storage: add abstract interface

Prepare for the plugin interface.

11 files changed, 149 insertions, 63 deletions

diff --git a/Makefile.am b/Makefile.am
index fe3932975..1a61ea5a7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -418,6 +418,7 @@ if ENABLE_DATABASE
 noinst_LIBRARIES += libstorage.a
 
 libstorage_a_SOURCES = \
+	src/storage/StorageInterface.cxx src/storage/StorageInterface.hxx \
 	src/storage/LocalStorage.cxx src/storage/LocalStorage.hxx \
 	src/storage/FileInfo.hxx
 
diff --git a/src/db/update/Service.hxx b/src/db/update/Service.hxx
index cc5a61588..936c2bb55 100644
--- a/src/db/update/Service.hxx
+++ b/src/db/update/Service.hxx
@@ -61,7 +61,7 @@ class UpdateService final : DeferredMonitor {
 
 public:
 	UpdateService(EventLoop &_loop, SimpleDatabase &_db,
-		      LocalStorage &_storage,
+		      Storage &_storage,
 		      DatabaseListener &_listener);
 
 	/**
diff --git a/src/db/update/UpdateGlue.cxx b/src/db/update/UpdateGlue.cxx
index 037d280b0..c1d563ffd 100644
--- a/src/db/update/UpdateGlue.cxx
+++ b/src/db/update/UpdateGlue.cxx
@@ -151,7 +151,7 @@ UpdateService::RunDeferred()
 }
 
 UpdateService::UpdateService(EventLoop &_loop, SimpleDatabase &_db,
-			     LocalStorage &_storage,
+			     Storage &_storage,
 			     DatabaseListener &_listener)
 	:DeferredMonitor(_loop), db(_db), listener(_listener),
 	 progress(UPDATE_PROGRESS_IDLE),
diff --git a/src/db/update/UpdateIO.cxx b/src/db/update/UpdateIO.cxx
index 58b1fe296..73295cb02 100644
--- a/src/db/update/UpdateIO.cxx
+++ b/src/db/update/UpdateIO.cxx
@@ -22,7 +22,7 @@
 #include "UpdateDomain.hxx"
 #include "db/Directory.hxx"
 #include "storage/FileInfo.hxx"
-#include "storage/LocalStorage.hxx"
+#include "storage/StorageInterface.hxx"
 #include "fs/Traits.hxx"
 #include "fs/FileSystem.hxx"
 #include "util/Error.hxx"
@@ -32,7 +32,7 @@
 #include <unistd.h>
 
 bool
-GetInfo(LocalStorage &storage, const char *uri_utf8, FileInfo &info)
+GetInfo(Storage &storage, const char *uri_utf8, FileInfo &info)
 {
 	Error error;
 	bool success = storage.GetInfo(uri_utf8, true, info, error);
@@ -42,7 +42,7 @@ GetInfo(LocalStorage &storage, const char *uri_utf8, FileInfo &info)
 }
 
 bool
-GetInfo(LocalDirectoryReader &reader, FileInfo &info)
+GetInfo(StorageDirectoryReader &reader, FileInfo &info)
 {
 	Error error;
 	bool success = reader.GetInfo(true, info, error);
@@ -52,7 +52,7 @@ GetInfo(LocalDirectoryReader &reader, FileInfo &info)
 }
 
 bool
-DirectoryExists(LocalStorage &storage, const Directory &directory)
+DirectoryExists(Storage &storage, const Directory &directory)
 {
 	FileInfo info;
 	if (!storage.GetInfo(directory.GetPath(), true, info, IgnoreError()))
@@ -65,7 +65,7 @@ DirectoryExists(LocalStorage &storage, const Directory &directory)
 }
 
 static bool
-GetDirectoryChildInfo(LocalStorage &storage, const Directory &directory,
+GetDirectoryChildInfo(Storage &storage, const Directory &directory,
 		      const char *name_utf8, FileInfo &info, Error &error)
 {
 	const auto uri_utf8 = PathTraitsUTF8::Build(directory.GetPath(),
@@ -74,7 +74,7 @@ GetDirectoryChildInfo(LocalStorage &storage, const Directory &directory,
 }
 
