[*_restore] Add progress bar to cache_restore and era_restore.

A lot of refactoring common code between the restore tools.

base/xml_utils.cc

@@ -1,5 +1,67 @@
 #include "xml_utils.h"
 
+#include "persistent-data/file_utils.h"
+#include <fstream>
+#include <iostream>
+
+using namespace xml_utils;
+
+//----------------------------------------------------------------
+
+void
+xml_parser::parse(std::string const &backup_file, bool quiet)
+{
+	persistent_data::check_file_exists(backup_file);
+	ifstream in(backup_file.c_str(), ifstream::in);
+
+	std::auto_ptr<base::progress_monitor> monitor = create_monitor(quiet);
+
+	size_t total = 0;
+	size_t input_length = get_file_length(backup_file);
+
+	while (!in.eof()) {
+		char buffer[4096];
+		in.read(buffer, sizeof(buffer));
+		size_t len = in.gcount();
+		int done = in.eof();
+
+		if (!XML_Parse(parser_, buffer, len, done)) {
+			ostringstream out;
+			out << "Parse error at line "
+			    << XML_GetCurrentLineNumber(parser_)
+			    << ":\n"
+			    << XML_ErrorString(XML_GetErrorCode(parser_))
+			    << endl;
+			throw runtime_error(out.str());
+		}
+
+		total += len;
+		monitor->update_percent(total * 100 / input_length);
+	}
+}
+
+size_t
+xml_parser::get_file_length(string const &file) const
+{
+	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;
+}
+
+auto_ptr<base::progress_monitor>
+xml_parser::create_monitor(bool quiet)
+{
+	if (!quiet && isatty(fileno(stdout)))
+		return base::create_progress_bar("Restoring");
+	else
+		return base::create_quiet_progress_monitor();
+}
+
 //----------------------------------------------------------------
 
 void
@@ -21,5 +83,4 @@ xml_utils::build_attributes(attributes &a, char const **attr)
 	}
 }
 
-
 //----------------------------------------------------------------