libsaria: Remove files that no longer exist

I scan a library path, do an lstat() and remove the files that can't be
found.

Signed-off-by: Bryan Schumaker <bjschuma@gmail.com>

include/libsaria/fs.h

@@ -12,6 +12,7 @@ enum DataState {
 
 namespace libsaria
 {
+	bool exists(string);
 	void list_dir(string &, list<string> &);
 
 	namespace app

libsaria/fs.cpp

@@ -42,6 +42,12 @@ static void handle_entry(string &dir, list<string> &file_list, struct dirent *di
 namespace libsaria
 {
 
+	bool exists(string filepath)
+	{
+		struct stat stat;
+		return lstat(filepath.c_str(), &stat) == 0;
+	}
+
 	void list_dir(string &dir, list<string> &file_list)
 	{
 		DIR *dp;

libsaria/library/update.cpp

@@ -2,11 +2,24 @@
 #include <libsaria/library.h>
 #include <libsaria/track.h>
 #include <libsaria/print.h>
+#include <libsaria/deck.h>
 #include <libsaria/idle.h>
+#include <libsaria/fs.h>
 #include "library.h"
 
 static unsigned int MAX_SCAN = 20;
 
+class ValidateTask : public IdleTask
+{
+	private:
+		struct libsaria::library::Path *path;
+
+	public:
+		ValidateTask(struct libsaria::library::Path *);
+		~ValidateTask();
+		void run_task();
+};
+
 class ScanTask : public IdleTask
 {
 	private:
@@ -30,6 +43,36 @@ class ReaddirTask : public IdleTask
 		void run_task();
 };
 
+ValidateTask::ValidateTask(struct libsaria::library::Path *p)
+{
+	path = p;
+}
+
+ValidateTask::~ValidateTask()
+{
+}
+
+void ValidateTask::run_task()
+{
+	list<libsaria::Track> to_rm;
+	list<libsaria::Track>::iterator it, it_mv;
+
+	for (it = path->tracks.begin(); it != path->tracks.end(); it++) {
+		if (!libsaria::exists(it->get_filepath())) {
+			println("Reaping: " + it->get_filepath());
+			/* Iterators are no longer valid after splice */
+			it_mv = it;
+			it--;
+			to_rm.splice(to_rm.begin(), path->tracks, it_mv);
+			path->data_state = DIRTY;
+		}
+	};
+
+	libsaria::deck::tracks_removed(to_rm);
+	notify_path_updated(path);
+	save_path(path);
+}
+
 ScanTask::ScanTask(struct libsaria::library::Path *p, list<string> &files)
 {
 	list<string>::iterator it;
@@ -114,6 +157,14 @@ void ReaddirTask::run_task()
 void do_update_path(struct libsaria::library::Path *path)
 {
 	println("Updating path: " + path->path);
+
+	if (!libsaria::exists(path->path)) {
+		libsaria::library::delete_path(path);
+		return;
+	}
+
+	ValidateTask *validate = new ValidateTask(path);
 	ReaddirTask *task = new ReaddirTask(path);
+	validate->queue();
 	task->queue();
 }