1 files changed, 279 insertions, 0 deletions
diff --git a/src/db/update/Service.cxx b/src/db/update/Service.cxx
new file mode 100644
index 000000000..e8a1f6b02
--- /dev/null
+++ b/src/db/update/Service.cxx
@@ -0,0 +1,279 @@
+/*
+ * 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 "Service.hxx"
+#include "Walk.hxx"
+#include "UpdateDomain.hxx"
+#include "db/DatabaseListener.hxx"
+#include "db/DatabaseLock.hxx"
+#include "db/plugins/simple/SimpleDatabasePlugin.hxx"
+#include "db/plugins/simple/Directory.hxx"
+#include "storage/CompositeStorage.hxx"
+#include "Idle.hxx"
+#include "util/Error.hxx"
+#include "Log.hxx"
+#include "Instance.hxx"
+#include "system/FatalError.hxx"
+#include "thread/Id.hxx"
+#include "thread/Thread.hxx"
+#include "thread/Util.hxx"
+
+#ifndef NDEBUG
+#include "event/Loop.hxx"
+#endif
+
+#include <assert.h>
+
+UpdateService::UpdateService(EventLoop &_loop, SimpleDatabase &_db,
+			     CompositeStorage &_storage,
+			     DatabaseListener &_listener)
+	:DeferredMonitor(_loop),
+	 db(_db), storage(_storage),
+	 listener(_listener),
+	 progress(UPDATE_PROGRESS_IDLE),
+	 update_task_id(0),
+	 walk(nullptr)
+{
+}
+
+UpdateService::~UpdateService()
+{
+	CancelAllAsync();
+
+	if (update_thread.IsDefined())
+		update_thread.Join();
+
+	delete walk;
+}
+
+void
+UpdateService::CancelAllAsync()
+{
+	assert(GetEventLoop().IsInsideOrNull());
+
+	queue.Clear();
+
+	if (walk != nullptr)
+		walk->Cancel();
+}
+
+void
+UpdateService::CancelMount(const char *uri)
+{
+	/* determine which (mounted) database will be updated and what
+	   storage will be scanned */
+
+	db_lock();
+	const auto lr = db.GetRoot().LookupDirectory(uri);
+	db_unlock();
+
+	if (!lr.directory->IsMount())
+		return;
+
+	bool cancel_current = false;
+
+	Storage *storage2 = storage.GetMount(uri);
+	if (storage2 != nullptr) {
+		queue.Erase(*storage2);
+		cancel_current = next.IsDefined() && next.storage == storage2;
+	}
+
+	Database &_db2 = *lr.directory->mounted_database;
+	if (_db2.IsPlugin(simple_db_plugin)) {
+		SimpleDatabase &db2 = static_cast<SimpleDatabase &>(_db2);
+		queue.Erase(db2);
+		cancel_current |= next.IsDefined() && next.db == &db2;
+	}
+
+	if (cancel_current && walk != nullptr) {
+		walk->Cancel();
+
+		if (update_thread.IsDefined())
+			update_thread.Join();
+	}
+}
+
+inline void
+UpdateService::Task()
+{
+	assert(walk != nullptr);
+
+	if (!next.path_utf8.empty())
+		FormatDebug(update_domain, "starting: %s",
+			    next.path_utf8.c_str());
+	else
+		LogDebug(update_domain, "starting");
+
+	SetThreadIdlePriority();
+
+	modified = walk->Walk(next.db->GetRoot(), next.path_utf8.c_str(),
+			      next.discard);
+
+	if (modified || !next.db->FileExists()) {
+		Error error;
+		if (!next.db->Save(error))
+			LogError(error, "Failed to save database");
+	}
+
+	if (!next.path_utf8.empty())
+		FormatDebug(update_domain, "finished: %s",
+			    next.path_utf8.c_str());
+	else
+		LogDebug(update_domain, "finished");
+
+	progress = UPDATE_PROGRESS_DONE;