 bool
-directory_child_is_regular(LocalStorage &storage, const Directory &directory,
+directory_child_is_regular(Storage &storage, const Directory &directory,
 			   const char *name_utf8)
 {
 	FileInfo info;
@@ -84,7 +84,7 @@ directory_child_is_regular(LocalStorage &storage, const Directory &directory,
 }
 
 bool
-directory_child_access(LocalStorage &storage, const Directory &directory,
+directory_child_access(Storage &storage, const Directory &directory,
 		       const char *name, int mode)
 {
 #ifdef WIN32
diff --git a/src/db/update/UpdateIO.hxx b/src/db/update/UpdateIO.hxx
index d5cbb2a5b..2dbb4ae83 100644
--- a/src/db/update/UpdateIO.hxx
+++ b/src/db/update/UpdateIO.hxx
@@ -25,30 +25,30 @@
 
 struct Directory;
 struct FileInfo;
-class LocalStorage;
-class LocalDirectoryReader;
+class Storage;
+class StorageDirectoryReader;
 
 /**
- * Wrapper for LocalStorage::GetInfo() that logs errors instead of
+ * Wrapper for Storage::GetInfo() that logs errors instead of
  * returning them.
  */
 bool
-GetInfo(LocalStorage &storage, const char *uri_utf8, FileInfo &info);
+GetInfo(Storage &storage, const char *uri_utf8, FileInfo &info);
 
 /**
  * Wrapper for LocalDirectoryReader::GetInfo() that logs errors
  * instead of returning them.
  */
 bool
-GetInfo(LocalDirectoryReader &reader, FileInfo &info);
+GetInfo(StorageDirectoryReader &reader, FileInfo &info);
 
 gcc_pure
 bool
-DirectoryExists(LocalStorage &storage, const Directory &directory);
+DirectoryExists(Storage &storage, const Directory &directory);
 
 gcc_pure
 bool
-directory_child_is_regular(LocalStorage &storage, const Directory &directory,
+directory_child_is_regular(Storage &storage, const Directory &directory,
 			   const char *name_utf8);
 
 /**
@@ -56,7 +56,7 @@ directory_child_is_regular(LocalStorage &storage, const Directory &directory,
  */
 gcc_pure
 bool
-directory_child_access(LocalStorage &storage, const Directory &directory,
+directory_child_access(Storage &storage, const Directory &directory,
 		       const char *name, int mode);
 
 #endif
diff --git a/src/db/update/Walk.cxx b/src/db/update/Walk.cxx
index d8b998f9e..5750f0223 100644
--- a/src/db/update/Walk.cxx
+++ b/src/db/update/Walk.cxx
@@ -27,7 +27,7 @@
 #include "db/Song.hxx"
 #include "db/PlaylistVector.hxx"
 #include "db/Uri.hxx"
-#include "storage/LocalStorage.hxx"
+#include "storage/StorageInterface.hxx"
 #include "playlist/PlaylistRegistry.hxx"
 #include "Mapper.hxx"
 #include "ExcludeList.hxx"
@@ -49,7 +49,7 @@
 #include <errno.h>
 
 UpdateWalk::UpdateWalk(EventLoop &_loop, DatabaseListener &_listener,
-		       LocalStorage &_storage)
+		       Storage &_storage)
 	:storage(_storage),
 	 editor(_loop, _listener)
 {
@@ -140,7 +140,7 @@ UpdateWalk::PurgeDeletedFromDirectory(Directory &directory)
 
