_tagv3, title_unknown);
+	lyricist = tracker_extract_coalesce (2, lyricist_tagv2, lyricist_unknown);
+
+	performer = g_strdup ("Stone Gods");
+	composer = NULL;
+	album = g_strdup ("Silver Spoons And Broken Bones");
+	genre = g_strdup ("Rock");
+	recording_time = NULL;
+	publisher = NULL;
+	text = g_strdup ("Some description");
+	copyright = g_strdup ("Who knows?");
+	comment = g_strdup ("I love this track");
+	track_number = 1;
+	track_count = 12;
+	duration = 32;
+
+	/* TODO: Do any pre-updates
+	 *
+	 * (This involves creating any database nodes for consistent
+	 *  data objects, for example, an artist which might be used n times)
+	 */
+	if (performer) {
+		performer_uri = tracker_uri_printf_escaped ("urn:artist:%s", performer);
+
+		tracker_sparql_builder_insert_open (preupdate, NULL);
+		tracker_sparql_builder_subject_iri (preupdate, performer_uri);
+		tracker_sparql_builder_predicate (preupdate, "a");
+		tracker_sparql_builder_object (preupdate, "nmm:Artist");
+		tracker_sparql_builder_predicate (preupdate, "nmm:artistName");
+		tracker_sparql_builder_object_unvalidated (preupdate, performer);
+		tracker_sparql_builder_insert_close (preupdate);
+	} else {
+		performer_uri = NULL;
+	}
+
+	if (composer) {
+		composer_uri = tracker_uri_printf_escaped ("urn:artist:%s", composer);
+
+		tracker_sparql_builder_insert_open (preupdate, NULL);
+		tracker_sparql_builder_subject_iri (preupdate, composer_uri);
+		tracker_sparql_builder_predicate (preupdate, "a");
+		tracker_sparql_builder_object (preupdate, "nmm:Artist");
+		tracker_sparql_builder_predicate (preupdate, "nmm:artistName");
+		tracker_sparql_builder_object_unvalidated (preupdate, composer);
+		tracker_sparql_builder_insert_close (preupdate);
+	} else {
+		composer_uri = NULL;
+	}
+
+	if (lyricist) {
+		lyricist_uri = tracker_uri_printf_escaped ("urn:artist:%s", lyricist);
+
+		tracker_sparql_builder_insert_open (preupdate, NULL);
+		tracker_sparql_builder_subject_iri (preupdate, lyricist_uri);
+		tracker_sparql_builder_predicate (preupdate, "a");
+		tracker_sparql_builder_object (preupdate, "nmm:Artist");
+		tracker_sparql_builder_predicate (preupdate, "nmm:artistName");
+		tracker_sparql_builder_object_unvalidated (preupdate, lyricist);
+		tracker_sparql_builder_insert_close (preupdate);
+	} else {
+		lyricist_uri = NULL;
+	}
+
+	if (album) {
+		album_uri = tracker_uri_printf_escaped ("urn:album:%s", album);
+
+		tracker_sparql_builder_insert_open (preupdate, NULL);
+		tracker_sparql_builder_subject_iri (preupdate, album_uri);
+		tracker_sparql_builder_predicate (preupdate, "a");
+		tracker_sparql_builder_object (preupdate, "nmm:MusicAlbum");
+		tracker_sparql_builder_predicate (preupdate, "nmm:albumTitle");
+		tracker_sparql_builder_object_unvalidated (preupdate, album);
+		tracker_sparql_builder_insert_close (preupdate);
+
+		if (track_count > 0) {
+			tracker_sparql_builder_delete_open (preupdate, NULL);
+			tracker_sparql_builder_subject_iri (preupdate, album_uri);
+			tracker_sparql_builder_predicate (preupdate, "nmm:albumTrackCount");
+			tracker_sparql_builder_object_variable (preupdate, "unknown");
+			tracker_sparql_builder_delete_close (preupdate);
+
+			tracker_sparql_builder_where_open (preupdate);
+			tracker_sparql_builder_subject_iri (preupdate, album_uri);
+			tracker_sparql_builder_predicate (preupdate, "nmm:albumTrackCount");
+			tracker_sparql_builder_object_variable (preupdate, "unknown");
+			tracker_sparql_builder_where_close (preupdate);
+
+			tracker_sparql_builder_insert_open (preupdate, NULL);
+			tracker_sparql_builder_subject_iri (preupdate, album_uri);
+			tracker_sparql_builder_predicate (preupdate, "nmm:albumTrackCount");
+			tracker_sparql_builder_object_int64 (preupdate, track_count);
+			tracker_sparql_builder_insert_close (preupdate);
+		}
+	} else {
+		album_uri = NULL;
+	}
+
+	/* TODO: Do any metadata updates
+	 *
+	 * (This is where you can use entities created in the
+	 *  pre-updates part, like an artist).
