ArchivePlugin: replace scan_reset(), scan_next() with visit()

Makefile.am

@@ -398,6 +398,7 @@ libarchive_a_SOURCES = \
 	src/ArchiveLookup.cxx src/ArchiveLookup.hxx \
 	src/ArchiveList.cxx src/ArchiveList.hxx \
 	src/ArchivePlugin.cxx src/ArchivePlugin.hxx \
+	src/ArchiveVisitor.hxx \
 	src/ArchiveInternal.hxx \
 	src/input/ArchiveInputPlugin.cxx src/input/ArchiveInputPlugin.hxx
 libarchive_a_CPPFLAGS = $(AM_CPPFLAGS) \

src/ArchivePlugin.cxx

@@ -38,8 +38,7 @@ archive_file_open(const struct archive_plugin *plugin, const char *path,
 	if (file != NULL) {
 		assert(file->plugin != NULL);
 		assert(file->plugin->close != NULL);
-		assert(file->plugin->scan_reset != NULL);
-		assert(file->plugin->scan_next != NULL);
+		assert(file->plugin->visit != nullptr);
 		assert(file->plugin->open_stream != NULL);
 		assert(error_r == NULL || *error_r == NULL);
 	} else {
@@ -60,24 +59,13 @@ archive_file_close(struct archive_file *file)
 }
 
 void
-archive_file_scan_reset(struct archive_file *file)
+archive_file_visit(archive_file *file, ArchiveVisitor &visitor)
 {
 	assert(file != NULL);
 	assert(file->plugin != NULL);
-	assert(file->plugin->scan_reset != NULL);
-	assert(file->plugin->scan_next != NULL);
+	assert(file->plugin->visit != nullptr);
 
-	file->plugin->scan_reset(file);
-}
-
-const char *
-archive_file_scan_next(struct archive_file *file)
-{
-	assert(file != NULL);
-	assert(file->plugin != NULL);
-	assert(file->plugin->scan_next != NULL);
-
-	return file->plugin->scan_next(file);
+	file->plugin->visit(file, visitor);
 }
 
 struct input_stream *

src/ArchivePlugin.hxx

@@ -26,6 +26,7 @@
 
 struct input_stream;
 struct archive_file;
+class ArchiveVisitor;
 
 struct archive_plugin {
 	const char *name;
@@ -51,18 +52,9 @@ struct archive_plugin {
 	struct archive_file *(*open)(const char *path_fs, GError **error_r);
 
 	/**
-	 * reset routine will move current read index in archive to default
-	 * position and then the filenames from archives can be read
-	 * via scan_next routine
+	 * Visit all entries inside this archive.
 	 */
-	void  (*scan_reset)(struct archive_file *);
-
-	/**
-	 * the read method will return corresponding files from archive
-	 * (as pathnames) and move read index to next file. When there is no
-	 * next file it return NULL.
-	 */
-	const char *(*scan_next)(struct archive_file *);
+	void (*visit)(archive_file *af, ArchiveVisitor &visitor);
 
 	/**
 	 * Opens an input_stream of a file within the archive.
@@ -96,10 +88,7 @@ void
 archive_file_close(struct archive_file *file);
 
 void
-archive_file_scan_reset(struct archive_file *file);
-
-const char *
-archive_file_scan_next(struct archive_file *file);
+archive_file_visit(archive_file *file, ArchiveVisitor &visitor);
 
 struct input_stream *
 archive_file_open_stream(struct archive_file *file, const char *path,

src/ArchiveVisitor.hxx

+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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.
+ */
+
+#ifndef MPD_ARCHIVE_VISITOR_HXX
+#define MPD_ARCHIVE_VISITOR_HXX
+
+class ArchiveVisitor {
+public:
+	virtual void VisitArchiveEntry(const char *path_utf8) = 0;
+};
+
+#endif

src/UpdateArchive.cxx

@@ -27,6 +27,7 @@
 #include "fs/Path.hxx"
 #include "ArchiveList.hxx"
 #include "ArchivePlugin.hxx"
+#include "ArchiveVisitor.hxx"
 
 #include <glib.h>
 
@@ -122,14 +123,21 @@ update_archive_file2(Directory *parent, const char *name,
 
 	directory->mtime = st->st_mtime;
 
-	archive_file_scan_reset(file);
+	class UpdateArchiveVisitor final : public ArchiveVisitor {
+		Directory *directory;
 