 #ifndef WIN32
 static bool
-update_directory_stat(LocalStorage &storage, Directory &directory)
+update_directory_stat(Storage &storage, Directory &directory)
 {
 	FileInfo info;
 	if (!GetInfo(storage, directory.GetPath(), info))
@@ -152,7 +152,7 @@ update_directory_stat(LocalStorage &storage, Directory &directory)
 #endif
 
 static int
-find_inode_ancestor(LocalStorage &storage, Directory *parent,
+find_inode_ancestor(Storage &storage, Directory *parent,
 		    unsigned inode, unsigned device)
 {
 #ifndef WIN32
@@ -320,7 +320,7 @@ UpdateWalk::UpdateDirectory(Directory &directory, const FileInfo &info)
 	directory_set_stat(directory, info);
 
 	Error error;
-	LocalDirectoryReader *const reader =
+	StorageDirectoryReader *const reader =
 		storage.OpenDirectory(directory.GetPath(), error);
 	if (reader == nullptr) {
 		LogError(error);
diff --git a/src/db/update/Walk.hxx b/src/db/update/Walk.hxx
index 33387ab55..2bd56b067 100644
--- a/src/db/update/Walk.hxx
+++ b/src/db/update/Walk.hxx
@@ -29,7 +29,7 @@ struct stat;
 struct FileInfo;
 struct Directory;
 struct archive_plugin;
-class LocalStorage;
+class Storage;
 class ExcludeList;
 
 class UpdateWalk final {
@@ -48,13 +48,13 @@ class UpdateWalk final {
 	bool walk_discard;
 	bool modified;
 
-	LocalStorage &storage;
+	Storage &storage;
 
 	DatabaseEditor editor;
 
 public:
 	UpdateWalk(EventLoop &_loop, DatabaseListener &_listener,
-		   LocalStorage &_storage);
+		   Storage &_storage);
 
 	/**
 	 * Returns true if the database was modified.
diff --git a/src/storage/LocalStorage.cxx b/src/storage/LocalStorage.cxx
index a229b3fe7..f0a1726e0 100644
--- a/src/storage/LocalStorage.cxx
+++ b/src/storage/LocalStorage.cxx
@@ -81,14 +81,6 @@ LocalStorage::MapFS(const char *uri_utf8) const
 	return MapFS(uri_utf8, IgnoreError());
 }
 
-AllocatedPath
-LocalStorage::MapChildFS(const char *uri_utf8,
-			 const char *child_utf8) const
-{
-	const auto uri2 = PathTraitsUTF8::Build(uri_utf8, child_utf8);
-	return MapFS(uri2.c_str());
-}
-
 bool
 LocalStorage::GetInfo(const char *uri_utf8, bool follow, FileInfo &info,
 		      Error &error)
diff --git a/src/storage/LocalStorage.hxx b/src/storage/LocalStorage.hxx
index 73c11dd80..4acea3d2a 100644
--- a/src/storage/LocalStorage.hxx
+++ b/src/storage/LocalStorage.hxx
@@ -21,14 +21,13 @@
 #define MPD_STORAGE_LOCAL_HXX
 
 #include "check.h"
+#include "StorageInterface.hxx"
 #include "fs/AllocatedPath.hxx"
 #include "fs/DirectoryReader.hxx"
 
 #include <string>
 
-struct FileInfo;
-
-class LocalDirectoryReader {
+class LocalDirectoryReader final : public StorageDirectoryReader {
 	AllocatedPath base_fs;
 
 	DirectoryReader reader;
@@ -43,12 +42,13 @@ public:
 		return reader.HasFailed();
 	}
 
-	const char *Read();
-
-	bool GetInfo(bool follow, FileInfo &info, Error &error);
+	/* virtual methods from class StorageDirectoryReader */
+	virtual const char *Read() override;
+	virtual bool GetInfo(bool follow, FileInfo &info,
+			     Error &error) override;
 };
 
-class LocalStorage {
+class LocalStorage final : public Storage {
 	const std::string base_utf8;
 	const AllocatedPath base_fs;
 
@@ -58,29 +58,16 @@ public:
 
 	LocalStorage(const LocalStorage &) = delete;
 
