[thin_restore] Add a progress monitor

Makefile.in

@@ -46,6 +46,7 @@ SOURCE=\
 	base/base64.cc \
 	base/endian_utils.cc \
 	base/error_state.cc \
+	base/progress_monitor.cc \
 	\
 	caching/hint_array.cc \
 	caching/superblock.cc \
@@ -377,6 +378,7 @@ ERA_DUMP_SOURCE=\
 	base/base64.cc \
 	base/error_state.cc \
 	base/endian_utils.cc \
+	base/progress_monitor.cc \
 	\
 	era/writeset_tree.cc \
 	era/era_detail.cc \

base/progress_monitor.cc

@@ -0,0 +1,75 @@
+#include "base/progress_monitor.h"
+
+#include <iostream>
+
+//----------------------------------------------------------------
+
+namespace {
+	using namespace std;
+
+	class progress_bar : public base::progress_monitor {
+	public:
+		progress_bar(string const &title)
+			: title_(title),
+			  progress_width_(50),
+			  spinner_(0) {
+
+			update_percent(0);
+		}
+
+		void update_percent(unsigned p) {
+			unsigned nr_equals = max<unsigned>(progress_width_ * p / 100, 1);
+			unsigned nr_spaces = progress_width_ - nr_equals;
+
+			cout << title_ << ": [";
+
+			for (unsigned i = 0; i < nr_equals - 1; i++)
+				cout << '=';
+
+			if (nr_equals < progress_width_)
+				cout << '>';
+
+			for (unsigned i = 0; i < nr_spaces; i++)
+				cout << ' ';
+
+			cout << "] " << spinner_char() << " " << p << "%\r" << flush;
+
+			spinner_++;
+		}
+
+	private:
+		char spinner_char() const {
+			char cs[] = {'|', '/', '-', '\\'};
+
+			unsigned index = spinner_ % sizeof(cs);
+			return cs[index];
+		}
+
+		std::string title_;
+		unsigned progress_width_;
+		unsigned spinner_;
+	};
+
+	class quiet_progress : public base::progress_monitor {
+	public:
+		void update_percent(unsigned p) {
+		}
+	};
+
+}
+
+//----------------------------------------------------------------
+
+base::progress_monitor::ptr
+base::create_progress_bar(std::string const &title)
+{
+	return progress_monitor::ptr(new progress_bar(title));
+}
+
+base::progress_monitor::ptr
+base::create_quiet_progress_monitor()
+{
+	return progress_monitor::ptr(new quiet_progress());
+}
+
+//----------------------------------------------------------------

base/progress_monitor.h

@@ -0,0 +1,25 @@
+#ifndef BASE_PROGRESS_MONITOR_H
+#define BASE_PROGRESS_MONITOR_H
+
+#include <boost/shared_ptr.hpp>
+#include <string>
+
+//----------------------------------------------------------------
+
+namespace base {
+	class progress_monitor {
+	public:
+		typedef boost::shared_ptr<progress_monitor> ptr;
+
+		virtual ~progress_monitor() {}
+
+		virtual void update_percent(unsigned) = 0;
+	};
+
+	progress_monitor::ptr create_progress_bar(std::string const &title);
+	progress_monitor::ptr create_quiet_progress_monitor();
+}
+
+//----------------------------------------------------------------
+
+#endif

thin-provisioning/thin_restore.cc

@@ -41,6 +41,24 @@ using namespace thin_provisioning;
 //----------------------------------------------------------------
 
 namespace {
+	size_t get_file_length(string const &file) {
+		struct stat info;
+		int r;
+
+		r = ::stat(file.c_str(), &info);
+		if (r)
+			throw runtime_error("Couldn't stat backup path");
+
+		return info.st_size;
+	}
+
+	progress_monitor::ptr create_monitor() {
+		if (isatty(fileno(stdout)))
+			return create_progress_bar("Restoring");
+		else
+			return create_quiet_progress_monitor();
+	}
+
 	int restore(string const &backup_file, string const &dev) {
 		try {
 			// The block size gets updated by the restorer.
@@ -49,7 +67,9 @@ namespace {
 
 			check_file_exists(backup_file);
 			ifstream in(backup_file.c_str(), ifstream::in);
-			parse_xml(in, restorer);
+
+			progress_monitor::ptr monitor = create_monitor();
+			parse_xml(in, restorer, get_file_length(backup_file), monitor);
 
 		} catch (std::exception &e) {
 			cerr << e.what() << endl;

thin-provisioning/xml_format.cc

@@ -256,7 +256,8 @@ tp::create_xml_emitter(ostream &out)
 }
 
 void
-tp::parse_xml(std::istream &in, emitter::ptr e)
+tp::parse_xml(std::istream &in, emitter::ptr e,
+	      size_t input_length, base::progress_monitor::ptr monitor)
 {
 	XML_Parser parser = XML_ParserCreate(NULL);
 	if (!parser)
@@ -265,8 +266,10 @@ tp::parse_xml(std::istream &in, emitter::ptr e)
 	XML_SetUserData(parser, e.get());
 	XML_SetElementHandler(parser, start_tag, end_tag);
 
+	size_t total = 0;
+
 	while (!in.eof()) {
-		char buffer[4096];
+		char buffer[1024 * 1024];
 		in.read(buffer, sizeof(buffer));
 		size_t len = in.gcount();
 		int done = in.eof();
@@ -280,6 +283,9 @@ tp::parse_xml(std::istream &in, emitter::ptr e)
 			    << endl;
 			throw runtime_error(out.str());
 		}
+
+		total += len;
+		monitor->update_percent(total * 100 / input_length);
 	}
 }
 

thin-provisioning/xml_format.h

@@ -20,6 +20,7 @@
 #define XML_FORMAT_H
 
 #include "emitter.h"
+#include "base/progress_monitor.h"
 
 #include <iosfwd>
 
@@ -27,7 +28,8 @@
 
 namespace thin_provisioning {
 	emitter::ptr create_xml_emitter(std::ostream &out);
-	void parse_xml(std::istream &in, emitter::ptr e);
+	void parse_xml(std::istream &in, emitter::ptr e,
+		       size_t input_length, base::progress_monitor::ptr p);
 }
 
 //----------------------------------------------------------------