-	const char *filepath;
-	while ((filepath = archive_file_scan_next(file)) != NULL) {
-		/* split name into directory and file */
-		g_debug("adding archive file: %s", filepath);
-		update_archive_tree(directory, filepath);
-	}
+	public:
+		UpdateArchiveVisitor(Directory *_directory)
+			:directory(_directory) {}
+
+		virtual void VisitArchiveEntry(const char *path_utf8) override {
+			g_debug("adding archive file: %s", path_utf8);
+			update_archive_tree(directory, path_utf8);
+		}
+	};
+
+	UpdateArchiveVisitor visitor(directory);
+	archive_file_visit(file, visitor);
 
 	archive_file_close(file);
 }

src/archive/Bzip2ArchivePlugin.cxx

@@ -25,6 +25,7 @@
 #include "Bzip2ArchivePlugin.hxx"
 #include "ArchiveInternal.hxx"
 #include "ArchivePlugin.hxx"
+#include "ArchiveVisitor.hxx"
 #include "InputInternal.hxx"
 #include "InputStream.hxx"
 #include "InputPlugin.hxx"
@@ -47,7 +48,6 @@ struct Bzip2ArchiveFile {
 	struct refcount ref;
 
 	char *name;
-	bool reset;
 	struct input_stream *istream;
 
 	Bzip2ArchiveFile() {
@@ -152,24 +152,11 @@ bz2_open(const char *pathname, GError **error_r)
 }
 
 static void
-bz2_scan_reset(struct archive_file *file)
+bz2_visit(archive_file *file, ArchiveVisitor &visitor)
 {
 	Bzip2ArchiveFile *context = (Bzip2ArchiveFile *) file;
-	context->reset = true;
-}
-
-static const char *
-bz2_scan_next(struct archive_file *file)
-{
-	Bzip2ArchiveFile *context = (Bzip2ArchiveFile *) file;
-	const char *name = NULL;
-
-	if (context->reset) {
-		name = context->name;
-		context->reset = false;
-	}
 
-	return name;
+	visitor.VisitArchiveEntry(context->name);
 }
 
 static void
@@ -318,8 +305,7 @@ const struct archive_plugin bz2_archive_plugin = {
 	nullptr,
 	nullptr,
 	bz2_open,
-	bz2_scan_reset,
-	bz2_scan_next,
+	bz2_visit,
 	bz2_open_stream,
 	bz2_close,
 	bz2_extensions,

src/archive/Iso9660ArchivePlugin.cxx

@@ -25,6 +25,7 @@
 #include "Iso9660ArchivePlugin.hxx"
 #include "ArchiveInternal.hxx"
 #include "ArchivePlugin.hxx"
+#include "ArchiveVisitor.hxx"
 #include "InputInternal.hxx"
 #include "InputStream.hxx"
 #include "InputPlugin.hxx"
@@ -46,22 +47,14 @@ struct Iso9660ArchiveFile {
 	struct refcount ref;
 
 	iso9660_t *iso;
-	GSList	*list;
-	GSList	*iter;
 
 	Iso9660ArchiveFile(iso9660_t *_iso)
-		:iso(_iso), list(nullptr) {
+		:iso(_iso) {
 		archive_file_init(&base, &iso9660_archive_plugin);
 		refcount_init(&ref);
 	}
 
 	~Iso9660ArchiveFile() {
-		//free list
-		for (GSList *tmp = list; tmp != NULL; tmp = g_slist_next(tmp))
-			g_free(tmp->data);
-		g_slist_free(list);
-
-		//close archive
 		iso9660_close(iso);
 	}
 
@@ -70,7 +63,7 @@ struct Iso9660ArchiveFile {
 			delete this;
 	}
 
-	void CollectRecursive(const char *path);
+	void Visit(const char *path, ArchiveVisitor &visitor);
 };
 
 extern const struct input_plugin iso9660_input_plugin;
@@ -83,8 +76,8 @@ iso9660_quark(void)
 
 /* archive open && listing routine */
 
-void
-Iso9660ArchiveFile::CollectRecursive(const char *psz_path)
+inline void
+Iso9660ArchiveFile::Visit(const char *psz_path, ArchiveVisitor &visitor)
 {
 	CdioList_t *entlist;
 	CdioListNode_t *entnode;
@@ -105,11 +98,11 @@ Iso9660ArchiveFile::CollectRecursive(const char *psz_path)
 		if (iso9660_stat_s::_STAT_DIR == statbuf->type ) {
 			if (strcmp(statbuf->filename, ".") && strcmp(statbuf->filename, "..")) {
 				strcat(pathname, "/");
-				CollectRecursive(pathname);
+				Visit(pathname, visitor);
 			}
 		} else {
 			//remove leading /
-			list = g_slist_prepend(list, g_strdup(pathname + 1));
+			visitor.VisitArchiveEntry(pathname + 1);
 		}
 	}
 	_cdio_list_free (entlist, true);
@@ -127,33 +120,16 @@ iso9660_archive_open(const char *pathname, GError **error_r)
 	}
 