-	bool GetInfo(const char *uri_utf8, bool follow, FileInfo &info,
-		     Error &error);
-
-	LocalDirectoryReader *OpenDirectory(const char *uri_utf8,
-					    Error &error);
-
-	/**
-	 * Map the given relative URI to an absolute URI.
-	 */
-	gcc_pure
-	std::string MapUTF8(const char *uri_utf8) const;
-
-	/**
-	 * Map the given relative URI to a local file path.  Returns
-	 * AllocatedPath::Null() on error or if this storage does not
-	 * support local files.
-	 */
-	gcc_pure
-	AllocatedPath MapFS(const char *uri_utf8) const;
-
-	gcc_pure
-	AllocatedPath MapChildFS(const char *uri_utf8,
-				 const char *child_utf8) const;
+	/* virtual methods from class Storage */
+	virtual bool GetInfo(const char *uri_utf8, bool follow, FileInfo &info,
+			     Error &error) override;
+
+	virtual LocalDirectoryReader *OpenDirectory(const char *uri_utf8,
+						    Error &error) override;
+
+	virtual std::string MapUTF8(const char *uri_utf8) const override;
+
+	virtual AllocatedPath MapFS(const char *uri_utf8) const override;
 
 private:
 	AllocatedPath MapFS(const char *uri_utf8, Error &error) const;
diff --git a/src/storage/StorageInterface.cxx b/src/storage/StorageInterface.cxx
new file mode 100644
index 000000000..93c50a8ac
--- /dev/null
+++ b/src/storage/StorageInterface.cxx
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2003-2014 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.
+ */
+
+#include "config.h"
+#include "StorageInterface.hxx"
+#include "fs/AllocatedPath.hxx"
+#include "fs/Traits.hxx"
+
+AllocatedPath
+Storage::MapFS(gcc_unused const char *uri_utf8) const
+{
+	return AllocatedPath::Null();
+}
+
+AllocatedPath
+Storage::MapChildFS(const char *uri_utf8,
+		    const char *child_utf8) const
+{
+	const auto uri2 = PathTraitsUTF8::Build(uri_utf8, child_utf8);
+	return MapFS(uri2.c_str());
+}
diff --git a/src/storage/StorageInterface.hxx b/src/storage/StorageInterface.hxx
new file mode 100644
index 000000000..ecdc882b6
--- /dev/null
+++ b/src/storage/StorageInterface.hxx
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2003-2014 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_STORAGE_INTERFACE_HXX
+#define MPD_STORAGE_INTERFACE_HXX
+
+#include "check.h"
+#include "fs/AllocatedPath.hxx"
+#include "fs/DirectoryReader.hxx"
+
+#include <string>
+
+struct FileInfo;
+class AllocatedPath;
+
+class StorageDirectoryReader {
+public:
+	virtual ~StorageDirectoryReader() {}
+
+	virtual const char *Read() = 0;
+	virtual bool GetInfo(bool follow, FileInfo &info, Error &error) = 0;
+};
+
+class Storage {
+public:
+	virtual ~Storage() {}
+
+	virtual bool GetInfo(const char *uri_utf8, bool follow, FileInfo &info,
+			     Error &error) = 0;
+
+	virtual StorageDirectoryReader *OpenDirectory(const char *uri_utf8,
+						      Error &error) = 0;
+
+	/**
+	 * Map the given relative URI to an absolute URI.
+	 */
+	gcc_pure
+	virtual std::string MapUTF8(const char *uri_utf8) const = 0;
+
+	/**
+	 * Map the given relative URI to a local file path.  Returns
+	 * AllocatedPath::Null() on error or if this storage does not
+	 * support local files.
+	 */
+	gcc_pure
+	virtual AllocatedPath MapFS(const char *uri_utf8) const;
+
+	gcc_pure
+	AllocatedPath MapChildFS(const char *uri_utf8,
+				 const char *child_utf8) const;
+};
+
+#endif