+	 */
+	tracker_sparql_builder_predicate (metadata, "a");
+	tracker_sparql_builder_object (metadata, "nmm:MusicPiece");
+	tracker_sparql_builder_object (metadata, "nfo:Audio");
+
+	if (title) {
+		tracker_sparql_builder_predicate (metadata, "nie:title");
+		tracker_sparql_builder_object_unvalidated (metadata, title);
+		g_free (title);
+	}
+
+	if (lyricist_uri) {
+		tracker_sparql_builder_predicate (metadata, "nmm:lyricist");
+		tracker_sparql_builder_object_iri (metadata, lyricist_uri);
+		g_free (lyricist_uri);
+	}
+
+	if (performer_uri) {
+		tracker_sparql_builder_predicate (metadata, "nmm:performer");
+		tracker_sparql_builder_object_iri (metadata, performer_uri);
+		g_free (performer_uri);
+	}
+
+	if (composer_uri) {
+		tracker_sparql_builder_predicate (metadata, "nmm:composer");
+		tracker_sparql_builder_object_iri (metadata, composer_uri);
+		g_free (composer_uri);
+	}
+
+	if (album_uri) {
+		tracker_sparql_builder_predicate (metadata, "nmm:musicAlbum");
+		tracker_sparql_builder_object_iri (metadata, album_uri);
+		g_free (album_uri);
+	}
+
+	if (recording_time) {
+		tracker_sparql_builder_predicate (metadata, "nie:contentCreated");
+		tracker_sparql_builder_object_unvalidated (metadata, recording_time);
+		g_free (recording_time);
+	}
+
+	if (genre) {
+		tracker_sparql_builder_predicate (metadata, "nfo:genre");
+		tracker_sparql_builder_object_unvalidated (metadata, genre);
+		g_free (genre);
+	}
+
+	if (copyright) {
+		tracker_sparql_builder_predicate (metadata, "nie:copyright");
+		tracker_sparql_builder_object_unvalidated (metadata, copyright);
+		g_free (copyright);
+	}
+
+	if (comment) {
+		tracker_sparql_builder_predicate (metadata, "nie:comment");
+		tracker_sparql_builder_object_unvalidated (metadata, comment);
+		g_free (comment);
+	}
+
+	if (publisher) {
+		tracker_sparql_builder_predicate (metadata, "nco:publisher");
+		tracker_sparql_builder_object_blank_open (metadata);
+		tracker_sparql_builder_predicate (metadata, "a");
+		tracker_sparql_builder_object (metadata, "nco:Contact");
+		tracker_sparql_builder_predicate (metadata, "nco:fullname");
+		tracker_sparql_builder_object_unvalidated (metadata, publisher);
+		tracker_sparql_builder_object_blank_close (metadata);
+		g_free (publisher);
+	}
+
+	if (track_number > 0) {
+		tracker_sparql_builder_predicate (metadata, "nmm:trackNumber");
+		tracker_sparql_builder_object_int64 (metadata, track_number);
+	}
+
+	if (duration > 0) {
+		tracker_sparql_builder_predicate (metadata, "nfo:duration");
+		tracker_sparql_builder_object_int64 (metadata, duration);
+	}
+
+	if (text) {
+		/* NOTE: This is for Full Text Search (FTS) indexing content */
+		tracker_sparql_builder_predicate (metadata, "nie:plainTextContent");
+		tracker_sparql_builder_object_unvalidated (metadata, text);
+		g_free (text);
+	}
+
+	/* TODO: Clean up */
+	g_free (album);
+	g_free (composer);
+	g_free (performer);
+	g_free (filename);
+}
+
+TrackerExtractData *
+tracker_extract_get_data (void)
+{
+	/* NOTE: This function has to exist, tracker-extract checks
+	 * the symbole table for this function and if it doesn't
+	 * exist, the module is not loaded to be used as an extractor.
+	 */
+	return data;
+}