 	Iso9660ArchiveFile *archive = new Iso9660ArchiveFile(iso);
-	archive->CollectRecursive("/");
 	return &archive->base;
 }
 
 static void
-iso9660_archive_scan_reset(struct archive_file *file)
-{
-	Iso9660ArchiveFile *context =
-		(Iso9660ArchiveFile *)file;
-
-	//reset iterator
-	context->iter = context->list;
-}
-
-static const char *
-iso9660_archive_scan_next(struct archive_file *file)
+iso9660_archive_visit(archive_file *file, ArchiveVisitor &visitor)
 {
 	Iso9660ArchiveFile *context =
 		(Iso9660ArchiveFile *)file;
 
-	const char *data = NULL;
-	if (context->iter != NULL) {
-		///fetch data and goto next
-		data = (const char *)context->iter->data;
-		context->iter = g_slist_next(context->iter);
-	}
-	return data;
+	context->Visit("/", visitor);
 }
 
 static void
@@ -296,8 +272,7 @@ const struct archive_plugin iso9660_archive_plugin = {
 	nullptr,
 	nullptr,
 	iso9660_archive_open,
-	iso9660_archive_scan_reset,
-	iso9660_archive_scan_next,
+	iso9660_archive_visit,
 	iso9660_archive_open_stream,
 	iso9660_archive_close,
 	iso9660_archive_extensions,

src/archive/ZzipArchivePlugin.cxx

@@ -25,6 +25,7 @@
 #include "ZzipArchivePlugin.hxx"
 #include "ArchiveInternal.hxx"
 #include "ArchivePlugin.hxx"
+#include "ArchiveVisitor.hxx"
 #include "InputInternal.hxx"
 #include "InputStream.hxx"
 #include "InputPlugin.hxx"
@@ -40,8 +41,6 @@ struct ZzipArchiveFile {
 	struct refcount ref;
 
 	ZZIP_DIR *dir;
-	GSList	*list;
-	GSList	*iter;
 
 	ZzipArchiveFile() {
 		archive_file_init(&base, &zzip_archive_plugin);
@@ -52,17 +51,13 @@ struct ZzipArchiveFile {
 		if (!refcount_dec(&ref))
 			return;
 
-		if (list) {
-			//free list
-			for (GSList *tmp = list; tmp != NULL; tmp = g_slist_next(tmp))
-				g_free(tmp->data);
-			g_slist_free(list);
-		}
 		//close archive
 		zzip_dir_close (dir);
 
 		delete this;
 	}
+
+	void Visit(ArchiveVisitor &visitor);
 };
 
 extern const struct input_plugin zzip_input_plugin;
@@ -79,10 +74,8 @@ static struct archive_file *
 zzip_archive_open(const char *pathname, GError **error_r)
 {
 	ZzipArchiveFile *context = new ZzipArchiveFile();
-	ZZIP_DIRENT dirent;
 
 	// open archive
-	context->list = NULL;
 	context->dir = zzip_dir_open(pathname, NULL);
 	if (context->dir  == NULL) {
 		g_set_error(error_r, zzip_quark(), 0,
@@ -90,36 +83,27 @@ zzip_archive_open(const char *pathname, GError **error_r)
 		return NULL;
 	}
 
-	while (zzip_dir_read(context->dir, &dirent)) {
-		//add only files
-		if (dirent.st_size > 0) {
-			context->list = g_slist_prepend(context->list,
-							g_strdup(dirent.d_name));
-		}
-	}
-
 	return &context->base;
 }
 
-static void
-zzip_archive_scan_reset(struct archive_file *file)
+inline void
+ZzipArchiveFile::Visit(ArchiveVisitor &visitor)
 {
-	ZzipArchiveFile *context = (ZzipArchiveFile *) file;
-	//reset iterator
-	context->iter = context->list;
+	zzip_rewinddir(dir);
+
+	ZZIP_DIRENT dirent;
+	while (zzip_dir_read(dir, &dirent))
+		//add only files
+		if (dirent.st_size > 0)
+			visitor.VisitArchiveEntry(dirent.d_name);
 }
 
-static const char *
-zzip_archive_scan_next(struct archive_file *file)
+static void
+zzip_archive_visit(archive_file *file, ArchiveVisitor &visitor)
 {
 	ZzipArchiveFile *context = (ZzipArchiveFile *) file;
-	const char *data = NULL;
-	if (context->iter != NULL) {
-		///fetch data and goto next
-		data = (const char *)context->iter->data;
-		context->iter = g_slist_next(context->iter);
-	}
-	return data;
+
+	context->Visit(visitor);
 }
 
 static void
@@ -260,8 +244,7 @@ const struct archive_plugin zzip_archive_plugin = {
 	nullptr,
 	nullptr,
 	zzip_archive_open,
-	zzip_archive_scan_reset,
-	zzip_archive_scan_next,
+	zzip_archive_visit,
 	zzip_archive_open_stream,
 	zzip_archive_close,
 	zzip_archive_extensions,