+	DeferredMonitor::Schedule();
+}
+
+void
+UpdateService::Task(void *ctx)
+{
+	UpdateService &service = *(UpdateService *)ctx;
+	return service.Task();
+}
+
+void
+UpdateService::StartThread(UpdateQueueItem &&i)
+{
+	assert(GetEventLoop().IsInsideOrNull());
+	assert(walk == nullptr);
+
+	progress = UPDATE_PROGRESS_RUNNING;
+	modified = false;
+
+	next = std::move(i);
+	walk = new UpdateWalk(GetEventLoop(), listener, *next.storage);
+
+	Error error;
+	if (!update_thread.Start(Task, this, error))
+		FatalError(error);
+
+	FormatDebug(update_domain,
+		    "spawned thread for update job id %i", next.id);
+}
+
+unsigned
+UpdateService::GenerateId()
+{
+	unsigned id = update_task_id + 1;
+	if (id > update_task_id_max)
+		id = 1;
+	return id;
+}
+
+unsigned
+UpdateService::Enqueue(const char *path, bool discard)
+{
+	assert(GetEventLoop().IsInsideOrNull());
+
+	/* determine which (mounted) database will be updated and what
+	   storage will be scanned */
+	SimpleDatabase *db2;
+	Storage *storage2;
+
+	db_lock();
+	const auto lr = db.GetRoot().LookupDirectory(path);
+	db_unlock();
+	if (lr.directory->IsMount()) {
+		/* follow the mountpoint, update the mounted
+		   database */
+
+		Database &_db2 = *lr.directory->mounted_database;
+		if (!_db2.IsPlugin(simple_db_plugin))
+			/* cannot update this type of database */
+			return 0;
+
+		db2 = static_cast<SimpleDatabase *>(&_db2);
+
+		if (lr.uri == nullptr) {
+			storage2 = storage.GetMount(path);
+			path = "";
+		} else {
+			assert(lr.uri > path);
+			assert(lr.uri < path + strlen(path));
+			assert(lr.uri[-1] == '/');
+
+			const std::string mountpoint(path, lr.uri - 1);
+			storage2 = storage.GetMount(mountpoint.c_str());
+			path = lr.uri;
+		}
+	} else {
+		/* use the "root" database/storage */
+
+		db2 = &db;
+		storage2 = storage.GetMount("");
+	}
+
+	if (storage2 == nullptr)
+		/* no storage found at this mount point - should not
+		   happen */
+		return 0;
+
+	if (progress != UPDATE_PROGRESS_IDLE) {
+		const unsigned id = GenerateId();
+		if (!queue.Push(*db2, *storage2, path, discard, id))
+			return 0;
+
+		update_task_id = id;
+		return id;
+	}
+
+	const unsigned id = update_task_id = GenerateId();
+	StartThread(UpdateQueueItem(*db2, *storage2, path, discard, id));
+
+	idle_add(IDLE_UPDATE);
+
+	return id;
+}
+
+/**
+ * Called in the main thread after the database update is finished.
+ */
+void
+UpdateService::RunDeferred()
+{
+	assert(progress == UPDATE_PROGRESS_DONE);
+	assert(next.IsDefined());
+	assert(walk != nullptr);
+
+	/* wait for thread to finish only if it wasn't cancelled by
+	   CancelMount() */
+	if (update_thread.IsDefined())
+		update_thread.Join();
+
+	delete walk;
+	walk = nullptr;
+
+	next = UpdateQueueItem();
+
+	idle_add(IDLE_UPDATE);
+
+	if (modified)
+		/* send "idle" events */
+		listener.OnDatabaseModified();
+
+	auto i = queue.Pop();
+	if (i.IsDefined()) {
+		/* schedule the next path */
+		StartThread(std::move(i));
+	} else {
+		progress = UPDATE_PROGRESS_IDLE;
+	}
+}