add background file eraser class for asynchronous file deletion

1 files changed, 83 insertions, 0 deletions

diff --git a/lib/components/file_eraser.cpp b/lib/components/file_eraser.cpp
new file mode 100644
index 00000000..bc26bf7c
--- /dev/null
+++ b/lib/components/file_eraser.cpp
@@ -0,0 +1,83 @@
+#include <lib/components/file_eraser.h>
+#include <lib/base/eerror.h>
+#include <lib/base/init.h>
+#include <lib/base/init_num.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <errno.h>
+
+eBackgroundFileEraser *eBackgroundFileEraser::instance;
+
+eBackgroundFileEraser::eBackgroundFileEraser()
+	:messages(this,1), stop_thread_timer(this)
+{
+	if (!instance)
+		instance=this;
+	CONNECT(messages.recv_msg, eBackgroundFileEraser::gotMessage);
+	CONNECT(stop_thread_timer.timeout, eBackgroundFileEraser::idle);
+}
+
+void eBackgroundFileEraser::idle()
+{
+	quit(0);
+}
+
+eBackgroundFileEraser::~eBackgroundFileEraser()
+{
+	messages.send(Message::quit);
+	if ( thread_running() )
+		kill();
+	if (instance==this)
+		instance=0;
+}
+
+void eBackgroundFileEraser::thread()
+{
+	nice(5);
+	reset();
+	runLoop();
+	stop_thread_timer.stop();
+}
+
+void eBackgroundFileEraser::erase(const char *filename)
+{
+	if (filename)
+	{
+		char buf[255];
+		snprintf(buf, 255, "%s.$$$", filename);
+		if (rename(filename, buf)<0)
+			;/*perror("rename file failed !!!");*/
+		else
+		{
+			messages.send(Message(Message::erase, strdup(buf)));
+			if (!thread_running())
+				run();
+		}
+	}
+}
+
+void eBackgroundFileEraser::gotMessage(const Message &msg )
+{
+	switch (msg.type)
+	{
+		case Message::erase:
+			if ( msg.filename )
+			{
+				if ( ::unlink(msg.filename) < 0 )
+					eDebug("remove file %s failed (%m)", msg.filename);
+				else
+					eDebug("file %s erased", msg.filename);
+				free((char*)msg.filename);
+			}
+			stop_thread_timer.start(2000, true); // stop thread in two seconds
+			break;
+		case Message::quit:
+			quit(0);
+			break;
+		default:
+			eDebug("unhandled thread message");
+	}
+}
+
+eAutoInitP0<eBackgroundFileEraser> init_eBackgroundFilEraser(eAutoInitNumbers::configuration+1, "Background File Eraser");